BDD电极电化学氧化降解废乳化液

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Na2S2O8为电解质,电流密度超过60 mA/cm2时,降...

ELECTROCHEMICAL OXIDATION OF WASTE EMULSION WITH BORON-DOPED DIAMOND ANODES(BDD)

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 Na₂S₂O₈ was used as the electrolyte and the current density was greater than 60 mA/cm2, 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/cm2 to 60 mA/cm2, the COD degradation rate increased by about 13 percentage points, and the energy consumption increased accordingly. When the current density was 60 mA/cm2 and the reaction time was 2 hours, the degradation efficiency of COD using Na₂S₂O₈ as the supporting electrolyte was about 10% higher than that with NaCl and Na₂SO₄ 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 k and the current density kept basically linear when the current density was lower than 60 mA/cm2.