广西某铅锌矿汛期废水中重金属铅、锌的应急处理技术研究

Study on Emergency Treatment of Heavy Metals Lead and Zinc in Flood Season Wastewater from a Lead-Zinc Mine in Guangxi

摘要: 本研究对广西某铅锌矿矿井涌水处理现状进行分析，针对其目前存在的药剂投加缺少定量化和自动控制的问题，开展了最佳沉淀条件试验、最佳混凝条件试验等，筛选出“混凝剂PFS + 氢氧化钙 + 絮凝剂PAM”的处理工艺作为企业汛期废水中重金属铅、锌的应急处理工艺；同时根据试验结果，最佳反应pH值控制在7.5~8，反应时间控制在1 h，按推荐的药剂用量投加药剂即可对设计的高、中、低浓度水质中的总铅、总锌同时去除，去除率在99%以上，出水满足企业内部管控指标要求(即总铅 ≤ 0.04 mg/L、总锌 ≤ 0.3 mg/L)。最终结合试验结果和现场条件提出了针对汛期废水中重金属铅、锌可能超标时的应急处理方案，包括药剂控制点和控制方式等，为企业落实矿井涌水铅、锌污染应急现场处置设施，加强环境风险管控提供了依据。

Abstract: This study analyzed the current situation of mine water treatment in a lead-zinc mine in Guangxi. In response to the existing problems of the lack of quantification and automatic control in the addition of chemicals, experiments on the best sedimentation conditions and the best coagulation conditions were carried out. The treatment process of “coagulant PFS + calcium hydroxide + flocculant PAM” was selected as the emergency treatment process for heavy metals lead and zinc in the enterprise’s flood season wastewater. At the same time, based on the experimental results, the optimal reaction pH was controlled at 7.5 to 8, and the reaction time was controlled at 1 hour. By adding chemicals according to the recommended dosage, the total lead and total zinc in the designed high, medium and low concentration water quality could be removed simultaneously, with a removal rate of over 99%, and the effluent met the internal control index requirements of the enterprise (i.e., total lead ≤ 0.04 mg/L, total zinc ≤ 0.3 mg/L). Finally, based on the experimental results and on-site conditions, an emergency treatment plan for heavy metals lead and zinc that may exceed the standard in flood season wastewater was proposed, including the control points and control methods of chemicals, providing a basis for the enterprise to implement on-site emergency treatment facilities for lead and zinc pollution in mine water and strengthen environmental risk control.