Worldwide extensive use of plasticized plastics has resulted in phthalates pollution in different environment. Nitrates from industry and agriculture are also widely disseminated in the soils, natural waters and waste...Worldwide extensive use of plasticized plastics has resulted in phthalates pollution in different environment. Nitrates from industry and agriculture are also widely disseminated in the soils, natural waters and wastewaters. Dimethyl phthalate （DMP） biodegradation by activated sludge cultures under nitrate-reducing conditions was investigated. Under one optimized condition, DMP was biodegraded from 102.20 mg/L to undetectable level in 56 h under anoxic conditions and its reaction fitted well with the first-order kinetics. Using the high-performance liquid chromatography （HPLC） and liquid chromatography mass spectrometry （LC-MS） analysis, mono-methyl phthalate （MMP） and phthalic acid （PA） were detected as the major intermediates of DMP biodegradation. When combined with the determination of chemical oxygen demand （CODer） removal capacity and pH, DMP was found to be mineralized completely under anoxic conditions. The biodegradation pathway was proposed as DMP → MMP→ PA→…→ CO2 ＋ H2O. The molar ratio of DMP to nitrate consumed was found to be 9.0：1, which agrees well with the theoretical stoichiometric values of DMP biodegradation by nitrate-reducing bacteria. The results of the non-linear simulation showed that the optimum pH and temperature for the degradation were 7.56 and 31.4℃, respectively.展开更多
The anodic oxidation of aqueous solutions containing dimethyl phthalate （DMP） up to 125 mg/L with sodium sulfate （Na2SO4） as supporting electrolyte within the pH range 2.0-10.0 was studied using a one-compartment ...The anodic oxidation of aqueous solutions containing dimethyl phthalate （DMP） up to 125 mg/L with sodium sulfate （Na2SO4） as supporting electrolyte within the pH range 2.0-10.0 was studied using a one-compartment batch reactor employing a boron-doped diamond （BDD） as anode. Electrolyses were carded out at constant current density （1.5-4.5 mA/cm^2）. Complete mineralization was always achieved owing to the great concentration of hydroxyl radical （-OH） generated at the BDD surface. The effects of pH, apparent current density and initial DMP concentration on the degradation rate of DMP, the specific charge required for its total mineralization and mineralization current efficiency were investigated systematically. The mineralization rate of DMP was found to be pH-independent and to increase with increasing applied current density. Results indicated that this electrochemical process was subjected, at least partially, to the mass transfer of organics onto the BDD surface. Kinetic analysis of the temporal change of DMP concentration during electrolysis determined by High Performance Liquid Chromatography （HPLC） revealed that DMP decay under all tested conditions followed a pseudo first-order reaction. Aromatic intermediates and generated carboxylic acids were identified by Gas Chromatography- Mass Spectrometry （GC-MS） and a general pathway for the electrochemical incineration of DMP on BDD was proposed.展开更多
The degradation mechanism of dimethyl phthalate（DMP） in the drinking water was investigated using strong ionization discharge technology in this study. Under the optimized condition, the degradation efficiency of DM...The degradation mechanism of dimethyl phthalate（DMP） in the drinking water was investigated using strong ionization discharge technology in this study. Under the optimized condition, the degradation efficiency of DMP in drinking water was up to 93% in 60 min. A series of analytical techniques including high-performance liquid chromatography, liquid chromatography mass spectrometry, total organic carbon analyzer and ultraviolet–visible spectroscopy were used in the study. It was found that a high concentration of ozone（O_3） produced by dielectric barrier discharge reactor was up to 74.4 mg l^（-1） within 60 min. Tert-butanol, isopropyl alcohol,carbonate ions（CO_3^（2-）） and bicarbonate ions （HCO_3^-） was added to the sample solution to indirectly prove the presence and effect of hydroxyl radicals（·OH）. These analytical findings indicate that mono-methyl phthalate, phthalic acid（PA） and methyl ester PA were detected as the major intermediates in the process of DMP degradation. Finally, DMP and all products were mineralized into carbon dioxide（CO_2） and water（H_2O） ultimately. Based on these analysis results, the degradation pathway of DMP by strong ionization discharge technology were proposed.展开更多
To investigate the influence of radiolysis on kinetics and factors of dimethyl phthalate(DMP),the aqueous DMP solution is degraded by 1.8 MeV E-beam,following pseudo-first-order kinetics.The rate constant of DMP degra...To investigate the influence of radiolysis on kinetics and factors of dimethyl phthalate(DMP),the aqueous DMP solution is degraded by 1.8 MeV E-beam,following pseudo-first-order kinetics.The rate constant of DMP degradation decreased exponentially with increasing initial DMP concentration.The DMP is favorably degraded by radical scavengers under its low concentration and alkaline condition.At high doses,the DMP is attacked by eaq-and ·OH,producing monomethyl phthalate,phthalate acid,and a series of aliphatic carboxylic acids,which are completelymineralized into H2O and CO2.展开更多
The biodegradation of dimethyl phthalate(DMP)was investigated under fermentative conditions in this study.The nature of the intermediate compounds and the extent of mineralization were probed using high-pressure liqui...The biodegradation of dimethyl phthalate(DMP)was investigated under fermentative conditions in this study.The nature of the intermediate compounds and the extent of mineralization were probed using high-pressure liquid chromatography(HPLC)and liquid chromatography-mass spectrometry(LC-MS)methods.The fermentative bacteria were able to biodegrade the DMP under anaerobic conditions,with the biodegradation rate of 0.36 mg DMP/(L·h).The results demonstrated that the DMP degradation under fermentative conditions ...展开更多
unaliella tertiolecta has an ability to biodegrade dimethyl phthalate(DMP) was found in this study, and the average of the biodegradation rates were 113 mg/(L·d) and 305 mg/(L·d), and the average of the ph...unaliella tertiolecta has an ability to biodegrade dimethyl phthalate(DMP) was found in this study, and the average of the biodegradation rates were 113 mg/(L·d) and 305 mg/(L·d), and the average of the phthalic acid (PA) production rates were 15 mg/(L·d) and 36 mg/(L·d), for initial 100 mg/L and 300 mg/L DMP, respectively. The larger amount of accumulation by D. tertiolecta under higher DMP concentration may be responsible for the increase of biodegradation rate, and one of products of DMP biodegradation by D. tertiolecta may be PA. By fitting the process of DMP biodegradation by D. tertiolecta with a kinetic equation newly suggested, the standard deviations between calculated and observed values were 25 mg/L and 57 mg/L, respectively.展开更多
邻苯二甲酸二甲酯(DMP)作为一种在环境中广泛存在的有毒化合物,已被中国列为优先控制污染物。采用无机盐培养基从长期覆盖农膜的黑土中分离鉴定了一株能够以DMP为碳源的菌株QD-9-10,根据菌落的形态特征及16S r DNA碱基序列同源性分析,鉴...邻苯二甲酸二甲酯(DMP)作为一种在环境中广泛存在的有毒化合物,已被中国列为优先控制污染物。采用无机盐培养基从长期覆盖农膜的黑土中分离鉴定了一株能够以DMP为碳源的菌株QD-9-10,根据菌落的形态特征及16S r DNA碱基序列同源性分析,鉴定QD-9-10为Bacillus sp.。正交实验结果表明,菌株QD-9-10的最优降解条件为p H 8.0,温度35.0℃,摇床转速124.0 r·min-1,DMP初始浓度100.4 mg·L-1,在32 h时内可将DMP完全降解。底物利用能力测试表明,菌种QD-9-10具有可降解多种邻苯二甲酸酯(PAE)的能力。由此可见,Bacillus sp.QD-9-10在修复PAEs污染环境方面有一定应用前景。展开更多
文摘Worldwide extensive use of plasticized plastics has resulted in phthalates pollution in different environment. Nitrates from industry and agriculture are also widely disseminated in the soils, natural waters and wastewaters. Dimethyl phthalate （DMP） biodegradation by activated sludge cultures under nitrate-reducing conditions was investigated. Under one optimized condition, DMP was biodegraded from 102.20 mg/L to undetectable level in 56 h under anoxic conditions and its reaction fitted well with the first-order kinetics. Using the high-performance liquid chromatography （HPLC） and liquid chromatography mass spectrometry （LC-MS） analysis, mono-methyl phthalate （MMP） and phthalic acid （PA） were detected as the major intermediates of DMP biodegradation. When combined with the determination of chemical oxygen demand （CODer） removal capacity and pH, DMP was found to be mineralized completely under anoxic conditions. The biodegradation pathway was proposed as DMP → MMP→ PA→…→ CO2 ＋ H2O. The molar ratio of DMP to nitrate consumed was found to be 9.0：1, which agrees well with the theoretical stoichiometric values of DMP biodegradation by nitrate-reducing bacteria. The results of the non-linear simulation showed that the optimum pH and temperature for the degradation were 7.56 and 31.4℃, respectively.
基金supported by the National Natural Science Foundation of China (No 50778172) the Funds for Creative Research Groups of China (No 50621804)
文摘The anodic oxidation of aqueous solutions containing dimethyl phthalate （DMP） up to 125 mg/L with sodium sulfate （Na2SO4） as supporting electrolyte within the pH range 2.0-10.0 was studied using a one-compartment batch reactor employing a boron-doped diamond （BDD） as anode. Electrolyses were carded out at constant current density （1.5-4.5 mA/cm^2）. Complete mineralization was always achieved owing to the great concentration of hydroxyl radical （-OH） generated at the BDD surface. The effects of pH, apparent current density and initial DMP concentration on the degradation rate of DMP, the specific charge required for its total mineralization and mineralization current efficiency were investigated systematically. The mineralization rate of DMP was found to be pH-independent and to increase with increasing applied current density. Results indicated that this electrochemical process was subjected, at least partially, to the mass transfer of organics onto the BDD surface. Kinetic analysis of the temporal change of DMP concentration during electrolysis determined by High Performance Liquid Chromatography （HPLC） revealed that DMP decay under all tested conditions followed a pseudo first-order reaction. Aromatic intermediates and generated carboxylic acids were identified by Gas Chromatography- Mass Spectrometry （GC-MS） and a general pathway for the electrochemical incineration of DMP on BDD was proposed.
基金supported by the Science and Technology Support Project Plan and Social Development of Jiangsu Province,China(Grant No.BE2011732)the Science and Technology Support Project Plan and Social Development of Zhenjiang city,China(Grant No.SH2012013)
文摘The degradation mechanism of dimethyl phthalate（DMP） in the drinking water was investigated using strong ionization discharge technology in this study. Under the optimized condition, the degradation efficiency of DMP in drinking water was up to 93% in 60 min. A series of analytical techniques including high-performance liquid chromatography, liquid chromatography mass spectrometry, total organic carbon analyzer and ultraviolet–visible spectroscopy were used in the study. It was found that a high concentration of ozone（O_3） produced by dielectric barrier discharge reactor was up to 74.4 mg l^（-1） within 60 min. Tert-butanol, isopropyl alcohol,carbonate ions（CO_3^（2-）） and bicarbonate ions （HCO_3^-） was added to the sample solution to indirectly prove the presence and effect of hydroxyl radicals（·OH）. These analytical findings indicate that mono-methyl phthalate, phthalic acid（PA） and methyl ester PA were detected as the major intermediates in the process of DMP degradation. Finally, DMP and all products were mineralized into carbon dioxide（CO_2） and water（H_2O） ultimately. Based on these analysis results, the degradation pathway of DMP by strong ionization discharge technology were proposed.
基金Supported by National Natural Science Foundation of China (No. 40830744 and 40973073)National Key Technology R&D Program in the 11th Five-year Plan of China (No.2008BAC32B03)+2 种基金Shanghai Leading Academic Discipline Project (No.S30109)Science and Technology Commission of Shanghai Municipality (No. 09ZR1411300A.10-0111-07-003)
文摘To investigate the influence of radiolysis on kinetics and factors of dimethyl phthalate(DMP),the aqueous DMP solution is degraded by 1.8 MeV E-beam,following pseudo-first-order kinetics.The rate constant of DMP degradation decreased exponentially with increasing initial DMP concentration.The DMP is favorably degraded by radical scavengers under its low concentration and alkaline condition.At high doses,the DMP is attacked by eaq-and ·OH,producing monomethyl phthalate,phthalate acid,and a series of aliphatic carboxylic acids,which are completelymineralized into H2O and CO2.
文摘The biodegradation of dimethyl phthalate(DMP)was investigated under fermentative conditions in this study.The nature of the intermediate compounds and the extent of mineralization were probed using high-pressure liquid chromatography(HPLC)and liquid chromatography-mass spectrometry(LC-MS)methods.The fermentative bacteria were able to biodegrade the DMP under anaerobic conditions,with the biodegradation rate of 0.36 mg DMP/(L·h).The results demonstrated that the DMP degradation under fermentative conditions ...
文摘unaliella tertiolecta has an ability to biodegrade dimethyl phthalate(DMP) was found in this study, and the average of the biodegradation rates were 113 mg/(L·d) and 305 mg/(L·d), and the average of the phthalic acid (PA) production rates were 15 mg/(L·d) and 36 mg/(L·d), for initial 100 mg/L and 300 mg/L DMP, respectively. The larger amount of accumulation by D. tertiolecta under higher DMP concentration may be responsible for the increase of biodegradation rate, and one of products of DMP biodegradation by D. tertiolecta may be PA. By fitting the process of DMP biodegradation by D. tertiolecta with a kinetic equation newly suggested, the standard deviations between calculated and observed values were 25 mg/L and 57 mg/L, respectively.
文摘邻苯二甲酸二甲酯(DMP)作为一种在环境中广泛存在的有毒化合物,已被中国列为优先控制污染物。采用无机盐培养基从长期覆盖农膜的黑土中分离鉴定了一株能够以DMP为碳源的菌株QD-9-10,根据菌落的形态特征及16S r DNA碱基序列同源性分析,鉴定QD-9-10为Bacillus sp.。正交实验结果表明,菌株QD-9-10的最优降解条件为p H 8.0,温度35.0℃,摇床转速124.0 r·min-1,DMP初始浓度100.4 mg·L-1,在32 h时内可将DMP完全降解。底物利用能力测试表明,菌种QD-9-10具有可降解多种邻苯二甲酸酯(PAE)的能力。由此可见,Bacillus sp.QD-9-10在修复PAEs污染环境方面有一定应用前景。
