聚硫酸铁铝制备改进及其处理重金属废水

Improvement of preparation of PFAS and its effect on treating heavy metal in wastewater

以亚铁盐和硫酸铝为原料,采用先氧化后水解聚合方式制备4种固体聚合硫酸铁铝(polyfer-ric-alum inum sulfate,PFAS).考察其表观状态、铁铝形态分布及其对重金属废水的处理效果,确定其优化制备方法及分子式.通过正交试验确定最适处理条件:PFAS和聚丙烯酰胺(polyacrylam ide,PAM)的投量分别为200 mg/L和2.0 mg/L.pH值是影响PFAS处理效果的主要因素,在最适pH值下,PFAS处理含Cu2+、N i2+和Cr(Ⅵ)的单一或混合废水时,对Cu2+和N i2+的去除率分别达到99.89%和99.72%,其残留质量浓度均达排放标准,Cu2+和N i2+的共沉淀有利于去除Cr(Ⅵ).

Taking FeSO4 and Al2（SO4）3 as the raw materials,we prepared four types of solid polyferric-aluminum sulfate（PFAS） by oxidation and hydrolytic polymerization.We studied the surface morphology,the distribution of Fe and Al species and its removal rate of heavy metal,so as to confirm the preparation of PFAS and its formula.In this preparation method,PFAS had the security,stability and efficient flocculating ability.Orthogonal experimental method was used to determine the optimal preparation conditions：the dosage of PFAS and polyacrylamide（PAM） were 200 mg/L and 2.0 mg/L,respectively.pH was the major influential factor of PFAS on treatment of heavy metals.In the treatment of the single and the mixed heavy metal wastewater（Cu2＋,Ni2＋ and Cr（Ⅵ）） under optimal pH values,the removal rates of Cu2＋ and Ni2＋ were 99.89% and 99.72%,respectively.The residual concentration could reach the effluent standard.The coprecipitation of Cu2＋ and Ni2＋ was in favor of the removal of Cr（Ⅵ）.