The aim of this study was to develop a new pulsed switching peroxi-coagulation system to control hydroxyl radical(∙OH)production and to enhance 2,4-Dichlorophenoxyacetic acid(2,4-D)degradation.The system was construct...The aim of this study was to develop a new pulsed switching peroxi-coagulation system to control hydroxyl radical(∙OH)production and to enhance 2,4-Dichlorophenoxyacetic acid(2,4-D)degradation.The system was constructed with a sacrifice iron anode,a Pt anode,and a gas diffusion cathode.Production of H_(2)O_(2) and Fe^(2+)was controlled separately by time delayers with different pulsed switching frequencies.Under current densities of 5.0 mA/cm^(2)(H_(2)O_(2))and 0.5 mA/cm^(2)(Fe^(2+)),the∙OH production was optimized with the pulsed switching frequency of 1.0 s(H_(2)O_(2)):0.3 s(Fe^(2+))and the ratio of H_(2)O_(2) to Fe^(2+)molar concentrations of 6.6.Under the optimal condition,2,4-D with an initial concentration of 500 mg/L was completely removed in the system within 240 min.The energy consumption for the 2,4-D removal in the system was much lower than that in the electro-Fenton process(686 vs.13610 kWh/kg TOC).The iron consumption in the system was~20 times as low as that in the peroxi-coagulation process(19620 vs.3940400 mg/L)within 240 min.The system should be a promising peroxi-coagulation method for organic pollutants removal in wastewater.展开更多
基金supported by grants from the National Key Scientific Instrument and Equipment Development Project(No.2012YQ03011108)research fund program of Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology(No.2016K0013)+1 种基金the National Natural Science Foundation of China(Grant Nos.51608547,51278500 and 51308557)the Fundamental Research Funds for the Central Universities(No.16lgjc65).
文摘The aim of this study was to develop a new pulsed switching peroxi-coagulation system to control hydroxyl radical(∙OH)production and to enhance 2,4-Dichlorophenoxyacetic acid(2,4-D)degradation.The system was constructed with a sacrifice iron anode,a Pt anode,and a gas diffusion cathode.Production of H_(2)O_(2) and Fe^(2+)was controlled separately by time delayers with different pulsed switching frequencies.Under current densities of 5.0 mA/cm^(2)(H_(2)O_(2))and 0.5 mA/cm^(2)(Fe^(2+)),the∙OH production was optimized with the pulsed switching frequency of 1.0 s(H_(2)O_(2)):0.3 s(Fe^(2+))and the ratio of H_(2)O_(2) to Fe^(2+)molar concentrations of 6.6.Under the optimal condition,2,4-D with an initial concentration of 500 mg/L was completely removed in the system within 240 min.The energy consumption for the 2,4-D removal in the system was much lower than that in the electro-Fenton process(686 vs.13610 kWh/kg TOC).The iron consumption in the system was~20 times as low as that in the peroxi-coagulation process(19620 vs.3940400 mg/L)within 240 min.The system should be a promising peroxi-coagulation method for organic pollutants removal in wastewater.
