DO对催化铁内电解预处理混合化工废水的影响

Influence of Dissolved Oxygen on Catalyzed Iron Internal Electrolysis Process for Mixed Chemical Wastewater Pretreatment

上海市西北某工业区排放的污水以化工和医药废水为主，其水量占排放总量的75％以上，属于典型的混合化工废水。目前该区的污水处理厂采用SBR工艺，但出水水质达不到有关的排放标准，尤其是色度超标严重。为此，开展了催化铁内电解法预处理该混合化工废水的生产性试验研究。结果表明，溶解氧浓度对预处理效果影响较大，在缺氧（DO〈0．5mg／L）条件下，对色度的去除效果较为明显，平均去除率可达42％，但对COD的平均去除率仅为14％左右；在高氧（DO=5．3～5．9mg／L）条件下，对COD的平均去除率可达44％左右，对色度的平均去除率为34％；在低氧（DO=0．9～1．4mg／L）条件下，对COD的平均去除率可达54．5％，对色度的平均去除率为43％，是比较理想的工况。

75% of the total amount of wastewater discharged from an industrial area in the northwest of Shanghai is chemical industrial and pharmaceutical wastewater, which is a typical mixed chemical industrial wastewater. Currently, SBR process is used in the wastewater treatment plant of this area and its effluent fails to meet the discharge standard, especially the color index standard. Therefore, the pilotscale experiment using catalyzed iron internal electrolysis for pretreatment of the mixed chemical industrial wastewater was carried out. The results show that dissolved oxygen has great influence on the pretreatment. Under the conditions that dissolved oxygen depletion is 〈 0.5 mg/L, the removal of the color level appears efficiently and averages 42%. However, only about 14% of COD is removed. At high dissolved oxygen （5.3 -5.9 mg/L） , the average removal efficiencies of COD and color are 44.0% and 34% respectively. At low dissolved oxygen （0.9 -1.4 mg/L） , the average removal efficiencies of COD and col- or are 54.5% and 43% , which is a more appropriate operation condition.