Thermodynamic and Kinetic Controls on Haidingerite Dissolution: Implications for Arsenic Mobilization

This dataset contains the experimental and derived data supporting the study “Thermodynamics, Kinetics, and Mechanisms of Haidingerite Dissolution.” The data were generated from dissolution experiments using phase-pure synthetic haidingerite (CaHAsO₄·H₂O) at 25, 35, and 50 °C. The dataset includes: (1) aqueous Ca and As concentration data from long-term dissolution experiments used to determine equilibrium solubility; (2) short-term dissolution data used to determine initial dissolution rates; (3) equilibrium concentrations, aqueous-species activities, and calculated solubility products (Ksp) at different temperatures; (4) temperature-dependent thermodynamic parameters derived from the solubility data; (5) kinetic data used for Arrhenius and Eyring analyses, including the calculation of apparent activation energy and apparent activation enthalpy; and (6) surface-area-normalized dissolution rates and corresponding Gibbs free energy changes (ΔG) used to evaluate the nonlinear rate–affinity relationship and Burch–Hellmann-type kinetic behavior. The results show that haidingerite solubility decreases with increasing temperature, with logKsp values of −4.54, −4.75, and −4.87 at 25, 35, and 50 °C, respectively. The dissolution kinetics exhibit relatively weak temperature dependence and a strongly nonlinear, sigmoidal relationship between dissolution rate and reaction affinity. These data provide quantitative constraints on the thermodynamic stability and dissolution kinetics of haidingerite, as well as on the influence of thermodynamic driving force on dissolution behavior, and provide a data basis for evaluating arsenic release from haidingerite in Ca-rich environments. The deposited files include consolidated numerical datasets together with the corresponding Origin project files used for data processing, fitting, and figure preparation. Variable definitions and units are provided in the accompanying data workbook.本数据集包含支撑《羟砷钙石（Haidingerite）溶解的热力学、动力学及反应机制》研究的实验与衍生数据。所用数据来自于25、35和50 ℃条件下，以纯相合成羟砷钙石（CaHAsO₄·H₂O）开展的溶解实验。 本数据集涵盖以下内容： (1) 用于测定平衡溶解度的长期溶解实验所得水相钙（Ca）与砷（As）浓度数据； (2) 用于确定初始溶解速率的短期溶解实验数据； (3) 不同温度下的平衡浓度、水相物种活度及计算得到的溶度积（Ksp）； (4) 由溶解度数据推导得到的温度依赖性热力学参数； (5) 用于阿伦尼乌斯（Arrhenius）与埃林（Eyring）分析的动力学数据，包括表观活化能与表观活化焓的计算； (6) 以比表面积归一化的溶解速率及对应的吉布斯自由能变化（ΔG），用于评估速率-亲和力非线性关系与Burch-Hellmann型动力学行为。 研究结果表明，羟砷钙石的溶解度随温度升高而降低，在25、35和50 ℃下的logKsp值分别为−4.54、−4.75和−4.87。其溶解动力学对温度的依赖性较弱，且溶解速率与反应亲和力之间呈现显著的非线性S型关系。 本数据集为羟砷钙石的热力学稳定性与溶解动力学，以及热力学驱动力对溶解行为的影响提供了定量约束，同时为评估富钙环境中羟砷钙石释砷过程提供了数据基础。 所提交的存档文件包含整合后的数值数据集，以及用于数据处理、拟合与图表绘制的Origin项目文件。配套的数据手册中提供了变量定义与单位说明。