摘要：

采用两级氢氧化钠中和-硫酸亚铁沉淀法处理高浓度含砷废水,考察了废水pH、n(Fe):n(As)、曝气流量、曝气时间、搅拌速度等因素对As(Ⅲ)氧化率和总砷(As_T)去除率的影响。结果表明,在适宜的条件下,经一级处理后,废水中As(Ⅲ)的氧化率和As_T去除率分别为93.98%和78.60%;经二级处理后,废水中As_T去除率为99.99%,As_T残留质量浓度为0.10 mg/L,低于《污水综合排放标准》(GB 8978—1996)的要求。

关键词: 高砷废水, 沉淀, 氧化, 硫酸亚铁

Abstract:

The two-step sodium hydroxide neutralization-ferrous sulfate precipitation process has been used for treating high arsenic content wastewater. The influences of factors,such as pH,n(Fe):n(As),aeration flow,aeration time,stirring speed,etc.,on the oxidation rate of As(Ⅲ) and the removing rate of As_T are investigated. The results show that under optimum conditions,after the primary treatment,the oxidation rate of As(Ⅲ) is 93.98% and the removing rate of As_T 78.60%. After the secondary treatment,the removing rate of As_T is 99.99%,and the residual mass concentration of As_T 0.10 mg/L in wastewater,which is lower than the requirements specified in “Integrated Wastewater Discharge Standard”(GB 8978—1996).

Key words: high arsenic content wastewater, precipitation, oxidation, ferrous sulfate

中图分类号: 

• X703.1