Two main challenges in activated sludge wastewater treatment plant (WWTP) are cost and effluent quality, which has forced the wastewater treatment operator to find an alternative to improve the existing control strategy. The Benchmark Simulation Model No. 1 (BSM1) is applied as operational settings for this study. In BSM1, the standard control variables are the internal recirculation flow rate and the oxygen transfer rate. To improve the existing control strategy of BSM1, three alternative control handles are proposed, which are the individual aeration intensity control, carbon source addition and combination of both. The effect of each control handles in terms of the effluent violation, effluent quality, aeration cost, and total operational cost index are examined. The simulation result has shown that the individual control of aeration intensity improved the effluent quality index, and reduced the aeration, pumping, and total operational cost index when compared to the standard BSM1 control handle. Nonetheless, the addition of a fixed external carbon source has shown a significantly improved effluent quality with a lower number of total nitrogen violations as compared to the standard BSM1 control handles. Thus, the proposed control handles may be beneficial if applied in a real WWTP.
HYBRID FUZZY LOGIC AND PID CONTROLLER FOR PH NEUTRALIZATION PILOT PLANTijfls
Use of Control theory within process control industries has changed rapidly due to the increase complexity
of instrumentation, real time requirements, minimization of operating costs and highly nonlinear
characteristics of chemical process. Previously developed process control technologies which are mostly
based on a single controller are not efficient in terms of signal transmission delays, processing power for
computational needs and signal to noise ratio. Hybrid controller with efficient system modelling is essential
to cope with the current challenges of process control in terms of control performance. This paper presents
an optimized mathematical modelling and advance hybrid controller (Fuzzy Logic and PID) design along
with practical implementation and validation of pH neutralization pilot plant. This procedure is
particularly important for control design and automation of Physico-chemical systems for process control
industry.
Presentation on "Study of process intensification of CO2 capture through modelling and simulation" given by Dr Meihong Wang from University of Hull in the Process Engineering Technical Session at the UKCCSRC Biannual Meeting in Cambridge on 2-3 April 2014
Important theoretical issues that significantly affect the accuracy of predicted concentrations subject to downwash effects have been identified in AERMOD/PRIME. These issues have prompted a number of industry groups to fund new research aiming at overcoming these shortcomings. The Plume Rise Model Enhancements (PRIME) building downwash algorithms1 (Schulman et al. 2000) in AERMOD2 are being updated to address some of the most critical limitations in the current theory. These enhancements will incorporate the latest advancements related to building downwash effects. The technical aspects of these enhancements are discussed in more detail in a recent publication "PRIME2: Development and Evaluation of Improved Building Downwash Algorithms for Solid and Streamlined Structures". The updates to the PRIME code include new equations to account for building wake effects that decay rapidly back to ambient levels above the top of the building; reduced wake effects for streamlined structures; and reduced wake effects for high approach roughness. A comparison with field data was conducted with the Bowline Point, Alaska North Slope, Millstone Nuclear Power Station, and the Duane Arnold Energy Center databases. A new experimental BPIP-PRM version is also discussed.
This document describes how off-gas analysis using a BioPAT® Xgas system can be used for metabolic calculations during fermentation processes. It provides details on how gas flow rates and compositions are measured and used to calculate values like oxygen uptake rate, carbon evolution rate, and respiratory quotient. The document outlines different gassing strategies and gas measurement cases that must be accounted for in the calculations. Examples of metabolic calculations, data interpretation, and a test fermentation process are also described to demonstrate the application of off-gas analysis.
New Guideline on Air Quality Models and the Electric Utility IndustrySergio A. Guerra
The new EPA guideline on air quality models makes several changes, including adopting AERMOD version 16216r as the new default model. It establishes a two-tiered approach for modeling ozone and secondary PM2.5 formation, using existing empirical relationships (Tier 1) or chemical transport models (Tier 2). CALPUFF is no longer preferred for long-range transport modeling beyond 50 km. The guideline also allows the use of prognostic meteorological data in some cases. While the changes aim to promote consistency, the increased flexibility may lead to legal challenges and delays.
This document reviews research on using computational fluid dynamics (CFD) to analyze coal/air flow in power plant pipelines in order to maintain uniform fuel feed rates at burners. Several studies are summarized that use CFD to simulate coal/air flow and model the effects of orifice flow restrictors placed in pipes. Correlations developed from CFD results relate pressure drop to factors like geometry, coal/gas loading ratio, and mass flux. CFD is shown to be an effective method for determining the optimal geometry and sizing of orifice flow restrictors to balance flow rates across burners.
This document discusses formulas for calculating the heating value of coal and coal char based on their composition. It describes the development of several existing formulas and presents the results of tests of four formulas on a database of 775 coal samples. A new formula is developed through regression analysis of the database that shows less bias and a lower standard deviation than the existing formulas tested. The accuracy of the new formula is comparable to a more complex existing formula but does not require determining pyritic sulfur content.
HYBRID FUZZY LOGIC AND PID CONTROLLER FOR PH NEUTRALIZATION PILOT PLANTijfls
Use of Control theory within process control industries has changed rapidly due to the increase complexity
of instrumentation, real time requirements, minimization of operating costs and highly nonlinear
characteristics of chemical process. Previously developed process control technologies which are mostly
based on a single controller are not efficient in terms of signal transmission delays, processing power for
computational needs and signal to noise ratio. Hybrid controller with efficient system modelling is essential
to cope with the current challenges of process control in terms of control performance. This paper presents
an optimized mathematical modelling and advance hybrid controller (Fuzzy Logic and PID) design along
with practical implementation and validation of pH neutralization pilot plant. This procedure is
particularly important for control design and automation of Physico-chemical systems for process control
industry.
Presentation on "Study of process intensification of CO2 capture through modelling and simulation" given by Dr Meihong Wang from University of Hull in the Process Engineering Technical Session at the UKCCSRC Biannual Meeting in Cambridge on 2-3 April 2014
Important theoretical issues that significantly affect the accuracy of predicted concentrations subject to downwash effects have been identified in AERMOD/PRIME. These issues have prompted a number of industry groups to fund new research aiming at overcoming these shortcomings. The Plume Rise Model Enhancements (PRIME) building downwash algorithms1 (Schulman et al. 2000) in AERMOD2 are being updated to address some of the most critical limitations in the current theory. These enhancements will incorporate the latest advancements related to building downwash effects. The technical aspects of these enhancements are discussed in more detail in a recent publication "PRIME2: Development and Evaluation of Improved Building Downwash Algorithms for Solid and Streamlined Structures". The updates to the PRIME code include new equations to account for building wake effects that decay rapidly back to ambient levels above the top of the building; reduced wake effects for streamlined structures; and reduced wake effects for high approach roughness. A comparison with field data was conducted with the Bowline Point, Alaska North Slope, Millstone Nuclear Power Station, and the Duane Arnold Energy Center databases. A new experimental BPIP-PRM version is also discussed.
This document describes how off-gas analysis using a BioPAT® Xgas system can be used for metabolic calculations during fermentation processes. It provides details on how gas flow rates and compositions are measured and used to calculate values like oxygen uptake rate, carbon evolution rate, and respiratory quotient. The document outlines different gassing strategies and gas measurement cases that must be accounted for in the calculations. Examples of metabolic calculations, data interpretation, and a test fermentation process are also described to demonstrate the application of off-gas analysis.
New Guideline on Air Quality Models and the Electric Utility IndustrySergio A. Guerra
The new EPA guideline on air quality models makes several changes, including adopting AERMOD version 16216r as the new default model. It establishes a two-tiered approach for modeling ozone and secondary PM2.5 formation, using existing empirical relationships (Tier 1) or chemical transport models (Tier 2). CALPUFF is no longer preferred for long-range transport modeling beyond 50 km. The guideline also allows the use of prognostic meteorological data in some cases. While the changes aim to promote consistency, the increased flexibility may lead to legal challenges and delays.
This document reviews research on using computational fluid dynamics (CFD) to analyze coal/air flow in power plant pipelines in order to maintain uniform fuel feed rates at burners. Several studies are summarized that use CFD to simulate coal/air flow and model the effects of orifice flow restrictors placed in pipes. Correlations developed from CFD results relate pressure drop to factors like geometry, coal/gas loading ratio, and mass flux. CFD is shown to be an effective method for determining the optimal geometry and sizing of orifice flow restrictors to balance flow rates across burners.
This document discusses formulas for calculating the heating value of coal and coal char based on their composition. It describes the development of several existing formulas and presents the results of tests of four formulas on a database of 775 coal samples. A new formula is developed through regression analysis of the database that shows less bias and a lower standard deviation than the existing formulas tested. The accuracy of the new formula is comparable to a more complex existing formula but does not require determining pyritic sulfur content.
Pairing aermod concentrations with the 50th percentile monitored valueSergio A. Guerra
This document proposes a new method for combining modeled concentrations from AERMOD with monitored background concentrations.
The current practice of adding the maximum or 98th percentile monitored concentration is overly conservative. Instead, the document suggests using the 50th percentile (median) monitored concentration.
Pairing the 98th percentile modeled concentration with the 50th percentile monitored concentration results in a combined 99th percentile concentration. This provides a more conservative estimate than the form of the short-term air quality standards, while avoiding the mismatch of temporal pairing in AERMOD and the influence of exceptional events.
The proposed method is presented as a simple, protective approach for demonstrating compliance with air quality standards when considering both modeled and monitored background concentrations.
Application of a Reaction Kinetic Model for OnlLine Model Dynamic Control & O...James Bixby
1) The document describes how a reaction kinetic model was developed and applied for online dynamic control and optimization of batch and continuous reactor systems.
2) The model was used to optimize temperature profiles, increase reactor capacity, and improve product consistency for both batch and continuous processes.
3) For the continuous process, the model also helped improve transient response to disturbances by evaluating control strategies to tightly control intermediate species concentrations like B.
Study & Review of Heat Recovery Systems for SO2 Gas Generation Process in Sug...IRJET Journal
This document summarizes a study on heat recovery systems for the SO2 gas generation process in the sugar industry. It begins with an introduction to waste heat recovery and its importance. It then reviews various methods for recovering waste heat. The document discusses factors that affect waste heat recovery systems like heat quantity and quality. It reviews several past studies on waste heat recovery in different industries. It proposes studying heat recovery from the SO2 gas generation process in sugar production to make the process more efficient. The conclusion emphasizes the need for waste heat recovery techniques in industries to conserve energy.
PRIME2_consequence_analysis_and _model_evaluationSergio A. Guerra
The Plume Rise Model Enhancements (PRIME) building downwash algorithms1 (Schulman et al. 2000) in AERMOD2 are being updated to address some of the most critical limitations in the current theory. These enhancements will incorporate the latest advancements related to building downwash effects. The technical aspects of these enhancements are discussed in more detail in a companion paper titled “PRIME2: Development and Evaluation of Improved Building Downwash Algorithms for Solid and Streamlined Structures (MO13)”. The updates to the PRIME code include new equations to account for building wake effects that decay rapidly back to ambient levels above the top of the building; reduced wake effects for streamlined structures; and reduced wake effects for high approach roughness. A consequence analysis comparing the current AERMOD/PRIME model versus the new AERMOD/PRIME2 model was performed. Additionally, a field data evaluation was conducted with the Bowline Point database. The results from these analyses are discussed below.
INNOVATIVE DISPERSION MODELING PRACTICES TO ACHIEVE A REASONABLE LEVEL OF CON...Sergio A. Guerra
Presentation delivered at the Annual Air and Waste Management Association conference in Long beach, California on June 26, 2014.
Innovative dispersion modeling techniques are presented including ARM2, EMVAP and the 50th percentile background concentration. Case study involves peaking engines that are used 250 hour per year. These intermittent sources are required to undergo a modeling evaluation in many states. Current modeling techniques grossly overestimate the emissions from these sporadic sources.
INNOVATIVE DISPERSION MODELING PRACTICES TO ACHIEVE A REASONABLE LEVEL OF CON...Sergio A. Guerra
Presentation delivered at the Board meeting for the Upper Midwest section of the Air and Waste Management Association meeting on September 16, 2014.
Innovative dispersion modeling techniques are presented including ARM2, EMVAP and the 50th percentile background concentration. Case study involves peaking engines that are used 250 hour per year. These intermittent sources are required to undergo a modeling evaluation in many states. Current modeling techniques grossly overestimate the emissions from these sporadic sources.
Fuzzy logic for plant-wide control of biological wastewater treatment process...ISA Interchange
The application of control strategies is increasingly used in wastewater treatment plants with the aim of improving effluent quality and reducing operating costs. Due to concerns about the progressive growth of greenhouse gas emissions (GHG), these are also currently being evaluated in wastewater treatment plants. The present article proposes a fuzzy controller for plant-wide control of the biological wastewater treatment process. Its design is based on 14 inputs and 6 outputs in order to reduce GHG emissions, nutrient concentration in the effluent and operational costs. The article explains and shows the effect of each one of the inputs and outputs of the fuzzy controller, as well as the relationship between them. Benchmark Simulation Model no 2 Gas is used for testing the proposed control strategy. The results of simulation results show that the fuzzy controller is able to reduce GHG emissions while improving, at the same time, the common criteria of effluent quality and operational costs.
Using Physical Modeling to Refine Downwash Inputs to AERMODSergio A. Guerra
Achieving compliance in dispersion modeling can be quite challenging because of the tight National Ambient Air Quality Standards (NAAQS). In addition, AERMOD’s limitations can, in many cases, produce higher than normal concentrations due to the inherent assumptions and simplifications in its formulation. In the case of downwash, the theory used to estimate these effects was developed for a limited set of building types. However, these formulations are commonly used indiscriminately for all types of buildings. This presentation will cover how the basics of wind tunnel modeling can overcome some of these limitations and be used to mitigate downwash induced overpredictions to achieve compliance.
This document reports on analyses and experimentation conducted on a Quadrafire Classic Bay 1200 pellet stove to increase its efficiency and reduce emissions. The researchers have developed a theoretical model that characterizes the stove's heating output as a continuous function of distance along the heat exchanger, accounting for both convection and radiation heat transfer. Their experiments involved upgrading instrumentation to directly measure airflow rates and temperatures, validating assumptions in the previous model. Key findings include radiation significantly influencing heat output and an air-rich firepot reaction that reduces combustion efficiency. The updated model and experiments provide a foundation for redesigning the stove.
Advanced Modeling Techniques for Permit Modeling - Turning challenges into o...Sergio A. Guerra
Advance modeling techniques can be used in AERMOD to refine the inputs that are entered in the model to get more accurate results. This presentation covers:
-AERMOD’s Temporal Mismatch Limitation
-Building Downwash Limitations in BPIP/PRIME
-Advanced Modeling Techniques to Overcome these Limitations
Solutions include:
Equivalent Building Dimensions (EBD)
Emission Variability Processor (EMVAP)
Updated ambient ratio method (ARM2)
Pairing AERMOD values with the 50th % background concentrations in cumulative analyses.
An Iterative Method Applied to Correct the Actual Compressor Performance to t...ijctcm
This paper proposes a correction method, which corrects the actual compressor performance in real
operating conditions to the equivalent performance under specified reference condition. The purpose is to
make fair comparisons between actual performance against design performance or reference maps under
the same operating conditions. Then the abnormal operating conditions or early failure indications can be
identified through condition monitoring, which helps to avoid mandatory shutdown and reduces
maintenance costs. The corrections are based on an iterative scheme, which simultaneously correct the
main performance parameters known as the polytropic head, the gas power, and the polytropic efficiency.
The excellent performance of the method is demonstrated by performing the corrections over real industrial
measurements.
This document discusses the beta u-star option in AERMET for adjusting friction velocity (u*) calculations under low wind stable conditions. It provides background on studies conducted by AECOM and EPA to evaluate AERMOD's performance at low wind speeds. The document outlines the timeline of updates to u* in AERMET and reviews AECOM's 2014 evaluation of new meteorological databases using the beta u* option, finding impacts were most sensitive for low-level sources and tall buoyant stacks in complex terrain. It closes with considerations for justifying the beta u* option as an alternative refined model under EPA regulations.
Use of Wind Tunnel Refinements in the Dispersion Modeling Analysis of the Ala...Sergio A. Guerra
The proposed Alaska LNG Gas Treatment Plant project required dispersion modeling to evaluate impacts on ambient air quality standards. Initial modeling found inconsistent results due to complex building arrangements of two nearby facilities. Wind tunnel testing was used to determine equivalent building dimensions to refine building inputs, which significantly reduced predicted concentrations. The environmental regulator approved the wind tunnel analysis approach. The modeling now demonstrates operations will not cause exceedances of air quality standards.
IRJET- Performance Assessment of Hydrocarbon Refrigerant in Air ConditionerIRJET Journal
This document discusses an experimental analysis of hydrocarbon refrigerants in air conditioners as an alternative to traditional refrigerants. The researchers tested various mixtures of propane (R290) and isobutane (R600a) in an air conditioning system and analyzed the coefficient of performance (COP), cooling capacity, and energy consumption compared to R134a. They found that the hydrocarbon blend had a higher COP and cooling capacity but lower energy consumption than R134a. In conclusion, the hydrocarbon blend R290/R600a showed promising performance as a potential replacement for R134a in air conditioners and could help reduce environmental impacts.
Use of Probabilistic Statistical Techniques in AERMOD Modeling EvaluationsSergio A. Guerra
The advent of the short term National Ambient Air Quality Standards (NAAQS) prompted modelers to reassess the common practices in dispersion modeling analyses. The probabilistic nature of the new short term standards also opens the door to alternative modeling techniques that are based on probability. One of these is the Monte Carlo technique that can be used to account for emission variability in permit modeling.
Currently, it is assumed that a given emission unit is in operation at its maximum capacity every hour of the year. This assumption may be appropriate for facilities that operate at full capacity most of the time. However, in most cases, emission units operate at variable loads that produce variable emissions. Thus, assuming constant maximum emissions is overly conservative for facilities such as power plants that are not in operation all the time and which exhibit high concentrations during very short periods of time.
Another element of conservatism in NAAQS demonstrations relates to combining predicted concentrations from the AMS/EPA Regulatory Model (AERMOD) with observed (monitored) background concentrations. Normally, some of the highest monitored observations are added to the AERMOD results yielding a very conservative combined concentration.
A case study is presented to evaluate the use of alternative probabilistic methods to complement the shortcomings of current dispersion modeling practices. This case study includes the use of the Monte Carlo technique and the use of a reasonable background concentration to combine with the AERMOD predicted concentrations. The use of these methods is in harmony with the probabilistic nature of the NAAQS and can help demonstrate compliance through dispersion modeling analyses, while still being protective of the NAAQS.
Jonathan Lee (Newcastle University) - Intensification of Solvent Based Carbon Capture using Rotating Packed Beds - UKCCSRC Cranfield Biannual 21-22 April 2015
Innovative Dispersion Modeling Practices to Achieve a Reasonable Level of Con...Sergio A. Guerra
The document discusses innovative modeling practices to achieve reasonable conservatism in AERMOD modeling demonstrations. It presents a case study evaluating three modeling techniques: EMVAP, which assigns random emission rates over iterations; ARM2, which calculates NOx to NO2 conversion based on plume entrapment; and using the 50th percentile monitored background concentration. The case study found lower modeled concentrations using EMVAP and ARM2 compared to current practices, demonstrating these techniques can provide more realistic results while still protecting air quality standards. Pairing the 98th percentile predicted concentration with the 50th percentile monitored background provided a statistically conservative but reasonable level of conservatism.
Integration of Atmospheric Stability in CFD Modeling for Wind Energy Assessme...Jean-Claude Meteodyn
Atmospheric stability plays an important role in wind resource assessment. This study integrated methods for determining atmospheric stability into CFD modeling software. Validation on a wind farm in northern France showed including stability reduced the error in predicted mean annual energy production from 11% to 1%, compared to assuming a neutrally stable atmosphere. The stability determination methods were consistent and improved accuracy of wind flow simulations in complex terrain.
CPP is an air quality and wind engineering consulting firm that provides air permitting and advanced dispersion modeling services. They have expertise in AERMOD modeling, wind tunnel modeling, and other advanced analysis methods like equivalent building dimensions and emission variability processing. Using these advanced methods, CPP can help optimize clients' emission control equipment and stack heights to make projects compliant with permitting requirements in cases where initial modeling shows exceedances.
A New Solution to Improve Power Quality of Renewable Energy Sources Smart Gri...iosrjce
This document summarizes a research article that proposes a new solution to improve power quality from renewable energy sources in smart grids while also considering carbon footprint as a new element. The article presents a prototype carbon footprint control sub-protocol for a microbial fuel cell micro-grid setup that aims to minimize carbon footprint during electricity generation and distribution in order to meet climate change goals of improving power quality and efficiency in a sustainable way. Experimental results from a simulation of a five-level cascaded H-bridge inverter confirm that the proposed approach can significantly reduce computational efforts needed for voltage vector selection without impacting system performance or effectiveness.
This document summarizes a research article that proposes a new solution to improve power quality from renewable energy sources in smart grids while also considering carbon footprint as a new element. The article presents a prototype carbon footprint control sub-protocol for a microbial fuel cell micro-grid setup that aims to minimize carbon footprint during power quality improvements. Simulation and experimental results for a five-level H-bridge inverter confirm that the proposed approach can help manage goals to enhance electricity quality and efficiency while reducing carbon footprint impacts.
Pairing aermod concentrations with the 50th percentile monitored valueSergio A. Guerra
This document proposes a new method for combining modeled concentrations from AERMOD with monitored background concentrations.
The current practice of adding the maximum or 98th percentile monitored concentration is overly conservative. Instead, the document suggests using the 50th percentile (median) monitored concentration.
Pairing the 98th percentile modeled concentration with the 50th percentile monitored concentration results in a combined 99th percentile concentration. This provides a more conservative estimate than the form of the short-term air quality standards, while avoiding the mismatch of temporal pairing in AERMOD and the influence of exceptional events.
The proposed method is presented as a simple, protective approach for demonstrating compliance with air quality standards when considering both modeled and monitored background concentrations.
Application of a Reaction Kinetic Model for OnlLine Model Dynamic Control & O...James Bixby
1) The document describes how a reaction kinetic model was developed and applied for online dynamic control and optimization of batch and continuous reactor systems.
2) The model was used to optimize temperature profiles, increase reactor capacity, and improve product consistency for both batch and continuous processes.
3) For the continuous process, the model also helped improve transient response to disturbances by evaluating control strategies to tightly control intermediate species concentrations like B.
Study & Review of Heat Recovery Systems for SO2 Gas Generation Process in Sug...IRJET Journal
This document summarizes a study on heat recovery systems for the SO2 gas generation process in the sugar industry. It begins with an introduction to waste heat recovery and its importance. It then reviews various methods for recovering waste heat. The document discusses factors that affect waste heat recovery systems like heat quantity and quality. It reviews several past studies on waste heat recovery in different industries. It proposes studying heat recovery from the SO2 gas generation process in sugar production to make the process more efficient. The conclusion emphasizes the need for waste heat recovery techniques in industries to conserve energy.
PRIME2_consequence_analysis_and _model_evaluationSergio A. Guerra
The Plume Rise Model Enhancements (PRIME) building downwash algorithms1 (Schulman et al. 2000) in AERMOD2 are being updated to address some of the most critical limitations in the current theory. These enhancements will incorporate the latest advancements related to building downwash effects. The technical aspects of these enhancements are discussed in more detail in a companion paper titled “PRIME2: Development and Evaluation of Improved Building Downwash Algorithms for Solid and Streamlined Structures (MO13)”. The updates to the PRIME code include new equations to account for building wake effects that decay rapidly back to ambient levels above the top of the building; reduced wake effects for streamlined structures; and reduced wake effects for high approach roughness. A consequence analysis comparing the current AERMOD/PRIME model versus the new AERMOD/PRIME2 model was performed. Additionally, a field data evaluation was conducted with the Bowline Point database. The results from these analyses are discussed below.
INNOVATIVE DISPERSION MODELING PRACTICES TO ACHIEVE A REASONABLE LEVEL OF CON...Sergio A. Guerra
Presentation delivered at the Annual Air and Waste Management Association conference in Long beach, California on June 26, 2014.
Innovative dispersion modeling techniques are presented including ARM2, EMVAP and the 50th percentile background concentration. Case study involves peaking engines that are used 250 hour per year. These intermittent sources are required to undergo a modeling evaluation in many states. Current modeling techniques grossly overestimate the emissions from these sporadic sources.
INNOVATIVE DISPERSION MODELING PRACTICES TO ACHIEVE A REASONABLE LEVEL OF CON...Sergio A. Guerra
Presentation delivered at the Board meeting for the Upper Midwest section of the Air and Waste Management Association meeting on September 16, 2014.
Innovative dispersion modeling techniques are presented including ARM2, EMVAP and the 50th percentile background concentration. Case study involves peaking engines that are used 250 hour per year. These intermittent sources are required to undergo a modeling evaluation in many states. Current modeling techniques grossly overestimate the emissions from these sporadic sources.
Fuzzy logic for plant-wide control of biological wastewater treatment process...ISA Interchange
The application of control strategies is increasingly used in wastewater treatment plants with the aim of improving effluent quality and reducing operating costs. Due to concerns about the progressive growth of greenhouse gas emissions (GHG), these are also currently being evaluated in wastewater treatment plants. The present article proposes a fuzzy controller for plant-wide control of the biological wastewater treatment process. Its design is based on 14 inputs and 6 outputs in order to reduce GHG emissions, nutrient concentration in the effluent and operational costs. The article explains and shows the effect of each one of the inputs and outputs of the fuzzy controller, as well as the relationship between them. Benchmark Simulation Model no 2 Gas is used for testing the proposed control strategy. The results of simulation results show that the fuzzy controller is able to reduce GHG emissions while improving, at the same time, the common criteria of effluent quality and operational costs.
Using Physical Modeling to Refine Downwash Inputs to AERMODSergio A. Guerra
Achieving compliance in dispersion modeling can be quite challenging because of the tight National Ambient Air Quality Standards (NAAQS). In addition, AERMOD’s limitations can, in many cases, produce higher than normal concentrations due to the inherent assumptions and simplifications in its formulation. In the case of downwash, the theory used to estimate these effects was developed for a limited set of building types. However, these formulations are commonly used indiscriminately for all types of buildings. This presentation will cover how the basics of wind tunnel modeling can overcome some of these limitations and be used to mitigate downwash induced overpredictions to achieve compliance.
This document reports on analyses and experimentation conducted on a Quadrafire Classic Bay 1200 pellet stove to increase its efficiency and reduce emissions. The researchers have developed a theoretical model that characterizes the stove's heating output as a continuous function of distance along the heat exchanger, accounting for both convection and radiation heat transfer. Their experiments involved upgrading instrumentation to directly measure airflow rates and temperatures, validating assumptions in the previous model. Key findings include radiation significantly influencing heat output and an air-rich firepot reaction that reduces combustion efficiency. The updated model and experiments provide a foundation for redesigning the stove.
Advanced Modeling Techniques for Permit Modeling - Turning challenges into o...Sergio A. Guerra
Advance modeling techniques can be used in AERMOD to refine the inputs that are entered in the model to get more accurate results. This presentation covers:
-AERMOD’s Temporal Mismatch Limitation
-Building Downwash Limitations in BPIP/PRIME
-Advanced Modeling Techniques to Overcome these Limitations
Solutions include:
Equivalent Building Dimensions (EBD)
Emission Variability Processor (EMVAP)
Updated ambient ratio method (ARM2)
Pairing AERMOD values with the 50th % background concentrations in cumulative analyses.
An Iterative Method Applied to Correct the Actual Compressor Performance to t...ijctcm
This paper proposes a correction method, which corrects the actual compressor performance in real
operating conditions to the equivalent performance under specified reference condition. The purpose is to
make fair comparisons between actual performance against design performance or reference maps under
the same operating conditions. Then the abnormal operating conditions or early failure indications can be
identified through condition monitoring, which helps to avoid mandatory shutdown and reduces
maintenance costs. The corrections are based on an iterative scheme, which simultaneously correct the
main performance parameters known as the polytropic head, the gas power, and the polytropic efficiency.
The excellent performance of the method is demonstrated by performing the corrections over real industrial
measurements.
This document discusses the beta u-star option in AERMET for adjusting friction velocity (u*) calculations under low wind stable conditions. It provides background on studies conducted by AECOM and EPA to evaluate AERMOD's performance at low wind speeds. The document outlines the timeline of updates to u* in AERMET and reviews AECOM's 2014 evaluation of new meteorological databases using the beta u* option, finding impacts were most sensitive for low-level sources and tall buoyant stacks in complex terrain. It closes with considerations for justifying the beta u* option as an alternative refined model under EPA regulations.
Use of Wind Tunnel Refinements in the Dispersion Modeling Analysis of the Ala...Sergio A. Guerra
The proposed Alaska LNG Gas Treatment Plant project required dispersion modeling to evaluate impacts on ambient air quality standards. Initial modeling found inconsistent results due to complex building arrangements of two nearby facilities. Wind tunnel testing was used to determine equivalent building dimensions to refine building inputs, which significantly reduced predicted concentrations. The environmental regulator approved the wind tunnel analysis approach. The modeling now demonstrates operations will not cause exceedances of air quality standards.
IRJET- Performance Assessment of Hydrocarbon Refrigerant in Air ConditionerIRJET Journal
This document discusses an experimental analysis of hydrocarbon refrigerants in air conditioners as an alternative to traditional refrigerants. The researchers tested various mixtures of propane (R290) and isobutane (R600a) in an air conditioning system and analyzed the coefficient of performance (COP), cooling capacity, and energy consumption compared to R134a. They found that the hydrocarbon blend had a higher COP and cooling capacity but lower energy consumption than R134a. In conclusion, the hydrocarbon blend R290/R600a showed promising performance as a potential replacement for R134a in air conditioners and could help reduce environmental impacts.
Use of Probabilistic Statistical Techniques in AERMOD Modeling EvaluationsSergio A. Guerra
The advent of the short term National Ambient Air Quality Standards (NAAQS) prompted modelers to reassess the common practices in dispersion modeling analyses. The probabilistic nature of the new short term standards also opens the door to alternative modeling techniques that are based on probability. One of these is the Monte Carlo technique that can be used to account for emission variability in permit modeling.
Currently, it is assumed that a given emission unit is in operation at its maximum capacity every hour of the year. This assumption may be appropriate for facilities that operate at full capacity most of the time. However, in most cases, emission units operate at variable loads that produce variable emissions. Thus, assuming constant maximum emissions is overly conservative for facilities such as power plants that are not in operation all the time and which exhibit high concentrations during very short periods of time.
Another element of conservatism in NAAQS demonstrations relates to combining predicted concentrations from the AMS/EPA Regulatory Model (AERMOD) with observed (monitored) background concentrations. Normally, some of the highest monitored observations are added to the AERMOD results yielding a very conservative combined concentration.
A case study is presented to evaluate the use of alternative probabilistic methods to complement the shortcomings of current dispersion modeling practices. This case study includes the use of the Monte Carlo technique and the use of a reasonable background concentration to combine with the AERMOD predicted concentrations. The use of these methods is in harmony with the probabilistic nature of the NAAQS and can help demonstrate compliance through dispersion modeling analyses, while still being protective of the NAAQS.
Jonathan Lee (Newcastle University) - Intensification of Solvent Based Carbon Capture using Rotating Packed Beds - UKCCSRC Cranfield Biannual 21-22 April 2015
Innovative Dispersion Modeling Practices to Achieve a Reasonable Level of Con...Sergio A. Guerra
The document discusses innovative modeling practices to achieve reasonable conservatism in AERMOD modeling demonstrations. It presents a case study evaluating three modeling techniques: EMVAP, which assigns random emission rates over iterations; ARM2, which calculates NOx to NO2 conversion based on plume entrapment; and using the 50th percentile monitored background concentration. The case study found lower modeled concentrations using EMVAP and ARM2 compared to current practices, demonstrating these techniques can provide more realistic results while still protecting air quality standards. Pairing the 98th percentile predicted concentration with the 50th percentile monitored background provided a statistically conservative but reasonable level of conservatism.
Integration of Atmospheric Stability in CFD Modeling for Wind Energy Assessme...Jean-Claude Meteodyn
Atmospheric stability plays an important role in wind resource assessment. This study integrated methods for determining atmospheric stability into CFD modeling software. Validation on a wind farm in northern France showed including stability reduced the error in predicted mean annual energy production from 11% to 1%, compared to assuming a neutrally stable atmosphere. The stability determination methods were consistent and improved accuracy of wind flow simulations in complex terrain.
CPP is an air quality and wind engineering consulting firm that provides air permitting and advanced dispersion modeling services. They have expertise in AERMOD modeling, wind tunnel modeling, and other advanced analysis methods like equivalent building dimensions and emission variability processing. Using these advanced methods, CPP can help optimize clients' emission control equipment and stack heights to make projects compliant with permitting requirements in cases where initial modeling shows exceedances.
A New Solution to Improve Power Quality of Renewable Energy Sources Smart Gri...iosrjce
This document summarizes a research article that proposes a new solution to improve power quality from renewable energy sources in smart grids while also considering carbon footprint as a new element. The article presents a prototype carbon footprint control sub-protocol for a microbial fuel cell micro-grid setup that aims to minimize carbon footprint during electricity generation and distribution in order to meet climate change goals of improving power quality and efficiency in a sustainable way. Experimental results from a simulation of a five-level cascaded H-bridge inverter confirm that the proposed approach can significantly reduce computational efforts needed for voltage vector selection without impacting system performance or effectiveness.
This document summarizes a research article that proposes a new solution to improve power quality from renewable energy sources in smart grids while also considering carbon footprint as a new element. The article presents a prototype carbon footprint control sub-protocol for a microbial fuel cell micro-grid setup that aims to minimize carbon footprint during power quality improvements. Simulation and experimental results for a five-level H-bridge inverter confirm that the proposed approach can help manage goals to enhance electricity quality and efficiency while reducing carbon footprint impacts.
The document summarizes an energy audit conducted on a thermal power plant in Jordan. The power plant produces 14.36 MW through a Rankine cycle using natural gas. A preliminary energy audit evaluated the performance of the plant's components, including the boiler, turbine, condenser, and pumps. The results showed deviations in efficiency for all components compared to their design specifications. Specifically, the boiler had the largest deviation of 4.9% efficiency, likely due to poor water and fuel quality and heat loss. Several solutions were proposed to improve the plant's efficiency.
Exergy Based Performance Analysis of FGPS (NTPC Faridabad)Santosh Verma
The document discusses exergy analysis of a combined gas power station. It calculates the energy and exergy flows for various systems like the compressor, high pressure turbine, and low pressure turbine. The analysis found that the compressor had the highest exergy destruction, followed by the low pressure turbine and high pressure turbine. The conclusion is that minimizing exergy destruction in these components, especially the compressor, through proper operation and maintenance could improve the plant's efficiency.
Enhanced Multi – Agent Based Industrial Process AutomationIRJET Journal
This document presents a multi-agent control system for optimizing the operation of fossil-fuel power plants. The system uses multiple intelligent agents that make autonomous decisions based on plant conditions. One agent uses a neuro-fuzzy system to evaluate and optimize feedback control gains. A simulation showed this agent could successfully update gains to improve control when the plant output exceeded thresholds. The system allows for customizable, optimized multi-objective control to improve efficiency and operation of power plants.
Modified smith predictor based cascade control of unstable time delay processesISA Interchange
An improved cascade control structure with a modified Smith predictor is proposed for controlling open-loop unstable time delay processes. The proposed structure has three controllers of which one is meant for servo response and the other two are for regulatory responses. An analytical design method is derived for the two disturbance rejection controllers by proposing the desired closed-loop complementary sensitivity functions. These two closed-loop controllers are considered in the form of proportional–integral-derivative (PID) controller cascaded with a second order lead/lag filter. The direct synthesis method is used to design the setpoint tracking controller. By virtue of the enhanced structure, the proposed control scheme decouples the servo response from the regulatory response in case of nominal systems i.e., the setpoint tracking controller and the disturbance rejection controller can be tuned independently. Internal stability of the proposed cascade structure is analyzed. Kharitonov’s theorem is used for the robustness analysis. The disturbance rejection capability of the proposed scheme is superior as compared to existing methods. Examples are also included to illustrate the simplicity and usefulness of the proposed method.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Robustness enhancement study of augmented positive identification controller ...IAESIJAI
The dissolved oxygen concentration in the wastewater treatment process
(WWTP) must remain in a specific range while the factory operates. The
augmented positive identification (PID) controller with a nonlinear element
(sigmoid function) is proposed to assure stability and reduce uncertainties in
the wastewater direct reuse/recycling model. The nonlinear controller gains
(PID controller with sigmoid function) for uncertain wastewater treatment
processes are tuned using the particle swarm optimization (PSO) technique.
The proposed robust method for controlling wastewater treatment processes
has good robustness during model mismatching, reduces treatment time
compared to traditional positive identification (PID) controllers tuned by
PSO, is easy to apply, and has good performance, according to simulation
results.
Frequency regulation of deregulated power system having grc integrated with r...eSAT Journals
Abstract This paper addresses the automatic generation control of deregulated multi area power system including one of the most important renewable energy resource viz. wind power plant. The interconnected two area power system is thermal-hydro system with two GENCOs in thermal area and one GENCO in hydro area. Generation rate constraint (GRC) is considered in all the GENCOs separately. Integral square error technique is used to optimize the gains of various integral controllers. It is seen that system response becomes poorer in terms of peak overshoots and settling time by considering GRC. DISCO participation matrix is chosen on the basis of open market strategy which is continuously changing. So, effect of changing DPM on dynamic responses is studied, following a step load perturbation. It is revealed that there is no effect of changing DPM on system’s dynamic responses. Keywords – Automatic generation control (AGC), deregulated power system, DISCO participation matrix (DPM), wind turbines, generation rate constraint (GRC).
A New Control Method for the Multi-Area LFC System Based on Port-Hamiltonian ...IRJET Journal
This document presents a new control method for load frequency control (LFC) in a multi-area power system based on Port-Hamiltonian and cascade systems. The proposed method uses PID control laws that decouple total tie-line power flow and provide robust disturbance rejection. Simulation results in Matlab/Simulink validate that the proposed method performs better than existing PID methods by achieving faster response speeds and smaller overshoots for changes in tie-line power and frequency deviations in both two-area and four-area test systems with and without reheated turbines.
IRJET- A Review on Load Frequency Control StrategyIRJET Journal
This document provides a review of load frequency control strategies for integrating renewable energy sources into power grids. It discusses some of the challenges of integrating variable power sources like wind and solar that can cause fluctuations in voltage and frequency. It also summarizes several different control techniques that have been used for load frequency control, including classical control methods, adaptive and variable structure methods, robust control approaches, and intelligent techniques using neural networks and fuzzy logic. The review covers the objectives of load frequency control and provides examples of strategies that have been implemented, including adaptive control methods applied to power systems to manage changes in plant parameters.
Effcacious pitch angle control of variable-speed wind turbine using fuzzy bas...Kashif Mehmood
This document summarizes a research paper that proposes a fuzzy-based model predictive controller for pitch angle control of variable-speed wind turbines. The controller uses rotor speed and power output as inputs instead of wind speed to minimize loading effects and maximize power extraction. Simulation results on a 3MW wind turbine model show the proposed controller more effectively regulates power output, rotor speed, and pitch angle compared to a PI controller. It increases power capture and reduces mechanical loads on the turbine.
This document summarizes the use of fuzzy logic applications in a 500 MW power station. Specifically, it proposes fuzzy logic systems for soot blowing optimization and drum level control. For soot blowing optimization, a fuzzy rule-based system estimates the cleanliness factor of boiler sections to determine the correct soot blowing scheme. For drum level control, two fuzzy strategies are proposed: 1) Using fuzzy logic rules to vary the PID controller gains based on error and error derivative. 2) Varying the drum level setpoint based on fuzzy logic rules. Simulation results show the fuzzy approaches improve dynamic and steady-state performance for both control problems.
This document summarizes the use of fuzzy logic applications in a 500 MW power station. Specifically, it proposes fuzzy logic systems for soot blowing optimization and drum level control. For soot blowing optimization, a fuzzy rule-based system estimates the cleanliness factor of boiler sections to determine the correct soot blowing scheme. For drum level control, two fuzzy strategies are proposed: 1) Using fuzzy logic rules to vary the PID controller gains based on error and error derivative. 2) Varying the drum level setpoint based on fuzzy logic rules. Simulation results show the fuzzy approaches improve dynamic and steady-state performance for both control problems.
Quantum behaved artificial bee colony based conventional controller for opti...IJECEIAES
Since a multi area system (MAS) is characterized by momentary overshoot, undershoot and intolerable settling time so, neutral copper conductors are replaced by multilayer zigzag graphene nano ribbon (MLGNR) interconnects that are tremendously advantageous to copper interconnects for the future transmission line conductors necessitated for economic and emission dispatch (EED) of electric supply system giving rise to reduced overshoots and settling time and greenhouse effect as well. The recent work includes combinatorial algorithm involving proportional integral and derivative controller and heuristic swarm optimization; we say it as Hybridparticle swarm optimization (PSO) controller. The modeling of two multi area systems meant for EED is carried out by controlling the conventional proportional integral and derivative (PID) controller regulated and monitored by quantum behaved artificial bee colony (ABC) optimization based PID (QABCOPID) controller in MATLAB/Simulink platform. After the modelling and simulation of QABCOPID controller it is realized that QABCOPID is better as compared to multi span double display (MM), neural network based PID (NNPID), multi objective constriction PSO (MOCPSO) and multi objective PSO (MOPSO). The real power generation fixed by QABCOPID controller is used to estimate the combined cost and emission objectives yielding optimal solution, minimum losses and maximum efficiency of transmission line.
Flow regulation at constant head in feedwater pumps in a sugar industryIJECEIAES
In this paper the feasibility of energy saving by implementing flow regulation at constant load in feedwater pumps in a sugar industry is studied. As regulation strategy, the use of a variable speed drive in the hydraulic system is proposed. For the project evaluation, the Net Present Value and Payback Period techniques are used. Among the variables considered are the price of energy, the equipment useful life, financial data and those related to environmental impact. As a result, it was found that if only a commercial approach is considered, the energy saving strategy is profitable but not attractive, because investment is recovered in a period close to the useful life of technology. However, if a government focus that encourages the implementation of these energies saving strategies is considered, the investment of the project recovers in a short time.
Decentralised PI controller design based on dynamic interaction decoupling in...IJECEIAES
An enhanced method for design of decenralised proportional integral (PI) controllers to control various variables of flotation columns is proposed. These columns are multivariable processes characterised by multiple interacting manipulated and controlled variables. The control of more than one variable is not an easy problem to solve as a change in a specific manipulated variable affects more than one controlled variable. Paper proposes an improved method for design of decentralized PI controllers through the introduction of decoupling of the interconnected model of the process. Decoupling the system model has proven to be an effective strategy to reduce the influence of the interactions in the closed-loop control and consistently to keep the system stable. The mathematical derivations and the algorithm of the design procedure are described in detail. The behaviour and performance of the closed-loop systems without and with the application of the decoupling method was investigated and compared through simulations in MATLAB/Simulink. The results show that the decouplers - based closedloop system has better performance than the closed-loop system without decouplers. The highest improvement (2 to 50 times) is in the steady-state error and 1.2 to 7 times in the settling and rising time. Controllers can easily be implemented.
1. The document describes a control system for a fuel cell based distributed generation system. It includes mathematical models of the solid oxide fuel cell stack, DC/DC boost converters, and three-phase voltage source inverter.
2. Controllers are designed for the DC/DC converters and inverter using PI control schemes. A MATLAB/Simulink model is developed combining the individual component models and controllers.
3. Simulation results are presented showing the system performance, including its ability to regulate real and reactive power on the distribution system.
Plant-Wide Control: Eco-Efficiency and Control Loop ConfigurationISA Interchange
Since the eco-efficiency of all industrial processes/plants has become increasingly important, engineers need to find a way to integrate the control loop configuration and the measurements of eco-efficiency. A new measure of eco-efficiency, the exergy eco-efficiency factor, for control loop configuration, is proposed in this paper. The exergy eco-efficiency factor is based on the thermodynamic concept of exergy which can be used to analyse a process in terms of its efficiency associated with the control configuration. The combination of control pairing configuration techniques (such as the relative gain array, RGA and Niederlinski index, NI) and the proposed exergy eco-efficiency factor will guide the process designer to reach the optimal control design with low operational cost (i.e., energy consumption). The exergy eco-efficiency factor is implemented in the process simulation case study and the reliability of the proposed method is demonstrated by dynamic simulation results.
Coordination of blade pitch controller and battery energy storage using firef...TELKOMNIKA JOURNAL
Utilization of renewable energy sources (RESs) to generate electricity is increasing significantly in recent years due to global warming situation all over the world. Among RESs type, wind energy is becoming more favorable due to its sustainability and environmentally friendly characteristics. Although wind power system provides a promising solution to prevent global warming, they also contribute to the instability of the power system, especially in frequency stability due to uncertainty characteristic of the sources (wind speed). Hence, coordinated controller between blade pitch controller and battery energy storage (BES) system to enhance the frequency performance of wind power system is proposed in this work. Firefly algorithm (FA) is used as optimization method for achieving better coordination. From the investigated test systems, the frequency performance of wind power system can be increased by applying the proposed method. It is noticeable that by applying coordinated controller between blade pitch angle controller and battery energy storage using firefly algorithm the overshoot of the frequency can be reduced up to -0.2141 pu and accelerate the settling time up to 40.14 second.
Similar to Decentralized proportional-integral control with carbon addition for wastewater treatment plant (20)
Square transposition: an approach to the transposition process in block cipherjournalBEEI
The transposition process is needed in cryptography to create a diffusion effect on data encryption standard (DES) and advanced encryption standard (AES) algorithms as standard information security algorithms by the National Institute of Standards and Technology. The problem with DES and AES algorithms is that their transposition index values form patterns and do not form random values. This condition will certainly make it easier for a cryptanalyst to look for a relationship between ciphertexts because some processes are predictable. This research designs a transposition algorithm called square transposition. Each process uses square 8 × 8 as a place to insert and retrieve 64-bits. The determination of the pairing of the input scheme and the retrieval scheme that have unequal flow is an important factor in producing a good transposition. The square transposition can generate random and non-pattern indices so that transposition can be done better than DES and AES.
Hyper-parameter optimization of convolutional neural network based on particl...journalBEEI
The document proposes using a particle swarm optimization (PSO) algorithm to optimize the hyperparameters of a convolutional neural network (CNN) for image classification. The PSO algorithm is used to find optimal values for CNN hyperparameters like the number and size of convolutional filters. In experiments on the MNIST handwritten digit dataset, the optimized CNN achieved a testing error rate of 0.87%, which is competitive with state-of-the-art models. The proposed approach finds optimized CNN architectures automatically without requiring manual design or encoding strategies during training.
Supervised machine learning based liver disease prediction approach with LASS...journalBEEI
In this contemporary era, the uses of machine learning techniques are increasing rapidly in the field of medical science for detecting various diseases such as liver disease (LD). Around the globe, a large number of people die because of this deadly disease. By diagnosing the disease in a primary stage, early treatment can be helpful to cure the patient. In this research paper, a method is proposed to diagnose the LD using supervised machine learning classification algorithms, namely logistic regression, decision tree, random forest, AdaBoost, KNN, linear discriminant analysis, gradient boosting and support vector machine (SVM). We also deployed a least absolute shrinkage and selection operator (LASSO) feature selection technique on our taken dataset to suggest the most highly correlated attributes of LD. The predictions with 10 fold cross-validation (CV) made by the algorithms are tested in terms of accuracy, sensitivity, precision and f1-score values to forecast the disease. It is observed that the decision tree algorithm has the best performance score where accuracy, precision, sensitivity and f1-score values are 94.295%, 92%, 99% and 96% respectively with the inclusion of LASSO. Furthermore, a comparison with recent studies is shown to prove the significance of the proposed system.
A secure and energy saving protocol for wireless sensor networksjournalBEEI
The research domain for wireless sensor networks (WSN) has been extensively conducted due to innovative technologies and research directions that have come up addressing the usability of WSN under various schemes. This domain permits dependable tracking of a diversity of environments for both military and civil applications. The key management mechanism is a primary protocol for keeping the privacy and confidentiality of the data transmitted among different sensor nodes in WSNs. Since node's size is small; they are intrinsically limited by inadequate resources such as battery life-time and memory capacity. The proposed secure and energy saving protocol (SESP) for wireless sensor networks) has a significant impact on the overall network life-time and energy dissipation. To encrypt sent messsages, the SESP uses the public-key cryptography’s concept. It depends on sensor nodes' identities (IDs) to prevent the messages repeated; making security goals- authentication, confidentiality, integrity, availability, and freshness to be achieved. Finally, simulation results show that the proposed approach produced better energy consumption and network life-time compared to LEACH protocol; sensors are dead after 900 rounds in the proposed SESP protocol. While, in the low-energy adaptive clustering hierarchy (LEACH) scheme, the sensors are dead after 750 rounds.
Plant leaf identification system using convolutional neural networkjournalBEEI
This paper proposes a leaf identification system using convolutional neural network (CNN). This proposed system can identify five types of local Malaysia leaf which were acacia, papaya, cherry, mango and rambutan. By using CNN from deep learning, the network is trained from the database that acquired from leaf images captured by mobile phone for image classification. ResNet-50 was the architecture has been used for neural networks image classification and training the network for leaf identification. The recognition of photographs leaves requested several numbers of steps, starting with image pre-processing, feature extraction, plant identification, matching and testing, and finally extracting the results achieved in MATLAB. Testing sets of the system consists of 3 types of images which were white background, and noise added and random background images. Finally, interfaces for the leaf identification system have developed as the end software product using MATLAB app designer. As a result, the accuracy achieved for each training sets on five leaf classes are recorded above 98%, thus recognition process was successfully implemented.
Customized moodle-based learning management system for socially disadvantaged...journalBEEI
This study aims to develop Moodle-based LMS with customized learning content and modified user interface to facilitate pedagogical processes during covid-19 pandemic and investigate how teachers of socially disadvantaged schools perceived usability and technology acceptance. Co-design process was conducted with two activities: 1) need assessment phase using an online survey and interview session with the teachers and 2) the development phase of the LMS. The system was evaluated by 30 teachers from socially disadvantaged schools for relevance to their distance learning activities. We employed computer software usability questionnaire (CSUQ) to measure perceived usability and the technology acceptance model (TAM) with insertion of 3 original variables (i.e., perceived usefulness, perceived ease of use, and intention to use) and 5 external variables (i.e., attitude toward the system, perceived interaction, self-efficacy, user interface design, and course design). The average CSUQ rating exceeded 5.0 of 7 point-scale, indicated that teachers agreed that the information quality, interaction quality, and user interface quality were clear and easy to understand. TAM results concluded that the LMS design was judged to be usable, interactive, and well-developed. Teachers reported an effective user interface that allows effective teaching operations and lead to the system adoption in immediate time.
Understanding the role of individual learner in adaptive and personalized e-l...journalBEEI
Dynamic learning environment has emerged as a powerful platform in a modern e-learning system. The learning situation that constantly changing has forced the learning platform to adapt and personalize its learning resources for students. Evidence suggested that adaptation and personalization of e-learning systems (APLS) can be achieved by utilizing learner modeling, domain modeling, and instructional modeling. In the literature of APLS, questions have been raised about the role of individual characteristics that are relevant for adaptation. With several options, a new problem has been raised where the attributes of students in APLS often overlap and are not related between studies. Therefore, this study proposed a list of learner model attributes in dynamic learning to support adaptation and personalization. The study was conducted by exploring concepts from the literature selected based on the best criteria. Then, we described the results of important concepts in student modeling and provided definitions and examples of data values that researchers have used. Besides, we also discussed the implementation of the selected learner model in providing adaptation in dynamic learning.
Prototype mobile contactless transaction system in traditional markets to sup...journalBEEI
1) Researchers developed a prototype contactless transaction system using QR codes and digital payments to support physical distancing during the COVID-19 pandemic in traditional markets.
2) The system allows sellers and buyers in traditional markets to conduct fast, secure transactions via smartphones without direct cash exchange. Buyers scan sellers' QR codes to view product details and make e-wallet payments.
3) Testing showed the system's functions worked properly and users found it easy to use and useful for supporting contactless transactions and digital transformation of traditional markets. However, further development is needed to increase trust in digital payments for users unfamiliar with the technology.
Wireless HART stack using multiprocessor technique with laxity algorithmjournalBEEI
The use of a real-time operating system is required for the demarcation of industrial wireless sensor network (IWSN) stacks (RTOS). In the industrial world, a vast number of sensors are utilised to gather various types of data. The data gathered by the sensors cannot be prioritised ahead of time. Because all of the information is equally essential. As a result, a protocol stack is employed to guarantee that data is acquired and processed fairly. In IWSN, the protocol stack is implemented using RTOS. The data collected from IWSN sensor nodes is processed using non-preemptive scheduling and the protocol stack, and then sent in parallel to the IWSN's central controller. The real-time operating system (RTOS) is a process that occurs between hardware and software. Packets must be sent at a certain time. It's possible that some packets may collide during transmission. We're going to undertake this project to get around this collision. As a prototype, this project is divided into two parts. The first uses RTOS and the LPC2148 as a master node, while the second serves as a standard data collection node to which sensors are attached. Any controller may be used in the second part, depending on the situation. Wireless HART allows two nodes to communicate with each other.
Implementation of double-layer loaded on octagon microstrip yagi antennajournalBEEI
This document describes the implementation of a double-layer structure on an octagon microstrip yagi antenna (OMYA) to improve its performance at 5.8 GHz. The double-layer consists of two double positive (DPS) substrates placed above the OMYA. Simulation and experimental results show that the double-layer configuration increases the gain of the OMYA by 2.5 dB compared to without the double-layer. The measured bandwidth of the OMYA with double-layer is 14.6%, indicating the double-layer can increase both the gain and bandwidth of the OMYA.
The calculation of the field of an antenna located near the human headjournalBEEI
In this work, a numerical calculation was carried out in one of the universal programs for automatic electro-dynamic design. The calculation is aimed at obtaining numerical values for specific absorbed power (SAR). It is the SAR value that can be used to determine the effect of the antenna of a wireless device on biological objects; the dipole parameters will be selected for GSM1800. Investigation of the influence of distance to a cell phone on radiation shows that absorbed in the head of a person the effect of electromagnetic radiation on the brain decreases by three times this is a very important result the SAR value has decreased by almost three times it is acceptable results.
Exact secure outage probability performance of uplinkdownlink multiple access...journalBEEI
In this paper, we study uplink-downlink non-orthogonal multiple access (NOMA) systems by considering the secure performance at the physical layer. In the considered system model, the base station acts a relay to allow two users at the left side communicate with two users at the right side. By considering imperfect channel state information (CSI), the secure performance need be studied since an eavesdropper wants to overhear signals processed at the downlink. To provide secure performance metric, we derive exact expressions of secrecy outage probability (SOP) and and evaluating the impacts of main parameters on SOP metric. The important finding is that we can achieve the higher secrecy performance at high signal to noise ratio (SNR). Moreover, the numerical results demonstrate that the SOP tends to a constant at high SNR. Finally, our results show that the power allocation factors, target rates are main factors affecting to the secrecy performance of considered uplink-downlink NOMA systems.
Design of a dual-band antenna for energy harvesting applicationjournalBEEI
This report presents an investigation on how to improve the current dual-band antenna to enhance the better result of the antenna parameters for energy harvesting application. Besides that, to develop a new design and validate the antenna frequencies that will operate at 2.4 GHz and 5.4 GHz. At 5.4 GHz, more data can be transmitted compare to 2.4 GHz. However, 2.4 GHz has long distance of radiation, so it can be used when far away from the antenna module compare to 5 GHz that has short distance in radiation. The development of this project includes the scope of designing and testing of antenna using computer simulation technology (CST) 2018 software and vector network analyzer (VNA) equipment. In the process of designing, fundamental parameters of antenna are being measured and validated, in purpose to identify the better antenna performance.
Transforming data-centric eXtensible markup language into relational database...journalBEEI
eXtensible markup language (XML) appeared internationally as the format for data representation over the web. Yet, most organizations are still utilising relational databases as their database solutions. As such, it is crucial to provide seamless integration via effective transformation between these database infrastructures. In this paper, we propose XML-REG to bridge these two technologies based on node-based and path-based approaches. The node-based approach is good to annotate each positional node uniquely, while the path-based approach provides summarised path information to join the nodes. On top of that, a new range labelling is also proposed to annotate nodes uniquely by ensuring the structural relationships are maintained between nodes. If a new node is to be added to the document, re-labelling is not required as the new label will be assigned to the node via the new proposed labelling scheme. Experimental evaluations indicated that the performance of XML-REG exceeded XMap, XRecursive, XAncestor and Mini-XML concerning storing time, query retrieval time and scalability. This research produces a core framework for XML to relational databases (RDB) mapping, which could be adopted in various industries.
Key performance requirement of future next wireless networks (6G)journalBEEI
The document provides an overview of the key performance indicators (KPIs) for 6G wireless networks compared to 5G networks. Some of the major KPIs discussed for 6G include: achieving data rates of up to 1 Tbps and individual user data rates up to 100 Gbps; reducing latency below 10 milliseconds; supporting up to 10 million connected devices per square kilometer; improving spectral efficiency by up to 100 times through technologies like terahertz communications and smart surfaces; and achieving an energy efficiency of 1 pico-joule per bit transmitted through techniques like wireless power transmission and energy harvesting. The document outlines how 6G aims to integrate terrestrial, aerial and maritime communications into a single network to provide ubiquitous connectivity with higher
Noise resistance territorial intensity-based optical flow using inverse confi...journalBEEI
This paper presents the use of the inverse confidential technique on bilateral function with the territorial intensity-based optical flow to prove the effectiveness in noise resistance environment. In general, the image’s motion vector is coded by the technique called optical flow where the sequences of the image are used to determine the motion vector. But, the accuracy rate of the motion vector is reduced when the source of image sequences is interfered by noises. This work proved that the inverse confidential technique on bilateral function can increase the percentage of accuracy in the motion vector determination by the territorial intensity-based optical flow under the noisy environment. We performed the testing with several kinds of non-Gaussian noises at several patterns of standard image sequences by analyzing the result of the motion vector in a form of the error vector magnitude (EVM) and compared it with several noise resistance techniques in territorial intensity-based optical flow method.
Modeling climate phenomenon with software grids analysis and display system i...journalBEEI
This study aims to model climate change based on rainfall, air temperature, pressure, humidity and wind with grADS software and create a global warming module. This research uses 3D model, define, design, and develop. The results of the modeling of the five climate elements consist of the annual average temperature in Indonesia in 2009-2015 which is between 29oC to 30.1oC, the horizontal distribution of the annual average pressure in Indonesia in 2009-2018 is between 800 mBar to 1000 mBar, the horizontal distribution the average annual humidity in Indonesia in 2009 and 2011 ranged between 27-57, in 2012-2015, 2017 and 2018 it ranged between 30-60, during the East Monsoon, the wind circulation moved from northern Indonesia to the southern region Indonesia. During the west monsoon, the wind circulation moves from the southern part of Indonesia to the northern part of Indonesia. The global warming module for SMA/MA produced is feasible to use, this is in accordance with the value given by the validate of 69 which is in the appropriate category and the response of teachers and students through a 91% questionnaire.
An approach of re-organizing input dataset to enhance the quality of emotion ...journalBEEI
The purpose of this paper is to propose an approach of re-organizing input data to recognize emotion based on short signal segments and increase the quality of emotional recognition using physiological signals. MIT's long physiological signal set was divided into two new datasets, with shorter and overlapped segments. Three different classification methods (support vector machine, random forest, and multilayer perceptron) were implemented to identify eight emotional states based on statistical features of each segment in these two datasets. By re-organizing the input dataset, the quality of recognition results was enhanced. The random forest shows the best classification result among three implemented classification methods, with an accuracy of 97.72% for eight emotional states, on the overlapped dataset. This approach shows that, by re-organizing the input dataset, the high accuracy of recognition results can be achieved without the use of EEG and ECG signals.
Parking detection system using background subtraction and HSV color segmentationjournalBEEI
Manual system vehicle parking makes finding vacant parking lots difficult, so it has to check directly to the vacant space. If many people do parking, then the time needed for it is very much or requires many people to handle it. This research develops a real-time parking system to detect parking. The system is designed using the HSV color segmentation method in determining the background image. In addition, the detection process uses the background subtraction method. Applying these two methods requires image preprocessing using several methods such as grayscaling, blurring (low-pass filter). In addition, it is followed by a thresholding and filtering process to get the best image in the detection process. In the process, there is a determination of the ROI to determine the focus area of the object identified as empty parking. The parking detection process produces the best average accuracy of 95.76%. The minimum threshold value of 255 pixels is 0.4. This value is the best value from 33 test data in several criteria, such as the time of capture, composition and color of the vehicle, the shape of the shadow of the object’s environment, and the intensity of light. This parking detection system can be implemented in real-time to determine the position of an empty place.
Quality of service performances of video and voice transmission in universal ...journalBEEI
The universal mobile telecommunications system (UMTS) has distinct benefits in that it supports a wide range of quality of service (QoS) criteria that users require in order to fulfill their requirements. The transmission of video and audio in real-time applications places a high demand on the cellular network, therefore QoS is a major problem in these applications. The ability to provide QoS in the UMTS backbone network necessitates an active QoS mechanism in order to maintain the necessary level of convenience on UMTS networks. For UMTS networks, investigation models for end-to-end QoS, total transmitted and received data, packet loss, and throughput providing techniques are run and assessed and the simulation results are examined. According to the results, appropriate QoS adaption allows for specific voice and video transmission. Finally, by analyzing existing QoS parameters, the QoS performance of 4G/UMTS networks may be improved.
A SYSTEMATIC RISK ASSESSMENT APPROACH FOR SECURING THE SMART IRRIGATION SYSTEMSIJNSA Journal
The smart irrigation system represents an innovative approach to optimize water usage in agricultural and landscaping practices. The integration of cutting-edge technologies, including sensors, actuators, and data analysis, empowers this system to provide accurate monitoring and control of irrigation processes by leveraging real-time environmental conditions. The main objective of a smart irrigation system is to optimize water efficiency, minimize expenses, and foster the adoption of sustainable water management methods. This paper conducts a systematic risk assessment by exploring the key components/assets and their functionalities in the smart irrigation system. The crucial role of sensors in gathering data on soil moisture, weather patterns, and plant well-being is emphasized in this system. These sensors enable intelligent decision-making in irrigation scheduling and water distribution, leading to enhanced water efficiency and sustainable water management practices. Actuators enable automated control of irrigation devices, ensuring precise and targeted water delivery to plants. Additionally, the paper addresses the potential threat and vulnerabilities associated with smart irrigation systems. It discusses limitations of the system, such as power constraints and computational capabilities, and calculates the potential security risks. The paper suggests possible risk treatment methods for effective secure system operation. In conclusion, the paper emphasizes the significant benefits of implementing smart irrigation systems, including improved water conservation, increased crop yield, and reduced environmental impact. Additionally, based on the security analysis conducted, the paper recommends the implementation of countermeasures and security approaches to address vulnerabilities and ensure the integrity and reliability of the system. By incorporating these measures, smart irrigation technology can revolutionize water management practices in agriculture, promoting sustainability, resource efficiency, and safeguarding against potential security threats.
CHINA’S GEO-ECONOMIC OUTREACH IN CENTRAL ASIAN COUNTRIES AND FUTURE PROSPECTjpsjournal1
The rivalry between prominent international actors for dominance over Central Asia's hydrocarbon
reserves and the ancient silk trade route, along with China's diplomatic endeavours in the area, has been
referred to as the "New Great Game." This research centres on the power struggle, considering
geopolitical, geostrategic, and geoeconomic variables. Topics including trade, political hegemony, oil
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china’s geo economic outreach in central Asian countries and its future prospect. China is thriving in trade,
pipeline politics, and winning states, according to this study, thanks to important instruments like the
Shanghai Cooperation Organisation and the Belt and Road Economic Initiative. According to this study,
China is seeing significant success in commerce, pipeline politics, and gaining influence on other
governments. This success may be attributed to the effective utilisation of key tools such as the Shanghai
Cooperation Organisation and the Belt and Road Economic Initiative.
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Decentralized proportional-integral control with carbon addition for wastewater treatment plant
1. Bulletin of Electrical Engineering and Informatics
Vol. 9, No. 6, December 2020, pp. 2278~2285
ISSN: 2302-9285, DOI: 10.11591/eei.v9i6.2170 2278
Journal homepage: http://beei.org
Decentralized proportional-integral control with carbon
addition for wastewater treatment plant
M. H. Husin1
, M. F. Rahmat2
, N. A. Wahab3
1
Department of Electrical and Electronic Engineering, Faculty of Engineering, Universiti Malaysia Sarawak, Malaysia
2,3
School of Electrical Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, Malaysia
Article Info ABSTRACT
Article history:
Received Jan 15, 2020
Revised Mar 30, 2020
Accepted May 13, 2020
Two main challenges in activated sludge wastewater treatment plant
(WWTP) are cost and effluent quality, which has forced the wastewater
treatment operator to find an alternative to improve the existing control
strategy. The Benchmark Simulation Model No. 1 (BSM1) is applied as
operational settings for this study. In BSM1, the standard control variables
are the internal recirculation flow rate and the oxygen transfer rate.
To improve the existing control strategy of BSM1, three alternative control
handles are proposed, which are the individual aeration intensity control,
carbon source addition and combination of both. The effect of each control
handles in terms of the effluent violation, effluent quality, aeration cost,
and total operational cost index are examined. The simulation result
has shown that the individual control of aeration intensity improved
the effluent quality index, and reduced the aeration, pumping, and total
operational cost index when compared to the standard BSM1 control
handle. Nonetheless, the addition of a fixed external carbon source has
shown a significantly improved effluent quality with a lower number of total
nitrogen violations as compared to the standard BSM1 control handles.
Thus, the proposed control handles may be beneficial if applied in a real WWTP.
Keywords:
Activated sludge
Aeration intensity
Control handle
Effluent quality
Proportional-integral control
Wastewater treatment
This is an open access article under the CC BY-SA license.
Corresponding Author:
M. H. Husin,
Department of Electrical and Electronic Engineering,
Faculty of Engineering, Universiti Malaysia Sarawak,
94300 Kota Samarahan, Sarawak, Malaysia.
Email: hhmaimun@unimas.my
1. INTRODUCTION
Challenges in activated sludge wastewater treatment plant (WWTP) are divide into two main groups
which are to cut down the costs for operation, particularly the aeration energy and to maintain the effluent
quality of wastewater treatment plant. The energy consumption may range from 30-50% [1] of the total
operating costs of the WWTP with more than half of the energy demand comes from the aeration section.
The upsurges in the cost of energy escalated the cost even more. Standards are formed for the quality of
effluent discharged from the WWTP to the rivers. Fine or penalty will be charged caused by the release of
pollutants in the receiving water. Without a doubt, the WWTP are subject to large disturbances and
uncertainty in the elements of the incoming wastewater. Not only the control design is difficult, but the
modeling of WWTP is also a challenge due to the high dimensional and an outsized number of
parameters [2]. There are a few technologies available used to control effluent discharge from WWTP. One
of the common techniques is the activated sludge process (ASP) that make use of bacteria or microbes to
oxidize the organic and non-organic matters in the wastewater. There are two steps involved in the process, which
2. Bulletin of Electr Eng & Inf ISSN: 2302-9285
Decentralized proportional-integral control with carbon addition for wastewater… (M. H. Husin)
2279
are nitrification and denitrification. Nitrification is a process where the ammonium is converted to nitrate
under aerobic conditions. Denitrification, on the other hand, is a process of converting the nitrate into
gaseous nitrogen under anoxic conditions. This two-step procedure is crucial to achieving efficient nitrogen
removal in the ASP.
Conversely, the highly nonlinear and time-varying condition that exists in the dynamic behaviour of
the biological nitrogen removal makes a complex relationship between control input and output variables [3].
Thus, in controller design for the ASP, troubles triggered by the interaction of control parameters
are un-avoided. Hence, a decentralized controller is an option whereby the system is decomposed into several
equivalent single loops. The decentralized controller has been applied in many industrial systems such as
power systems [4], Heating, ventilation, and air conditioning (HVAC) [5] and many more. The BSM1 [6] is
the first benchmark plant that is developed by the IWA Task Group on Benchmarking of Control Strategies
for WWTPs. The BSM1 is a simulation setting made of five compartments activated sludge reactor
comprising of non-aerated compartments (two anoxic tanks) and aerated compartments (three aerobic tanks).
The plant layout of BSM1 is as shown in Figure 1. The plant mixes nitrification with pre-denitrification in a
composition that is normally operated for attaining biological nitrogen removal in a full-scale plant. The
arrangements are tailed by a secondary settler. The foremost two compartments are anoxic, the aerated
compartment 3 and 4 have fixed oxygen transfer coefficient (KLa=10, h-1
=240 d-1
) and forgoing compartment
5 has dissolved oxygen (DO) concentration regulated at 2 g(-COD).m-3
by control of KLa.
Figure 1. The plant layout of the BSM1
In the BSM1 closed-loop assessment instance, the control handles are the oxygen transfer rate (KLa)
in compartment number 5, KLa5 and internal recirculation flow rate (Qa) [6]. The controller used in the BSM1
is the PI controller. PID is one of the most frequently applied control strategies in the WWTP due to its
simplicity, robustness and close to optimum control performances. In the PI controller, the controller tries to
reduce the inaccuracy by fine-tuning the process control input. A lot of research has been done on
the existing BSM1 control handles, in terms of proposing a better control of DO [7-11], nitrate [12, 13] or
both [14-16]. These research focus on developing a better controller, usually a more advanced one to fulfill
the more stringent effluent standards set for all wastewater treatment plant. For the execution of alternative
control schemes on the benchmark plant, few control handles are considered to exist. These include
anoxic/aerobic volume, aeration intensity individually for each reactor (KLa1, KLa2, KLa3, KLa4, KLa5),
external carbon source flow rate (qEC1, qEC2, qEC3, qEC4, qEC5), influent distribution by use of step feed
(fQinflow1, fQinflow2, fQinflow3, fQinflow4, fQinflow5), distribution of internal flow recirculation (fQa1, fQa2, fQa3, fQa4, fQa5),
return sludge flow rate (Qr), wastage flow rate (Qw), and distribution of return sludge flow (fQr1, fQr2, fQr3, fQr4,
fQr5). The few control handles considered to exist on the BSM1 are shown in Figure 2. However, there are
limits to different control handles.
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Figure 2. A few control handles considered to exist on the BSM1
Nonetheless, too many control handles may not be workable for the actual plant. Still, the
abovementioned control handles are outlined for BSM1, to take for mostly any kind of common control
approach. Some of the studies were performed on a few control handles other than the default one. But, there
are only a few studies are found on individual aeration intensity control [16, 17], and external carbon
source [18-20]. Nevertheless, the previous work [16] is performed with different DO setpoint configurations, [17]
is using cascade control structure [18], [20] is not using BSM1 and [19] is using the COST simulation
benchmark [21]. The WWTP is naturally a system with a multivariable and usually, this kind of system
is defined using several control loops. Variations in any input values will commonly influence the outputs due to
the relations between the inputs and outputs variables. Thus, in this study, a decentralized controller is used instead
of a multivariable controller. A decentralized controller is an uncomplicated approach where the controlled plant
is made up of a group of detached sub plants where every section in the plant is created individually.
The decentralized PI controller in WWTP can be found in a few papers [3], [22-24]. In [23], an
adaptive interaction algorithm is developed together with a decentralized PI controller which targets to
auto-tune the PI control parameters. It is examined that the decentralized PI controller with a tuning
algorithm is effectively trailing the anticipated set point with substantial results. In [3], an adaptive
decentralized PI controller is developed to satisfy the effluent quality and improving the nitrogen elimination
for nonlinear activated sludge WWTP. The present work proposes three alternative control handles namely,
the aeration intensity for individual reactor, external carbon source flow rate and combination of both. For all
proposed alternative control handles, it is using a decentralized control structure. For the first control handle,
three PI controllers are used for manipulating the KLa3-KLa5. In this control handles, it focusses on the
enhancement of the ASP concerning DO concentration in all the aerated tanks. In the second proposed
control handle which is the external carbon source, a fixed value of carbon source flow rate is investigated.
The external carbon sources will affect the denitrification process in the activated sludge system [25]. As for
a comparison, BSM1 standard control handles are used. In BSM1, the aeration intensity for tank 1 and 2 are:
KLa1 and KLa2=0 h-1
while for tank 3 and 4 are: KLa3 and KLa4 fixed at 10 h-1
=240 d-1
. As for external carbon
source flow rate for BSM1: qEC1=qEC2=qEC3=qEC4=qEC5=0 m3
. d-1
. As mentioned previously, the BSM1
recommends a PI control scheme. The closed-loop control arrangement comprises of a PI that controls the
DO level in the 5th
compartment of the reactor at a predetermined setpoint value of 2 g(-COD).m-3
by
manipulation of the KLa5 and the NO3-N (nitrate) concentration in the second compartment at a
predetermined setpoint value of 1 g.m-3
by manipulation of the Qa.
2. RESEARCH METHOD
The alternative control handles are divided into three case studies, case A: individual aeration
intensity control, case B: addition of external carbon and case C: the combination of cases A and B.
2.1. Case A: Individually control aeration intensity
The first control case (A) is the DO control in three aeration zones, meaning that the aeration
intensity for reactor 3-5 are individually controlled by one controller each. For the decentralized control
structure, the WWTP is subdivided into three single input single output (SISO) subsystems, which made up
4. Bulletin of Electr Eng & Inf ISSN: 2302-9285
Decentralized proportional-integral control with carbon addition for wastewater… (M. H. Husin)
2281
the three PI controllers. The implementation of this control structure where a proportional-integral (PI)
controller for each tank (3 to 5) is shown in Figure 3. The concentration of DO at the end of each aerobic
tanks are computed and contrasted with the desired DO set point, which is supposed to have the standard
value of 2 mg O2/L. The individual controlled aeration intensity is proposed to help reduce the operational
cost and better achieved effluent quality. The concentration of DOs in tank 3-5 are all set to 2 mg/l. The control
signal for all three PI controllers used for manipulating the KLa3-KLa5 is according to the following equation:
( ) ( ) ∫ ( ) (1)
Where Kp and Ki are the proportional and integral coefficients of the PI controller, correspondingly.
The Kp and Ki are set to 25 and 25 000, respectively for each PI controller. Besides, the KLa3 - KLa5
are constrained to a maximum of 360 day-1
. As for nitrate concentration control in tank 2, the nitrate set point
is set to 1 mg/l. The Kp and Ki are set to 10000 and 800000, respectively. The Qa is constrained up to 5 times
of stabilized input flow rate, 92230 m3
day-1
Figure 3. Individual aeration intensity control set up
2.2. Case B: Fixed external carbon addition
Case B is a fixed external carbon addition in the foremost anoxic tank reactor with configuration as
shown in Figure 4. The value for carbon source is set at fixed at 0.25 m3
. d-1
. The second control strategy
is proposed for the reduction of effluent violation percentage. The value for carbon source is preferred to be
small so that the cost for additional carbon dosage would not be that too large.
Figure 4. Fixed external carbon addition set up
2.3. Case C: Combination of individually control aeration intensity and fixed carbon source addition
The last case (C) is a combination of A and B strategies, with configuration as shown in Figure 5.
The decentralized PI control together with carbon source addition configuration is predicted to produce
a much lower total cost as compared to case B.
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Figure 5. Individual aeration intensity control with a fixed external carbon addition set up
The performance assessment specifies quantifies for the outcome of the control approach on plant
performance including the effluent quality, the cost factors for operations, overall cost index (OCI)
and the measurement of an interval that the effluent maximums are violated. The effluent concentrations
across the three assessment stages (weathers-dry/rain/storm) should follow the thresholds given in Table 1.
Table 1. The effluent quality limit
Variable SNH TSS Ntot CODt BOD5
Value < 4 g N.m-3
< 30 g SS.m-3
< 18 g N.m-3
< 100 g COD.m-3
< 10 g BOD.m-3
3. RESULTS AND DISCUSSION
The simulation procedure for BSM1 can be checked in [6]. At first, the BSM1 is simulated for 150
days using the constant influent input, which ideally is a procedure to attain a quasi-steady-state.
This procedure is executed to assure that all the initial conditions of the states are consistent with the reading
obtained from the BSM1 manual. The next step is to continue with setting-up the plant for the dynamic
benchmark simulation by executing a 14-day simulation of dry influent. Lastly, the BSM1 is run for the 14
days of the dynamic test input weather (dry, rain or storm weather) with the presence of noise. For all
the aeration intensity control, the DO sensor is of class A with a measurement range of 0 to 10 g(-COD).m-3
and measurement noise of 0.25 g (-COD).m-3
is used. As for nitrate control, the sensor is of class B0 with
a measurement range of 0 to 20 g N.m-3
and a measurement noise of 0.5 g N.m-3
.
The main aims of an activated sludge process control strategy are to minimize the operational cost
and to keep the effluent concentrations within the regulation limits. Since tanks 1 and 2 of BSM1 are non-
reacted compartments, no aeration control is performed at these two reactors. Three individual KLa control
for reactor 3-5 is proposed to control the aerated tank 3-5. It is expected that the aeration energy cost will be
lower than only KLa5 control and no-change or a slightly better effluent quality is expected since there is no
additional controller for nitrate control.
3.1. Average effluent violation
The controller assessment examines the outcome of the proposed control scheme on the plant
process. Initially, the performance of the average effluent violation is evaluated to the default benchmark,
BSM1. The comparative results of effluent violation in dry and storm weather are shown in Table 2.
From five key process variables that are evaluated, two variables which are total ammonia (SNH) and total
nitrogen (Ntot) showed improved results in dry and storm influent, mainly using case A and C. The pollutants
ammonia and Ntot are the parameters that are more challenging to be held below the determined
boundaries [26]. A better Ntot removal is achieved through individually aeration control, thereby improving
denitrification. The other process variables that are also evaluated show a small rise in the average effluent
violation value as compared to BSM1 standard control handles. It can be observed that strategy is case A can
reduce the SNH effluent violation in dry by 4% and in storm weather by 2%. Addition of fixed external
carbon at 0.25 m3
. d-1
has shown a reduction of 3% of Ntot effluent violation in both kinds of weather.
More reduction of Ntot effluent violation in both kinds of weather is achieved using Case C strategy.
6. Bulletin of Electr Eng & Inf ISSN: 2302-9285
Decentralized proportional-integral control with carbon addition for wastewater… (M. H. Husin)
2283
Table 2. The effluent quality limit
Effluent average SNH
(< 4 g N.m-3
)
TSS
(< 30 g SS.m-3
)
Ntot
(< 18 g N.m-3
)
CODt
(< 100 g COD.m-3
)
BOD5
(< 10 g BOD.m-3
)
Dry
BSM1 2.4783 13.0248 16.8908 48.2470 2.7587
A 2.3743 ▼ 13.0252 16.8685 ▼ 48.2459 ▼ 2.7585 ▼
B 2.5196 13.0739 16.2733 ▼ 48.3192 2.7822
C 2.4136 ▼ 13.0743 16.2443 ▼ 48.3180 2.7819
Storm
BSM1 2.9953 15.2935 15.8340 ▼ 47.6875 3.2065
A 2.9318 ▼ 15.2941 15.7840 ▼ 47.6878 3.2066
B 3.0272 15.3393 15.3034 ▼ 47.7540 3.2306
C 2.9613▼ 15.3400 15.2493 ▼ 47.7543 3.2306
3.2. Number of effluent violations
Table 3 shows the comparative results of several effluent violations using three different control
case studies in dry and storm weather. It can be seen that using case A, the number of Ntot violation was
reduced by 5% in storm weather and the number of SNH violation was reduced by 5% in both dry and storm
weather. The addition of a fixed external carbon source has greatly reduced the number of Ntot violation by
27% in dry, and 30% in storm weather. However, the number of SNH violation is slightly increased using
this B strategy (3% in dry, and 1% in storm weather). The combination of A and B has improved this, with
a reduction of the number of SNH violation is 3% in dry and storm weather while maintaining the same
number of Ntot violation in both kinds of weather.
External carbon sources can improve the denitrification rate and hence decrease the nitrate level.
It can be observed from Figure 6. that in dry weather, strategy B (blue line) and C (yellow line) show a huge
reduction in Ntot violation as compared to BSM1 (black line) and strategy A (red line). In BSM1 and A, the
limit was breached at seven different instances while for B and C, the limit was violated at only five different
occasions. It is observed from this study that the reduction of Ntot peaks is accomplished by adding additional
external carbon dosage in the first tank. As for ammonia violation, as can be observed from Figure 7 (using
storm weather), A (red line) and C (yellow line) showed a slightly better ammonia violation compared to
BSM1 (black line). The strategy in case B (blue line) does not reduce the SNH violation, and in the case
when the external carbon is added in dry and storm weather, SNH value is increased.
Table 3. The average effluent violation
Effluent violation limit Ntot
(< 18 mg N/l)
SNH
(< 4 mg N/l)
TSS
(< 30 mg SS/l)
Days % Days % Days %
Dry
BSM1 1.2500 17.86 1.1771 16.82 - -
A 1.2500 17.86 1.1146 ▼ 15.92 ▼ - -
B 0.9167 ▼ 13.10 ▼ 1.2083 17.26 - -
C 0.9271 ▼ 13.24 ▼ 1.1458 ▼ 16.37 ▼ - -
Storm
BSM1 1.0833 15.48 1.8438 26.34 0.0208 0.30
A 1.0313 ▼ 14.73 ▼ 1.7604 ▼ 25.00 ▼ 0.0208 0.30
B 0.7604 ▼ 10.86 ▼ 1.8542 26.49 0.0208 0.30
C 0.7500 ▼ 10.71 ▼ 1.7917 ▼ 25.60 ▼ 0.0208 0.30
Figure 6. Comparison of total nitrogen violation for control strategies A, B, C and BSM1
7. ISSN: 2302-9285
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Figure 7. Comparison of ammonia violation for control strategies A, B, C and BSM1
3.3. Effluent quality and operational cost
Table 4 shows the effluent quality and cost for dry weather. A better effluent quality index
is achieved as compared to BSM1. However, the lowest aeration energy consumed is obtained using strategy
in case A. The results show that strategy in case A, which is individual control for reactor tank 3 to 5 display
good improvement in the aeration energy which is lower by 4% as weigh against to the BSM1 control strategy.
Table 4. The effluent quality and cost (dry weather)
+ BSM1 A B C
Effluent Quality (E.Q) index 6096.71330 6054.87430 -1% 6008.16450 -1% 5964.35840 -2%
Aeration energy cost index 3697.5737 3534.4583 -4% 3706.8623 0% 3545.5703 -4%
Total OCI 16366.2631 16203.3652 -1% 16853.5017 3% 16692.3536 2%
It is well known that the most effective solutions to increase denitrification and to manipulate
the nitrate recirculation flow rate is to add-on an external carbon source into the anoxic part of
the process [12]. In cases B and C where the additional fixed carbon is introduced at tank 1, it is observed
that effluent quality is better compared to BSM1. The case B strategy costs more compared to BSM1 and
strategy in case A. In the case of C, the overall Total OCI is reduced by 1% as compared to the strategy proposed
in case B.
4. CONCLUSION
Three alternatives control handles for BSM1 are proposed and compared to BSM1 control handles
to evaluate its’ effectiveness. Case A has a better effluent quality index and much lower aeration energy and
total OCI compared to BSM1. The aeration energy cost index is lower by 4% and total OCI is reduced by 1%
overall. The effluent quality index is 1% better than the BSM1. As for case B, significant improvement in
terms of reduction in the number of Ntot violation is achieved as a result of the addition of a fixed external
carbon source for tank 1. Using a strategy in case B alone, the total OCI is increased by 3%. The introduction
of strategy in case C has shown a slight improvement recorded, where the aeration energy is lower by 4% and
effluent quality is better by 2% when compared to BSM1. To conclude, the main objectives of this study are
achieved which is to propose alternative strategies that minimize the operational cost and to keep the effluent
concentrations within the limits.
ACKNOWLEDGEMENTS
The authors wish to thank the Ministry of Education Malaysia, Universiti Teknologi Malaysia and
FRGS vote R.J130000.7811.4F817 for their financial support. Their support is gratefully acknowledged.
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