预氧化-亚铁盐除砷工艺研究

Study on the Arsenic Removal Process by Pre-Oxidation Ferrous Salt

采用预氧化-亚铁盐除砷法,对模拟含砷废水亚砷酸钠溶液进行了除砷研究。以过氧化氢为氧化剂,将As(Ⅲ)氧化成As(Ⅴ),加入氯化亚铁生成砷酸铁。考察反应时间、溶液pH值、反应温度、铁砷物质的量之比对砷酸铁生成的影响。研究结果表明,当反应时间为2 h、反应温度为85℃、溶液pH值为4、铁砷物质的量之比为2.2时,氯化亚铁除砷效率最高,达99.85%。X-ray分析结果表明沉淀产物为砷酸铁,SEM分析结果表明沉淀为直径5μm左右砷酸铁。

research has been carried out on the arsenic removal from simulated arsenic containing wastewater by sodium arsenite solution with the pre-oxidation ferrous salt method adopted.Using hydrogen peroxide as its oxidant,an oxidization of As(Ⅲ)to As(Ⅴ)can be achieved,followed by the formation of iron arsenate with the addition of ferrous chloride.An investigation is to be conducted on the effects of reaction time,solution pH,reaction temperature and molar ratio of iron and arsenic on the formation of iron arsenate.The results show that the removal efficiency of arsenic by ferrous chloride reaches the highest point,i.e.99.85%,with the reaction time being 2 h,the reaction temperature being 85℃,the pH value of the solution being 4,and the molar ratio of iron to arsenic being 2.2.An X-ray analysis shows that the precipitation product is to be iron arsenate,and SEM analysis shows that the precipitation is to be ferric arsenate slag with a diameter of about 5 micron.