预氧化-铁盐沉淀法处理高浓度含砷废水的试验研究

Experimental Study on the Treatment of High Concentration Arsenic Wastewater by Pre-oxidation and Ferric Salt Precipitation Method

对某砷化镓半导体企业生产过程中产生的高浓度含砷(As)废水,采用过氧化氢(H_(2)O_(2))预氧化结合氯化铁(FeCl_(3))沉淀法进行处理。研究确定了H_(2)O_(2)的投加量,并考察了Fe与As物质的量比、pH值和反应时间等试验条件对砷去除效果的影响。结果表明,当30%H_(2)O_(2)用量为1.5 mL/L,Fe与As物质的量比为2.5,pH值为8.0,反应时间为2 h时,废水中的总砷浓度可从884 mg/L降低至0.164 mg/L,达到项目环评要求的0.2 mg/L的排放标准。

The wastewater containing high concentration arsenic(As)produced in the production process of a gallium arsenide semiconductor enterprise is treated by hydrogen peroxide(H_(2)O_(2))pre-oxidation combined with ferric chloride(FeCl_(3))precipitation.The dosage of H_(2)O_(2) is determined,and the effects of experimental conditions such as n(Fe)/n(As),pH value and reaction time on arsenic removal are investigated.The results show that the dosage of 30%H_(2)O_(2) is 1.5 mL/L,the amount ratio of n(Fe)/n(As)is 2.5,the pH value is 8.0 and the reaction time is 2 h,the total arsenic concentration in the wastewater can be reduced from 884 mg/L to 0.164 mg/L,reaches the project environmental assessment requirement of 0.2 mg/L emission standards.