The Experts below are selected from a list of 151551 Experts worldwide ranked by ideXlab platform
Bruce E Rittmann - One of the best experts on this subject based on the ideXlab platform.
-
coupling uv h2o2 to accelerate dimethyl phthalate dmp Biodegradation and oxidation
Biodegradation, 2015Co-Authors: Bin Chen, Jiaxiu Song, Lihui Yang, Qi Bai, Yongming Zhang, Bruce E RittmannAbstract:Dimethyl phthalate (DMP), an important industrial raw material, is an endocrine disruptor of concern for human and environmental health. DMP exhibits slow Biodegradation, and its coupled treatment by means of advanced oxidation may enhance its biotransformation and mineralization. We evaluated two ways of coupling UV–H2O2 advanced oxidation to Biodegradation: sequential coupling and intimate coupling in an internal circulation baffled biofilm reactor (ICBBR). During sequential coupling, UV–H2O2 pretreatment generated carboxylic acids that depressed the pH, and subsequent Biodegradation generated phthalic acid; both factors inhibited DMP Biodegradation. During intimately coupled UV–H2O2 with Biodegradation, carboxylic acids and phthalic acid (PA) did not accumulate, and the Biodegradation rate was 13 % faster than with Biodegradation alone and 78 % faster than with Biodegradation after UV–H2O2 pretreatment. Similarly, DMP oxidation with intimate coupling increased by 5 and 39 %, respectively, compared with Biodegradation alone and sequential coupling. The enhancement effects during intimate coupling can be attributed to the rapid catabolism of carboxylic acids, which generated intracellular electron carriers that directly accelerated di-oxygenation of PA and relieved the inhibition effect of PA and low pH. Thus, intimate coupling optimized the impacts of energy input from UV irradiation used together with Biodegradation.
-
Intimately coupling of photolysis accelerates nitrobenzene Biodegradation, but sequential coupling slows Biodegradation
Journal of hazardous materials, 2015Co-Authors: Lihui Yang, Qi Bai, Yongming Zhang, Ning Yan, Bruce E RittmannAbstract:Abstract Photo(cata)lysis coupled with Biodegradation is superior to photo(cata)lysis or Biodegradation alone for removal of recalcitrant organic compounds. The two steps can be carried out sequentially or simultaneously via intimate coupling. We studied nitrobenzene (NB) removal and mineralization to evaluate why intimate coupling of photolysis with Biodegradation was superior to sequential coupling. Employing an internal circulation baffled biofilm reactor, we compared direct Biodegradation (B), Biodegradation after photolysis (P + B), simultaneous photolysis and Biodegradation (PB NP and OA were NB’s main UV-photolysis products. Compared with B, the Biodegradation rate P + B was lower by 13–29%, but intimately coupling (PB mineralization showed similar trends. B + OA gave results similar to P&B, B + NP gave results similar to P + B, and B + OA + NP gave results between P + B and P&B, depending on the amount of OA and NP added. The photolysis product OA accelerated NB Biodegradation through a co-substrate effect, but NP was inhibitory. Although decreasing the UV photolysis time could minimize the inhibition impact of NP in P + B, P&B gave the fastest removal of NB by accentuating the co-substrate effect of OA.
-
UV photolysis for accelerated quinoline Biodegradation and mineralization
Applied microbiology and biotechnology, 2013Co-Authors: Ning Yan, Yongming Zhang, Ling Chang, Lu Gan, Rui Liu, Bruce E RittmannAbstract:Sequentially and intimately coupled photolysis with Biodegradation were evaluated for their ability to accelerate quinoline-removal and quinoline-mineralization kinetics. UV photolysis sequentially coupled to Biodegradation significantly improved biomass-growth kinetics, which could be represented well by the Aiba self-inhibition model: UV photolysis increased the maximum specific growth rate (μ max) by 15 %, and the inhibition constant (K SI) doubled. An internal loop photo-Biodegradation reactor (ILPBR) was used to realize intimately coupled photolysis with Biodegradation. The ILPBR was operated with batch experiments following three protocols: photolysis alone (P), Biodegradation alone (B), and intimately coupled photolysis and Biodegradation (PB the composite result was a doubling of the quinoline-Biodegradation rate for most of the concentration range tested. The degree of mineralization was increased by both forms of photolysis coupled to Biodegradation, and the impact was greater for intimate coupling (18 % increase) than sequential coupling (5 %). The benefits of UV photolysis were greater with intimate coupling than with sequential coupling due to parallel transformation by Biodegradation and photolysis.
Bea-ven Chang - One of the best experts on this subject based on the ideXlab platform.
-
Biodegradation of phenanthrene in river sediment
Chemosphere, 2001Co-Authors: S Y Yuan, J.s. Chang, Bea-ven ChangAbstract:The aerobic Biodegradation potential of phenanthrene (a polycyclic aromatic hydrocarbon [PAH]) in river sediment was investigated in the laboratory. Biodegradation rate constants (k1) and half-lives (t1/2) for phenanthrene in sediment samples collected at five sites along the Keelung River in densely populated northern Taiwan ranged from 0.12 to 1.13 l/day and 0.61 to 5.78 day, respectively. Higher Biodegradation rate constants were noted in the absence of sediment. Two of the sediment samples were capable of biodegrading phenanthrene at initial concentrations 5–100 μg/g; lower Biodegradation rates occurred at higher concentrations. Optimal Biodegradation conditions were determined as 30°C and pH 7.0. Biodegradation was not significantly influenced by the addition of such carbon sources as acetate, pyruvate, and yeast extract, but was significantly influenced by the addition of ammonium, sulfate, and phosphate. Results show that anthracene, fluorene, and pyrene Biodegradation was enhanced by the presence of phenanthrene, but that phenanthrene treatment did not induce benzo[a]pyrene Biodegradation during a 12-day incubation period.
-
Biodegradation of phenanthrene in river sediment.
Chemosphere, 2001Co-Authors: S Y Yuan, J.s. Chang, J.h Yen, Bea-ven ChangAbstract:The aerobic Biodegradation potential of phenanthrene (a polycyclic aromatic hydrocarbon [PAH]) in river sediment was investigated in the laboratory. Biodegradation rate constants (k1) and half-lives (t1/2) for phenanthrene (5 microg/g) in sediment samples collected at five sites along the Keelung River in densely populated northern Taiwan ranged from 0.12 to 1.13 l/day and 0.61 to 5.78 day, respectively. Higher Biodegradation rate constants were noted in the absence of sediment. Two of the sediment samples were capable of biodegrading phenanthrene at initial concentrations 5-100 microg/g; lower Biodegradation rates occurred at higher concentrations. Optimal Biodegradation conditions were determined as 30 degreesC and pH 7.0. Biodegradation was not significantly influenced by the addition of such carbon sources as acetate, pyruvate, and yeast extract, but was significantly influenced by the addition of ammonium, sulfate, and phosphate. Results show that anthracene, fluorene, and pyrene Biodegradation was enhanced by the presence of phenanthrene, but that phenanthrene treatment did not induce benzo[a]pyrene Biodegradation during a 12-day incubation period.
S Y Yuan - One of the best experts on this subject based on the ideXlab platform.
-
Biodegradation of phenanthrene in river sediment
Chemosphere, 2001Co-Authors: S Y Yuan, J.s. Chang, Bea-ven ChangAbstract:The aerobic Biodegradation potential of phenanthrene (a polycyclic aromatic hydrocarbon [PAH]) in river sediment was investigated in the laboratory. Biodegradation rate constants (k1) and half-lives (t1/2) for phenanthrene in sediment samples collected at five sites along the Keelung River in densely populated northern Taiwan ranged from 0.12 to 1.13 l/day and 0.61 to 5.78 day, respectively. Higher Biodegradation rate constants were noted in the absence of sediment. Two of the sediment samples were capable of biodegrading phenanthrene at initial concentrations 5–100 μg/g; lower Biodegradation rates occurred at higher concentrations. Optimal Biodegradation conditions were determined as 30°C and pH 7.0. Biodegradation was not significantly influenced by the addition of such carbon sources as acetate, pyruvate, and yeast extract, but was significantly influenced by the addition of ammonium, sulfate, and phosphate. Results show that anthracene, fluorene, and pyrene Biodegradation was enhanced by the presence of phenanthrene, but that phenanthrene treatment did not induce benzo[a]pyrene Biodegradation during a 12-day incubation period.
-
Biodegradation of phenanthrene in river sediment.
Chemosphere, 2001Co-Authors: S Y Yuan, J.s. Chang, J.h Yen, Bea-ven ChangAbstract:The aerobic Biodegradation potential of phenanthrene (a polycyclic aromatic hydrocarbon [PAH]) in river sediment was investigated in the laboratory. Biodegradation rate constants (k1) and half-lives (t1/2) for phenanthrene (5 microg/g) in sediment samples collected at five sites along the Keelung River in densely populated northern Taiwan ranged from 0.12 to 1.13 l/day and 0.61 to 5.78 day, respectively. Higher Biodegradation rate constants were noted in the absence of sediment. Two of the sediment samples were capable of biodegrading phenanthrene at initial concentrations 5-100 microg/g; lower Biodegradation rates occurred at higher concentrations. Optimal Biodegradation conditions were determined as 30 degreesC and pH 7.0. Biodegradation was not significantly influenced by the addition of such carbon sources as acetate, pyruvate, and yeast extract, but was significantly influenced by the addition of ammonium, sulfate, and phosphate. Results show that anthracene, fluorene, and pyrene Biodegradation was enhanced by the presence of phenanthrene, but that phenanthrene treatment did not induce benzo[a]pyrene Biodegradation during a 12-day incubation period.
Yongming Zhang - One of the best experts on this subject based on the ideXlab platform.
-
coupling uv h2o2 to accelerate dimethyl phthalate dmp Biodegradation and oxidation
Biodegradation, 2015Co-Authors: Bin Chen, Jiaxiu Song, Lihui Yang, Qi Bai, Yongming Zhang, Bruce E RittmannAbstract:Dimethyl phthalate (DMP), an important industrial raw material, is an endocrine disruptor of concern for human and environmental health. DMP exhibits slow Biodegradation, and its coupled treatment by means of advanced oxidation may enhance its biotransformation and mineralization. We evaluated two ways of coupling UV–H2O2 advanced oxidation to Biodegradation: sequential coupling and intimate coupling in an internal circulation baffled biofilm reactor (ICBBR). During sequential coupling, UV–H2O2 pretreatment generated carboxylic acids that depressed the pH, and subsequent Biodegradation generated phthalic acid; both factors inhibited DMP Biodegradation. During intimately coupled UV–H2O2 with Biodegradation, carboxylic acids and phthalic acid (PA) did not accumulate, and the Biodegradation rate was 13 % faster than with Biodegradation alone and 78 % faster than with Biodegradation after UV–H2O2 pretreatment. Similarly, DMP oxidation with intimate coupling increased by 5 and 39 %, respectively, compared with Biodegradation alone and sequential coupling. The enhancement effects during intimate coupling can be attributed to the rapid catabolism of carboxylic acids, which generated intracellular electron carriers that directly accelerated di-oxygenation of PA and relieved the inhibition effect of PA and low pH. Thus, intimate coupling optimized the impacts of energy input from UV irradiation used together with Biodegradation.
-
Intimately coupling of photolysis accelerates nitrobenzene Biodegradation, but sequential coupling slows Biodegradation
Journal of hazardous materials, 2015Co-Authors: Lihui Yang, Qi Bai, Yongming Zhang, Ning Yan, Bruce E RittmannAbstract:Abstract Photo(cata)lysis coupled with Biodegradation is superior to photo(cata)lysis or Biodegradation alone for removal of recalcitrant organic compounds. The two steps can be carried out sequentially or simultaneously via intimate coupling. We studied nitrobenzene (NB) removal and mineralization to evaluate why intimate coupling of photolysis with Biodegradation was superior to sequential coupling. Employing an internal circulation baffled biofilm reactor, we compared direct Biodegradation (B), Biodegradation after photolysis (P + B), simultaneous photolysis and Biodegradation (PB NP and OA were NB’s main UV-photolysis products. Compared with B, the Biodegradation rate P + B was lower by 13–29%, but intimately coupling (PB mineralization showed similar trends. B + OA gave results similar to P&B, B + NP gave results similar to P + B, and B + OA + NP gave results between P + B and P&B, depending on the amount of OA and NP added. The photolysis product OA accelerated NB Biodegradation through a co-substrate effect, but NP was inhibitory. Although decreasing the UV photolysis time could minimize the inhibition impact of NP in P + B, P&B gave the fastest removal of NB by accentuating the co-substrate effect of OA.
-
UV photolysis for accelerated quinoline Biodegradation and mineralization
Applied microbiology and biotechnology, 2013Co-Authors: Ning Yan, Yongming Zhang, Ling Chang, Lu Gan, Rui Liu, Bruce E RittmannAbstract:Sequentially and intimately coupled photolysis with Biodegradation were evaluated for their ability to accelerate quinoline-removal and quinoline-mineralization kinetics. UV photolysis sequentially coupled to Biodegradation significantly improved biomass-growth kinetics, which could be represented well by the Aiba self-inhibition model: UV photolysis increased the maximum specific growth rate (μ max) by 15 %, and the inhibition constant (K SI) doubled. An internal loop photo-Biodegradation reactor (ILPBR) was used to realize intimately coupled photolysis with Biodegradation. The ILPBR was operated with batch experiments following three protocols: photolysis alone (P), Biodegradation alone (B), and intimately coupled photolysis and Biodegradation (PB the composite result was a doubling of the quinoline-Biodegradation rate for most of the concentration range tested. The degree of mineralization was increased by both forms of photolysis coupled to Biodegradation, and the impact was greater for intimate coupling (18 % increase) than sequential coupling (5 %). The benefits of UV photolysis were greater with intimate coupling than with sequential coupling due to parallel transformation by Biodegradation and photolysis.
J.s. Chang - One of the best experts on this subject based on the ideXlab platform.
-
Biodegradation of phenanthrene in river sediment
Chemosphere, 2001Co-Authors: S Y Yuan, J.s. Chang, Bea-ven ChangAbstract:The aerobic Biodegradation potential of phenanthrene (a polycyclic aromatic hydrocarbon [PAH]) in river sediment was investigated in the laboratory. Biodegradation rate constants (k1) and half-lives (t1/2) for phenanthrene in sediment samples collected at five sites along the Keelung River in densely populated northern Taiwan ranged from 0.12 to 1.13 l/day and 0.61 to 5.78 day, respectively. Higher Biodegradation rate constants were noted in the absence of sediment. Two of the sediment samples were capable of biodegrading phenanthrene at initial concentrations 5–100 μg/g; lower Biodegradation rates occurred at higher concentrations. Optimal Biodegradation conditions were determined as 30°C and pH 7.0. Biodegradation was not significantly influenced by the addition of such carbon sources as acetate, pyruvate, and yeast extract, but was significantly influenced by the addition of ammonium, sulfate, and phosphate. Results show that anthracene, fluorene, and pyrene Biodegradation was enhanced by the presence of phenanthrene, but that phenanthrene treatment did not induce benzo[a]pyrene Biodegradation during a 12-day incubation period.
-
Biodegradation of phenanthrene in river sediment.
Chemosphere, 2001Co-Authors: S Y Yuan, J.s. Chang, J.h Yen, Bea-ven ChangAbstract:The aerobic Biodegradation potential of phenanthrene (a polycyclic aromatic hydrocarbon [PAH]) in river sediment was investigated in the laboratory. Biodegradation rate constants (k1) and half-lives (t1/2) for phenanthrene (5 microg/g) in sediment samples collected at five sites along the Keelung River in densely populated northern Taiwan ranged from 0.12 to 1.13 l/day and 0.61 to 5.78 day, respectively. Higher Biodegradation rate constants were noted in the absence of sediment. Two of the sediment samples were capable of biodegrading phenanthrene at initial concentrations 5-100 microg/g; lower Biodegradation rates occurred at higher concentrations. Optimal Biodegradation conditions were determined as 30 degreesC and pH 7.0. Biodegradation was not significantly influenced by the addition of such carbon sources as acetate, pyruvate, and yeast extract, but was significantly influenced by the addition of ammonium, sulfate, and phosphate. Results show that anthracene, fluorene, and pyrene Biodegradation was enhanced by the presence of phenanthrene, but that phenanthrene treatment did not induce benzo[a]pyrene Biodegradation during a 12-day incubation period.
