Adsorption performance and physicochemical mechanism of MnO_(2)-polyethylenimine-tannic acid composites for the removal of Cu(Ⅱ) and Cr(Ⅵ) from aqueous solution  

作　　者：Xiaoyan Deng Luxing Wang Qihui Xiu Ying Wang Hong Han Dongmei Dai Yongji Xu Hongtao Gao Xien Liu 

机构地区：[1]College of Environment and Safety Engineering,State Key Laboratory Base of Eco-Chemical Engineering,Qingdao University of Science&Technology,Qingdao 266042,China [2]College of Chemistry and Molecular Engineering,State Key Laboratory Base of Eco-Chemical Engineering,Qingdao University of Science&Technology,Qingdao 266042,China

出　　处：《Frontiers of Chemical Science and Engineering》2021年第3期538-551,共14页化学科学与工程前沿（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.41573103,41340037);the Shandong Provincial Key Research and Development Program(Grant Nos.2017GSF16105,2018GGX102004,2018GSF117007);the Taishan Scholar Program(Grant No.ts201712045)of Shandong Province of China.

摘　　要：In this work,an adsorbent,which we call MnPT,was prepared by combining MnO_(2),polyethylenimine and tannic acid,and exhibited efficient performance for Cu(Ⅱ) and Cr(VI) removal from aqueous solution.The oxygen/nitrogen-containing functional groups on the surface of MnPT might increase the enrichment of metal ions by complexation.The maximum adsorption capacities of MnPT for Cu(Ⅱ) and Cr(Ⅵ) were 121.5 and 790.2 mg·g^(-1),respectively.The surface complexation formation model was used to elucidate the physicochemical interplay in the process of Cu(Ⅱ) and Cr(Ⅵ) co-adsorption on MnPT.Electrostatic force,solvation action,adsorbate-adsorbate lateral interaction,and complexation were involved in the spontaneous adsorption process.Physical electrostatic action was dominant in the initial stage,whereas chemical action was the driving force leading to adsorption equilibrium.It should be noted that after adsorption on the surface of MnPT,Cr(Ⅵ) reacted with some reducing functional groups(hydroxylamine-NH_(2))and was converted into Cr(Ⅲ).The adsorption capacity declined by 12% after recycling five times.Understanding the adsorption mechanism might provide a technical basis for the procedural design of heavy metal adsorbents.This MnPT nanocomposite has been proven to be a low-cost,efficient,and promising adsorbent for removing heavy metal ions from wastewater.

关 键 词：MnO_(2)-polyethylenimine-tannic acid composite surface complexation formation model Cu(Ⅱ) Cr(Ⅵ) physicochemical mechanism 

分 类 号：O64[理学—物理化学]