This document discusses biofiltration as an innovative technology for treating air contaminants. It begins by describing how biofiltration works using naturally bioactive media like soil and compost. However, these have limitations like low degradation rates and nutrient depletion. The document then describes how biotrickling filters use synthetic media to support biofilm growth, overcoming many of the natural media limitations. Several mechanisms facilitate contaminant degradation in biotrickling filters. While more complex than compost biofilters, biotrickling filters allow better process control and higher degradation rates.
This document discusses biofiltration as an innovative technology for treating contaminants in gas streams, such as air. It provides details on the types of biofilter support media, including naturally bioactive media like compost and soil, as well as synthetic media used in biotrickling filters. The mechanisms involved in biofiltration and the advantages of biotrickling filters over traditional compost biofilters are also summarized. Biotrickling filters can achieve higher degradation rates, treat higher contaminant concentrations, and offer better pH and nutrient control compared to compost biofilters.
This document discusses the microbiology of trickling filters, which are used in wastewater treatment. It contains the following key points:
1. Trickling filters use an attached growth process where microorganisms develop biofilms on the surface of media. Extracellular polymeric substances help attach microorganisms to the media and each other.
2. The biofilm is about 0.1-0.2mm thick and contains a diverse community of bacteria, fungi, algae, protozoa, and other microbes. Nitrifying bacteria oxidize ammonia to nitrite and nitrate.
3. The biofilm sloughs off periodically as oxygen diffusion decreases and anaerobic conditions develop deeper
The document summarizes a pilot-scale study on ex-situ bioremediation of chlorobenzenes in contaminated soil. Three 6 m3 soil cells were treated with varying amounts (0-35%) of organic amendments and nutrients to stimulate native microorganisms. Over 2-3 weeks, approximately 90% of dichlorobenzene was removed from soils, with residual levels below detection limits. Laboratory tests confirmed the presence of microorganisms capable of mineralizing chlorobenzenes in the treated soils. The study demonstrates that vented ex-situ biotreatment can effectively remove chlorobenzenes through biodegradation without excessive losses from volatilization.
In-Situ Bioremediation for Contaminated SoilMonisha Alam
This document outlines in-situ bioremediation, which uses microorganisms to break down contaminants in place at contaminated sites. It describes the process of bioremediation and various methods like biostimulation, bioaugmentation, bioventing, and phytoremediation. The advantages are that it is low-cost and combines with other technologies, while disadvantages include long treatment times and potential increased contaminant mobility. Factors like soil and contaminant properties, nutrients, temperature, and oxygen levels must be suitable for bioremediation to be applicable. A case study highlights successful bioremediation of BTEX at a gas plant site in Alberta, Canada.
The document discusses various methods for remediating contaminated land, including conventional methods and bioremediation. Conventional methods are very expensive, involve transporting hazardous materials, and do not destroy contaminants. Bioremediation uses natural biological processes and is a potentially better approach. It can destroy or immobilize contaminants on-site inexpensively using microorganisms and plants. The document outlines different types of bioremediation including in situ and ex situ techniques like bioaugmentation, phytoremediation, and rhizofiltration that use microbes and plants to remediate contamination.
Bioremediation uses microorganisms to degrade contaminants in soil and water. It is more cost effective than other remediation methods like incineration. There are three main techniques - in situ treats contamination on site, ex situ treats excavated material on or off site, and ex situ slurry treats soil-water mixtures in bioreactors or ponds. Specific in situ methods include land farming, bioventing, biosparging, and bioaugmentation which introduce oxygen and nutrients to stimulate microbes. Ex situ methods are composting, biopiles, and bioreactors which accelerate degradation through aeration and temperature/nutrient control.
Microbiology of sewage and sewage treatmentFatimah Tahir
Sewage or wastewater contains water and solids separated from various sources like domestic, industrial, and stormwater runoff. It contains pathogens and organic material. Treatment aims to remove solids, reduce biochemical oxygen demand (BOD), and eliminate pathogens through primary, secondary, and sometimes tertiary processes. Primary treatment removes 50% of solids and 25% of BOD through settling. Secondary treatment further reduces BOD through microbial degradation. Sludge from primary treatment is anaerobically digested by microbes to produce methane and reduce pathogens before disposal or reuse. Disinfection with chemicals or UV light is sometimes applied before releasing the treated water.
Water Pollution and its control through biotechnologyRachana Tiwari
Water pollution occurs from both point and non-point sources and can be physical, chemical, or biological in nature. It affects plants and organisms in bodies of water. Biotechnological control of water pollution uses aerobic and anaerobic treatment processes. Aerobic processes use microorganisms like Pseudomonas and algae to break down pollutants, and occur in suspended growth systems like activated sludge or attached growth systems like trickling filters. Anaerobic processes use microbes like Peptococcus anaerobus and Escherichia coli to treat waste in the absence of oxygen in digesters.
This document discusses biofiltration as an innovative technology for treating contaminants in gas streams, such as air. It provides details on the types of biofilter support media, including naturally bioactive media like compost and soil, as well as synthetic media used in biotrickling filters. The mechanisms involved in biofiltration and the advantages of biotrickling filters over traditional compost biofilters are also summarized. Biotrickling filters can achieve higher degradation rates, treat higher contaminant concentrations, and offer better pH and nutrient control compared to compost biofilters.
This document discusses the microbiology of trickling filters, which are used in wastewater treatment. It contains the following key points:
1. Trickling filters use an attached growth process where microorganisms develop biofilms on the surface of media. Extracellular polymeric substances help attach microorganisms to the media and each other.
2. The biofilm is about 0.1-0.2mm thick and contains a diverse community of bacteria, fungi, algae, protozoa, and other microbes. Nitrifying bacteria oxidize ammonia to nitrite and nitrate.
3. The biofilm sloughs off periodically as oxygen diffusion decreases and anaerobic conditions develop deeper
The document summarizes a pilot-scale study on ex-situ bioremediation of chlorobenzenes in contaminated soil. Three 6 m3 soil cells were treated with varying amounts (0-35%) of organic amendments and nutrients to stimulate native microorganisms. Over 2-3 weeks, approximately 90% of dichlorobenzene was removed from soils, with residual levels below detection limits. Laboratory tests confirmed the presence of microorganisms capable of mineralizing chlorobenzenes in the treated soils. The study demonstrates that vented ex-situ biotreatment can effectively remove chlorobenzenes through biodegradation without excessive losses from volatilization.
In-Situ Bioremediation for Contaminated SoilMonisha Alam
This document outlines in-situ bioremediation, which uses microorganisms to break down contaminants in place at contaminated sites. It describes the process of bioremediation and various methods like biostimulation, bioaugmentation, bioventing, and phytoremediation. The advantages are that it is low-cost and combines with other technologies, while disadvantages include long treatment times and potential increased contaminant mobility. Factors like soil and contaminant properties, nutrients, temperature, and oxygen levels must be suitable for bioremediation to be applicable. A case study highlights successful bioremediation of BTEX at a gas plant site in Alberta, Canada.
The document discusses various methods for remediating contaminated land, including conventional methods and bioremediation. Conventional methods are very expensive, involve transporting hazardous materials, and do not destroy contaminants. Bioremediation uses natural biological processes and is a potentially better approach. It can destroy or immobilize contaminants on-site inexpensively using microorganisms and plants. The document outlines different types of bioremediation including in situ and ex situ techniques like bioaugmentation, phytoremediation, and rhizofiltration that use microbes and plants to remediate contamination.
Bioremediation uses microorganisms to degrade contaminants in soil and water. It is more cost effective than other remediation methods like incineration. There are three main techniques - in situ treats contamination on site, ex situ treats excavated material on or off site, and ex situ slurry treats soil-water mixtures in bioreactors or ponds. Specific in situ methods include land farming, bioventing, biosparging, and bioaugmentation which introduce oxygen and nutrients to stimulate microbes. Ex situ methods are composting, biopiles, and bioreactors which accelerate degradation through aeration and temperature/nutrient control.
Microbiology of sewage and sewage treatmentFatimah Tahir
Sewage or wastewater contains water and solids separated from various sources like domestic, industrial, and stormwater runoff. It contains pathogens and organic material. Treatment aims to remove solids, reduce biochemical oxygen demand (BOD), and eliminate pathogens through primary, secondary, and sometimes tertiary processes. Primary treatment removes 50% of solids and 25% of BOD through settling. Secondary treatment further reduces BOD through microbial degradation. Sludge from primary treatment is anaerobically digested by microbes to produce methane and reduce pathogens before disposal or reuse. Disinfection with chemicals or UV light is sometimes applied before releasing the treated water.
Water Pollution and its control through biotechnologyRachana Tiwari
Water pollution occurs from both point and non-point sources and can be physical, chemical, or biological in nature. It affects plants and organisms in bodies of water. Biotechnological control of water pollution uses aerobic and anaerobic treatment processes. Aerobic processes use microorganisms like Pseudomonas and algae to break down pollutants, and occur in suspended growth systems like activated sludge or attached growth systems like trickling filters. Anaerobic processes use microbes like Peptococcus anaerobus and Escherichia coli to treat waste in the absence of oxygen in digesters.
•Introduction of bioremediation: Bioremediation refers to the process of using microorganisms to remove the environmental pollutants i.e. toxic wastes found in soil, water, air etc.
•In situ bioremediation:
It involves a direct approach for the microbial
degradation of xenobiotics at the sites of pollution
(soil, ground water).
•Types of in situ bioremediation:
Natural attenuation.
Engineered in situ bioremediation.
- Bioventing, biosparging, bioslurping,
phytoremediation.
•Ex situ bioremediation:
Waste or toxic pollutants can be collected from the polluted sites and bioremediation can be carried out at a designated place or site.
• Types of ex situ bioremediation
Land farming, windrow, biopiles, bioreactors.
•Microorganisms use in bioremediation:
A number of naturally occurring marine microbes
such as Pseudomonas sp. is capable of degrading oil and other hydrocarbons.
•Factors affecting bioremediation:
Nutrient availability, moisture content, pH, temperature, contaminant availability.
•References:
Satyanarayana U. Biotechnology. BOOKS AND ALLIED (P) Ltd.
Sharma P.D. Environmental Microbiology. RASTOGI PUBLICATIONS.
Gupta P.K. Biotechnology and Genomics. RASTOGI PUBLICATIONS.
Dubey R.C. A Textbook of Biotechnology. S Chand And Company Ltd.
Dubey R.C. A Textbook of Microbiology. S Chand And Company Ltd.
Willey/Sherwood/Woolverton. Prescott’s Microbiology. McGRAW-HILL INTERNATIONAL EDITION.
www.sciencedirect.com/bioremediation.
Anaerobic digestion is a technologically simple process used to convert organic material into methane through microbial action in the absence of air. The methanogenic activity occurs at 55°C or higher with a neutral pH of 6.5-7.5. High-rate anaerobic reactors like UASB reactors are widely used for wastewater treatment and can achieve organic loading rates of 1-20 kg COD/m3-day with removal efficiencies of 75-85% and retention times of 4-24 hours. Biofilters use microorganisms attached to a solid media to biologically degrade pollutants from air and wastewater streams, while bioscrubbers first absorb gases before biological oxidation in a separate basin
This document discusses bioremediation and phytoremediation processes. It covers key topics like site characterization, physical and chemical properties of contaminants, factors that influence biodegradation rates, and microbiological characterization. Environmental factors that can impact bioremediation like pH, nutrients, temperature and oxygen levels are also examined. Prediction of degradation rates and the importance of factors like contaminant bioavailability, sorption, and toxicity of breakdown products are summarized.
This document discusses bioremediation, which uses microorganisms to remove pollution from soil, water, and air. There are two types of bioremediation - in situ, which treats pollution at the site, and ex situ, which treats pollution off site. In situ bioremediation can be intrinsic, using native microbes, or engineered, by adding nutrients or microbes. Ex situ involves removing contaminated material and treating it through methods like slurry phase bioremediation, which mixes soil and water, or solid phase bioremediation using land farming or piles. Bioremediation is effective but performance is difficult to evaluate and volatile organic compounds remain challenging to degrade.
This document discusses bioremediation, which uses microorganisms like bacteria and fungi to degrade environmental pollutants. It defines bioremediation and describes how it works by stimulating existing microbes or adding specialized microbes. The key factors for effective bioremediation like nutrients, water, oxygen and temperature are outlined. In-situ and ex-situ bioremediation methods are compared, and applications to treat soil, groundwater, marine spills and air are reviewed. Advantages like low cost are balanced with longer timescales. Related technologies like phytoremediation and bioventing are also mentioned.
Bioremediation uses living organisms like bacteria and fungi to break down pollutants. There are two types - in situ remediation which treats pollutants on site, and ex situ which treats them off site. Phytoextraction uses plants to absorb contaminants from soil or water. Essential factors for effective microbial bioremediation include microbial populations, oxygen, water, nutrients, temperature, and pH. A case study describes using oil-eating bacteria to clean an oil spill in Mumbai. Bioremediation was also used to clean Railadevi Lake in Thane, India. Limitations include the long time needed and potential food chain contamination.
Microorganism in sewage treatment,Biodiversity and rolesNibal mousa
This document discusses microorganisms found in sewage treatment. It begins by describing the composition of sewage and how it provides an ideal environment for microorganism growth. It then examines the roles of various bacteria, including acetogenic, coliform, denitrifying, fermentative, and nitrifying bacteria. It also discusses archaea like methanogens, as well as algae, fungi, protozoa, and viruses present in sewage treatment. The document provides examples of important microorganisms and their roles in removing pollutants from wastewater.
This document discusses various types of bioremediation techniques used to clean up contaminated soil and groundwater. It defines bioremediation as using living microorganisms to degrade environmental pollutants or prevent pollution. The two main types of bioremediation are in situ, which treats contaminants in place, and ex situ, which involves removing contaminated material to be treated elsewhere. Specific techniques discussed include bioaugmentation, bioslurping, biosparging, natural attenuation, bioventing, and biostimulation. The advantages and limitations of bioremediation are also summarized.
Packaging material in bio-filtration systems: Woodchip vs. Pumiceosilblossom
The document compares woodchip and pumice as packing materials for biofiltration systems. It finds that while woodchip absorbs more moisture, pumice retains it better. Woodchip degrades over time and may contain odors, while pumice is inert and odorless. Colonization experiments show woodchip has a more diverse initial microbial population, while pumice promotes more uniform colonization deeper in its porous structure. Overall, both can be suitable depending on factors like cost and availability, but pumice paired with inoculation promotes strong microbial performance in biofilters.
The document summarizes a study on screening paint-degrading microorganisms isolated from wall scrapings. Bacteria were isolated from paint samples on mineral salt medium and their ability to degrade paint was tested. Biochemical tests identified the isolates. Testing found the secondary metabolites of isolate PI-4, identified as Brevibacterium sp. through DNA sequencing, degraded paint most effectively by leaching it from coated metal strips. The study aimed to obtain paint-degrading bacteria and evaluate their potential for bioremediation of paint waste.
This document summarizes a study on the bioremediation of toxic compounds from textile industry effluent using dead fungal biomass. The study investigated the biosorption of the azo dye Methyl Orange and heavy metals chromium and lead using dead biomass of the fungus Aspergillus flavus. The maximum biosorption for each compound was determined under different parameters such as pH, contact time, concentration of solution, temperature, and biomass concentration. Methyl Orange biosorption was found to be 53.62% at pH 5.5 and 40 minutes. Chromium biosorption was 72.18% at pH 6 and 10 minutes. Lead biosorption was 76.12% at pH 7
Bioremediation of soil contaminated polycyclic aromatic hydrocarbonRizwan Ullah
This document discusses bioremediation techniques for soil contaminated with polycyclic aromatic hydrocarbons (PAHs). It describes PAHs and their natural and anthropogenic sources. The most commonly used bioremediation techniques for PAHs are described as land farming, bioreactors, phytoremediation, and rhizoremediation. Land farming and bioreactors place contaminated soil in prepared beds where conditions are optimized for microbial degradation of PAHs. Bioreactors allow for enhanced control of bioremediation conditions compared to land farming.
This document discusses bioremediation, which is the use of microorganisms like bacteria and fungi to break down pollutants and contaminants in the environment. It can be used to degrade a variety of compounds, including crude oil, refined oil, pesticides, and herbicides. There are two main types - in situ bioremediation treats contaminants on-site, while ex situ removes and treats contaminated soil and water elsewhere. Bioremediation offers advantages like being cost effective and causing little disruption, but is limited to biodegradable compounds and products of biodegradation could potentially be more toxic.
Phytoremediation is the direct use of living green plants for in situ, or in place, removal, degradation, or containment of contaminants in soils, sludges, sediments, surface water and groundwater. Phytoremediation is: A low cost, solar energy driven cleanup technique.
This document discusses the roles of microbes in bioremediation. It defines bioremediation as using microorganisms such as bacteria and fungi to degrade contaminants in soils, groundwater, and sediments. The key factors that affect microbial bioremediation are discussed, including the microbial population, oxygen, water, nutrients, temperature, and pH. Different types of bioremediation techniques are described, as well as examples of bioremediation applications in soils, groundwater, marine oil spills, and air pollution control.
bio remediation ppt with audio sol220 h1803KaminiKumari13
The document discusses bioremediation techniques for treating contaminated soil and groundwater. It defines bioremediation as using microorganisms to break down pollutants by altering environmental conditions. Both aerobic and anaerobic bioremediation processes are described in detail. Aerobic uses oxygen as the electron acceptor while anaerobic adds an electron donor to stimulate reduction of oxidized pollutants. Limitations include incomplete degradation of some pollutants and the need for optimal environmental conditions for microbial activity.
Bioremediation uses microorganisms to return contaminated environments to their original condition. There are two main types: in situ bioremediation, which cleans up contamination on site, and ex situ bioremediation, which removes waste for off-site treatment. In situ bioremediation can occur intrinsically or be engineered through additions like fertilizers or microbes. Ex situ approaches include solid phase treatments like composting of wastes or slurry phase treatments where contaminated materials are mixed into liquid in bioreactors. Key factors that affect bioremediation include moisture, pH, temperature, nutrients, contaminant concentration, and microbial populations.
Role of Microbes in Sewage Treatment, in Biogas production, as Biocontrol age...indranil chatterjee
The document discusses the roles of microbes in sewage treatment, biogas production, and as biocontrol agents and biofertilizers. Microbes play key roles in breaking down waste in sewage treatment plants and converting organic materials into biogas through anaerobic digestion. They also act as natural enemies to control agricultural pests and help fertilize soils by fixing nitrogen and making nutrients available to plants.
The document discusses bioremediation, which uses microorganisms to degrade environmental pollutants. It describes different types of bioremediation including in situ and ex situ methods. In situ bioremediation occurs on-site and can be intrinsic or engineered, while ex situ involves removing contaminated material for treatment using methods like land farming, composting, or biopiles. The document also outlines factors influencing bioremediation and lists some advantages and limitations.
Bioremediation is the use of microorganisms (e.g., bacteria, fungi), plants (termed phytoremediation), or biological enzymes to achieve treatment of hazardous waste. Treatment can target a variety of media (wastewater, groundwater, soil/sludge, gas) with several possible objectives (e.g., mineralization of organic compounds, immobilzation of contaminants). In situ bioremediation (ISB) is the application of bioremediation in the subsurface – as compared to ex situ bioremediation, which applies to media readily accessible aboveground (e.g., in treatment cells/soil piles or bioreactors). In situ bioremediation may be applied in the unsaturated/vadoze zone (e.g., bioventing) or in saturated soils and groundwater (Sharma S. 2012).
•Introduction of bioremediation: Bioremediation refers to the process of using microorganisms to remove the environmental pollutants i.e. toxic wastes found in soil, water, air etc.
•In situ bioremediation:
It involves a direct approach for the microbial
degradation of xenobiotics at the sites of pollution
(soil, ground water).
•Types of in situ bioremediation:
Natural attenuation.
Engineered in situ bioremediation.
- Bioventing, biosparging, bioslurping,
phytoremediation.
•Ex situ bioremediation:
Waste or toxic pollutants can be collected from the polluted sites and bioremediation can be carried out at a designated place or site.
• Types of ex situ bioremediation
Land farming, windrow, biopiles, bioreactors.
•Microorganisms use in bioremediation:
A number of naturally occurring marine microbes
such as Pseudomonas sp. is capable of degrading oil and other hydrocarbons.
•Factors affecting bioremediation:
Nutrient availability, moisture content, pH, temperature, contaminant availability.
•References:
Satyanarayana U. Biotechnology. BOOKS AND ALLIED (P) Ltd.
Sharma P.D. Environmental Microbiology. RASTOGI PUBLICATIONS.
Gupta P.K. Biotechnology and Genomics. RASTOGI PUBLICATIONS.
Dubey R.C. A Textbook of Biotechnology. S Chand And Company Ltd.
Dubey R.C. A Textbook of Microbiology. S Chand And Company Ltd.
Willey/Sherwood/Woolverton. Prescott’s Microbiology. McGRAW-HILL INTERNATIONAL EDITION.
www.sciencedirect.com/bioremediation.
Anaerobic digestion is a technologically simple process used to convert organic material into methane through microbial action in the absence of air. The methanogenic activity occurs at 55°C or higher with a neutral pH of 6.5-7.5. High-rate anaerobic reactors like UASB reactors are widely used for wastewater treatment and can achieve organic loading rates of 1-20 kg COD/m3-day with removal efficiencies of 75-85% and retention times of 4-24 hours. Biofilters use microorganisms attached to a solid media to biologically degrade pollutants from air and wastewater streams, while bioscrubbers first absorb gases before biological oxidation in a separate basin
This document discusses bioremediation and phytoremediation processes. It covers key topics like site characterization, physical and chemical properties of contaminants, factors that influence biodegradation rates, and microbiological characterization. Environmental factors that can impact bioremediation like pH, nutrients, temperature and oxygen levels are also examined. Prediction of degradation rates and the importance of factors like contaminant bioavailability, sorption, and toxicity of breakdown products are summarized.
This document discusses bioremediation, which uses microorganisms to remove pollution from soil, water, and air. There are two types of bioremediation - in situ, which treats pollution at the site, and ex situ, which treats pollution off site. In situ bioremediation can be intrinsic, using native microbes, or engineered, by adding nutrients or microbes. Ex situ involves removing contaminated material and treating it through methods like slurry phase bioremediation, which mixes soil and water, or solid phase bioremediation using land farming or piles. Bioremediation is effective but performance is difficult to evaluate and volatile organic compounds remain challenging to degrade.
This document discusses bioremediation, which uses microorganisms like bacteria and fungi to degrade environmental pollutants. It defines bioremediation and describes how it works by stimulating existing microbes or adding specialized microbes. The key factors for effective bioremediation like nutrients, water, oxygen and temperature are outlined. In-situ and ex-situ bioremediation methods are compared, and applications to treat soil, groundwater, marine spills and air are reviewed. Advantages like low cost are balanced with longer timescales. Related technologies like phytoremediation and bioventing are also mentioned.
Bioremediation uses living organisms like bacteria and fungi to break down pollutants. There are two types - in situ remediation which treats pollutants on site, and ex situ which treats them off site. Phytoextraction uses plants to absorb contaminants from soil or water. Essential factors for effective microbial bioremediation include microbial populations, oxygen, water, nutrients, temperature, and pH. A case study describes using oil-eating bacteria to clean an oil spill in Mumbai. Bioremediation was also used to clean Railadevi Lake in Thane, India. Limitations include the long time needed and potential food chain contamination.
Microorganism in sewage treatment,Biodiversity and rolesNibal mousa
This document discusses microorganisms found in sewage treatment. It begins by describing the composition of sewage and how it provides an ideal environment for microorganism growth. It then examines the roles of various bacteria, including acetogenic, coliform, denitrifying, fermentative, and nitrifying bacteria. It also discusses archaea like methanogens, as well as algae, fungi, protozoa, and viruses present in sewage treatment. The document provides examples of important microorganisms and their roles in removing pollutants from wastewater.
This document discusses various types of bioremediation techniques used to clean up contaminated soil and groundwater. It defines bioremediation as using living microorganisms to degrade environmental pollutants or prevent pollution. The two main types of bioremediation are in situ, which treats contaminants in place, and ex situ, which involves removing contaminated material to be treated elsewhere. Specific techniques discussed include bioaugmentation, bioslurping, biosparging, natural attenuation, bioventing, and biostimulation. The advantages and limitations of bioremediation are also summarized.
Packaging material in bio-filtration systems: Woodchip vs. Pumiceosilblossom
The document compares woodchip and pumice as packing materials for biofiltration systems. It finds that while woodchip absorbs more moisture, pumice retains it better. Woodchip degrades over time and may contain odors, while pumice is inert and odorless. Colonization experiments show woodchip has a more diverse initial microbial population, while pumice promotes more uniform colonization deeper in its porous structure. Overall, both can be suitable depending on factors like cost and availability, but pumice paired with inoculation promotes strong microbial performance in biofilters.
The document summarizes a study on screening paint-degrading microorganisms isolated from wall scrapings. Bacteria were isolated from paint samples on mineral salt medium and their ability to degrade paint was tested. Biochemical tests identified the isolates. Testing found the secondary metabolites of isolate PI-4, identified as Brevibacterium sp. through DNA sequencing, degraded paint most effectively by leaching it from coated metal strips. The study aimed to obtain paint-degrading bacteria and evaluate their potential for bioremediation of paint waste.
This document summarizes a study on the bioremediation of toxic compounds from textile industry effluent using dead fungal biomass. The study investigated the biosorption of the azo dye Methyl Orange and heavy metals chromium and lead using dead biomass of the fungus Aspergillus flavus. The maximum biosorption for each compound was determined under different parameters such as pH, contact time, concentration of solution, temperature, and biomass concentration. Methyl Orange biosorption was found to be 53.62% at pH 5.5 and 40 minutes. Chromium biosorption was 72.18% at pH 6 and 10 minutes. Lead biosorption was 76.12% at pH 7
Bioremediation of soil contaminated polycyclic aromatic hydrocarbonRizwan Ullah
This document discusses bioremediation techniques for soil contaminated with polycyclic aromatic hydrocarbons (PAHs). It describes PAHs and their natural and anthropogenic sources. The most commonly used bioremediation techniques for PAHs are described as land farming, bioreactors, phytoremediation, and rhizoremediation. Land farming and bioreactors place contaminated soil in prepared beds where conditions are optimized for microbial degradation of PAHs. Bioreactors allow for enhanced control of bioremediation conditions compared to land farming.
This document discusses bioremediation, which is the use of microorganisms like bacteria and fungi to break down pollutants and contaminants in the environment. It can be used to degrade a variety of compounds, including crude oil, refined oil, pesticides, and herbicides. There are two main types - in situ bioremediation treats contaminants on-site, while ex situ removes and treats contaminated soil and water elsewhere. Bioremediation offers advantages like being cost effective and causing little disruption, but is limited to biodegradable compounds and products of biodegradation could potentially be more toxic.
Phytoremediation is the direct use of living green plants for in situ, or in place, removal, degradation, or containment of contaminants in soils, sludges, sediments, surface water and groundwater. Phytoremediation is: A low cost, solar energy driven cleanup technique.
This document discusses the roles of microbes in bioremediation. It defines bioremediation as using microorganisms such as bacteria and fungi to degrade contaminants in soils, groundwater, and sediments. The key factors that affect microbial bioremediation are discussed, including the microbial population, oxygen, water, nutrients, temperature, and pH. Different types of bioremediation techniques are described, as well as examples of bioremediation applications in soils, groundwater, marine oil spills, and air pollution control.
bio remediation ppt with audio sol220 h1803KaminiKumari13
The document discusses bioremediation techniques for treating contaminated soil and groundwater. It defines bioremediation as using microorganisms to break down pollutants by altering environmental conditions. Both aerobic and anaerobic bioremediation processes are described in detail. Aerobic uses oxygen as the electron acceptor while anaerobic adds an electron donor to stimulate reduction of oxidized pollutants. Limitations include incomplete degradation of some pollutants and the need for optimal environmental conditions for microbial activity.
Bioremediation uses microorganisms to return contaminated environments to their original condition. There are two main types: in situ bioremediation, which cleans up contamination on site, and ex situ bioremediation, which removes waste for off-site treatment. In situ bioremediation can occur intrinsically or be engineered through additions like fertilizers or microbes. Ex situ approaches include solid phase treatments like composting of wastes or slurry phase treatments where contaminated materials are mixed into liquid in bioreactors. Key factors that affect bioremediation include moisture, pH, temperature, nutrients, contaminant concentration, and microbial populations.
Role of Microbes in Sewage Treatment, in Biogas production, as Biocontrol age...indranil chatterjee
The document discusses the roles of microbes in sewage treatment, biogas production, and as biocontrol agents and biofertilizers. Microbes play key roles in breaking down waste in sewage treatment plants and converting organic materials into biogas through anaerobic digestion. They also act as natural enemies to control agricultural pests and help fertilize soils by fixing nitrogen and making nutrients available to plants.
The document discusses bioremediation, which uses microorganisms to degrade environmental pollutants. It describes different types of bioremediation including in situ and ex situ methods. In situ bioremediation occurs on-site and can be intrinsic or engineered, while ex situ involves removing contaminated material for treatment using methods like land farming, composting, or biopiles. The document also outlines factors influencing bioremediation and lists some advantages and limitations.
Bioremediation is the use of microorganisms (e.g., bacteria, fungi), plants (termed phytoremediation), or biological enzymes to achieve treatment of hazardous waste. Treatment can target a variety of media (wastewater, groundwater, soil/sludge, gas) with several possible objectives (e.g., mineralization of organic compounds, immobilzation of contaminants). In situ bioremediation (ISB) is the application of bioremediation in the subsurface – as compared to ex situ bioremediation, which applies to media readily accessible aboveground (e.g., in treatment cells/soil piles or bioreactors). In situ bioremediation may be applied in the unsaturated/vadoze zone (e.g., bioventing) or in saturated soils and groundwater (Sharma S. 2012).
Biofiltration is a pollution control technique that uses a bioreactor containing living material to biologically degrade pollutants in waste water, surface runoff, or contaminated air. It is a green process that uses small amounts of power compared to thermal or catalytic control units. There are different types of biofilters based on layout, support media used, and shape. The biofiltration process involves contaminated air passing through a moist filter medium that provides conditions for microorganisms to absorb and degrade the contaminants into carbon dioxide through a combination of adsorption, absorption, and microbial degradation. Major considerations for the filter medium include its ability to retain moisture and microbes, provide a large surface area, retain nutrients, and allow low resistance air
This document provides an overview of bioremediation and phytoremediation. It defines bioremediation as using biological organisms like microbes and plants to treat contaminated soil and water. The document discusses the history of bioremediation and categorizes different bioremediation techniques. It also outlines the pros and cons of various in-situ and ex-situ bioremediation methods like bioventing, bioaugmentation, biostimulation, biosparging, land farming and composting. Finally, it introduces the concept of phytoremediation and notes that it involves using plants to remediate environmental contaminants.
The document discusses various methods of bioremediation and biodegradation to remediate contaminated soil and groundwater. It defines bioremediation as using biological organisms such as bacteria and fungi to solve environmental problems through technological innovation. Biodegradation is the natural breakdown of materials by microorganisms. The document then describes various in situ and ex situ bioremediation techniques in detail, including bioventing, biosparging, bioslurping, phytoremediation, land farming, biopiles, and windrows. The key factors in selecting a bioremediation method are the contaminants present, their accessibility to microbes, and any environmental conditions that could inhibit microbial activity.
The document discusses bioremediation, which uses microorganisms to break down environmental pollutants and clean contaminated sites. It describes different types of bioremediation including microbial remediation, which uses bacteria and fungi, and phytoremediation, which uses plants. The goals, methods, applications, advantages and limitations of bioremediation are summarized. Key bioremediation techniques mentioned are bioventing, land-farming, bioaugmentation, and biopiles.
Activated Sludge Process.pptx By Vikrant SirVikrantBute1
The activated sludge process uses microorganisms to break down organic matter in wastewater. Raw wastewater enters an aeration tank where microbes consume organic matter, producing new cell growth. The mixture is then sent to a clarifier where microbes are separated from treated water. Excess sludge is removed for drying. Key parameters include mixed liquor suspended solids, which must be maintained at optimal levels for effective treatment. The process requires less space than lagoon systems and can produce effluent that meets standards.
The document discusses biological treatment as a method for removing contaminants from wastewater. It describes how bacteria and microorganisms break down organic materials through assimilation. There are various physical, chemical, and biological treatment methods outlined, with biological treatment being the focus. The key types of biological treatment systems discussed are activated sludge treatment, trickling filtration, and constructed wetlands. The document provides details on the process, equipment, advantages, and output quality of biological wastewater treatment.
Biological and Advanced Water Treatment.pptxYalelet Abera
Micro-organisms play an essential role in the biological treatment of wastewater by converting organic waste into more stable substances. There are three main types of biological wastewater treatment processes - aerobic, anaerobic, and anoxic. Two common biological wastewater treatment methods are trickling filters and activated sludge processes. Trickling filters use microorganisms attached to media to treat wastewater as it trickles down. Activated sludge processes use air and microorganisms in suspension to treat wastewater in aeration tanks, with the treated wastewater then sent to secondary clarifiers. Design considerations for biological wastewater treatment systems include organic loading rates, hydraulic loading rates, and detention
Biotechnology in Microbiology- includes the how microbial associations are worked out in secondary treatment techniques like activated sludge process, trickling filters, rotating biological contractors, composting, bioremediation etc.
The document discusses a study that will examine the use of organic and inorganic fertilizers, as well as their combinations, to stimulate oil-degrading microbes in ex-situ bioremediation of a soil sample polluted with crude oil. The study aims to determine the treatment that maximizes the removal of total petroleum hydrocarbons from the soil, while also enumerating the abundance and diversity of oil-degrading microbes. The biodegradation process will be monitored by measuring various indicators over time. A soil analysis will first be conducted to obtain baseline properties of the polluted sample before treatments are applied. Lastly, the study will identify hydrocarbon-degrading bacteria to analyze changes in their relative diversity and
This document discusses bioreactors and their applications in waste water treatment. It begins with an introduction to bioreactors and their role in biotechnology. It then describes different types of bioreactors, including suspended growth reactors like batch and continuous stirred-tank reactors, as well as biofilm reactors like packed bed and fluidized bed reactors. The document concludes by discussing various applications of bioreactors in treating gaseous, liquid and solid wastes through bioconversion.
This document provides an overview of biological treatments of water. It begins with an abstract describing biological treatment systems that use microorganisms to break down organic materials. It then discusses water treatment processes generally before focusing on biological methods. The key biological methods described are aerobic treatment which uses oxygen and aerobic microorganisms, and anaerobic treatment which does not use oxygen and relies on anaerobic microorganisms. Specific biological treatment technologies summarized include conventional activated sludge processes, cyclic activated sludge systems, trickling filters, and phytoremediation. The document emphasizes that both aerobic and anaerobic biological methods are often used together to effectively treat wastewater.
Bio oxidation- a technology for sustainable pollution controlPriyam Jyoti Borah
Bio-oxidation is a. biological air pollution. control technology. that utilizes bacteria & fungi to biologically absorb and digest vapor-phase VOCs and odorous compounds commonly found in industrial and municipal applications.
Moving Bed Biofilm Reactor -A New Perspective In Pulp And Paper Waste Water T...IJERA Editor
The pulp and paper mill effluent is one of the high polluting effluent amongst the effluents obtained
from polluting industries. All the available methods for treatment of pulp and paper mill effluent have certain
drawbacks. In this work, experiments were conducted to treat the pulp and paper mill effluent using moving bed
biofilm reactor (MBBR).The wastewater generated by these industries contains high COD, BOD, colour, organic
substances and toxic chemicals. This study was carried out on laboratory scale Moving Bed Biofilm Reactor with
proflex type biocarriers, where the biofilm grows on small, free floating plastic elements with a large surface area
and a density slightly less than 1.0 g/cm3
. The reactor was operated continuously at 50% percentages filling of
biocarriers. During the filling percentage, the removal efficiencies of COD & BOD were monitored at the time
period of 2h, 4h, 6h and 8h. The result showed that the maximum COD and BOD removal of 87% were achieved
for the 50 percent filling of biocarriers at the HRT of 8 h. From the experimental results, the moving bed biofilm
reactor could be used as an ideal and efficient option for the organic and inorganic removal from the wastewater
of pulp and paper industry
BIOTECHNOLOGICAL APPROACHES TOWARDS WATER WASTE MANAGEMENT saadmughal1271
This document discusses various biotechnological approaches for wastewater treatment, including engineered biosorbents for heavy metal removal, displaying metal binding peptides on microorganisms, and designing strains for enhanced biodegradation. It describes common wastewater treatment processes like the trickling filter, activated sludge process, and anaerobic digestion. Finally, it discusses using these biotechnological methods to treat wastewater from textile and desiccated coconut industries.
A biofilter is a bed of media on which microorganisms attach and grow to form a biological layer.
The layer thus formed is referred as a Bio film.
The biofilm is formed by a community of different microorganisms bacteria, fungi, yeast, macro-organisms like protozoa, worms, insect's larvae, etc.
Bioremediation
Bioremediation refers to the use of either naturally occurring or
deliberately introduced microorganisms to consume and break down
environmental pollutants, in order to clean a polluted site.
The process of bioremediation enhances the rate of the natural
microbial degradation of contaminants by supplementing the
indigenous microorganisms (bacteria or fungi) with nutrients, carbon
sources, or electron donors (biostimulation, biorestoration) or by
adding an enriched culture of microorganisms that have specific
characteristics that allow them to degrade the desired contaminant at
a quicker rate (bioaugmentation).
It is a cleaning process that degrades dangerous contaminants using
naturally existing microbes. These bacteria may consume and
degrade organic chemicals as a source of food and energy, degrade
organic substances that are dangerous to living creatures, including
humans, and degrade the organic pollutants into inert products.
Because the bacteria already exist in nature, they offer no pollution
concern
Bioremediation is the use of
microorganisms or microbial processes
to detoxify and degrade environmental
contaminants.
Microorganisms have been used for the
routine treatment and transformation
of waste products for several decades
Bioremediation strategies rely on
having the correct microorganisms in
the right location at the right time in the
right environment for degradation to
occur. The appropriate microorganisms
are bacteria and fungi that have the
physiological and metabolic
competence to breakdown pollutants
Objective of Bioremediation
The objective of bioremediation is to decrease pollutant levels to
undetectable, nontoxic, or acceptable levels, i.e., within regulatory
limits, or, ideally, to totally mineralize organopollutants to carbon
dioxide
BIOREMEDIATION AND THEIR IMPORTANCE IN ENVIRONMENT
PROTECTION
Bioremediation is defined as ‘the process of using microorganisms to remove
the environmental pollutants where microbes serve as scavengers’.
• The removal of organic wastes by microbes leads to environmental clean-up.
The other names/terms used for bioremediation are biotreatment,
bioreclamation, and biorestoration.
• The term “Xenobiotics” (xenos means foreign) refers to the unnatural, foreign
and synthetic chemicals, such as pesticides, herbicides, refrigerants, solvents
and other organic compounds.
• The microbial degradation of xenobiotics also helps in reducing the
environmental pollution. Pseudomonas which is a soil microorganism
effectively degrades xenobiotics.
• Different strains of Pseudomonas that are capable of detoxifying more than
100 organic compounds (e.g. phenols, biphenyls, organophosphates,
naphthalene, etc.) have been identified.
• Some other microbial strains are also known to have the capacity to degrade
xenobiotics such as Mycobacterium, Alcaligenes, Norcardia, etc.
Factors affecting biodegradation
The factors that affect the
biodegradation are:
• the chemical nature of
xenobiotics,
• the conc
1. BIOFILTRATION: AN INNOVATIVE TECHNOLOGY
FOR THE FUTURE
Dr. Rakesh Govind
Professor of Chemical Engineering
University of Cincinnati
Cincinnati, OH 45221-0171
Tel: (513) 556-2666
Fax: (513) 556-3473
Email: rgovind@alpha.che.uc.edu
1
2. Introduction
Biofiltration refers to the biological transformation or treatment of contaminants present
in the gas phase, usually air. The fact that air contaminants can be biodegraded by active bacteria
has been known for quite some time. However, it is only in the last 10 years, that biofiltration has
begun to emerge as an economically viable treatment process. Initially, biofiltration involved the
use of naturally bioactive media, such as soil, peat, compost, etc. In naturally bioactive media,
microorganisms present in the soil, peat or compost, have been known to biodegrade
contaminants, and this has been successfully employed in bioremediation of contaminated sites.
However, when contaminated air is passed through soil, peat, or compost, the naturally present
microorganisms also begin to biodegrade the air contaminants. This led to the development of
soil biofilters, in which soil with low clay and high organic carbon content was packed in a bed
and contaminated air was passed through the soil bed to biodegrade the air contaminants.
However, as more research was conducted on this simple process, it became clear that the
biodegradation rates were low and hence the size of the biofilter bed required to achieve high
destruction efficiencies was very large. Since, compost had a higher concentration of
microorganisms, compost became the media of choice for biofilters. Major problems encountered
were settling of the compost, resulting in increased gas-phase pressure drop, availability of
nutrients, such as nitrogen and phosphorus, pH maintenance, and drying of the compost material
due to moisture transferring to the flowing gas phase. These problems were countered to some
extent by adding wood chips, which provided mechanical support to minimize settling,
humidifying the inlet air to maintain proper water content in the compost material, adding lime
pellets for pH control, and fortifying the compost with fertilizers containing nitrogen and
phosphorus compounds. Further, in compost beds, it was necessary to have shallow beds (height
< 1.5 m or 4.5 feet), to prevent compaction of the material and drying of the bed from the top
surface. This required the beds to have large cross-sectional areas, and in many cases were
simply left completely open from the top. In some cases, powdered activated carbon was also
added to buffer the concentration changes, since activated carbon is known to adsorb
contaminants. Currently, there are several companies that offer compost biofilters for treatment
of odorous and volatile chemicals.
2
3. Types of Biofilter Support Media
There are two kinds of air contamination problems: (1) when the air contaminants are
present at low concentration (< 25 ppmv); and (2) when the concentration of the air contaminants
is higher (> 25 ppmv). The reason for making this distinction is that soil, peat and compost
materials exhibit low biodegradation rates, have limited supply of nitrogen and phosphorus,
eventually begin to plug due to growth of microorganisms, and have limited capacity to neutralize
acidic products of degradation. Hence, compost biofilters are capable of treating low
concentration contaminants (< 25 ppmv) and are not ideally suited for treating air contaminated
with high concentration organics.
Other types of support media used in biofilters are synthetic media, such as ceramic,
plastic, etc., with active bacteria immobilized on the surface in the form of biofilms. These
synthetic media biofilters, known as biotrickling filters, are shown schematically in Figure 1.
Synthetic support media are used in trickling filters for wastewater treatment, gas absorption
towers, catalytic reactors, etc. However, the design of support media in biotrickling filters is
different than in any other application, the major difference being the growth of biomass. In
trickling filters, used for waste water treatment, the water flows as a liquid film on the biofilm
surface, and sufficient distance between the support media is designed to accommodate biomass
growth and air, which provides oxygen for the biodegradation reaction. The contaminants,
present in the waste water, diffuse into the biofilm as the water flows over the biofilms, and
biodegrades. In a biotrickling filter, the contaminants, present in air, diffuse perpendicular to the
direction of flow, and biodegrade in the supported biofilms. Since the process is diffusion
controlled, designing a large distance between the supported biofilms reduces the overall
degradation rate in the filter. Further, unlike the submerged biofilms in the case of the
wastewater trickling filter, the biofilms in a biotrckling filter have to be kept moist to maintain
bioactivity. Air flowing through the biotricling filter draws moisture away from the biofilms, and
a trickling flow of aqueous nutrients has to be maintained to provide nutrients and water to the
active bacteria in the biofilms.
Synthetic support media can be in the form of high surface area pellets, with either a
porous or non-porous surface. In some cases, the support media may be coated with activated
carbon, to enhance adsorption of contaminant(s). The synthetic support media can be synthesized
from plastic, ceramic, metallic, or any other composite material.
3
4. Figure 1. Schematic of a Single-Stage Typical Counter-Current Biotrickling Filter.
TREATED AIR
LIQUID RECYCLE
FRESH
SYNTHETIC SUPPORT NUTRIENTS
BED WITH ACTIVE FROM NUTRIENT
SUPPLY TANK
BACTERIAL CULTURES
SUPPORTED ON THE
SURFACE
AIR WITH NUTRIENT TANK
ODORS, WITH pH CONTROL
VOLATILE
COMPOUNDS BLOWER
WASTE SLUDGE
4
5. The desired features of a good support media are as follows:
1. High void fraction, i.e., the fraction of empty space in the synthetic media should be large (>
80%). This provides greater space for the biofilms to grow and biomass growth does not easily
clog up the support media.
2. High surface area per unit volume of the biofilter bed. The biofilms grow only on the surface of
the support media. Hence, if this exposed surface area is large, the contact between the biofilms
and the gas phase contaminants is also large.
3. Low gas-phase pressure drop. Gas-phase pressure drop is very critical, since the operating cost is
proportional to the pressure drop across the biofilter bed. In a typical biofilter bed, the total gas
pressure drop is less than 0.3 inches of water.
5. Hydrophilic surface, to allow good water wettability. It is very important to maintain water in the
attached biofilms. Hence good water wettability of the support media enhances biofilm
attachment, retains water within the biofilm, and does not dry easily.Low overall density. The
total weight of the biofilter bed depends on the bulk density of the support media. To reduce the
cost of the supports for the biofilter bed, a lighter support media is preferred.
6. Low cost. Cost of biofilter media is very important, since compost in compost biofilters is a low
cost media.
Mechanisms in Biofilter Operation
There are various transport mechanisms which operate simultaneously or sequentially in
a biotrickling filter and these mechanisms, schematically shown in Figure 2, include: (1) diffusion
of the contaminant(s) from the bulk gas flow to the active biofilm surface; (2) sorption of the
contaminants directly on the biofilm surface; (3) solubilization of the contaminant(s) into the
water content of he biofilms; (4) direct adsorption of the contaminant(s) on the surface of the
support media; (5) diffusion and biodegradation of the contaminant(s) in the active biofilm; (6)
surface diffusion of the contaminant(s) in the support media surface; and (7) back diffusion of the
adsorbed contaminant(s) from the support media surface into the active biofilms. The effect of
adsorption of contaminant(s) on support media surface, surface diffusion, and back diffusion of
the adsorbed contaminant(s) from the support media surface into the active biofilms,
predominantly occurs in activated carbon-coated support media and contaminant(s) which have
affinity for the support media surface.
In the case of compost biofilters (refer to Figure 3) the contaminant(s) diffuse into the
porous compost particles, dissolve into the sorbed water films, adsorb on the organic and
5
6. inorganic fraction of the compost, and biodegrade by the attached active compost bacteria,
entrapped within the compost particles.
Figure 2. Diffusion Mechanisms operating in a Biotrickling Filter.
FLOW OF AIR +
CONTAMINANT(S)
1
11
2
3
10
4
9
8
7
5
6
Mechanism Description
1 Diffusion from bulk gas to biofilm surface
2 Diffusion from bulk gas to water in support media
3 Diffusion from bulk gas to water film on support media
4 Diffusion from bulk gas to dry support media
5 Diffusion from bulk gas to water layer on biofilm
6 Diffusion from water layer into active biofilm
7 Diffusion through biofilm with biodegradation and into
water in support media
8 Diffusion from water in support media into support media
9 Surface diffusion in support media
10 Back diffusion from water in support media into water film
11 Back diffusion from wet support media into biofilm
6
7. Figure 3. Diffusion Mechanisms operating in a Compost Biofilter
AIR +
CONTAMINANTS
SOIL BACTERIA ( )
ORGANIC
FRACTION ( )
1
WATER IN
COMPOST
INORGANIC
FRACTION ( )
COMPOST
PARTICLE
Mechanism Description
1 Diffusion from bulk gas to compost
2 (not shown) Diffusion within compost particle
3 (not shown) Solubilization in water within compost
4 (not shown) Adsorption to organic fraction of compost
5 (not shown) Adsortion to inorganic fraction of compost
6 (not shown) Biodegradation by bacteria in compost
7 (not shown) Diffusion between organic fraction, water
content and inorganic fraction
7
8. Effect of Biofilter Media
The main advantages of the biotrickling filter compared to the compost biofilter are as
follows:
1. The biotrickling filter had no height limitation, and hence could be designed as a tower, with a
reasonable diameter. The problem of support media drying , as in compost biofilters, is inapplicable to
biotrickling filters, since there is a constant aqueous nutrient stream trickling down the surface of the
synthetic media;
2. The media never has to be replaced, as in the case of compost, since the mineral nutrients are supplied
from an external source. In the case of compost, once the nitrogen and phosphorus, initially present in
the compost are exhausted, the compost has to be changed. Since the air contaminants adsorb to the
organic fraction of the compost, the compost, when disposed, would be contaminated, and has to be
treated as solid waste;
3. The compost eventually begins to compact, inspite of adding wood chips to provide support. Growth
of biomass (microorganisms) due to biodegradation, also causes the compost to become heavier and
settle. This type of settling results in increased gas-phase pressure drop, which causes the gas flow to
actually decrease, since the gas blower has to operate against a higher pressure drop. In the case of
biotrickling filters, employing synthetic support media, settling is not a problem; however, plugging of
the media due to biomass growth, which results in increased gas-phase pressure drop is a major
problem.
4. In some cases, when air contaminants contain nitrogen or sulfur or oxygen, intermediate products of
biodegradation (biotransformation) may be acidic, which causes the pH in the biofilter bed to decrease.
For example, when hydrogen sulfide is biotransformed to sulfate, the pH in the bed decreases. In
compost beds, declining pH results in decreased bioactivity, which eventually causes the entire bed to
acidify and shut-down. In biotrickling filters, the pH can be controlled by adding buffers in the
nutrient flow. In the case of hydrogen sulfide, the sulfate formed is continuously removed from the
process by the flowing nutrient stream, and this sulfate is neutralized before the nutrients are recycled
back to the biotrickling filter bed.
5. The biodegradation rates in a biotrickling filter are much higher than in compost beds. This is mainly
due to higher surface area and increased concentration of immobilized microorganisms in biotrickling
filters when compared to compost media. Hence, the volume of biotrickling filter bed is much smaller
than the volume of compost required for the same destruction efficiency.
6. In compost biofilters, the compost has to replaced periodically, to replenish the nitrogen and
phosphorus and remove the excess biomass which results in plugging and settling. In biotrickling
filters, the media does not have to be replaced.
8
9. 7. In compost biofilters, the inlet gases have to be humidified to prevent bed drying. Since 100%
humidity is difficult to achieve in practice, some bed drying always occurs, and this results in reduced
bioactivity. In some compost beds, water is also sprayed from the top of the bed, although this is kept
to a minimum to prevent bed settling;
8. In compost beds, gas channeling is a big problem, especially since compost beds are shallow with large
cross-sectional areas. As biomass growth begins to plug the bed, gas begins to bypass compost regions
which have increased biomass concentrations. Since biotrickling filter beds are smaller diameter and
taller, gas channeling is not a major issue.
9. Compost biofilters require large areas for installation, due to large footprints. They are also very
heavy, and often require structural modifications, especially when installed on building roofs.
Biotrickling filters are much lighter, since the support media is synthetic and has a large void fraction.
The footprint of a biotrickling filter is also much smaller, and can be easily installed on building roofs.
10. Transfer of oxygen into compost materials is very inefficient, since oxygen is also consumed by
compost due to intrinsic biodegradation of the organic fraction, present in compost media. Hence, if
air is blown through moist compost media, the air leaving will have increased levels of carbon dioxide
gas. Due to inefficient oxygen transfer, if the water content of compost material is not maintained in a
narrow range, anaerobic regions are created in the compost material, wherein anaerobic
microorganisms begin to thrive and anaerobic microorganisms are known to create acidic by-products,
which creates pH in the compost material to decrease. In biotrickling filters, since the synthetic media
is very open, and high gas velocities can be maintained, the oxygen transfer is much higher, and hence
anaerobic regions are not created in the biofilter bed.
Hence, it can be concluded that compost biofilters have significant disadvantages when
compared with synthetic media biotrickling filters. However, not all biotrickling filters are
created equal. The design of the support media is very critical to the performance of the
biotrickling filter. Table 1 (Govind and Bishop, 1997) summarizes the advantages and
disadvantages of various biofilter support media and Figure 4 (Wang and Govind, 1998) shows
the relative performance of various support media.
9
10. Figure 4. Relative Performance of Different Support Media (Wang and Govind, 1998)
Iso-pentane Destruction Rate (g/m3/h)
20
15
10
5
0
Peat Compost Celite Cordierite Activated
Pellets Carbon
Coated
Cordierite
10
11. Table 1. Advantages and Disadvantages of Various Support Media.
Biofilter Media Advantages Disadvantages
• Well established technology • Prone to channeling and maldistribution
• Suitable for low contaminant concentrations or • Humidification needed
Soil odor control • Lmited ability to neutralize acidic degradation products
• Low cost media • Low adsorption capacity
• Eventual media replacement required
• Low biodegradation capacity
(0.02 - 0.1 gms of contaminant/Liter.day)
• Lomited supply of macronutrients (nitrogen,
phosphorus) and micronutrients (iron, manganese, etc.)
• Commercial technology • Prone to channeling and maldistribution
• Suitable for low contaminant concentrations • Limited ability to neutralize acidic degradation products
Peat/Compost • Low cost media • Humidification of air required to prevent drying of bed
• Eventual media replacement required
• Low degradation capacity (0.02 - 0.4 gms/Liter.day)
• Lomited supply of macronutrients (nitrogen,
phosphorus) and micronutrients (iron, manganese, etc.)
• Can be easily cleaned • Higher media cost than soil, peat, compost
• Fast start-up of biofilter • Eventual plugging of bed unless support media is
• Can handle high contaminant concentrations properly designed
Synthetic Support ( > 25 ppmv)
Media • Cheaper than activated carbon coated media
• Can degrade contaminants requiring
cometabolites by supplying it with trickling
nutrients
• pH can be controlled
• Can be seeded with preacclimated
microorganisms
• Both macro and micro nutrients can be supplied
continuously by trickling liquid
• High degradation capacity (0.2 - 0.7 g/L.day)
• High adsorption capacity for most contaminants • Higher media cost than soil, peat, compost
• Good biomass adhesion • Eventual plugging of bed requiring cleaning or media
Activated Carbon • Fast start-up of biofilter replacement unless support media is properly designed
Coated Synthetic • Can handle high contaminant
Support Media concentrations ( > 200 ppmv) and
pH can be controlled
• Can degrade contaminants requiring
cometabolites by preadsorption
• Can be seeded with preacclimated
microorganisms
• Both macro and micro nutrients can be
supplied continuously by trickling liquid
• High degradation capacity (0.4 – 1.5 g/L.day)
11
12. Commercial Potential of Biofiltration
Biofiltration is capable of biodegrading a wide variety of air contaminants. Table 2
shows a list of the types of organic and inorganic air contaminants that can be treated in a
biofilter. Table 3 shows the applicability of various air pollution control technologies, including
compost biofiltration and biotrickling filters. Figure 4 shows the differences in investing and
operating costs for biofiltration, when compared with catalytic oxidation and adsorption.
Table 2. Types of Compounds that can be Treated by Biofiltration
Contaminant Biodegradability Contaminant Biodegradability
Aliphatic Hydrocarbons 1-2 Aldehydes 3
(Methane, Propane, etc.)
Aromatic Hydrocarbons 2-3 Esters 3
(Benzene, Phenol, Toluene, etc.)
Chlorinated Hydrocarbons Inorganic Compounds
Carbon tetrachloride 1
Chloroform 1 Ammonia 3
Trichloroethylene (TCE) 2 Hydrogen Sulfide 3
(co-metabolic)
Nitrogen oxide 1
Perchloroethylene (PCE) Recalcitrant
Amines 3 Ketones 3
Nitriles 1 Sulfur containing Compounds 1-2
Alcohols 3 Terpenes 1-2
Note: 1 = Some Biodegradability; 2 = Moderate Biodegradability; 3 = Good Biodegradability
12
14. Figure 4. Comparison of Biofiltration Cost with Other Processes. Note that “Biofilter” in
these graphs refers to “Biotrickling Filter” with Synthetic Media. These costs were obtained
for iso-pentane treatment with an inlet concentration of 1,000 ppmv and destruction
efficiency of 95%.
500000
CAPITAL COST ($)
Incineration
400000
Carbon
300000 Adsorption
Absorption
200000
Biofilter
100000
0
5000 10000 15000
GAS FLOW RATE (scfm)
OPERATING COST ($/year)
400000
350000
300000 Absorption
250000 Carbon
Adsorption
200000
Incineration
150000
100000 Biofilter
50000
0
5000 10000 15000
GAS FLOW RATE (scfm)
14
15. The future of biofiltration (compost and biotrickling filters) depends on the
regulatory requirements placed on industry. However there are specific trends which will
impact the market for biofiltration technology, and these trends are:
1. Increased regulatory concern about emission of nitrogen oxides, which are emitted from thermal
treatment processes. Biofilters do not create any additional nitrogen oxides;
2. Increased public complaints about odorous emissions from public owned wastewater treatment
plants, manufacturing industries, solid waste treatment facilities, etc.;
3. Implementation of pollution prevention methodologies which has resulted in greater use of
biodegradable solvents, reduced concentration of air emissions, and emphasis on achieving zero
discharge processes; and
4. Increased concern about emission of air contaminants, worker exposure to organics, emphasis on
environmentally friendly and low-cost treatment technologies.
The application of biofiltration technology has increased rapidly during the latter part of
the twentieth century and will continue to grow throughout the twenty-first century. Though
recent studies vary, depending on the underlying assumptions, the U.S. biofiltration market for
1996 was estimated to be about $10 million (Kosteltz et al., 1996), and economic models
speculate that by the year 2000, the market may reach over $100 million (Yudelson, 1996).
Potential markets for biofiltration include the following:
(1) treatment of odors;
(2) treatment of volatile organic compounds (VOCs) and hazardous air pollutants (HAPs); and
(3) treatment of petroleum hydrocarbons.
Odor treatment is a significant portion of the marketplace. Industries that produce
odorous emissions include wastewater treatment plants, composting and sludge treatment
facilities, foundries, pulp and paper plants and tobacco products manufacturing plants. In recent
years, communities have begun to encroach near the fence lines of wastewater treatment plants.
Wastewater treatment plants are treating increased flows, thereby increasing odor loads at the
plant. Further, since flows are being pumped from greater distances, the age of the wastewater
and its septicity is increasing, resulting in greater amounts of reduced nitrogen and sulfur
compounds. In addition, water conservation has resulted in decreasing water flow rates with
increased strength, which results in greater odor production. Many wastewater treatment plants
have begun to implement odor control strategies, and biofiltration will play a major role in many
15
16. such cases. Recently, biotrickling filter technology was shown to be effective in treating odorous
emissions from the “Zimpro” sludge heat treatment process, which has been known for creating
very high intensity odors (Govind and Melarkode, 1998).
Biofiltration of volatile organic compounds (VOCs) and hazardous air pollutants (HAPs)
is an important problem in the wood products, pulp and paper, and surface coating operations. In
the case of surface coating operations, exposure of workers to organic chemicals, such as styrene,
is an important issue. While attempts are being made to develop low VOC emitting solvent
formulations, some worker exposure is inevitable, and the use of biofiltration systems on the shop
floor can reduce concentrations of organics in the ambient air. Recently, a pilot-scale study was
conducted to demonstrate biotrickling filter technology for treating ethanol emissions from
bakeries (Govind, Melarkode, Fang, 1998).
Petroleum hydrocarbons are released during refining, transfer operations, from storage
tanks, etc. Most of these hydrocarbons consist of aliphatic and aromatic compounds, which are
easily biodegraded in biofilters. Leaking underground storage tanks pose another environmental
hazard, where the hydrocarbon contaminant can be separated from the soil and/or groundwater
table using air sparging, bioventing or vapor extraction. The volatile hydrocarbons are transferred
into the air phase, wherein they can be effectively treated using biofiltration.
As knowledge on biofiltration increases, and more pilot-scale studies are conducted, the
market for biofiltration is expected to increase in the future. Increasing number of industries are
already beginning to realize the potential advantages of biofiltration, which include:
1. The only by-product of biofiltration is waste biomass, which can be easily disposed in the sewers.
Thermal processes produce nitrogen oxides, which causes ozone depletion and smog formation.
Chemical oxidation processes which use hypochlorite produce chlorine and chlorinated products.
2. Biofiltration is an ambient temperature and pressure process, which produces minimal carbon dioxide,
a greenhouse gas. Thermal processes require additional natural gas for achieving high temperatures,
which significantly increases carbon dioxide production, a greenhouse gas.
3. The investment and operating costs of biofiltration are lower than for thermal and chemical oxidation
processes. There is no chemical handling in biofiltration, whereas in chemical oxidation, chemicals,
such as hypochlorite, hydrogen peroxide, chlorine dioxide, etc. have to be stored and handled.
16
17. Conclusions
Biofiltration will play a major role in the treatment of organic and inorganic emissions
from a variety of industrial and waste water treatment processes. Biofiltration, when compared to
other available technologies, has significant technical and cost advantages. Compost biofilters
are better suited for treatment of odors and low concentration (< 25 ppmv) contaminants.
Biotrickling filters have significant advantages over compost biofilters and are capable of
handling significantly higher contaminant concentrations ( 20 ppmv – 5,000 ppmv). The major
issues in biotrickling filters is the design of the support media and handling of biomass growth.
Support media design has a significant impact on biotrickling filter performance. The market for
biofilters will increase in the next millennium, as new applications arise in the future.
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18. References
Govind, R. and Dolloff F. Bishop, “Biofiltration for Treatment of Volatile Organic Compounds
(VOCs) in Air”, Chapter in Biodegradation Technology Developments, Volume II, Eds. Subhas
K. Sikdar and Robert L. Irvine, Technolmic Publishing Company, Lancaster, PA (1998).
Govind, R. and Zhao Wang, “Effect of Support Media on Is0-pentane Biofiltration”, Paper
submitted to Environmental Progress (1998).
Govind, R. and R. Melarkode, “Pilot-Scale Test of the Biotreatment of Odors from ZimproTM
Sludge Conditioning Process”, Report Submitted to Sanitation District No. 1, Fort Wright, KY,
by PRD TECH, Inc., Florence, KY (1998).
Govind, R., Fang, J., R. Melarkode, “Biotrckling Filter Pilot Study for Ethanol Emissions
Control”, A Report prepared for the Food Manufacturing Coalition for Innovation and
Technology Transfer, by PRD TECH, Inc., Florence, KY (1998).
Kosteltz, A.M., A. Finkelstein and G. Sears, “What are the real opportunities in biological gas
cleaning for North America, in Proceedings of the 89th Annual Meeting and Exhibition of the
Air and Waste Management Association, Air and Waste Management Association, Pittsburgh,
PA (1996).
Yudelson, J.M., “The future of the U.S. biofiltration industry, in Proceedings of the 1996
Conference on Biofiltration (an Air Pollution Control Technology), Reynolds, F.E., Ed., The
Reynolds Group, Tustin, CA, page 1 (1996).
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