低浓度含氟废水的粉煤灰综合处理

摘要

处理低浓度含氟废水以达到排放要求,试验利用粉煤灰直接除去废水中的氟离子,分别考察了pH值、粉煤灰用量和处理时间对氟去除率的影响,获得了合适的工艺条件.但单独采用粉煤灰直接处理的结果达不到排放标准,另又做了如下复合改进:先用电石渣预处理,后配合使用A型混凝剂进一步处理.考察了不同电石渣用量、搅拌时间、不同A型混凝剂用量和混凝沉降时间对氟去除率的影响,得出了适宜的工艺条件能使含氟为70 mg/L的原始废水(原水)经两级除氟后,氟除去率达97%,达到了良好的效果.%This study was research on removal of low concentration fluoride from wastewater using fly ash.Fly ash dosage, pH and treatment time on removal of fluoride were investigated and the appropriate condition was achieved.Fly ash was modified by calcium carbide residue and A-coagulant.The effects of different carbide content, mixing time, A-coagulant dosage and the coagulation time on fluoride removal were examined, after twice treatments to 70 mg/L fluoride-containing wastewater,defluoridation rate was up to 97％ under the optimum condition.The effectiveness of the modified fly ash was satisfactory.