稀土高氟废水超低排放的技术策略研究与工程案例  

TECHNICAL STRATEGY AND AN ENGINEERING CASE ON ULTRA-LOW DISCHARGE OF HIGH FLUORIDE WASTEWATER RARE EARTH INDUSTRY

作　　者：朱利轩 王湘徽 辛少菲 豆小敏[1] 徐康宁[1] ZHU Lixuan;WANG Xianghui;XIN Shaofei;DOU Xiaomin;XU Kangning(College of Environmental Science and Engineering,Beijing Forestry University,Beijing 100083,China;Shanghai SUS Environment Co.,Ltd.,Shanghai 201703,China;State Grid Dongying Electric Power Supply Company,Dongying 257091,China)

机构地区：[1]北京林业大学环境科学与工程学院,北京100083 [2]上海康恒环境股份有限公司,上海201703 [3]国家电网东营供电公司,山东东营257091

出　　处：《环境工程》2024年第10期11-16,共6页Environmental Engineering

摘　　要：针对某稀土化工厂产生的碱性高氟废水氟超低排放的问题,研究了除氟技术方案及其条件优化,并提出了工艺方案和开展了工程设计。结果表明:氟化钙化学沉淀法更适合高氟废水的除氟,钙氟比的增加有助于化学沉淀除氟效果的提升,但是,过量的CaCl_(2)投加[c(Ca)∶c(F)>0.7]会导致污泥产量的急剧增加;而混凝沉淀更适合低氟废水(<20 mg/L)的进一步深度除氟,c(Al)∶c(F)为13.5且初始pH为6时,出水氟浓度可以稳定在约0.37 mg/L。并基于此提出了高氟废水超低排放工艺方案,开展了工程设计,利用企业产生的高钙酸性废水预处理碱性高氟废水后,再使用化学沉淀-混凝沉淀耦合工艺,可以使得出水氟浓度稳定达到<1.5 mg/L的排放标准。Aiming at the problem of ultra-low fluorine discharge from alkaline high-fluorine wastewater produced by a rare earth chemical plant,the technical scheme and condition optimization of fluorine removal was studied.The process scheme was proposed,and an engineering design was carried out.The results showed that the calcium fluoride chemical precipitation method was more suitable for removing fluoride from high-fluorine wastewater.The increase in the calcium-fluorine ratio helped improve the effect of chemical precipitation.However,excessive CaCl_(2)dosing(Ca∶F>0.7)would lead to a sharp increase in sludge production,while coagulation sedimentation was more suitable for further deep fluoride removal of low-fluorine wastewater(<20 mg F/L).When the molar ratio of aluminum to fluorine was 13.5,and the initial pH was 6,the fluorine concentration of the effluent could be stabilized at about 0.37 mg/L.The ultra-low discharge process plan for high-fluorine wastewater was proposed,and the engineering design was carried out.The high-calcium acid wastewater produced by the enterprise was used to pretreat the alkaline high-fluoride wastewater,and then the chemical precipitation-coagulation precipitation coupling process was used to stabilize the fluorine concentration of the effluent,to meet the limiting value of the emission standard of 1.5 mg/L below.

关 键 词：稀土化工 含氟废水 化学沉淀 混凝沉淀 

分 类 号：X75[环境科学与工程—环境工程]