氧化-铁盐混凝沉淀法处理钨冶炼含砷废水的试验研究

Experimental Study on the Treatment of Arsenic-containing Waste Water in Tungsten Metallurgy by Iron Oxide-Coagulation Precipitation

钨冶炼生产实践中遇到的主要问题之一就是含砷废水的处理。研究采用氧化-铁盐混凝沉淀工艺处理赣南某钨冶炼废水。试验研究了氧化剂种类、氧化剂用量、铁盐种类、铁盐用量、p H值对砷去除效果的影响。结果表明:"双氧水+水合硫酸亚铁"除砷效果较好,当双氧水用量0.44 m L/L,氧化反应时间5~10 min,水合硫酸亚铁投入量1.48 g/L,混凝反应p H=9~10时,废水中砷的去除率达到99.0%,反应过后残留砷的浓度降至0.49 mg/L,达到《污水综合排放标准》(GB8978—1996)一级标准。

One of the main problems encountered in the practice of tungsten smelting production is the treatment of arsenic-containing wastewater.In this study,an oxide-iron salt coagulation and sedimentation process was used to treat a certain tungsten smelting wastewater in southern Jiangxi.The effects of the type of oxidant,the amount of oxidant,the type of iron salt,the amount of iron salt,and the pH on the removal of arsenic were investigated.The results show that"hydrogen peroxide+hydrated ferrous sulfate"has favorable arsenic removal effect.When the amount of hydrogen peroxide is 0.44 mL/L,the oxidation time 5~10 min,the hydrated ferrous sulfate input was 1.48 g/L,and the pH is 9~10,the removal rate of arsenic in the wastewater reaches 99.0%.After the reaction,the residual arsenic concentration is reduced to 0.49 mg/L,which meets the first-grade standard of Integrated Wastewater Discharge Standard(GB8978-1996).