Study on Treatment of acidic and highly concentrated fluoride waste water using calcium oxide-calcium chloride

International Conference on Water Resource and Environment 2016

地球科学;生态环境科学

Ren, T.^1 ; Gao, X.R.^1 ; Zheng, T.^1 ; Wang, P.^1,2

School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin

150090, China^1

State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin

150090, China^2

关键词: Chemical precipitation;    Combined treatment;    Fluoride concentrations;    Optimal combination;    Polyacrylamide(PAM);    Polymeric aluminum chlorides;    Sludge characteristics;    Sludge volume index;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/39/1/012003/pdf
DOI  :  10.1088/1755-1315/39/1/012003

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

There are problems with treating acidic waste water containing high concentration fluorine by chemical precipitation, including the low sludge setting velocity and the high difficulty of reaching the criterion. In Heilongjiang province, a graphite factory producing high-purity graphite generates acidic waste water with a high concentration of fluorine. In this paper, the effect of removals on the concentration of fluoride with the combined treatment of calcium oxide and calcium chloride were discussed with regard to acid waste water. The study improved the sludge characteristics by using polyacrylamide (PAM) and polymeric aluminum chloride (PAC). The effect of different coagulants on sludge was evaluated by the sludge settlement ratio (SV), sludge volume index (SVI) and sludge moisture content. The results showed that the optimal combination for 100 ml waste water was calcium oxide addition amount of 14 g, a calcium chloride addition amount of 2.5 g, a PAM addition amount of 350 mg/L, and the effluent fluoride concentration was below 6 mg/L. PAM significantly improved the sludge settling velocity. The sludge settlement ratio reduced from 87.6% to 60%. The process for wastewater treatment was easily operated and involved low expenditure.