镧离子辅助混凝沉淀去除水体中氟离子的研究  

La^(3+)-Assisted coagulation approach for fluoride removal from water

作　　者：刘雨秋 代林莉 张永奎[1] 刘小龙[2] 王雅博 LIU Yu-qiu;DAI Lin-li;ZHANG Yong-kui;LIU Xiao-long;WANG Ya-bo(School of Chemical Engineering,Sichuan University,Chengdu 610065,China;Science and Technology on Reactor Fuel and Materials Laboratory,Nuclear Power Institute of China,Chengdu 610213,China)

机构地区：[1]四川大学化学工程学院,四川成都610065 [2]中国核动力研究设计院反应堆燃料及材料重点实验室,四川成都610213

出　　处：《应用化工》2024年第1期1-5,共5页Applied Chemical Industry

基　　金：国家自然科学基金(21808147);四川大学“化工之星”优秀青年人才培养计划(2021);反应堆燃料及材料重点实验室基金(STRFML-2020-22)。

摘　　要：通过在含氟废水中投加可溶性镧盐,形成La-F胶体,再利用氯化铁-氧化钙-聚丙烯酰胺(PAM)混凝体系沉淀去除水体中的氟离子。利用较优的除氟工艺,即La^(3+)∶F-(摩尔比)=2∶3,pH=5,PAM∶F-(质量比)=5∶1,处理初始氟离子浓度为20~200 mg/L的含氟废水,可将出水氟离子浓度控制在1 mg/L以下。由于La^(3+)与F-之间较强的亲和作用,二者在水中可形成以LaF_(x)(OH)_(3-x)形式存在的胶体颗粒,后续加入的氯化铁和氧化钙破坏了胶体体系的稳定状态,并通过Fe^(3+)和PAM的凝聚-絮凝作用去除水体中的氟离子。该工艺的沉淀副产物可作为染料废水脱色用吸附剂,其对模拟污染物刚果红的吸附容量达337.8 mg/g,且大部分有效吸附发生在前3 min。Fluoride ions in water were effectively removed by adding soluble lanthanum salt to form La-F colloid and then using ferric chloride-calcium oxide-polyacrylamide(PAM)coagulation system.Under a certain reaction conditions,e.g.,La^(3+)∶F-(molar ratio)=2∶3,pH=5,PAM∶F-(mass ratio)=5∶1,F--containing wastewater with initial concentration of 20~200 mg/L could be well controlled to F-<1 mg/L.Due to the strong affinity between La^(3+)and F-,they could form colloidal particles in the form of LaF_(x)(OH)_(3-x)in water,and the subsequent addition of ferric chloride and calcium oxide destroyed the stable colloidal system.Through the coagulation effect brought by Fe^(3+)and PAM,fluoride ions in water were eventually removed.The as-formed precipitate by-product could be adopted as adsorbent for organic dye removal from water,which showed an adsorption capacity of 337.8 mg/g for model dye of Congo red.And most of the effective adsorption occurred in the first reaction stage of 3 min.

关 键 词：镧离子 含氟废水 胶体 混凝沉淀 

分 类 号：TQ124[化学工程—无机化工] X523[环境科学与工程—环境工程] X703