硫氧协同效应增强生物炭修复矿区铅污染土壤  

S-O synergistic effect enhanced the remediation of lead-contaminated soil by biochar in mining area

作　　者：赵莹莹[1] 顾高源 ZHAO Ying-ying;GU Gao-yuan(School of Chemistry and Materials Engineering,Bohai University,Jinzhou 121000,China)

机构地区：[1]渤海大学化学与材料工程学院,辽宁锦州121000

出　　处：《化学研究与应用》2025年第3期599-605,共7页Chemical Research and Application

摘　　要：采矿工业产生的铅锌伴生矿,所含的具有强神经和血液毒性的铅离子易通过渗滤液的形式进入周边农田中,进而威胁其生产力与食品安全。生物炭因含有丰富的含氧官能团,成为土壤重金属的热门修复剂。然而,具有硬碱性质的含氧官能团难以与具有交界酸性质的铅离子形成稳定的结合态,这为铅污染土壤的有效治理带来了挑战。本研究中,采用浸渍-热解法合成的Mn-S功能化咖啡渣生物炭(MSF)被一系列表征与DFT计算证实了可以通过硫离子(S^(2-))对半占据态费米子的消除效应提高吸附体系的稳定性。另一方面,巯基的参与使羟基吸附态铅离子的能隙(HOMO-LUMO gap)由1.33 eV提高到1.38 eV,这表明巯基、羟基与铅离子将通过协同效应构成具有更高稳定性的三元体系。此外,分子动力学(MD)模拟结果揭示了MSF对溶液中Pb(Ⅱ)的外扩散和表面扩散的促进作用,证实了MSF与土壤含水率在铅离子钝化中的协同作用。土壤模拟实验中,MSF驱使90.22%的铅离子转化为具有低环境风险的钝化态。在矿区污染农田中施加MSF 120天后,所种植的牛皮菜株高、鲜重和根长分别提高2.03,9.53和5.59倍,体现出其对Pb胁迫优异的缓解性能。综上所述,MSF不仅体现出优秀的矿区农田修复能力,离子硫和巯基硫对铅离子和羟基之间结合的调制作用可为铅离子高效钝化提供新的方案与策略。The lead-zinc associated ores produced by the mining industry contain lead ions with strong neurological and hematological toxicity that can easily enter the neighboring farmland in the form of leachate,which in turn threatens its productivity and food safety.Biochar is a popular remediation agent for heavy metals in soil due to its rich content of oxygen-containing functional groups.However,oxygen-containing functional groups with hard-base properties are difficult to form stable binding states with lead ions with borderline acid properties,which poses a challenge for the effective remediation of lead-contaminated soils.In this study,Mn-S functionalized coffee ground biochar(MSF)synthesized by impregnation-pyrolysis method was confirmed by a series of characterizations and DFT calculations to improve the stability of the adsorption system through the elimination effect of sulfur ions(S^(2-))on the semioccupied fermions.On the other hand,the participation of sulfhydryl groups increased the energy gap(HOMO-LUMO gap)of lead ions in the hydroxyl adsorption state from 1.33 eV to 1.38 eV,which suggests that sulfhydryl groups,hydroxyl groups,and lead ions will constitute a ternary system with higher stability through synergistic effects.In addition,the molecular dynamics(MD)simulation results revealed the promotion of MSF on the external and surface diffusion of Pb(Ⅱ)in solution,confirming the synergistic effect of MSF and soil water content in the passivation of lead ions.In soil simulation experiments,MSF drove 90.22%of lead ions to passivated states with low environmental risks.After 120 days of MSF application in the polluted farmland in the mining area,the plant height,fresh weight and root length of the planted kohlrabi increased by 2.03,9.53 and 5.59 times,respectively,which demonstrated its excellent mitigation performance against Pb stress.In conclusion,MSF not only demonstrated the excellent ability to remediate the farmland in the mining area,but also the modulation of the binding between Pb ions and hydro

关 键 词：生物炭 铅污染 土壤修复 桥联效应 

分 类 号：O614.4[理学—无机化学]