Degradation of 2, 4, 6 trichlorophenol(TCP) with co immobilizing anaerobic granular sludge and isolated aerobic bacterial species was studied in coupled anaerobic/aerobic integrated reactors. The synergism of aerobe...Degradation of 2, 4, 6 trichlorophenol(TCP) with co immobilizing anaerobic granular sludge and isolated aerobic bacterial species was studied in coupled anaerobic/aerobic integrated reactors. The synergism of aerobes and anaerobes within co immobilized granule might facilitate degrading the TCP and exchange of anaerobic metabolites 4 CP, which promoted system organic removal efficiency and recovered from organic shock loads more quickly. The biomass specific activities experiment further confirmed that strict anaerobes be not affected over the course of this experiment by the presence of an oxic environment, aerobic activity predominated in the outer co immobilized granule layers, while the interior was characterized by anaerobic activity. The co immobilized granule could thus enable both aerobic and anaerobic microbes function in the same reactor and thereby integrate the oxidative and reductive catabolism.展开更多
Designing efficient and sustainable catalyst for peroxymonosulfate(PMS)activation and refractory 2,4,6-trichlorophenol(2,4,6-TCP)removal is an imminent task.This study synthesized a novelγ-MnO_(2)/NF catalyst,which h...Designing efficient and sustainable catalyst for peroxymonosulfate(PMS)activation and refractory 2,4,6-trichlorophenol(2,4,6-TCP)removal is an imminent task.This study synthesized a novelγ-MnO_(2)/NF catalyst,which has advantages in saving manganese dioxide demand and reducing manganese leaching.Theγ-MnO_(2)/NF+PMS oxidation system achieved a 0.219 min^(−1)2,4,6-TCP apparent rate constant at 20℃,and removed>90%of 2,4,6-TCP at the 5th cycle.Both free radical identification and DFT calculations revealed that•OH and SO_(4)^(•−),rather than 1O_(2),were the dominant reactive species duringγ-MnO_(2)/NF+PMS oxidation.The results indicated that the inner-sphere complexation betweenγ-MnO_(2)/NF and PMS facilitated the formation of•OH and SO_(4)^(•−).To fill the research gap in the molecular-level dissimilarities between•OH and SO_(4)^(•−)in 2,4,6-TCP degradation mechanism,experimental testing and quantum chemical analysis methods were used.The DFT calculation found that the HAA reaction at H13 site and RAF reaction at C1 site were more favorable for both•OH and SO_(4)^(•−).For most reaction sites,SO_(4)^(•−)demonstrates greater energy barriers and substrate selectivity than•OH,attributed to steric constraints.The•OH acted as the predominant oxidative agents responsible for 2,4,6-TCP decomposition.Combining DFT calculation and intermediate identification,potential degradation routes of 2,4,6-TCP were proposed.The ecotoxicity assays verified a substantial reduction in acute toxicity of the treated 2,4,6-TCP solution.This study opens up new avenues for activating PMS withγ-MnO_(2)/NF,and helps to select preferred radical oxidation processes for optimal 2,4,6-TCP removal in practical engineering.展开更多
文摘Degradation of 2, 4, 6 trichlorophenol(TCP) with co immobilizing anaerobic granular sludge and isolated aerobic bacterial species was studied in coupled anaerobic/aerobic integrated reactors. The synergism of aerobes and anaerobes within co immobilized granule might facilitate degrading the TCP and exchange of anaerobic metabolites 4 CP, which promoted system organic removal efficiency and recovered from organic shock loads more quickly. The biomass specific activities experiment further confirmed that strict anaerobes be not affected over the course of this experiment by the presence of an oxic environment, aerobic activity predominated in the outer co immobilized granule layers, while the interior was characterized by anaerobic activity. The co immobilized granule could thus enable both aerobic and anaerobic microbes function in the same reactor and thereby integrate the oxidative and reductive catabolism.
基金supported by“Pioneer and Leading Goose+X”S&T Program of Zhejiang,China(No.2025C02230)the National Natural Science Foundation of China(Nos.52400110 and 52070111).
文摘Designing efficient and sustainable catalyst for peroxymonosulfate(PMS)activation and refractory 2,4,6-trichlorophenol(2,4,6-TCP)removal is an imminent task.This study synthesized a novelγ-MnO_(2)/NF catalyst,which has advantages in saving manganese dioxide demand and reducing manganese leaching.Theγ-MnO_(2)/NF+PMS oxidation system achieved a 0.219 min^(−1)2,4,6-TCP apparent rate constant at 20℃,and removed>90%of 2,4,6-TCP at the 5th cycle.Both free radical identification and DFT calculations revealed that•OH and SO_(4)^(•−),rather than 1O_(2),were the dominant reactive species duringγ-MnO_(2)/NF+PMS oxidation.The results indicated that the inner-sphere complexation betweenγ-MnO_(2)/NF and PMS facilitated the formation of•OH and SO_(4)^(•−).To fill the research gap in the molecular-level dissimilarities between•OH and SO_(4)^(•−)in 2,4,6-TCP degradation mechanism,experimental testing and quantum chemical analysis methods were used.The DFT calculation found that the HAA reaction at H13 site and RAF reaction at C1 site were more favorable for both•OH and SO_(4)^(•−).For most reaction sites,SO_(4)^(•−)demonstrates greater energy barriers and substrate selectivity than•OH,attributed to steric constraints.The•OH acted as the predominant oxidative agents responsible for 2,4,6-TCP decomposition.Combining DFT calculation and intermediate identification,potential degradation routes of 2,4,6-TCP were proposed.The ecotoxicity assays verified a substantial reduction in acute toxicity of the treated 2,4,6-TCP solution.This study opens up new avenues for activating PMS withγ-MnO_(2)/NF,and helps to select preferred radical oxidation processes for optimal 2,4,6-TCP removal in practical engineering.
