桂林理工大学学报2023，Vol.43Issue(4)：671-678,8.DOI:10.3969/j.issn.1674-9057.2023.04.017
铅离子对白云岩溶解作用的影响
Effect of lead ions on the dissolution of dolomite
摘要
Abstract
X-ray photoelectron spectroscopy(XPS),field emission scanning electron microscopy(SEM)com-bined energy dispersive spectrometer(EDS),X-ray diffraction(XRD)and hydrochemical detection methods were used to study the absorption of divalent Pb from natural dolomite powder and observe the influence of diva-lent Pb on dolomite dissolution.The adsorption of Pb on the surface of dolomite is obvious after 15 days of expo-sure in the divalent lead salt solution at the concentration of 1 and 50 mg/L,and the high concentration of Pb solution increases the adsorption amount of Pb on the surface.It is speculated that the Pb surface phase is main-ly PbCO3or solid solution of calcium and magnesium carbonate containing Pb.SEM+EDS results show that the surface topography of dolomite exposed to the divalent lead salt solution at the concentration of 50 mg/L shows curve dissolution step,and the etch pit is gone.Pb preferentially adsorbs in the dissolution step area.XPS re-sults show that Pb is absorbed by dolomite surface to form a new solid phase dominated by PbCO3.Through the phase analysis of the characteristic peak of single compound by XRD pattern,it is found that new PbCO3 and new CaCO3 are generated.The hydrochemistry results show that the total alkalinity and conductivity of the closed system containing Pb(1 mg/L)are lower than those of the system without Pb,and the pH difference is small,indicating that the divalent metal ion Pb inhibits the dissolution process of dolomite.Pb in the system with CO2 has little effect on pH,and Pb has more significant inhibition on dolomite dissolution.Due to the relatively small solubility product constant of PbCO3 in the system with CO2,Pb is adsorbed by dolomite on the surface active sites gradually,such as kink,etc.The surface active sites are occupied,which changes the dissolution mor-phology and prevents the further development of the dissolution morphology,leading to the inhibition of the dis-solution process on the surface of dolomite.关键词
Pb2+/白云岩溶解/表面形貌/溶解抑制/XPS/SEMKey words
divalent metal/dolomite dissolution/surface morphology/dissolution inhibition/XPS/SEM分类
资源环境引用本文复制引用
关天宇,李亮,刘瑞,吴秉津..铅离子对白云岩溶解作用的影响[J].桂林理工大学学报,2023,43(4):671-678,8.基金项目
国家自然科学基金项目(51979046) （51979046）
广西科技计划项目(桂科AD21075013) （桂科AD21075013）
广西高校中青年教师科研基础能力提升项目(2020KY06034) （2020KY06034）
