The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform

Jean-marc Bollag - One of the best experts on this subject based on the ideXlab platform.

  • Photolytic and Microbial Degradation of 3,5,6‐trichloro‐2‐pyridinol
    Environmental Toxicology and Chemistry, 1998
    Co-Authors: Yucheng Feng, Robert D. Minard, Jean-marc Bollag
    Abstract:

    The photolytic and Microbial Degradation of 3,5.6-trichloro-2-pyridinol (TCP), a metabolite of the insecticide chlorpyrifos and the herbicide triclopyr, has been investigated. TCP (80 mg/L) was decomposed to nondetectable levels within 2 h of ultraviolet irradiation. Release of 14 CO 2 and chloride ion was observed; however, approximately 60% of the initial radioactivity remained in the solution. Dichlorodihydroxypyridine isomers and reductive dechlorination products were found as intermediate products of TCP photolysis. It was proposed that both hydrolytic and reductive dechlorination occurred during photoDegradation of TCP Although TCP can be degraded via photolysis, many Degradation products remained in the aqueous medium and only some of them, the reductive dechlorination products, can be mineralized by Pseudomonas sp. ATCC 700113. The Degradation of the parent compound, TCP. by Pseudomonas sp. ATCC 700113 also appears to involve a reductive dechlorination mechanism. A consortium of microorganisms may be needed if a treatment process combining Microbial and photolytic activity is to be used to remove TCP in industrial wastewater.

  • photolytic and Microbial Degradation of 3 5 6 trichloro 2 pyridinol
    Environmental Toxicology and Chemistry, 1998
    Co-Authors: Yucheng Feng, Robert D. Minard, Jean-marc Bollag
    Abstract:

    The photolytic and Microbial Degradation of 3,5.6-trichloro-2-pyridinol (TCP), a metabolite of the insecticide chlorpyrifos and the herbicide triclopyr, has been investigated. TCP (80 mg/L) was decomposed to nondetectable levels within 2 h of ultraviolet irradiation. Release of 14 CO 2 and chloride ion was observed; however, approximately 60% of the initial radioactivity remained in the solution. Dichlorodihydroxypyridine isomers and reductive dechlorination products were found as intermediate products of TCP photolysis. It was proposed that both hydrolytic and reductive dechlorination occurred during photoDegradation of TCP Although TCP can be degraded via photolysis, many Degradation products remained in the aqueous medium and only some of them, the reductive dechlorination products, can be mineralized by Pseudomonas sp. ATCC 700113. The Degradation of the parent compound, TCP. by Pseudomonas sp. ATCC 700113 also appears to involve a reductive dechlorination mechanism. A consortium of microorganisms may be needed if a treatment process combining Microbial and photolytic activity is to be used to remove TCP in industrial wastewater.

Yucheng Feng - One of the best experts on this subject based on the ideXlab platform.

  • Photolytic and Microbial Degradation of 3,5,6‐trichloro‐2‐pyridinol
    Environmental Toxicology and Chemistry, 1998
    Co-Authors: Yucheng Feng, Robert D. Minard, Jean-marc Bollag
    Abstract:

    The photolytic and Microbial Degradation of 3,5.6-trichloro-2-pyridinol (TCP), a metabolite of the insecticide chlorpyrifos and the herbicide triclopyr, has been investigated. TCP (80 mg/L) was decomposed to nondetectable levels within 2 h of ultraviolet irradiation. Release of 14 CO 2 and chloride ion was observed; however, approximately 60% of the initial radioactivity remained in the solution. Dichlorodihydroxypyridine isomers and reductive dechlorination products were found as intermediate products of TCP photolysis. It was proposed that both hydrolytic and reductive dechlorination occurred during photoDegradation of TCP Although TCP can be degraded via photolysis, many Degradation products remained in the aqueous medium and only some of them, the reductive dechlorination products, can be mineralized by Pseudomonas sp. ATCC 700113. The Degradation of the parent compound, TCP. by Pseudomonas sp. ATCC 700113 also appears to involve a reductive dechlorination mechanism. A consortium of microorganisms may be needed if a treatment process combining Microbial and photolytic activity is to be used to remove TCP in industrial wastewater.

  • photolytic and Microbial Degradation of 3 5 6 trichloro 2 pyridinol
    Environmental Toxicology and Chemistry, 1998
    Co-Authors: Yucheng Feng, Robert D. Minard, Jean-marc Bollag
    Abstract:

    The photolytic and Microbial Degradation of 3,5.6-trichloro-2-pyridinol (TCP), a metabolite of the insecticide chlorpyrifos and the herbicide triclopyr, has been investigated. TCP (80 mg/L) was decomposed to nondetectable levels within 2 h of ultraviolet irradiation. Release of 14 CO 2 and chloride ion was observed; however, approximately 60% of the initial radioactivity remained in the solution. Dichlorodihydroxypyridine isomers and reductive dechlorination products were found as intermediate products of TCP photolysis. It was proposed that both hydrolytic and reductive dechlorination occurred during photoDegradation of TCP Although TCP can be degraded via photolysis, many Degradation products remained in the aqueous medium and only some of them, the reductive dechlorination products, can be mineralized by Pseudomonas sp. ATCC 700113. The Degradation of the parent compound, TCP. by Pseudomonas sp. ATCC 700113 also appears to involve a reductive dechlorination mechanism. A consortium of microorganisms may be needed if a treatment process combining Microbial and photolytic activity is to be used to remove TCP in industrial wastewater.

Kontro, Merja H. - One of the best experts on this subject based on the ideXlab platform.

  • Improved Short-Term Microbial Degradation in Circulating Water Reducing High Stagnant Atrazine Concentrations in Subsurface Sediments
    'MDPI AG', 2020
    Co-Authors: Liu Xinxin, Hui Nan, Kontro, Merja H.
    Abstract:

    The triazine herbicide atrazine easily leaches with water through soil layers into groundwater, where it is persistent. Its behavior during short-term transport is poorly understood, and there is no in situ remediation method for it. The aim of this study was to investigate whether water circulation, or circulation combined with bioaugmentation (Pseudomonassp. ADP, or four isolates from atrazine-contaminated sediments) alone or with biostimulation (Na-citrate), could enhance atrazine dissipation in subsurface sediment-water systems. Atrazine concentrations (100 mg L-1) in the liquid phase of sediment slurries and in the circulating water of sediment columns were followed for 10 days. Atrazine was rapidly degraded to 53-64 mg L(-1)in the slurries, and further to 10-18 mg L(-1)in the circulating water, by the inherent microbes of sediments collected from 13.6 m in an atrazine-contaminated aquifer. Bioaugmentation without or with biostimulation had minor effects on atrazine Degradation. The Microbial number simultaneously increased in the slurries from 1.0 x 10(3)to 0.8-1.0 x 10(8)cfu mL(-1), and in the circulating water from 0.1-1.0 x 10(2)to 0.24-8.8 x 10(4)cfu mL(-1). In sediments without added atrazine, the cultivable Microbial numbers remained low at 0.82-8.0 x 10(4)cfu mL(-1)in the slurries, and at 0.1-2.8 x 10(3)cfu mL(-1)in the circulating water. The cultivated microorganisms belonged to the nine generaAcinetobacter,Burkholderia,Methylobacterium,Pseudomonas,Rhodococcus,Sphingomonas,Streptomyces,VariovoraxandWilliamsia; i.e., biodiversity was low. Water flow through the sediments released adsorbed and complex-bound atrazine for Microbial Degradation, though the residual concentration of 10-64 mg L(-1)was high and could contaminate large groundwater volumes from a point source, e.g., during heavy rain or flooding.Peer reviewe

  • Improved Short-Term Microbial Degradation in Circulating Water Reducing High Stagnant Atrazine Concentrations in Subsurface Sediments
    Multidisciplinary Digital Publishing Institute, 2020
    Co-Authors: Liu Xinxin, Hui Nan, Kontro, Merja H.
    Abstract:

    The triazine herbicide atrazine easily leaches with water through soil layers into groundwater, where it is persistent. Its behavior during short-term transport is poorly understood, and there is no in situ remediation method for it. The aim of this study was to investigate whether water circulation, or circulation combined with bioaugmentation (Pseudomonas sp. ADP, or four isolates from atrazine-contaminated sediments) alone or with biostimulation (Na-citrate), could enhance atrazine dissipation in subsurface sediment–water systems. Atrazine concentrations (100 mg L−1) in the liquid phase of sediment slurries and in the circulating water of sediment columns were followed for 10 days. Atrazine was rapidly degraded to 53–64 mg L−1 in the slurries, and further to 10–18 mg L−1 in the circulating water, by the inherent microbes of sediments collected from 13.6 m in an atrazine-contaminated aquifer. Bioaugmentation without or with biostimulation had minor effects on atrazine Degradation. The Microbial number simultaneously increased in the slurries from 1.0 × 103 to 0.8–1.0 × 108 cfu mL−1, and in the circulating water from 0.1–1.0 × 102 to 0.24–8.8 × 104 cfu mL−1. In sediments without added atrazine, the cultivable Microbial numbers remained low at 0.82–8.0 × 104 cfu mL−1 in the slurries, and at 0.1–2.8 × 103 cfu mL−1 in the circulating water. The cultivated microorganisms belonged to the nine genera Acinetobacter, Burkholderia, Methylobacterium, Pseudomonas, Rhodococcus, Sphingomonas, Streptomyces, Variovorax and Williamsia; i.e., biodiversity was low. Water flow through the sediments released adsorbed and complex-bound atrazine for Microbial Degradation, though the residual concentration of 10–64 mg L−1 was high and could contaminate large groundwater volumes from a point source, e.g., during heavy rain or flooding

Robert D. Minard - One of the best experts on this subject based on the ideXlab platform.

  • Photolytic and Microbial Degradation of 3,5,6‐trichloro‐2‐pyridinol
    Environmental Toxicology and Chemistry, 1998
    Co-Authors: Yucheng Feng, Robert D. Minard, Jean-marc Bollag
    Abstract:

    The photolytic and Microbial Degradation of 3,5.6-trichloro-2-pyridinol (TCP), a metabolite of the insecticide chlorpyrifos and the herbicide triclopyr, has been investigated. TCP (80 mg/L) was decomposed to nondetectable levels within 2 h of ultraviolet irradiation. Release of 14 CO 2 and chloride ion was observed; however, approximately 60% of the initial radioactivity remained in the solution. Dichlorodihydroxypyridine isomers and reductive dechlorination products were found as intermediate products of TCP photolysis. It was proposed that both hydrolytic and reductive dechlorination occurred during photoDegradation of TCP Although TCP can be degraded via photolysis, many Degradation products remained in the aqueous medium and only some of them, the reductive dechlorination products, can be mineralized by Pseudomonas sp. ATCC 700113. The Degradation of the parent compound, TCP. by Pseudomonas sp. ATCC 700113 also appears to involve a reductive dechlorination mechanism. A consortium of microorganisms may be needed if a treatment process combining Microbial and photolytic activity is to be used to remove TCP in industrial wastewater.

  • photolytic and Microbial Degradation of 3 5 6 trichloro 2 pyridinol
    Environmental Toxicology and Chemistry, 1998
    Co-Authors: Yucheng Feng, Robert D. Minard, Jean-marc Bollag
    Abstract:

    The photolytic and Microbial Degradation of 3,5.6-trichloro-2-pyridinol (TCP), a metabolite of the insecticide chlorpyrifos and the herbicide triclopyr, has been investigated. TCP (80 mg/L) was decomposed to nondetectable levels within 2 h of ultraviolet irradiation. Release of 14 CO 2 and chloride ion was observed; however, approximately 60% of the initial radioactivity remained in the solution. Dichlorodihydroxypyridine isomers and reductive dechlorination products were found as intermediate products of TCP photolysis. It was proposed that both hydrolytic and reductive dechlorination occurred during photoDegradation of TCP Although TCP can be degraded via photolysis, many Degradation products remained in the aqueous medium and only some of them, the reductive dechlorination products, can be mineralized by Pseudomonas sp. ATCC 700113. The Degradation of the parent compound, TCP. by Pseudomonas sp. ATCC 700113 also appears to involve a reductive dechlorination mechanism. A consortium of microorganisms may be needed if a treatment process combining Microbial and photolytic activity is to be used to remove TCP in industrial wastewater.

Liu Xinxin - One of the best experts on this subject based on the ideXlab platform.

  • Improved Short-Term Microbial Degradation in Circulating Water Reducing High Stagnant Atrazine Concentrations in Subsurface Sediments
    'MDPI AG', 2020
    Co-Authors: Liu Xinxin, Hui Nan, Kontro, Merja H.
    Abstract:

    The triazine herbicide atrazine easily leaches with water through soil layers into groundwater, where it is persistent. Its behavior during short-term transport is poorly understood, and there is no in situ remediation method for it. The aim of this study was to investigate whether water circulation, or circulation combined with bioaugmentation (Pseudomonassp. ADP, or four isolates from atrazine-contaminated sediments) alone or with biostimulation (Na-citrate), could enhance atrazine dissipation in subsurface sediment-water systems. Atrazine concentrations (100 mg L-1) in the liquid phase of sediment slurries and in the circulating water of sediment columns were followed for 10 days. Atrazine was rapidly degraded to 53-64 mg L(-1)in the slurries, and further to 10-18 mg L(-1)in the circulating water, by the inherent microbes of sediments collected from 13.6 m in an atrazine-contaminated aquifer. Bioaugmentation without or with biostimulation had minor effects on atrazine Degradation. The Microbial number simultaneously increased in the slurries from 1.0 x 10(3)to 0.8-1.0 x 10(8)cfu mL(-1), and in the circulating water from 0.1-1.0 x 10(2)to 0.24-8.8 x 10(4)cfu mL(-1). In sediments without added atrazine, the cultivable Microbial numbers remained low at 0.82-8.0 x 10(4)cfu mL(-1)in the slurries, and at 0.1-2.8 x 10(3)cfu mL(-1)in the circulating water. The cultivated microorganisms belonged to the nine generaAcinetobacter,Burkholderia,Methylobacterium,Pseudomonas,Rhodococcus,Sphingomonas,Streptomyces,VariovoraxandWilliamsia; i.e., biodiversity was low. Water flow through the sediments released adsorbed and complex-bound atrazine for Microbial Degradation, though the residual concentration of 10-64 mg L(-1)was high and could contaminate large groundwater volumes from a point source, e.g., during heavy rain or flooding.Peer reviewe

  • Improved Short-Term Microbial Degradation in Circulating Water Reducing High Stagnant Atrazine Concentrations in Subsurface Sediments
    Multidisciplinary Digital Publishing Institute, 2020
    Co-Authors: Liu Xinxin, Hui Nan, Kontro, Merja H.
    Abstract:

    The triazine herbicide atrazine easily leaches with water through soil layers into groundwater, where it is persistent. Its behavior during short-term transport is poorly understood, and there is no in situ remediation method for it. The aim of this study was to investigate whether water circulation, or circulation combined with bioaugmentation (Pseudomonas sp. ADP, or four isolates from atrazine-contaminated sediments) alone or with biostimulation (Na-citrate), could enhance atrazine dissipation in subsurface sediment–water systems. Atrazine concentrations (100 mg L−1) in the liquid phase of sediment slurries and in the circulating water of sediment columns were followed for 10 days. Atrazine was rapidly degraded to 53–64 mg L−1 in the slurries, and further to 10–18 mg L−1 in the circulating water, by the inherent microbes of sediments collected from 13.6 m in an atrazine-contaminated aquifer. Bioaugmentation without or with biostimulation had minor effects on atrazine Degradation. The Microbial number simultaneously increased in the slurries from 1.0 × 103 to 0.8–1.0 × 108 cfu mL−1, and in the circulating water from 0.1–1.0 × 102 to 0.24–8.8 × 104 cfu mL−1. In sediments without added atrazine, the cultivable Microbial numbers remained low at 0.82–8.0 × 104 cfu mL−1 in the slurries, and at 0.1–2.8 × 103 cfu mL−1 in the circulating water. The cultivated microorganisms belonged to the nine genera Acinetobacter, Burkholderia, Methylobacterium, Pseudomonas, Rhodococcus, Sphingomonas, Streptomyces, Variovorax and Williamsia; i.e., biodiversity was low. Water flow through the sediments released adsorbed and complex-bound atrazine for Microbial Degradation, though the residual concentration of 10–64 mg L−1 was high and could contaminate large groundwater volumes from a point source, e.g., during heavy rain or flooding