我国铅锌冶炼工业废水铊污染状况与处理技术

Thallium pollution status and treatment technology of wastewater from lead-zinc smelting industry in China

铊及其化合物毒性较高,含铊废水排入水环境易造成地表水水质异常。总结和分析了铅锌冶炼企业含铊废水来源、主要特征以及污染现状,讨论了各类含铊废水的处理技术,归纳了铅锌冶炼企业采用的废水除铊工艺。结果表明:铊及其化合物在铅锌矿高温冶炼过程中挥发进入烟气,在烟气酸洗过程中进入废水,烟气净化废水中总铊浓度较高,调研企业废水中总铊浓度平均值为0.76 mg/L;含铊废水处理技术包括氧化法、沉淀法、吸附法等,目前铅锌冶炼企业主要在原有废水治理工艺基础上进行改造,多采用硫化物沉淀、生物制剂沉淀、电絮凝法等沉淀法除铊。提出了强化源头污染预防、加强含铊废水排放管理、推进含铊废水处理技术研发等铅锌冶炼工业含铊废水污染防治对策。

Thallium and its compounds are highly toxic.The discharge of thallium containing wastewater into the water environment can easily cause abnormal surface water quality.The sources,main characteristics and pollution status of thallium-containing wastewater from some lead-zinc smelting enterprises were summarized and analyzed.Various treatment technologies for thallium-containing wastewater were discussed,and thallium removal processes adopted by lead-zinc smelting enterprises were summarized.The results showed that thallium and its compounds volatilized into the flue gas in the high-temperature smelting process of the lead-zinc smelter,and entered the wastewater in the process of acid pickling of flue gas.The total thallium concentration in the wastewater from flue gas purification was relatively high,and the average value of total thallium in the wastewater of investigation enterprises was 0.76 mg/L.The treatment technologies of thallium-containing wastewater included oxidation method,precipitation method and adsorption method,etc.At present,the lead-zinc smelting enterprises mainly carried out modifications based on the original wastewater treatment process,and mostly adopted sedimentation methods such as sulfide precipitation,biological agent precipitation and electric flocculation to remove thallium.Prevention and control countermeasures for thallium containing wastewater in the lead-zinc smelting industry were proposed,such as strengthening source pollution prevention,strengthening management of thallium-containing wastewater discharge and promoting the research and development of thallium-containing wastewater treatment technologies.