某企业高浓度碱减量废水预处理方案探讨与分析

摘要

Alkali decrementwastewater produced by printing and dyeing industries is difficult to treat because of its high COD and strong alkaline.In this paper, pretreatmentof alkali decrementwastewaterusingthe method of coagulation with calcium salts and acideduction were discussed.Various influencing factors such as selection of reagents, reaction temperature, reaction time, pHval-ue were discussed as well.The results indicated that the value of COD decreased 75%by coagulationat 18℃.The most economi-cal dosage ofCaCl2 is 6 g/Land flocculation pH is 10.When pH is 3,COD removal efficiencyreached 77% and terephthalic acid can be recycled with a purity of 92%by acid eduction.PAM was added in this procedure.Based on the business demand and the wastewater characteristics, coagulation method should be used in preference.%印染行业产生的碱减量废水因其高COD和强碱性等特点难以处理。本研究利用含有钙盐的改良型混凝沉淀法和酸析法分别对某企业碱减量废水进行处理，并对药剂的选择、反应温度、反应时间和反应pH进行了探讨。结果表明：18℃条件下，调节pH＝10，CaCl2最佳投加浓度6 g/L，混凝后废水COD降低75％；调节pH＝3，投加PAM进行酸析处理，COD去除率为77％，回收的TA纯度为92％。结合企业要求与废水特点，改良型混凝沉淀法为现阶段适宜的处理方案。