连续微滤分离膜和硫酸铝混凝除氟的研究

Study of fluoride ion removal by the combination of aluminum sulfate coagulation and continuous micro filtration membrane technology

天津经济技术开发区污水处理厂二级出水的氟离子质量浓度为1.8～3 mg/L,研究去除二级出水中氟离子对超标的地下水或其他高氟水的开发、利用具有重要意义,作者主要研究了硫酸铝混凝除氟工艺,并提出和探讨连续微滤膜分离技术(CMF)和铝盐混凝组合除氟的新工艺.CMF系统出水中氟离子质量浓度小于1 mg/L,系统出水的SDI值小于3,悬浮物质量浓度低于5 mg/L,浊度低于0.5 NTU,实验结果令人满意.

The fluoride ion concentration of treated secondary effluent in Tianjin Economic Technical Development Area Sewage Treatment Plant is 1.8 mg/L to 3 mg/L. The process of coagulation defluorination with alumin-um sulfate is discussed, and the pH is 6.5 ± 0.2 and the concentration of aluminum salt added is 25 mg/L(the ratio of aluminum sulfate dosing concentration and that of fluoride ion in the wastewater is 8.5). A new defluorination combination process of aluminum salt coagulation and continuous micro filtration (CMF) membrane separation technology is proposed and discussed, and the CMF system could reject the forming flocs in the aluminum sulfate coagulation efficiently. The concentration of fluoride ion in CMF effluent is below 1 mg/L, the SDI value is smaller than 3, the suspended solid concentration is below 5 mg/L, and the turbidity value is below 0.5 NTU, so the result is very satisfactory. It would be a model for exploitation and use of ground water and other water resources with high fluoride ion.