摘要
通过批试验研究了天然菱锌矿(ZnCO_(3))在不同水环境中的溶解作用。结果表明:菱锌矿在纯净水、空气饱和水、CO_(2)饱和水、初始pH值分别为3和9的溶液中溶解时,Zn浓度随着溶解时间的增加逐渐升高,在2640 h(110 d)后达到溶解平衡或稳定状态,浓度分别为0.093~0.097 mmol/L、0.090~0.093 mmol/L、0.102~0.105 mmol/L、0.599和0.083 mmol/L;菱锌矿的溶度积(Ksp)为10-10.91±0.21~10-11.11±0.13,吉布斯生成自由能(ΔG_(f)^(o))在(-737.18±1.18)~(-738.30±0.74)kJ/mol。在地表水和地下水中溶解时,Zn浓度随着溶解时间的增加初始时呈上升趋势,随后逐渐下降,并且远低于在实验室配水中的浓度;溶解过程中方解石、文石、白云石和菱镁矿等的沉淀会抑制菱锌矿在天然水体中的溶解,降低水中Zn的浓度。
Natural smithsonite(ZnCO_(3))was used to investigate its dissolution in different waters at room temperature(±25℃)by batch experiment.The results showed that for the dissolutions of smithsonite in pure water,air-saturated pure water,CO2-saturated pure water,solution of initial pH 3 and solution of initial pH 9,the aqueous Zn concentrations increased with time and reached equilibrium or steady state after 2640 h with the values of 0.093-0.097 mmol/L,0.090-0.093 mmol/L,0.102-0.105 mmol/L,0.599 and 0.083 mmol/L,respectively.The solubility product(Ksp)and the Gibbs free energy of formation(ΔG_(f)^(o))for smithsonite were estimated to be 10-10.91±0.21-10-11.11±0.13 and(-737.18±1.18)-(738.30±0.74)kJ/mol,respectively.For dissolutions in natural surface and ground waters,the aqueous Zn concentrations increased at the early stage and then decreased with time,far below those in artificial waters.The possible precipitation of calcite,aragonite,dolomite and magnesite could inhibit the dissolution of smithsonite and so decreased the Zn concentration in water.
作者
杨洪渠
玄惠灵
魏彩春
朱宗强
莫南
张立浩
朱义年
YANG Hong-qu;XUAN Hui-ling;WEI Cai-chun;ZHU Zong-qiang;MO Nan;ZHANG Li-hao;ZHU Yi-nian(Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology,Guilin University of Technology,Guilin 541006,China;Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area,Guilin University of Technology,Guilin 541006,China;Ecological Environment Monitoring Station of Hechuan District,Chongqing 401519,China)
出处
《桂林理工大学学报》
CAS
北大核心
2022年第4期960-967,共8页
Journal of Guilin University of Technology
基金
国家自然科学基金项目(42063003,41763012)
广西自然科学基金项目(2018GXNSFAA050044)。
关键词
菱锌矿
溶解作用
溶度积
吉布斯生成自由能
smithsonite
dissolution mechanism
solubility product
Gibbs free energy of formation
