Morphologically controlled synthesis of MgFe-LDH using MgO and succinic acid for enhanced arsenic adsorption:Kinetics,equilibrium,and mechanism studies  

作　　者：Yusuf Olalekan Zubair Shigeshi Fuchida Keishi Oyama Chiharu Tokoro 

机构地区：[1]Graduate school of Creative Science and Engineering,Waseda University,Okubo 3-4-1,Shinjuku,Tokyo,169-8555,Japan [2]Department of Marine Resources and Energy,Tokyo University of Marine Science and Technology,4-5-7 Konan,Minato-Ku,Tokyo 108-8477,Japan [3]Faculty of Science and Engineering,Waseda University,3-4-1 Okubo,Shinjuku-ku,Tokyo 169-8555,Japan [4]Faculty of Engineering,The University of Tokyo,7-3-1 Hongo,Bunkyo-Ku,Tokyo 113-8656,Japan

出　　处：《Journal of Environmental Sciences》2025年第2期637-649,共13页环境科学学报(英文版)

摘　　要：In this study,we investigated improving the performance of a layered double hydroxide(LDH)for the adsorption of As(III)and As(V)by controlling the morphology of LDH crystals.The LDH was synthesized via a simple coprecipitation method using barely soluble MgO as a precursor and succinic acid(SA)as a morphological control agent.Doping the LDH crystals with carboxylate ions(RCOO−)derived from SA caused the crystals to develop in a radial direction.This changed the pore characteristics and increased the density of active surface sites.Subsequently,SA/MgFe-LDH showed excellent affinity for As(III)and As(V)with maximum sorption densities of 2.42 and 1.60 mmol/g,respectively.By comparison,the pristine MgFe-LDH had sorption capacities of 1.56 and 1.31 mmol/g for As(III)and As(V),respectively.The LDH was effective over a wide pH range for As(III)adsorption(pH 3-8.5)and As(V)adsorption(pH 3-6.5).Using a combination of spectroscopy and sorption modeling calculations,the main sorption mechanism of As(III)and As(V)on SA/MgFe-LDH was identified as inner-sphere complexation via ligand exchangewith hydroxyl group(-OH)and RCOO−.Specifically,bidentate As-Fe complexeswere proposed for both As(III)and As(V)uptake,with the magnitude of formation varying with the initial As concentration.Importantly,the As-laden adsorbent had satisfactory stability in simulated real landfill leachate.These findings demonstrate that SA/MgFe-LDH exhibits considerable potential for remediation of As-contaminated water.

关 键 词：ARSENIC Heavy magnesium oxide Succinic acid Layered double hydroxide Adsorption Bidentate complex STABILIZATION 

分 类 号：X52[环境科学与工程—环境工程]