臭氧氧化法连续处理焦化废水生化出水

Advanced treatment of coking wastewater by ozone oxidation under continuous operation

采用连续通入废水和臭氧的方式,利用臭氧氧化法深度处理焦化废水生化出水(COD为151~183 mg/L、pH约为8),并通过添加羟基自由基抑制剂叔丁醇探究了臭氧氧化的机理。在不调节废水pH、臭氧投加量12.15mg/L、废水流量2 mL/min的最佳条件下,COD去除率达54.5%,出水COD达到GB 16171—2012《炼焦化学工业污染物排放标准》。稳定运行时,降解1 kg COD需投加臭氧741.1 mg。臭氧氧化过程中,臭氧自身氧化和羟基自由基氧化同时存在,且以羟基自由基氧化为主。反应过程符合准一级动力学模型,反应速率常数为0.01 min^(-1)。

The biochemical effluent from coking wastewater with 151-183 mg/L of COD and about 8 of pH was treated by ozone oxidization process with continuous inflow of wastewater and ozone. And the mechanism of ozone oxidation was explored by adding tert-butanol as hydroxyl radical inhibitor. Under the optimum conditions of ozone amount 12.15 mg/L, wastewater flow 2 mL/min and without wastewater pH adjustment, the COD removal rate reached 54.5% and the effluent COD met the national wastewater discharge standard GB 16171-2012. When the system was stable, 741.1 mg ozone was needed to degrade 1 kg COD. During the ozone oxidation process, both ozone self-oxidation and free hydroxyl radical oxidation were existed, in which the latter one was the primary oxidation reaction. The reaction process accorded with pseudo first order kinetics model with 0.01 min^-1 of reaction rate constant.