混凝法处理不锈钢电解抛光废水的试验研究

Experimental research on the coagulation treatment of electro-polishing wastewater of stainless steel

通过小试研究了混凝法预处理不锈钢电解抛光废水的处理效果。结果表明,投加PAC和Ca(OH)2都能达到较好的污染物去除效果,且废水中的TP随投加量的增加而下降。但当PAC和Ca(OH)2投加量达到4 g/L时,继续增加投加量TP下降不明显,因此采用单级混凝法很难实现较好的处理效果。分别采用PAC/PAC/Ca(OH)2和PAC/PAC/PAC三级混凝法处理电解抛光废水,结果表明,三级混凝法具有较好的处理效果,且PAC/PAC/PAC工艺优于PAC/PAC/Ca(OH)2工艺,其优化投加方案为8 g/L(一级)+5 g/L(二级)+2 g/L(三级)。

The treatment efficiency of stainless steel wastewater from electro-polishing has been studied by a series of laboratory-scale tests. The results indicate that adding either PAC or Ca （OH）2 can reach pretty good pollutant removing efficacy, and the TP in wastewater would decrease with the increase of the dosage of coagulant. However, when the dosage of PAC or Ca（OH）2 is above 4 g/L,the decrease of TP in wastewater is not obvious by adding coagu- lants sequentially. Therefore, it is difficult to achieve perfect treatment efficacy by one-stage coagulation. Therefore, PAC/PAC/Ca （OH）2 and PAC/PAC/PAC three-stage coagulation are used for treating electro-polishing wastewater, respectively. The results show that the three-stage method has good treatment capability. In addition, PAC/PAC/PAC process is superior to PAC/PAC/Ca （OH）2 process. The optimized adding project is 8 g/L（first stage）＋5 g/L （ second stage ） ＋2 g/L （third stage）.