BYA.PONMALR10-510-007ENS 505 WASTE WATERMANAGEMENTCOMPUTERIZATION AND MONITORING OFWASTE WATER TREATMENT SYSTEM
INTRODUCTION A Computer based software for monitoring the differenttreatment process. In order to perform the activity of analyzing a variety ofsampling points and type of samples depending on theobjective of control. Type of samples are1) Treated water.2) Raw water and waste water.3) Sludge from sewage works.4) Treatment reagents, etc.
DEFINITION Polluted wastewater pumped into the WastewaterTreatment Plant goes through a complex, multi-stage treatment process that takes about 22hours. The treatment plant uses physical, chemical andbiological processes to removed contaminants,producing a high quality discharge. All the process are carried out by computerizedsystem
Why Computer Aided Control andOperation?A lot of money is being invested into measurementand monitoring systems in most process industriestoday and the wastewater treatment industry is noexception.
System ComplexityThe operation and control of a modern process industry,such as wastewater treatment plants, is often associatedwith high complexity. The vast source of disturbances,e.g. changing ambient conditions, mechanicalbreakdowns, the large amount of data collected by themeasurement systems. A Dynamic conditions caused by changes in the influentwastewater. Complex cause-effect relationships caused by the use ofbiological cultures, recirculations and control actions.
Automation and Control in WastewaterTreatment The Treatment plants all over the world are equippedwith data collecting systems. These systems are used for monitoring, automaticcontrol and as a decision base for operationalstrategies. The sample values are often an average over thesampling period, during which some sensorscontinuously deliver values and others perhaps onlyonce a minute.
CONT… Some variables are controlled automatically withcontrollers. The controlled variables are1) Oxygen level in aerated basins2) Return and Recycling flow rates3) Adding of chemicals
Monitoring1. In most process industries, monitoring of the processand the process output is performed to achieveconformity with quality, safety and economicrequirements imposed on the production.2. The level of monitoring differs from various fields.3. Pioneering efforts can be found for petrochemical andpharmaceutical industries.4. Waste water treatment industries cannot be consideredto be the most diligent and systematic users ofmonitoring.
Industrial waste water monitoring checklistEach facility with anaerobic wastewater treatment mustmonitor these parameters. Volume of wastewater entering an anaerobicreactor or anaerobic lagoon. Concentration of COD or BOD of wastewaterentering an anaerobic reactor or lagoon.
Anaerobic wastewater or anaerobic sludge treatment processeswith biogas recovery must also monitor these parameters… Volumetric flow rate of recovered biogas. CH4 content of recovered biogas. Temperature Pressure Moisture content
CONT… An advanced monitoring system for controlling thetreatment process of wastewater containingchromium (VI) was developed by using a flowmethod as a chemical sensing probe. In this system, the acquisition of monitoringinformation and the control of the treatment processis computer-controllable
. SEP-1701002-DST 203 Chrome Removal Complete System. ENPROX 1500DWastewater Treatment System 15 GPM. ENPROX 500DWastewater Treatment System 5 GPM.Equipment for monitoring wastewatertreatment chemicals
Remote Monitoring of Waste WaterTreatment Equipment
Alarm functions enable rapid identification ofabnormalities. Reduces time required for periodic monitoring andpatrolling of facilities. Systems easy to set up, minimizing engineering manhours. Powerful software (DAQWORX) available for remotemonitoring. Measured data can also be saved to theCX1000/CX2000 storage media for extra security.
SCADA IN WASTEWATERTREATMENT SCADA (Supervisory Control and Data Acquisition) + HMI(Human Machine Interface) Its an assemblage of computer and communicationsequipment designed to work together for the purpose ofcontrolling a commercial process. SCADA is usually implemented on1) Manufacturing processes (chemical andpharmaceutical processing, food processing, and discretemanufacturing)
CONT2) Treatment processes (wastewatertreatment, municipal water treatmentsystems)3) Distribution systems (gas, oil and waterpipelines) Besides control, SCADA systems alsoperform monitoring, data logging, alarmingand diagnostic functions.
Cont… The term SCADA also refers to centralized systemswhich monitor and control entire sites or complexesof systems spread out over large areas. SCADA = CCC (Control, Cost reduction andConfidence)
Systems concepts Most control actions are performed automatically byRemote Terminal Units ("RTUs") or by programmable logic controllers ("PLCs").
FUNCTIONS IN SCADA Control function Monitoring function Data logging function
CONTROL FUNCTION SCADA systems are capable of running standardcontrol algorithms like P, PI, and PID regulatory. It is for maintaining1. Specific levels in tanks,2. Maintaining prescribed flow rates and3. Maintaining processes at specific temperaturesand pressures.
Monitoring Functions Providing an effective visual interfacebetween the process and an operator is oftenthe main function of the system.
Data Logging Functions Once data has been brought into the system, theSCADA system will archive selected data intoelectronic records that may be recalled and reviewedat a later time.
A SCADA System usually consists of thefollowing subsystems1) Human Machine Interface or HMIHMS is the apparatus which presentsprocess data to a human operator and through whichthe human operator monitors and controls theprocess.2) A supervisory (computer) system, gathering data onthe process and sending commands to the process.
Cont…3) Remote Terminal Units (RTUs) connecting tosensors in the process, converting sensor signals todigital data and sending digital data to thesupervisory system.4) Communication infrastructure connecting thesupervisory system to the Remote Terminal Units.
A SCADA system could beprogrammed to1. Monitor high and low levels in the day tanks.2. Fill them when a certain level is reached.3. Calculate and store the volume used.4. Monitor the level in the main feed tank.5. Alarm when a certain level is reached to notifypurchasing.6. Plot the usage of chemicals vs time, process, or anyother parameter.
ADVANTAGES Systems have multiple levels of security available sothat screens can be locked, hidden or displayeddepending on the security level. Higher levels of authorization can change set pointsand timing. Updating software is a remote operation and is easilydone without a site visit.
CONT… Once a system is running, program changes areeasily made at little cost. We can remotely monitor a system to debug orupdate software in real time. The system stays running while we work. Costs are relatively low and the new object orientedsystems can be programmed rapidly.
ABS (Absorbent Bio-filter System) ABS significantly lowers costs and increases treatmentperformance for rural areas. As an alternative to village-scale on-site wastewatertreatment units. The monitoring parameters -operational conditions ofthe systems are1) Oxidation Reduction Potential (ORP),2) Water level,3) Pump status,4) Power supply (on / off).
CONT… The monitoring system included measurement,control and display devices. The dispersed nature of such on-site units hasbrought about the need for remote monitoringsystems and integrated management with the leastnumber of operators in a central location.
CMMS (COMPUTERIZED MAINTENANCEMANAGEMENT SYSTEM) It is a software based information managementsystem used to automate the maintenanceprocess. One major benefit of CMMS is the ability toschedule equipment and maintenance in a way that does not interfere withuse of the equipment.
St. Marys New Wastewater TreatmentPlant Flow Equalization Equipment at the beginning of the treatment plantcontrols the volume of wastewater that can beprocessed for treatment. During high flow conditions (> 9,000,000 gallons perday) - plant cannot treat all of the flow- electric gate-divert a portion - 2,700,000 gallon equalization basin-storage.
CONT… The captured wastewater in the equalization basin isautomatically returned to the treatment plant fortreatment when system flows return to normal. A computerized process monitoring and controlsystem controls all aspects of flow equalization.
Wastewater Treatment Stages 1. Influent Screening & Vortex De-gritting - largeand heavy inorganic material are removed. 2. Oxidation Ditchwastewater is biologicallytreated to reduce biological oxygen demand andto oxidize ammonia. The ditch is sized to accommodate the designloading without the need for separate primarysettling. A chemical is added to removed phosphorus.
CONT… 5. Plant Effluent - treated wastewater is discharged tothe St. Marys River. 6. Cannibal Solids Reduction Process - solidsremoved or generated during treatment undergofurther treatment through a cannibal solids reductionprocess.
CONT… 3. Final Clarifiers1) Two peripheral feed clarifiers separate sludge fromtreated wastewater.2) Clear wastewater flows to the disinfection process.3) Sludge is returned to the oxidation ditch or wasted tothe solids reduction process. 4. UV Disinfection - the energy from ultraviolet lights isutilized to reduce the pathogen content of the wastewater.
CONT… 1. Solids Separation Module -screens small materialfrom the solids, and an interchange module. 2. Interchange Module -the solids are subjected toalternating periods of oxygen-available (aerobic) andoxygen-deficient (facultative) environments. which encourages cannibalization of themicroorganisms and reducing the volume of thesolids.
CONT… 7. Sludge Storage - solids ultimately are wasted fromthe cannibal process to one of two digesters forthickening and storage. Sludge is either applied to agricultural land as a soilconditioner (bio solids) or dewatered and disposed ofin a landfill.
The Klagshamn WastewaterTreatment Plant (WWTP) Southern parts of Malmo The treatment process has to be monitored and adjustedcontinuously through a computerized control system toensure that the effluent requirements are fulfilled.
COMPUTERIZED MONITORING The monitoring is carried out by meters which continuously measurethe 1) Phosphorus concentration 2) Water flow and 3) Other parameters. At the Klagshamn laboratory the water from the different stages of thetreatment process is analysed. The advantage of using meters is the opportunity to monitor, processand control the plant as changes occur.
REFERENCE: St. Marys New Wastewater Treatment Plant http://WWW.vasyd.se. Stephan J. Sosik, CEO, scada system in waste water treatment. S.-K. Kwun, Y.-H. Cho, J.-K. Chun, Development of monitoringsystem for a multiple on –site waste water treatment unit mo,American Society of Agricultural and Biological Engineers. "http://en.wikipedia.org/wiki/SCADA" Christian Rosen ,Monitoring Wastewater Treatment Systems,Department of Industrial Electrical Engineering and Automation. Sam Bastawros, P.E. Nosa Irenumaagho, P.E. Ewa Gorgi, P.E.,utilization of computerized maintenance management system atsouth side waste water treatment plant