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34 REMOVAL OF ORGANIC COMPOUNDS BY MICROBIAL BIOMASS Ariamalar Selvakumar, Graduate Student Hsin-Neng Hsieh, Assistant Professor Department of Civil & Environmental Engineering New Jersey Institute of Technology Newark, New Jersey 07102 INTRODUCTION Development of sophisticated industrial societies has led to proliferation of a vast number and variety of complex chemicals for industrial, agricultural, and domestic use. Many of these compounds exhibit toxic, carcinogenic, mutagenic or teratogenic properties. Many compounds of such concern eventually find their way into municipal and industrial wastewaters, and, unless specifically removed by waste treatment processes, ultimately appear in receiving waters and drinking water supplies and can have harmful effects on human and other organisms in the environment. The fate of hazardous organic pollutants discharged into conventional biological wastewater treatment processes is not well understood. These compounds may be removed from the wastewater stream by biodegradation, volatilization (air stripping), sorption by the biomass, precipitation, hydrolysis, etc. Of these processes, sorption would accumulate pollutants in the sludge and create potential environmental hazards when released back into the environment upon sludge landfilling or spreading the sludge on the land surface. LITERATURE REVIEW Recent studies have shown that the microbial cells tend to concentrate chemicals from their aquatic environment. Tsezos and Seto1 studied the adsorptive capacity of 1,1,2-trichloroethane (TCE) and 1,1,2,2-tetrachloroethane (TTCE) onto mainly two types of biomass. Their results showed that the combination of lower solubility, the higher octanol/water partition coefficient and reduced volatility favors the uptake of TTCE by microbial biomass. Bell and Tsezos^ found that the uptake capacity of biomass is generally less than that of activated carbon, but it is high enough to provide significant removal of trace quantities of hazardous compounds combined with domestic and industrial pollutants. The adsorptive capacity was very well correlated with octanol/water partition coefficient but not as well correlated with water solubility of the compounds. The extent of biosorption by the microorganisms varies from species to species. One suggestion that has often been mentioned in describing biosorptive phenomena is that the bioaccumulation of highly hydrophobic compounds is directly related to the lipid content of the organism.3-4 But experimental results of Tsezos and Seto1 did not confirm this. However, a comparison of the relative adsorptive capacities with the organic carbon content indicated a trend. Petrasek et al.5 concluded that the organic compounds are accumulated in the primary and secondary sludge in the treatment plants. Sorption of organic compounds to the biomass could be an important removal mechanism in the activated sludge process according to Ullrich and Smiths. Leo et al. i have shown that the octanol/water partition coefficient is a very useful tool in many situations where a substance's behavior is influenced by its partition into a lipid phase. Matter-Muller et al.8 have determined the partition coefficients, Kp, of several refractory organic compounds in a batch activated sludge process and found a linear dependence of log Kp upon log Kow. Karickhoff et al.9 concluded that the linear partition coefficients were directly related to organic carbon content for given particle size isolates in the different sediments. 43rd Purdue Industrial Waste Conference Proceedings, © 1989 Lewis Publishers, Inc., Chelsea, Michigan 48118. Printed in U.S.A. 275
Object Description
Purdue Identification Number | ETRIWC198834 |
Title | Removal of organic compounds by microbial biomass |
Author |
Selvakumar, Ariamalar Hsieh, Hsin-Neng |
Date of Original | 1988 |
Conference Title | Proceedings of the 43rd Industrial Waste Conference |
Conference Front Matter (copy and paste) | http://e-archives.lib.purdue.edu/u?/engext,39828 |
Extent of Original | p. 275-282 |
Collection Title | Engineering Technical Reports Collection, Purdue University |
Repository | Purdue University Libraries |
Rights Statement | Digital object copyright Purdue University. All rights reserved. |
Language | eng |
Type (DCMI) | text |
Format | JP2 |
Date Digitized | 2009-08-13 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Resolution | 300 ppi |
Color Depth | 8 bit |
Description
Title | page 275 |
Collection Title | Engineering Technical Reports Collection, Purdue University |
Repository | Purdue University Libraries |
Rights Statement | Digital copyright Purdue University. All rights reserved. |
Language | eng |
Type (DCMI) | text |
Format | JP2 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Transcript | 34 REMOVAL OF ORGANIC COMPOUNDS BY MICROBIAL BIOMASS Ariamalar Selvakumar, Graduate Student Hsin-Neng Hsieh, Assistant Professor Department of Civil & Environmental Engineering New Jersey Institute of Technology Newark, New Jersey 07102 INTRODUCTION Development of sophisticated industrial societies has led to proliferation of a vast number and variety of complex chemicals for industrial, agricultural, and domestic use. Many of these compounds exhibit toxic, carcinogenic, mutagenic or teratogenic properties. Many compounds of such concern eventually find their way into municipal and industrial wastewaters, and, unless specifically removed by waste treatment processes, ultimately appear in receiving waters and drinking water supplies and can have harmful effects on human and other organisms in the environment. The fate of hazardous organic pollutants discharged into conventional biological wastewater treatment processes is not well understood. These compounds may be removed from the wastewater stream by biodegradation, volatilization (air stripping), sorption by the biomass, precipitation, hydrolysis, etc. Of these processes, sorption would accumulate pollutants in the sludge and create potential environmental hazards when released back into the environment upon sludge landfilling or spreading the sludge on the land surface. LITERATURE REVIEW Recent studies have shown that the microbial cells tend to concentrate chemicals from their aquatic environment. Tsezos and Seto1 studied the adsorptive capacity of 1,1,2-trichloroethane (TCE) and 1,1,2,2-tetrachloroethane (TTCE) onto mainly two types of biomass. Their results showed that the combination of lower solubility, the higher octanol/water partition coefficient and reduced volatility favors the uptake of TTCE by microbial biomass. Bell and Tsezos^ found that the uptake capacity of biomass is generally less than that of activated carbon, but it is high enough to provide significant removal of trace quantities of hazardous compounds combined with domestic and industrial pollutants. The adsorptive capacity was very well correlated with octanol/water partition coefficient but not as well correlated with water solubility of the compounds. The extent of biosorption by the microorganisms varies from species to species. One suggestion that has often been mentioned in describing biosorptive phenomena is that the bioaccumulation of highly hydrophobic compounds is directly related to the lipid content of the organism.3-4 But experimental results of Tsezos and Seto1 did not confirm this. However, a comparison of the relative adsorptive capacities with the organic carbon content indicated a trend. Petrasek et al.5 concluded that the organic compounds are accumulated in the primary and secondary sludge in the treatment plants. Sorption of organic compounds to the biomass could be an important removal mechanism in the activated sludge process according to Ullrich and Smiths. Leo et al. i have shown that the octanol/water partition coefficient is a very useful tool in many situations where a substance's behavior is influenced by its partition into a lipid phase. Matter-Muller et al.8 have determined the partition coefficients, Kp, of several refractory organic compounds in a batch activated sludge process and found a linear dependence of log Kp upon log Kow. Karickhoff et al.9 concluded that the linear partition coefficients were directly related to organic carbon content for given particle size isolates in the different sediments. 43rd Purdue Industrial Waste Conference Proceedings, © 1989 Lewis Publishers, Inc., Chelsea, Michigan 48118. Printed in U.S.A. 275 |
Resolution | 300 ppi |
Color Depth | 8 bit |
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