氢氧化铁胶体对砷吸附行为的初步研究

研究了pH值、铁与砷的量比和初始砷浓度等因素对用氢氧化铁胶体吸附去除砷的影响,确定了最佳吸附条件。研究结果表明,在初始As(Ⅴ)或As(Ⅲ)浓度为0.1mmol/L条件下,去除As(Ⅴ)的最佳pH值为4～8,去除As(Ⅲ)最佳pH值为6～9;在初始As(Ⅴ)浓度为0.5mmol/L条件下,去除As(Ⅴ)的最佳pH值为5～7,吸附后溶液中砷含量低于0.5mg/L,达到了《污水综合排放标准(GB8978-1996)》中工业废水最高容许排放总砷浓度一级标准。通过等温吸附试验的研究,得出了As(Ⅴ)和As(Ⅲ)的饱和吸附容量分别为0.4971mol/kg和0.3068mol/kg。

Preliminary study on the arsenic adsorption by ferric hydroxide colloid

Effects of the pH value,the iron/arsenic ratio,the initial concentration of arsenic,and some other factors on the arsenic adsorption by ferric hydroxide colloid were studied with optimal condition for As(Ⅴ)and As(Ⅲ)adsorption determined.The results of the study showed that:when the initial concentration of As(Ⅴ)or As(Ⅲ)was 0.1 mmol/L,the optimal pH value for As(Ⅴ)and As(Ⅲ)removal were 4-8 and 6-9 respectively;while,when the initial concentration of As(Ⅴ)was 0.5 mmol/L,the optimal pH value for As(Ⅴ)removal was 5-7,the mass concentration of arsenic in solution after the adsorption was lower than 0.5 mg/L,which met the maximum permissible concentration of total arsenic for industrial wastewater discharge according to Integrated wastewater discharge standard(GB8978-1996)Grade one.Through the study of the adsorption isotherms experiment,the adsorption capacity of As(Ⅴ)and As(Ⅲ)were calculated to be 0.497 1 mol/kg and 0.306 8 mol/kg respectively.