6000t/a浆渣加工系统高浓废水的预处理工艺设计和应用OA

To treat the 3 600 m3/d of highly concentrated organic wastewater(chemical oxygen demand(CODCr)≈45 000 mg/L,suspended solids(SS)content≈21 000 mg/L)generated during the resource recovery process of 6 000 t/a pulping residue,this study designed and constructed a pretreatment process based on coagulation and clarification technology,which prior to discharging into the existing wastewater treatment system.Operational results indicated that,using a flocculant blend comprising polyaluminum chloride(PFC,Fe3+≥11%),polyacrylamide(PAM,mass fraction 0.1%),and clay emulsion(mass fraction from 1.5%to 1.7%),the pretreatment technology achieved a CODCr removal rate of≥75%for the high-concentration wastewater,with a SS content removal rate of≥95%.The effluent CODCr was≤918 mg/L and SS content was≤132 mg/L,meeting the influent requirements of the existing wastewater treatment system.Additionally,the biodegradability(BOD5/CODCr)of the effluent in the system improved by approximately 5%.It effectively resolved clogging issues in the subsequent wastewater treatment system,reduced chemical consumption in the shallow-bed flotation unit by 50%,and improved sludge dewatering efficiency.