不同来源生物炭对盐渍土吸附铜离子的影响  

Effects of biochar from different sources on the adsorption of Cu^(2+)in saline soil

作　　者：张娟香 李慧娟 李发永[1] 刘晓 胡雪菲[1] 钱晓燕 ZHANG Juanxiang;LI Huijuan;LI Fayong;LIU Xiao;HU Xuefei;QIAN Xiaoyan(College of Water Resources and Architectural Engineering,Tarim University,Aral,843300,China)

机构地区：[1]塔里木大学水利与建筑工程学院,阿拉尔843300

出　　处：《环境化学》2025年第2期617-627,共11页Environmental Chemistry

基　　金：国家兵团财政科技计划项目(2021DB019);国家自然科学基金(21767025);兵团科技人才计划项目(2022CB001-01);塔里木大学校长基金创新研究团队项目(TDZKCQ202002);塔里木大学校长基金硕士人才项目(TDZKSS202203)资助.

摘　　要：南疆典型农业废弃物和农田重金属污染问题日益凸显,同时盐渍化土壤中重金属离子的吸附迁移过程及相关影响因素尚不清楚.本文选择南疆特色农业废弃物(棉花秸秆)及养殖废弃物(猪粪)制备生物炭(CSBC和PSBC),通过批量平衡实验探究了盐渍土(Soil)及添加猪粪生物炭和棉花秸秆生物炭的盐渍土(Soil+PSBC及Soil+CSBC)对Cu^(2+)的吸附特征及吸附机制.结果表明,生物炭的施加提高了盐渍土对Cu^(2+)的吸附量,平衡吸附量的大小为Soil+CSBC(3.08 mg·g^(-1))>Soil+PSBC(3.05 mg·g^(-1))>Soil(2.95 mg·g^(-1)).动力学均符合准二级动力学模型,表明Soil、Soil+PSBC及Soil+CSBC对Cu^(2+)的吸附以化学吸附为主,颗粒内扩散方程表明颗粒内扩散不是唯一的控速过程.Langmuir方程能更合理地描述Cu^(2+)在上述3种土样中的吸附特性,说明吸附过程是多相表面的单分子层吸附.盐渍土中同时存在的Ca^(2+)、Mg^(2+)、K^(+)和Na^(+)离子不仅与Cu^(2+)竞争活性位点,还可削弱土样中的吸附点位与Cu^(2+)之间的静电作用,导致吸附量下降.结合吸附前后不同土样的FT-IR及XRD,施加CSBC、PSBC提高了盐渍土对Cu^(2+)的吸附,主要的作用机理有静电吸引、配体(酚羟基)/离子(H^(+))交换、阳离子-π键作用以及化学沉淀等作用.本研究不仅为南疆固体废弃物的治理提供了新思路,同时为南疆盐渍土重金属污染修复提供数据支撑.The increasing prominence of typical agricultural waste and heavy metal pollution in the farmlands of Southern Xinjiang,alongside the ambiguous understanding of the adsorption-migration process and associated factors of heavy metal ions in saline-alkali soils,call for comprehensive research.This paper focused on utilizing distinctive agricultural waste(cotton straw)and livestock waste(pig manure)from Southern Xinjiang to prepare cotton biochar(CSBC)and manure biochar(PSBC).Through batch equilibrium experiments,we explored the adsorption characteristics and mechanisms of Cu^(2+)in saline soil(Soil)and saline soil supplemented with pig manure biochar and cotton straw biochar(Soil+PSBC and Soil+CSBC).Results demonstrated that the application of biochar enhanced the adsorption capacity of saline soil for Cu^(2+).The equilibrium adsorption amounts were found to be in the order of Soil+CSBC(3.08 mg·g^(-1))>Soil+PSBC(3.05 mg·g^(-1))>Soil(2.95 mg·g^(-1)).The kinetics comply with the pseudo-second-order kinetic model,indicating that the adsorption of Cu^(2+)in Soil,Soil+PSBC,and Soil+CSBC predominantly involves chemical adsorption.The intraparticle diffusion equation suggested that intraparticle diffusion was not the sole rate-controlling step.The Langmuir equation more accurately described the adsorption characteristics of Cu^(2+)in the aforementioned soil samples,implying that the adsorption process occurred across multi-phase surfaces via monolayer adsorption.Concurrently present ions in saline soil,namely Ca^(2+),Mg^(2+),K^(+),and Na^(+),not only competed with Cu^(2+)for active sites but also attenuated the electrostatic interaction between adsorption sites in the soil and Cu^(2+),resulting in a reduction in adsorption amount.By correlating FT-IR and XRD of various soil samples before and after adsorption,the application of CSBC and PSBC enhanced the adsorption of Cu^(2+)in saline soil.The primary mechanisms involved electrostatic attraction,ligand(phenolic hydroxyl)/ion(H^(+))exchange,cation-πbonding,and chemical

关 键 词：盐渍土 生物炭 Cu^(2+) 吸附特性 吸附机理 

分 类 号：X-1[环境科学与工程] O6[理学—化学]