高校地质学报2024，Vol.30Issue(3)：297-311,15.DOI:10.16108/j.issn1006-7493.2024006
污染土壤中含锌矿物—溶液之间的同位素平衡分馏效应
Equilibrium Isotope Fractionation Effect between Zn-containing Minerals and Aqueous Solution in Contaminated Soils
摘要
Abstract
Zinc(Zn)isotope fractionation,resulting from multiple physicochemical processes under Earth's surface conditions,confounds the source identification of pollutants.The determination of Zn isotope fractionation factors between typical Zn-containing minerals and aqueous solutions in contaminated soils is crucial to trace Zn sources using isotopic tools.In this study,we used density functional theory based first principles calculations to investigate the most stable geometries of Zn-containing species,including hydrated Zn2+complexes,Zn in hydroxy-interlayered minerals(Zn-HIM),Zn-rich phyllosilicates(Talc),Zn-layered double hydroxide(Zn-LDH),and surface adsorbed Zn2+.Based on these optimized configurations,we calculated the equilibrium isotope fractionation factors between the aforementioned structures and Zn2+in aqueous phases.Our results showed that adsorbed Ⅵ Zn2+is slightly enriched in 64Zn(Δ66/64Zn=-0.29‰～-0.20‰),while adsorbed Ⅳ Zn2+is enriched in 66Zn(Δ66/64Zn=0.45 ‰～0.73‰).Secondary mineral phases are evidently enriched in 66Zn(Δ66/64Zn=0.51‰～1.1 1‰),if Zn transferred to stable crystalline precipitates.Using obtained fractionation factors,we successfully simulated the evolution trends of Zn isotope composition under the influence of single pollution sources(electroplating waste,sphalerite ore,emissions and metallurgical sludge)in equilibrium and Rayleigh fractionation modes.By comparing with available isotope data,these trends facilitate to find out the main source of Zn in contaminated soils.关键词
Zn迁移转化/密度泛函理论/第一性原理计算/次生矿物结晶/矿物表面吸附/污染源解析Key words
Zn migration and transformation/density functional theory/first principles calculation/secondary minerals precipitation/surface absorption,pollution source identification分类
资源环境引用本文复制引用
何洪涛,谷一帆,邢乐才,王艳芳,杨阳,蔡兴平,何雨旸..污染土壤中含锌矿物—溶液之间的同位素平衡分馏效应[J].高校地质学报,2024,30(3):297-311,15.基金项目
河北省自然科学基金(D2021402020 （）
D2020402004) （）
国家自然科学基金(42173041 （）
42373019) （）
中国科学院地质地球所重点部署项目资助(IGGCAS-202204)联合资助 （IGGCAS-202204）
