摘要
废乳化液是机械加工过程产生的一种高浓度有机废液,属于危险废物。通过实验研究了BDD电极电化学氧化处理废乳化液的降解效果,考察了电流密度、电解质种类及浓度、初始pH值和反应温度对降解效率的影响。结果表明:BDD电极电化学氧化可有效降解废乳化液中的有机物,当采用Na_(2)S_(2)O_(8)为电解质,电流密度超过60 mA/cm^(2)时,降解4 h后COD降解率达到99%以上,单位质量(1 kg)COD降解能耗最大,约25 kW·h/kg。电流密度由20 mA/cm^(2)增加至60 mA/cm^(2)时,COD去除率可提高13%左右,单位能耗也会随之增加;电流密度为60 mA/cm^(2)时,采用Na_(2)S_(2)O_(8)作为支持电解质降解2 h, COD降解率比NaCl和Na_(2)SO_(4)作为电解质高10%以上;提高反应温度和保持酸性条件均有利于增强COD降解效果。动力学分析表明:BDD电极电化学氧化降解废乳化液的过程符合一级反应动力学方程,电流密度<60 mA/cm^(2)时,一级反应动力学常数κ与电流密度基本呈线性关系。
Waste emulsion is a kind of high-concentration organic wastewater produced from mechanical processing, which belongs to hazardous waste. Electrochemical oxidation of BDD electrode is an effective method to treat waste emulsion. In this paper, the degradation effect of the waste emulsion treated by electrochemical oxidation of the BDD electrode was studied experimentally, and the effects of current density, electrolyte type and concentration, initial pH value and reaction temperature on the degradation efficiency were investigated. The results showed that the electrochemical oxidation of BDD electrode could effectively degrade the organic matter in the waste emulsion. When Na_(2)S_(2)O_(8)was used as the electrolyte and the current density was greater than 60 mA/cm^(2), the COD degradation rate reached more than 99% after 4 hours of reaction, and the maximum energy consumption is about 25 kW·h/kg for per 1 kg of COD. When the current density increased from 20 mA/cm^(2)to 60 mA/cm^(2), the COD degradation rate increased by about 13 percentage points, and the energy consumption increased accordingly. When the current density was 60 mA/cm^(2)and the reaction time was 2 hours, the degradation efficiency of COD using Na_(2)S_(2)O_(8)as the supporting electrolyte was about 10% higher than that with NaCl and Na_(2)SO_(4) as the electrolyte. Increasing electrolyte concentration, reaction temperature and acidic conditions was conducive to the degradation of organic matter. The kinetic analysis showed that the process of electrochemical oxidation of waste emulsion with BDD electrode conformed to the first-order reaction kinetic equation, and the relationship between the first-order reaction kinetic constant κ and the current density kept basically linear when the current density was lower than 60 mA/cm^(2).
作者
侯海盟
祁国恕
王坚
李宝磊
孔德勇
赵岩
陈明
曾乐
HOU Haimeng;QI Guoshu;WANG Jian;LI Baolei;KONG Deyong;ZHAO Yan;CHEN Ming;ZENG Le(Shenyang Academy of Environmental Sciences,Shenyang 110167,China;National Environmental Engineering Technology Center for Hazardous Waste Treatment,Shenyang 110167,China;Technology Innovation Center for Hazardous Waste Treatment of Liaoning Province,Shenyang 110167,China;Shenyang Huanke Testing Technology Co.,Ltd,Shenyang 110015,China)
出处
《环境工程》
CAS
CSCD
北大核心
2022年第1期46-51,共6页
Environmental Engineering
基金
国家水体污染控制与治理科技重大专项(2018ZX07601-001)
沈阳市科技计划项目(20-206-4-06)。
关键词
BDD电极
电化学
废乳化液
电流密度
电解质
动力学
BDD electrode
electrochemistry
waste emulsion
current density
supporting electrolyte
kinetics
