核壳结构Fe^(0)@Fe_(3)O_(4)复合材料活化过硫酸盐降解土壤中菲  

Degradation of phenanthrene in soil by persulfate activated with Fe^(0)@Fe_(3)O_(4)core-shell composites

作　　者：廖用开 钟雅琪 沈悦 林姗娜 曹鸿健 蔡超[1,2] LIAO Yongkai;ZHONG Yaqi;SHEN Yue;LIN Shanna;CAO Hongjian;CAI Chao(State Key Laboratory of Urban Environment and Health,Institute of Urban Environment,Chinese Academy of Sciences,Xiamen 361021;University of Chinese Academy of Sciences,Beijing 100049)

机构地区：[1]中国科学院城市环境研究所城市环境与健康重点实验室,厦门361021 [2]中国科学院大学,北京100049

出　　处：《环境科学学报》2025年第2期239-249,共11页Acta Scientiae Circumstantiae

基　　金：国家重点研发计划项目(No.2023YFC3709700);福建省科技计划引导性项目(No.2022Y0073)。

摘　　要：纳米零价铁用作过硫酸盐(PS)活化剂具有反应活性高和环境友好等优点,但因高表面能衍生的易钝化问题极大限制了纳米零价铁在场地污染土壤修复中的实际应用.本研究采用“液相还原+共沉淀”两步法成功制备了核壳结构零价铁/四氧化三铁复合材料(Fe^(0)@Fe_(3)O_(4)),并用于活化过硫酸盐降解土壤中菲.结果表明,Fe^(0)@Fe_(3)O_(4)/PS体系处理60 min后,菲的降解率可达63.93%,显著高于Fe^(0)/PS(52.95%)、Fe_(3)O_(4)/PS(29.16%)、Fe^(2+)/PS(44.88%)体系的降解效率.在Fe^(0)@Fe_(3)O_(4)投加量为5%、PS浓度为126 mmol·L^(-1)、土水比为1∶2(m/V,g·L^(-1))的条件下对菲的降解效果最佳,降解率在60 min内可达68.80%.Fe^(0)@Fe_(3)O_(4)/PS体系在较广泛的pH范围(3~11)内均表现出一致的菲降解效能.电子顺磁共振(EPR)谱和自由基淬灭实验证实了Fe^(0)@Fe_(3)O_(4)/PS体系中同时存在SO_(4)^(·-)、HO^(·)、O_(2)^(·-),其中,SO_(4)^(·-)对菲的降解起主要作用.Fe^(0)@Fe_(3)O_(4)/PS体系修复的土壤电导率和溶解性有机碳含量明显升高,土壤pH、氧化还原电位及有机碳含量均显著降低,而土壤总氮和总磷含量无明显变化.此外,Fe^(0)@Fe_(3)O_(4)/PS体系修复的土壤中部分重金属的环境风险发生变化,重金属Co、Ni、Cu的DTPA提取态含量分别增加了8.50、1.40和1.30倍,Zn和Pb的DTPA浸提态含量分别下降了21.57%和71.94%,而As和Cd的DTPA提取态含量无显著变化.研究成果可为Fe^(0)@Fe_(3)O_(4)/PS体系在土壤修复中的推广应用及化学氧化技术发展提供科技支撑.Nano zero valent iron(nZVI)as a persulfate(PS)activator offers advantages of high activity and environmental friendliness.However,the high surface energy of nZVI leads to easily passivate,significantly limiting its practical application in soil remediation of contaminated sites.To address these challenges,a novel nano Fe^(0)@Fe_(3)O_(4)core-shell composite was prepared using a reduction-precipitation method for activating PS to degrade phenanthrene in soil.The results showed that the degradation rate of phenanthrene reached 63.93%after 60 min in the Fe^(0)@Fe_(3)O_(4)/PS system,surpassing those observed in the Fe^(0)/PS(52.95%),Fe_(3)O_(4)/PS(29.16%)and Fe^(2+)/PS(44.88%)systems.Using a 5%dosage of Fe^(0)@Fe_(3)O_(4),PS concentration of 126 mmol·L^(-1),and soil-water ratio of 1∶2,the Fe^(0)@Fe_(3)O_(4)/PS system exhibited superior phenanthrene removal efficiency at 68.80%.Furthermore,the Fe^(0)@Fe_(3)O_(4)/PS system performed consistently across a wide pH range,from 3 to 11.The results of free radical quenching experiments and EPR tests revealed coexistence of SO_(4)^(·-),HO^(·),and O_(2)^(·-)in the Fe^(0)@Fe_(3)O_(4)/PS system,and SO_(4)^(·-)played a significant role in the degradation of phenanthrene.After the treatment with the Fe^(0)@Fe_(3)O_(4)/PS system,the electrical conductivity and dissolved organic carbon content in soil increased significantly,while pH levels,oxidation-reduction potential,and organic carbon content in soil decreased drastically.The total nitrogen and total phosphorus content of soil did not change significantly.In addition,after remediation with the Fe^(0)@Fe_(3)O_(4)/PS system,the contents of DTPA extracted Co,Ni and Cu in soil increased by 8.50,1.40 and 1.30 times,respectively.The contents of DTPA extracted Zn and Pb decreased by 21.57%and 71.94%,respectively.However,the contents of DTPA extracted As and Cd did not remarkably change.This study provides technical support for promoting the application of Fe^(0)@Fe_(3)O_(4)/PS system in soil remediation and the development of che

关 键 词：Fe^(0)@Fe_(3)O_(4) 过硫酸盐 菲 土壤修复 硫酸根自由基 

分 类 号：X53[环境科学与工程—环境工程]