混凝法处理含铬废水的工艺条件研究

摘要

Using coagulation sedimentation process to treat chromium-containing wastewater, the influence of reductant dosage, pH value, and reaction time of the reduction on Cr6+ removal, as well as the effect of PAM dosage on coagulation, were investigated. The conditions of reduction and coagulation reaction were optimized through the test, and the research results were applied to treat actual chromium-containing electroplating wastewater. The results of the engineering operation showed that the optimal condition for Cr6+ reduction was as follows: the pH value was 2-3, the mass ratio of Cr6+ to reductant was 1 : 5, the reaction time was 20 min, the PAM dosage was 8 mg/L. After the treatment under the above condition, the mass concentration of total chromium in the effluent water was lower than 0.005 mg/L.%采用混凝沉淀工艺处理含铬废水,考察了还原反应pH值、还原剂投加量和反应时间对六价铬去除效果的影响,以及PAM投加量对混凝反应的影响,试验优化了还原反应和混凝反应条件,并将研究结果应用于实际含铬电镀废水处理。工程运行结果表明,六价铬还原反应的最佳条件为： pH值为2~3,六价铬与还原剂的质量比为1：5,反应时间为20 min；混凝剂PAM的最佳投加量为8 mg/L,出水中总铬的质量浓度低于0.005 mg/L。