纳米零价铁对溶液中铅镉铬砷的去除性能研究

摘要

Nanoscale Zero-Valent Iron (NZVI) with average particle size of 40～80 nm,specific surface area of 19.713 4 m2/g,and better surface activity was synthesized in aqueous solutions by reduction of Fe2+ with KBH4.Experiment to remove Pb,Cr,Cd,and As in solution with initial concentration of 100 mg/L by NZVI under pH value of 2,7,12 respectively was carried out.The results show that removal efficiency of Pb,Cr and As is higher at pH=2 and pH=7,and removal rate is faster in the first 30 minutes.Removal efficiency of Cd is obvious at pH=12,and removal rate is faster in the first 40 minutes.Removal rate of ions under different pH conditions is different due to existence of ions.Removal of Pb,Cr,Cd,and As in solution with NVZI is not only efficient but also green without secondary pollution to environment.%通过液相还原法,采用KBH4还原Fe2+成功制备了平均粒径40～80 nm、比表面积19.713 4m2/g、有较好表面活性的纳米零价铁(NZVI),NZVI在含铅、砷、铬、镉初始浓度为100 mg/L的pH分别为2、7、12的溶液中进行去除试验.结果表明,在pH=2与pH=7的条件下NZVI对铅、砷、铬的去除效果较好,去除速率在前30 min较快;在pH=12条件下对镉的去除效果明显,去除速率在前40 min较快;不同pH条件下各离子的去除率差异较大,这主要与各离子在不同pH条件下的存在形态有关.NVZI去除溶液中的铅、砷、铬、镉,不仅效率高,而且绿色环保,不会对环境造成二次污染.