纳微米塑料的聚合铝铁强化混凝去除及铝残余特征  

Enhanced removal of micro-and nano-plastic and residual Al characteristics by using polymeric aluminium-ferric coagulant

作　　者：汪绮萱 田晨浩 冯成洪[1,3] WANG Qixuan;TIAN Chenhao;FENG Chenghong(State Key Laboratory of Water Environment Simulation,School of Environment,Beijing Normal University,Beijing 100875;State Key Laboratory of Environmental Aquatic Chemistry,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085;The Key Laboratory of Water and Sediment Sciences,Ministry of Education,School of Environment,Beijing Normal University,Beijing 100875)

机构地区：[1]北京师范大学环境学院,水环境模拟国家重点实验室,北京100875 [2]中国科学院生态环境研究中心,环境水质学国家重点实验,北京100085 [3]北京师范大学环境学院,水沙科学教育部重点实验室,北京100875

出　　处：《环境科学学报》2023年第12期259-267,I0006,共10页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.21677017,22206199);中国博士后科学基金面上项目(No.2022M723319)。

摘　　要：微纳塑料作为一种典型新污染物,广泛存在于水环境中,具有较强的生物毒性效应.混凝作为胶体和悬浮颗粒物去除的关键技术,主流铝铁絮凝剂对于微纳米塑料的去除效率相对较低,症结是对相关机制仍不明晰.为此,本研究通过预水解制备多种聚合铝铁絮凝剂,研究铁含量和预水解过程对微纳塑料去除效果的影响,解析微纳塑料絮体形成机制和混凝机理.结果表明,絮凝剂铁含量的增加对微米塑料的去除有促进作用,但对纳米塑料的去除有抑制作用.铝铁物质的量的比为9∶4的聚合絮凝剂对微纳塑料均具有较高的去除效率.微米塑料的去除以网捕卷扫为主,而纳米塑料的去除以电中和为主.预水解过程可以增强双金属絮凝剂对纳米塑料的吸附电中和能力,同时有效抑制铝残留.本研究从絮凝剂优化角度解析了微纳塑料的混凝去除机制,可为强化混凝高效去除微纳塑料同时控制铝残留提供参考.As emerging pollutants,micro-/nano-plastics(MPs/NPs)with bio-toxic effect have been widely distributed in aqueous environment.As a crucial technology to decontaminate colloids and suspended particles,the efficiency of MPs especially NPs removal by conventional aluminum and iron coagulants is relatively low due to the unclear removal mechanism.To enhance coagulation for MPs and NPs removal effectively,polyaluminium-ferric coagulants with varying Al/Fe ratios were prepared by pre-hydrolysis in this study to investigate the effect of Fe content and pre-hydrolysis process on MPs and NPs removal.This study aimed to elucidate the mechanisms of floc formation and the coagulation process.The results showed that the increase of Fe content in the coagulants enhanced the removal of MPs but inhibited that of NPs.Polymeric coagulants at an Al∶Fe ratio of 9∶4 performed better to remove both MPs and NPs.The main mechanism of MPs was sweeping flocculation while that of NPs was electrostatic neutralization.The prehydrolysis process could enhance the ability of the bimetallic coagulants to absorb and neutralize NPs and effectively inhibit Al residue.This work analyzed the coagulation removal mechanism of MPs and NPs from the perspective of coagulant optimization,which can provide a reference for both enhancing coagulation to efficiently remove MPs/NPs and controlling Al residue.

关 键 词：微/纳塑料 聚合铝铁絮凝剂 去除机制 铝残留 

分 类 号：X703[环境科学与工程—环境工程]