可见光分解-氯碱氧化法去除废水中的铁氰化物

Removal of Ferricyanide from Wastewater by Visible Light Photolysis-Chloroalkali Oxidation Process

采用可见光分解(光解)-氯碱氧化法去除模拟废水中的Fe(CN)63-。考察了光解过程中反应时间、初始Fe(CN)63-质量浓度和初始废水pH对Fe(CN)63-去除效果及表观反应速率常数(k(Fe(CN)63-))的影响,以及光解-氯碱氧化法对Fe(CN)63-模拟废水中总氰化物(TCN)的去除效果。实验结果表明:在初始Fe(CN)63-质量浓度6.7 mg/L、初始废水pH 12、反应时间8.0 h的条件下,Fe(CN)63-的去除率为83%,光解过程符合表观一级动力学模型;在初始Fe(CN)63-质量浓度6.7 mg/L、初始TCN质量浓度4.90 mg/L、初始废水pH 12、反应时间12.0 h的条件下,采用光解-氯碱氧化法可使Fe(CN)63-模拟废水的TCN质量浓度降至0.14 mg/L,低于GB 16171—2012的要求(0.2 mg/L),该过程的限速步骤为Fe(CN)63-的光解破络过程。

Fe（CN）63- was removed from the simulated wastewater by visible light photolysis-chloroalkali oxidation process. The effects of reaction time,initial Fe（CN）63- mass concentration and initial pH on Fe（CN）63- photolysis and the apparent reaction rate constant k（Fe（CN）63-） were studied,and the removal of TCN from the wastewater by the process were investigated. The experimental results show that：Under the conditions of initial Fe（CN）63- mass concentration 6.7 mg/L,initial wastewater pH 12 and reaction time 8.0 h,the Fe（CN）63- removal rate is 83%,and the process fits the apparent first-order kinetics model;When the initial Fe（CN）63- mass concentration is 6.7 mg/L,the initial TCN mass concentration is 4.90 mg/L,the initial wastewater pH is 12 and the reaction time is 12.0 h,the Fe（CN）63- simulated wastewater is treated by the process and the initial TCN mass concentration is decreased to 0.14 mg/L,which is lower than that of national standard GB 16171-2012（0.2 mg/L）. The rate limiting step of the process is the photolysis of Fe（CN）63-.