Experimental data are presented to test and validate a kinetic model for the oxidation of 2 chlorophenol wastewater by photo assisted Fenton process. The data showed that this process had produced good effects under a...Experimental data are presented to test and validate a kinetic model for the oxidation of 2 chlorophenol wastewater by photo assisted Fenton process. The data showed that this process had produced good effects under acidic conductions. Up to 90% 2 chlorophenol was removed after 90 minute reaction time with H 2O 2 of 25% COD Cr, in , while in UV/H 2O 2 system only 16 8% 2 chlorophenol was removed after one hour treatment. The optimal pH in this reaction occurred between pH 3 0 and pH 4.0. The reaction kinetics for photo assisted Fenton process experimented in this research was investigated. Kinetic models were proposed for the treatment of 2 chlorophenol wastewater. The reaction was found to follow the 2nd order. The equations of reaction kinetics are as follows:-d[RH]d t = K RH [RH][H 2O 2] 0exp (-K H 2O 2 t );-d[COD Cr ]d t = K COD Cr [COD Cr ][H 2O 2] 0exp(-K′ t ). The prediction of the models was found to be in a good agreement with experimental results, thus confirming the proposed reaction mechanism.展开更多
Fenton oxidation was used as the pretreatment of 2-chlorophenol wastewater with the objective of dechlorination, as it was considered that after breakage of aryl—Cl bond, the generated intermediates may be easily bio...Fenton oxidation was used as the pretreatment of 2-chlorophenol wastewater with the objective of dechlorination, as it was considered that after breakage of aryl—Cl bond, the generated intermediates may be easily biodegraded. Hence, the optimization of pH and the low Fenton reagent doses for dechlorination was investigated. More than 99% dechlorination is obtained at the optimal pH 4 and the Fenton reagent doses of 86 mmol/L H2 O2 and 2.87 mmol/L Fe2+. The corresponding 2-chlorophenol is degraded completely, 80.02% COD is also removed, and the biodegradability, evaluated in terms of the BOD5 /COD ratio, is increased up to 0.41. To test the effect of this pretreatment, the pretreated 2-chlorophenol wastewater was fed to a sequencing batch reactor(SBR). The results show that complete mineralization is achieved. It is demonstrated that, for the treatment of recalcitrant compounds like 2-chlorophenol, the Fenton pretreatment could be quite effective and economical for enhancing the biodegradability in a Fenton-biological coupled system.展开更多
A microscopic diffusion-reaction modei was developed to simulate in-situ ozonation for the remediation of contaminated soil, i.e., to predict the temporal and spatial distribution of target contaminant in the subsurfa...A microscopic diffusion-reaction modei was developed to simulate in-situ ozonation for the remediation of contaminated soil, i.e., to predict the temporal and spatial distribution of target contaminant in the subsurface. The sequential strategy was employed to obtain the numerical solution of the modei using finite difference method. A non-uniform grid of discretization points was emploved to increase the accuracy of the numerical solution by means of coordinate transformation. One-dimensional column tests were conducted to verify the modei. The column was packed with simulated soils that were spiked with 2-chlorophenol. Ozone gas passed through the column at a flow rate of 100ml·min-1. The residual 2-chlorophenol content at different depths of the column was determined at fixed time intervals. Compared the experimental data with the simulated values, it was found that the mathematical modei fitted data well during most time of the experiment.展开更多
In this paper,the aqueous two-phase systems(ATPS)containing n-ethylpyridinium tetrafluoroborate([EPy]BF_(4)),sodium-based salts,and water were studied and the extraction efficiency of 2-chlorophenol was measured to st...In this paper,the aqueous two-phase systems(ATPS)containing n-ethylpyridinium tetrafluoroborate([EPy]BF_(4)),sodium-based salts,and water were studied and the extraction efficiency of 2-chlorophenol was measured to study the ATPS performance in extracting phenolic compounds.The binodal curves of[EPy]BF_(4)+sodium carbonate(Na_(2)CO_(3))ATPS and[EPy]BF_(4)+sodium dihydrogen phosphate(NaH_(2)PO_(4))ATPS have been determined at 308.15 K,318.15 K,and 328.15 K and atmospheric pressure.After getting good correlation with Merchuk equation,the binodal curves together with gravimetric method were used to calculate the tie-lines data.Furthermore,the reliability of tie-lines data was verified using Othmer-Tobias and Bancroft equations.Then,the salt influence and temperature influence on the phase behavior were discussed and the results show the salt-outing ability of Na_(2)CO_(3) is better than NaH_(2)PO_(4).With the aim of studying the ATPS performance in extracting phenolic compounds,extraction efficiency for 2-chlorophenol at different temperatures were studied and the results show that[EPy]BF_(4)+Na_(2)CO_(3) ATPS is preferred than[EPy]BF_(4)+NaH_(2)PO_(4) ATPS in applications.展开更多
In order to address the complex cometabolic degradation of toxic compounds, batch experiments on the biodegradation of 2-chlorophenol （2-CP） and phenol by Pseudomonas putida were carried out. The experimental result...In order to address the complex cometabolic degradation of toxic compounds, batch experiments on the biodegradation of 2-chlorophenol （2-CP） and phenol by Pseudomonas putida were carried out. The experimental results show that 2-CP has an inhibitory effect on cell growth and phenol degradation, which demonstrates that the interaction between substrates affects cell growth and substrate degradation. A kinetic model of cell growth and substrate transformation was also developed. The square of the correlation coefficient from the experiment was 0.97, indicating that this model properly simulates the cometabolic degradation of 2-CP and phenol.展开更多
The effects of Cd^2＋ and Cu^2＋ at 300 mg/L on anaerobic microbial communities that degrade 2-cholorophenol （2-CP） were examined. Based on the polymerase chain reaction （PCR） of 16S rDNA, bacterial community dive...The effects of Cd^2＋ and Cu^2＋ at 300 mg/L on anaerobic microbial communities that degrade 2-cholorophenol （2-CP） were examined. Based on the polymerase chain reaction （PCR） of 16S rDNA, bacterial community diversity and archaeal community structure were analyzed with denaturing gradient gel electrophoresis （DGGE） and cloning, respectively. Degradation capabilities of the anaerobic microbial community were drastically abated and the degradation efficiency of 2-CP was reduced to 60% after shock by Cu^2＋ and Cd^2＋, respectively. The bacterial community structure was disturbed and the biodiversity was reduced after shock by Cu^2＋ and Cd^2＋ for 3 d. Some new metal-resistant microbes which could cope with the new condition appeared. The sequence analysis showed that there existed common Archaea species in control sludge and systems when treated with Cu^2＋ and Cd^2＋, such as Methanothrix soehngenii, Methanosaeta concilii, uncultured euryarchaeote, and so on. Both the abundance and diversity of archaeal species were altered with addition of Cd^2＋ and Cu^2＋ at high concentration. Although the abundance of the predominant archaeal species decreased with Cd^2＋ and Cu^2＋ addition for 3 d, they recovered to some extent after 10 d. The diversity of archaeal species was remarkably reduced after recovery for 10 d and the shift in archaeal composition seemed to be irreversible. The 2-CP-degradation anaerobic system was more sensitive to Cu^2＋ than Cd^2＋.展开更多
A series of metal oxide catalysts for catalytic oxidative degradation of 2-chlorophenol （2-CP） and 4-chlorophenol （4-CP） were prepared, and the supported CuO catalysts were studied particularly. The supported CuO ...A series of metal oxide catalysts for catalytic oxidative degradation of 2-chlorophenol （2-CP） and 4-chlorophenol （4-CP） were prepared, and the supported CuO catalysts were studied particularly. The supported CuO catalysts were characterized by XRD and NH3-TPD techniques, in which CuO/γ-Al2O3 exhibited high degradation activity. The addition of Na2O or K2O into CuO/γ-Al2O3 improved the oxidative degradation of CPs remarkably, in which Na2O was more efficient than K2O. Over CuO/γ-Al2O3-Na2O, CPs were completely converted and the liberation of the inorganic chloride from 2-CP or 4-CP reached 97% or 100% respectively at 30 ？C for 2 h. The supported CuO catalysts with good dispersion of CuO particles and less acid sites were favorable for the efficient oxidative degradation of CPs. In addition, the initial pH of the reaction solution was found to be an important factor which influenced the catalytic oxidative degradation of CPs and the initial pH of 11.2 and 9.8 was preferred for the oxidative degradation of 2-CP and 4-CP respectively over CuO/γ-Al2O3 catalyst.展开更多
文摘Experimental data are presented to test and validate a kinetic model for the oxidation of 2 chlorophenol wastewater by photo assisted Fenton process. The data showed that this process had produced good effects under acidic conductions. Up to 90% 2 chlorophenol was removed after 90 minute reaction time with H 2O 2 of 25% COD Cr, in , while in UV/H 2O 2 system only 16 8% 2 chlorophenol was removed after one hour treatment. The optimal pH in this reaction occurred between pH 3 0 and pH 4.0. The reaction kinetics for photo assisted Fenton process experimented in this research was investigated. Kinetic models were proposed for the treatment of 2 chlorophenol wastewater. The reaction was found to follow the 2nd order. The equations of reaction kinetics are as follows:-d[RH]d t = K RH [RH][H 2O 2] 0exp (-K H 2O 2 t );-d[COD Cr ]d t = K COD Cr [COD Cr ][H 2O 2] 0exp(-K′ t ). The prediction of the models was found to be in a good agreement with experimental results, thus confirming the proposed reaction mechanism.
基金Project(11JJ2031) supported by the Natural Science Fund of Hunan Province,China
文摘Fenton oxidation was used as the pretreatment of 2-chlorophenol wastewater with the objective of dechlorination, as it was considered that after breakage of aryl—Cl bond, the generated intermediates may be easily biodegraded. Hence, the optimization of pH and the low Fenton reagent doses for dechlorination was investigated. More than 99% dechlorination is obtained at the optimal pH 4 and the Fenton reagent doses of 86 mmol/L H2 O2 and 2.87 mmol/L Fe2+. The corresponding 2-chlorophenol is degraded completely, 80.02% COD is also removed, and the biodegradability, evaluated in terms of the BOD5 /COD ratio, is increased up to 0.41. To test the effect of this pretreatment, the pretreated 2-chlorophenol wastewater was fed to a sequencing batch reactor(SBR). The results show that complete mineralization is achieved. It is demonstrated that, for the treatment of recalcitrant compounds like 2-chlorophenol, the Fenton pretreatment could be quite effective and economical for enhancing the biodegradability in a Fenton-biological coupled system.
基金China Scholarship Council(No.97842039)National Natural Science Foundation of China(No.20107005)
文摘A microscopic diffusion-reaction modei was developed to simulate in-situ ozonation for the remediation of contaminated soil, i.e., to predict the temporal and spatial distribution of target contaminant in the subsurface. The sequential strategy was employed to obtain the numerical solution of the modei using finite difference method. A non-uniform grid of discretization points was emploved to increase the accuracy of the numerical solution by means of coordinate transformation. One-dimensional column tests were conducted to verify the modei. The column was packed with simulated soils that were spiked with 2-chlorophenol. Ozone gas passed through the column at a flow rate of 100ml·min-1. The residual 2-chlorophenol content at different depths of the column was determined at fixed time intervals. Compared the experimental data with the simulated values, it was found that the mathematical modei fitted data well during most time of the experiment.
基金sponsored by the Natural Science Foundation for Distinguished Young Scholars of Guangdong Provence (2019B151502038)the National Natural Science Foundation of China (21706038, 21808042, 21808039)+2 种基金the Fundamental Research Funds for the Central Universities (300102299202)the National Training Projects of the University Students’ Innovation and Entrepreneurship program (201910710125)the Scientific Innovation Practice Project of Postgraduates of Chang’an University (300103703058, 300103703016)
文摘In this paper,the aqueous two-phase systems(ATPS)containing n-ethylpyridinium tetrafluoroborate([EPy]BF_(4)),sodium-based salts,and water were studied and the extraction efficiency of 2-chlorophenol was measured to study the ATPS performance in extracting phenolic compounds.The binodal curves of[EPy]BF_(4)+sodium carbonate(Na_(2)CO_(3))ATPS and[EPy]BF_(4)+sodium dihydrogen phosphate(NaH_(2)PO_(4))ATPS have been determined at 308.15 K,318.15 K,and 328.15 K and atmospheric pressure.After getting good correlation with Merchuk equation,the binodal curves together with gravimetric method were used to calculate the tie-lines data.Furthermore,the reliability of tie-lines data was verified using Othmer-Tobias and Bancroft equations.Then,the salt influence and temperature influence on the phase behavior were discussed and the results show the salt-outing ability of Na_(2)CO_(3) is better than NaH_(2)PO_(4).With the aim of studying the ATPS performance in extracting phenolic compounds,extraction efficiency for 2-chlorophenol at different temperatures were studied and the results show that[EPy]BF_(4)+Na_(2)CO_(3) ATPS is preferred than[EPy]BF_(4)+NaH_(2)PO_(4) ATPS in applications.
基金supported by the Chinese Key Laboratory of Integrated Regulation and Resource Development of Shallow Lakes of China (Grant No. 2007KJ006)
文摘In order to address the complex cometabolic degradation of toxic compounds, batch experiments on the biodegradation of 2-chlorophenol （2-CP） and phenol by Pseudomonas putida were carried out. The experimental results show that 2-CP has an inhibitory effect on cell growth and phenol degradation, which demonstrates that the interaction between substrates affects cell growth and substrate degradation. A kinetic model of cell growth and substrate transformation was also developed. The square of the correlation coefficient from the experiment was 0.97, indicating that this model properly simulates the cometabolic degradation of 2-CP and phenol.
文摘The effects of Cd^2＋ and Cu^2＋ at 300 mg/L on anaerobic microbial communities that degrade 2-cholorophenol （2-CP） were examined. Based on the polymerase chain reaction （PCR） of 16S rDNA, bacterial community diversity and archaeal community structure were analyzed with denaturing gradient gel electrophoresis （DGGE） and cloning, respectively. Degradation capabilities of the anaerobic microbial community were drastically abated and the degradation efficiency of 2-CP was reduced to 60% after shock by Cu^2＋ and Cd^2＋, respectively. The bacterial community structure was disturbed and the biodiversity was reduced after shock by Cu^2＋ and Cd^2＋ for 3 d. Some new metal-resistant microbes which could cope with the new condition appeared. The sequence analysis showed that there existed common Archaea species in control sludge and systems when treated with Cu^2＋ and Cd^2＋, such as Methanothrix soehngenii, Methanosaeta concilii, uncultured euryarchaeote, and so on. Both the abundance and diversity of archaeal species were altered with addition of Cd^2＋ and Cu^2＋ at high concentration. Although the abundance of the predominant archaeal species decreased with Cd^2＋ and Cu^2＋ addition for 3 d, they recovered to some extent after 10 d. The diversity of archaeal species was remarkably reduced after recovery for 10 d and the shift in archaeal composition seemed to be irreversible. The 2-CP-degradation anaerobic system was more sensitive to Cu^2＋ than Cd^2＋.
基金financially supported by the Education Department of Liaoning Province(No.2009A421)
文摘A series of metal oxide catalysts for catalytic oxidative degradation of 2-chlorophenol （2-CP） and 4-chlorophenol （4-CP） were prepared, and the supported CuO catalysts were studied particularly. The supported CuO catalysts were characterized by XRD and NH3-TPD techniques, in which CuO/γ-Al2O3 exhibited high degradation activity. The addition of Na2O or K2O into CuO/γ-Al2O3 improved the oxidative degradation of CPs remarkably, in which Na2O was more efficient than K2O. Over CuO/γ-Al2O3-Na2O, CPs were completely converted and the liberation of the inorganic chloride from 2-CP or 4-CP reached 97% or 100% respectively at 30 ？C for 2 h. The supported CuO catalysts with good dispersion of CuO particles and less acid sites were favorable for the efficient oxidative degradation of CPs. In addition, the initial pH of the reaction solution was found to be an important factor which influenced the catalytic oxidative degradation of CPs and the initial pH of 11.2 and 9.8 was preferred for the oxidative degradation of 2-CP and 4-CP respectively over CuO/γ-Al2O3 catalyst.
