Organophosphorus pesticide, malathion, is used in public health, residential, and agricultural se... more Organophosphorus pesticide, malathion, is used in public health, residential, and agricultural settings worldwide to control the pest population. It is proven that exposure to malathion produce toxic effects in humans and other mammals. Due to high toxicity, studies are going on to design effective methods for removal of malathion and its associated compounds from the environment. Among various techniques available, degradation of malathion by microbes proves to be an effective and environment friendly method. Recently, research activities in this area have shown that a diverse range of microorganisms are capable of degrading malathion. Therefore, we aimed at providing an overview of research accomplishments on this subject and discussed the toxicity of malathion and its metabolites, various microorganisms involved in its biodegradation and effect of various environmental parameters on its degradation.
Explosives are synthesized globally mainly for military munitions. Nitrate esters, such as GTN an... more Explosives are synthesized globally mainly for military munitions. Nitrate esters, such as GTN and PETN, nitroaromatics like TNP and TNT and nitramines with RDX, HMX and CL20, are the main class of explosives used. Their use has resulted in severe contamination of environment and strategies are now being developed to clean these substances in an economical and eco-friendly manner. The incredible versatility inherited in microbes has rendered these explosives as a part of the biogeochemical cycle. Several microbes catalyze mineralization and/or nonspecific transformation of explosive waste either by aerobic or anaerobic processes. It is likely that ongoing genetic adaptation, with the recruitment of silent sequences into functional catabolic routes and evolution of substrate range by mutations in structural genes, will further enhance the catabolic potential of bacteria toward explosives and ultimately contribute to cleansing the environment of these toxic and recalcitrant chemicals. This review summarizes information on the biodegradation and biotransformation pathways of several important explosives. Isolation, characterization, utilization and manipulation of the major detoxifying enzymes and the molecular basis of degradation are also discussed. This may be useful in developing safer and economic microbiological methods for clean up of soil and water contaminated with such compounds. The necessity of further investigations concerning the microbial metabolism of these substances is also discussed.
This paper investigates the ability of modified rice straw, an agricultural biomaterial, to remov... more This paper investigates the ability of modified rice straw, an agricultural biomaterial, to remove Ni (II) ions from aqueous solution in a fixed-bed column. The experiments were performed with different bed heights (1.5 and 2.0 cm), influent Ni (II) concentrations (50, 75 and 100 mg/L) using flow rates (500 ll/min) in order to obtain experimental breakthrough curves. The maximum adsorption capacity of rice straw powder (RSP) was 43 mg/L at 75 mg/L influent concentration of divalent Ni (II) ions at 2 cm bed depth. Adams–Bohart model, Thomas model and Yoon and Nelson kinetic models were used to analyze the column performance. The value of rate constant for Adams–Bohart and Yoon and Nelson model decreased with increase of influent concentration, but increased with increasing bed depth. The rate constant for Thomas model increased with initial influent Ni (II) ions concentration, decreased with increase in bed depth.
Organophosphorus pesticide, malathion, is used in public health, residential, and agricultural se... more Organophosphorus pesticide, malathion, is used in public health, residential, and agricultural settings worldwide to control the pest population. It is proven that exposure to malathion produce toxic effects in humans and other mammals. Due to high toxicity, studies are going on to design effective methods for removal of malathion and its associated compounds from the environment. Among various techniques available, degradation of malathion by microbes proves to be an effective and environment friendly method. Recently, research activities in this area have shown that a diverse range of microorganisms are capable of degrading malathion. Therefore, we aimed at providing an overview of research accomplishments on this subject and discussed the toxicity of malathion and its metabolites, various microorganisms involved in its biodegradation and effect of various environmental parameters on its degradation.
Explosives are synthesized globally mainly for military munitions. Nitrate esters, such as GTN an... more Explosives are synthesized globally mainly for military munitions. Nitrate esters, such as GTN and PETN, nitroaromatics like TNP and TNT and nitramines with RDX, HMX and CL20, are the main class of explosives used. Their use has resulted in severe contamination of environment and strategies are now being developed to clean these substances in an economical and eco-friendly manner. The incredible versatility inherited in microbes has rendered these explosives as a part of the biogeochemical cycle. Several microbes catalyze mineralization and/or nonspecific transformation of explosive waste either by aerobic or anaerobic processes. It is likely that ongoing genetic adaptation, with the recruitment of silent sequences into functional catabolic routes and evolution of substrate range by mutations in structural genes, will further enhance the catabolic potential of bacteria toward explosives and ultimately contribute to cleansing the environment of these toxic and recalcitrant chemicals. This review summarizes information on the biodegradation and biotransformation pathways of several important explosives. Isolation, characterization, utilization and manipulation of the major detoxifying enzymes and the molecular basis of degradation are also discussed. This may be useful in developing safer and economic microbiological methods for clean up of soil and water contaminated with such compounds. The necessity of further investigations concerning the microbial metabolism of these substances is also discussed.
This paper investigates the ability of modified rice straw, an agricultural biomaterial, to remov... more This paper investigates the ability of modified rice straw, an agricultural biomaterial, to remove Ni (II) ions from aqueous solution in a fixed-bed column. The experiments were performed with different bed heights (1.5 and 2.0 cm), influent Ni (II) concentrations (50, 75 and 100 mg/L) using flow rates (500 ll/min) in order to obtain experimental breakthrough curves. The maximum adsorption capacity of rice straw powder (RSP) was 43 mg/L at 75 mg/L influent concentration of divalent Ni (II) ions at 2 cm bed depth. Adams–Bohart model, Thomas model and Yoon and Nelson kinetic models were used to analyze the column performance. The value of rate constant for Adams–Bohart and Yoon and Nelson model decreased with increase of influent concentration, but increased with increasing bed depth. The rate constant for Thomas model increased with initial influent Ni (II) ions concentration, decreased with increase in bed depth.
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Papers by baljinder singh
like TNP and TNT and nitramines with RDX, HMX and CL20, are the main class of explosives used. Their use has resulted
in severe contamination of environment and strategies are now being developed to clean these substances in an
economical and eco-friendly manner. The incredible versatility inherited in microbes has rendered these explosives
as a part of the biogeochemical cycle. Several microbes catalyze mineralization and/or nonspecific transformation
of explosive waste either by aerobic or anaerobic processes. It is likely that ongoing genetic adaptation, with the
recruitment of silent sequences into functional catabolic routes and evolution of substrate range by mutations in
structural genes, will further enhance the catabolic potential of bacteria toward explosives and ultimately contribute
to cleansing the environment of these toxic and recalcitrant chemicals. This review summarizes information on
the biodegradation and biotransformation pathways of several important explosives. Isolation, characterization,
utilization and manipulation of the major detoxifying enzymes and the molecular basis of degradation are also
discussed. This may be useful in developing safer and economic microbiological methods for clean up of soil and water
contaminated with such compounds. The necessity of further investigations concerning the microbial metabolism of
these substances is also discussed.
ions from aqueous solution in a fixed-bed column. The experiments were performed with different
bed heights (1.5 and 2.0 cm), influent Ni (II) concentrations (50, 75 and 100 mg/L) using flow rates
(500 ll/min) in order to obtain experimental breakthrough curves. The maximum adsorption capacity
of rice straw powder (RSP) was 43 mg/L at 75 mg/L influent concentration of divalent Ni (II) ions at
2 cm bed depth. Adams–Bohart model, Thomas model and Yoon and Nelson kinetic models were used
to analyze the column performance. The value of rate constant for Adams–Bohart and Yoon and Nelson
model decreased with increase of influent concentration, but increased with increasing bed depth. The
rate constant for Thomas model increased with initial influent Ni (II) ions concentration, decreased with
increase in bed depth.
like TNP and TNT and nitramines with RDX, HMX and CL20, are the main class of explosives used. Their use has resulted
in severe contamination of environment and strategies are now being developed to clean these substances in an
economical and eco-friendly manner. The incredible versatility inherited in microbes has rendered these explosives
as a part of the biogeochemical cycle. Several microbes catalyze mineralization and/or nonspecific transformation
of explosive waste either by aerobic or anaerobic processes. It is likely that ongoing genetic adaptation, with the
recruitment of silent sequences into functional catabolic routes and evolution of substrate range by mutations in
structural genes, will further enhance the catabolic potential of bacteria toward explosives and ultimately contribute
to cleansing the environment of these toxic and recalcitrant chemicals. This review summarizes information on
the biodegradation and biotransformation pathways of several important explosives. Isolation, characterization,
utilization and manipulation of the major detoxifying enzymes and the molecular basis of degradation are also
discussed. This may be useful in developing safer and economic microbiological methods for clean up of soil and water
contaminated with such compounds. The necessity of further investigations concerning the microbial metabolism of
these substances is also discussed.
ions from aqueous solution in a fixed-bed column. The experiments were performed with different
bed heights (1.5 and 2.0 cm), influent Ni (II) concentrations (50, 75 and 100 mg/L) using flow rates
(500 ll/min) in order to obtain experimental breakthrough curves. The maximum adsorption capacity
of rice straw powder (RSP) was 43 mg/L at 75 mg/L influent concentration of divalent Ni (II) ions at
2 cm bed depth. Adams–Bohart model, Thomas model and Yoon and Nelson kinetic models were used
to analyze the column performance. The value of rate constant for Adams–Bohart and Yoon and Nelson
model decreased with increase of influent concentration, but increased with increasing bed depth. The
rate constant for Thomas model increased with initial influent Ni (II) ions concentration, decreased with
increase in bed depth.