臭氧氧化法连续处理焦化废水生化出水

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)。

Advanced treatment of coking wastewater by ozone oxidation under continuous operation

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.