典型白炭黑工业园区废水的混凝沉淀试验研究

针对白炭黑产业园区废水污染成分较复杂的特性,选用氧化钙、氢氧化钙及聚合氯化铝作为混凝药剂,开展了不同加药量(0.1‰、0.2‰、0.4‰、0.6‰、0.8‰、1‰、2‰)的混凝试验,对废水中关键水质指标变化进行了重点分析,藉此全面展现此种废水混凝处理效果并获取最优适用药剂。试验结果表明:三种混凝药剂对于白炭黑废水混凝处理效果差异较大;总体上,混凝工艺对溶液COD、SO₄^2-处理效果较差,而对于表观浊度、活性硅、悬浮物SS及总磷TP有较好的去除效果;针对活性硅、SS及TP三项指标综合考量,可选取氢氧化钙为混凝药剂,药剂添加量为1‰,此条件下混凝试验后,活性硅、SS及TP的浓度分别为:10mg/L、30mg/L及0.12mg/L;氢氧化钙添加后将对溶液的pH产生影响,反应后需增加酸碱回调工序。此研究结果对于白炭黑废水混凝处理,尤其是活性硅的去除具有较好的生产实践指导意义。

Experimental Study on Coagulation and Sedimentation of Wastewater in Typical Silica Industrial Park

In view of the complex characteristics of the wastewater pollution components in the silica industrial park,this paper selects calcium oxide,calcium hydroxide and polyaluminum chloride as coagulation agents,and carries out different dosages(0.1‰,0.2‰,0.4‰,0.6‰,0.8‰,1‰,2‰)coagulation test.The key water quality indicator changes in the wastewater are analyzed,so as to fully demonstrate the coagulation treatment effect of this wastewater and obtain the best applicable chemicals.The test results show that the three coagulation agents have great differences in the coagulation treatment effect of silica wastewater;in general,the coagulation process has a poor treatment effect on the solution COD and SO₄^2-,while the apparent turbidity,active silicon,and suspension SS and total phosphorus TP have a good removal effect;for the comprehensive consideration of the three indicators of active silicon,SS and TP,calcium hydroxide can be selected as the coagulation agent,and the dosage of the agent is1‰.After the coagulation test under this condition,the concentration of active silicon,SS and TP are 10 mg/L,30 mg/L and 0.12 mg/L respectively;the addition of calcium hydroxide will affect the pH of the solution,and the acidbase callback process needs to be added after the reaction.This study has good practical guiding significance for the coagulation treatment of silica wastewater,especially the removal of active silicon.