化学-混凝沉淀处理含氟含重金属废水研究

Study on treatment of wastewater containing fluoride and heavy metals by chemical coagulation process

为解决某铝材电镀工业园含氟含重金属废水达标排放的问题,研究了化学混凝沉淀法同时处理该废水中氟与金属的效果及影响因素,采用正交和单因素实验确定了最佳工艺条件。结果表明,当CaCl2投加量与废水中氟离子摩尔比为5∶1(即CaCl2质量4 782 mg/L),聚氯化铝(PAC)用量为500 mg/L,pH为9.5,聚丙烯酰胺(PAM)用量2 mg/L时,出水中残留F离子浓度可降至8 mg/L,Cu2+、Ni2+、Cr6+和Zn2+出水浓度分别降至0.05、0.07、0.3和0.1 mg/L,出水能达到《水污染物排放限值》(DB44/26-2001)第二时段一级标准,且最为经济。

In order to meet the discharge standard of wastewater from an aluminum electroplating factory,the performances and impact factors by using chemical coagulation process were studied for removing fluoride and heavy metals simultaneously.The orthogonal and single factor experiments were used to determine the optimal operation conditions.The results show that when the molar ratio of CaCl2 and fluoride is 5∶1（the dosage of CaCl2 is 4 782 mg/L）,the dosage of PAC is 500 mg/L and PAM is 2 mg/L,the pH value is adjusted to 9.5,the content of F-and Cu2＋,Ni2＋,Cr6＋,Zn2＋ in effluent can be reduced to 8,0.05,0.07,0.3 and 0.1 mg/L,respectively.The effluent can reach the first level criteria of the second period specified in water pollution discharge limits（DB44/26-2001）.