The characteristic and mechanism of parachlorophenol(4-CP) degradation in an internal electrolysis system were investigated. The degradation rate of 4-CP was higher in acid solution than that of in neutral or alkaline...The characteristic and mechanism of parachlorophenol(4-CP) degradation in an internal electrolysis system were investigated. The degradation rate of 4-CP was higher in acid solution than that of in neutral or alkaline solution. Addition of activated carbon could make 4-CP easier be degraded by the surface contact catalysis. The dissolved oxygen in solution could take part in the electrode reaction and intensify the degradation of 4-CP. By the analysis of intermediates of degradation of 4-CP, it could be conferred that 4-CP was broken through the bond beside hydroxy firstly, then the bond beside chloride was broken and the chloride was dechlorinated simultaneously. Most intermediate products were glycerine, ethane diacid and acetic acid, while very few 1,4-butanedial and alcohols were found.展开更多
Actual pharmaceutical wastewater was treatedusing a combined ultrasonic irradiation (US) and iron/cokeinternal electrolysis (Fe/C) technology. A significantsynergetic effect was observed, showing that ultrasonicirradi...Actual pharmaceutical wastewater was treatedusing a combined ultrasonic irradiation (US) and iron/cokeinternal electrolysis (Fe/C) technology. A significantsynergetic effect was observed, showing that ultrasonicirradiation dramatically enhanced the chemical oxygendemand (COD) removal efficiencies by internal electrolysis.The effects of primary operating factors on CODremoval were evaluated systematically. Higher ultrasonicfrequency and lower pH values as well as longer reactiontime were favorable to COD removal. The ratio ofbiochemical oxygen demand (BOD) and COD (B/C) ofthe wastewater increased from 0.21 to 0.32 after US-Fe/Ctreatment. An acute biotoxicity assay measuring theinhibition of bioluminescence indicated that the wastewaterwith overall toxicity of 4.3 mg-Zn^(2+)·L^(-1) wasreduced to 0.5 mg-Zn^(2+)·L^(-1) after treatment. Both the rawand the treated wastewater samples were separated andidentified. The types of compounds suggested that theincreased biodegradability and reduced biotoxicityresulted mainly from the destruction of N,N-2 dimethylformamide and aromatic compounds in the pharmaceuticalwastewater.展开更多
文摘The characteristic and mechanism of parachlorophenol(4-CP) degradation in an internal electrolysis system were investigated. The degradation rate of 4-CP was higher in acid solution than that of in neutral or alkaline solution. Addition of activated carbon could make 4-CP easier be degraded by the surface contact catalysis. The dissolved oxygen in solution could take part in the electrode reaction and intensify the degradation of 4-CP. By the analysis of intermediates of degradation of 4-CP, it could be conferred that 4-CP was broken through the bond beside hydroxy firstly, then the bond beside chloride was broken and the chloride was dechlorinated simultaneously. Most intermediate products were glycerine, ethane diacid and acetic acid, while very few 1,4-butanedial and alcohols were found.
基金This study was supported by the Nation Water Pollution Control and Management of Major Special Science and Technology of China(No.2008ZX07314-001-02)the Key Projects in the National Science&Technology Pillar Program during the“Eleventh Five Year Plan”period(No.2009BAC60B02)the State Key Laboratory of Pollution Control and Resource Reuse Foundation(No.PCRRF10013).
文摘Actual pharmaceutical wastewater was treatedusing a combined ultrasonic irradiation (US) and iron/cokeinternal electrolysis (Fe/C) technology. A significantsynergetic effect was observed, showing that ultrasonicirradiation dramatically enhanced the chemical oxygendemand (COD) removal efficiencies by internal electrolysis.The effects of primary operating factors on CODremoval were evaluated systematically. Higher ultrasonicfrequency and lower pH values as well as longer reactiontime were favorable to COD removal. The ratio ofbiochemical oxygen demand (BOD) and COD (B/C) ofthe wastewater increased from 0.21 to 0.32 after US-Fe/Ctreatment. An acute biotoxicity assay measuring theinhibition of bioluminescence indicated that the wastewaterwith overall toxicity of 4.3 mg-Zn^(2+)·L^(-1) wasreduced to 0.5 mg-Zn^(2+)·L^(-1) after treatment. Both the rawand the treated wastewater samples were separated andidentified. The types of compounds suggested that theincreased biodegradability and reduced biotoxicityresulted mainly from the destruction of N,N-2 dimethylformamide and aromatic compounds in the pharmaceuticalwastewater.
