酸性废水絮凝沉淀特性的试验研究

The experimental research on the characteristics of flocculating precipitation of acid washing wastewater

含有金属离子成分的酸性废水一般采用石灰乳中和法进行处理,但该方法处理后生成的沉淀密度较小,沉降效率较低,外排水水质变化较大。为了提高沉淀效率并降低外排水的悬浮颗粒物(SS)质量浓度,通过试验研究了酸性废水絮凝沉淀特性,进而确定高分子絮凝剂最佳的絮凝沉淀条件以及最佳投药量。试验结果表明:在1mg/L阳离子型高分子絮凝剂CPAM和pH=8.5的条件下,沉淀速度较快,1min内SS沉淀87.9%,SS质量浓度可以控制在40mg/L,符合悬浮物排放标准。

During the acid washing process of steel tube, it can produce much acid wastewater which contains metal ions. Generally, this kind of wastewater is treated by neutralization of lime. But after that, the gravity of formed flocs is smaller, the precipitation efficiency is lower, and the outlet water quality is poorer. It confirms the condition of the flocculating precipitation and optimum amount of high polymer offering medicine with the test of the beaker. The purpose is to improve the efficiency of precipitation and reduce the density of suspended particulate substance （SS）. The results show that： under the condition of lmg/L cation type high polymer floccutant CPAM and pH = 8.5, the precipitation rate is quicker and it can precipitate 87.9% in one minute. The density of SS can be controlled in 40mg/L, which reaches the discharge standard of SS.