Recycling Fe and improving organic pollutant removal via in situ forming magnetic core-shell Fe_(3)O_(4)@CaFe-LDH in Fe(Ⅱ)-catalyzed oxidative wastewater treatment  

作　　者：Ting He Jie Sun Liangwei Deng Jialin Ming Changwei Hu 

机构地区：[1]Key Laboratory of Green Chemistry and Technology,Ministry of Education,College of Chemistry,Sichuan University,Chengdu 610064,China [2]Biogas Institute of Ministry of Agriculture and Rural Affairs,Chengdu 610041,China [3]Inner Mongolia Key Laboratory of Fine Organic Synthesis,Inner Mongolia University,Hohhot 010021,China

出　　处：《Journal of Environmental Sciences》2025年第1期523-537,共15页环境科学学报(英文版)

基　　金：supported by the Chinese Agriculture Research System(No.CARS-35-06B);111 Project(No.B17030);the Sichuan Science and Technology Program(No.2021ZDZX0012).

摘　　要：Due to its high efficiency,Fe(Ⅱ)-based catalytic oxidation has been one of the most popular types of technology for treating growing organic pollutants.A lot of chemical Fe sludge alongwith various refractory pollutantswas concomitantly produced,whichmay cause secondary environmental problemswithout proper disposal.We here innovatively proposed an effective method of achieving zero Fe sludge,reusing Fe resources(Fe recovery=100%)and advancing organics removal(final TOC removal>70%)simultaneously,based on the in situ formation of magnetic Ca-Fe layered double hydroxide(Fe_(3)O_(4)@CaFe-LDH)nano-material.Cations(Ca^(2+)and Fe^(3+))concentration(≥30 mmol/L)and their molar ratio(Ca:Fe≥1.75)were crucial to the success of the method.Extrinsic nano Fe_(3)O_(4)was designed to be involved in the Fe(Ⅱ)-catalytic wastewater treatment process,and was modified by oxidation intermediates/products(especially those with COO-structure),which promoted the co-precipitation of Ca^(2+)(originated from Ca(OH)_(2)added after oxidation process)and byproduced Fe^(3+)cations on its surface to in situ generate core-shell Fe_(3)O_(4)@CaFe-LDH.The oxidation products were further removed during Fe_(3)O_(4)@CaFe-LDH material formation via intercalation and adsorption.Thismethodwas applicable to many kinds of organicwastewater,such as bisphenol A,methyl orange,humics,and biogas slurry.The prepared magnetic and hierarchical CaFe-LDH nanocomposite material showed comparable application performance to the recently reported CaFe-LDHs.This work provides a new strategy for efficiently enhancing the efficiency and economy of Fe(Ⅱ)-catalyzed oxidative wastewater treatment by producing high value-added LDHs materials.

关 键 词：CaFe layered double hydroxide Fe(Ⅱ)-catalytic oxidation Fe recycling Magnetic nanomaterial in situ formation Fe_(3)O_(4)modification 

分 类 号：X832[环境科学与工程—环境工程]