Removal of Aqueous Uranyl and Arsenate Mixtures by Natural Limestone and Hydroxyapatite Precipitates, Rio Paguate, NM, 2022-2023

This dataset documents a series of laboratory batch experiments investigating the removal of aqueous uranyl (U) and arsenate (As) mixtures using natural limestone and precipitated hydroxyapatite (HAp, Ca₁₀(PO₄)₆(OH)₂) as reactive materials. The main objective of the study was to address the challenge of simultaneous removal of uranyl cations and arsenate oxyanions by using mineral-based adsorbents, such as limestone. The precipitation of HAp enhanced As removal while maintaining high uranium immobilization efficiency.The archived data include measurements of aqueous U and As at trace-level concentrations under varying experimental conditions, including pH (ranging from 7 to 11), initial contaminant concentrations (0.05–1 mM), and the addition of calcium (Ca²⁺) and phosphate (PO₄³⁻) to promote HAp precipitation. Experiments were conducted in triplicate to ensure reproducibility, and solid-phase characterization data (from pXRD, SEM/EDX, and electron microprobe analysis) are also included to support the interpretation of removal mechanisms. A key finding revealed from the data is that near-complete removal of U (>97%) with As removal between 30 and 98% were achieved under pH conditions around 9. This dataset provides a comprehensive record of solution chemistry and treatment performance, serving as a fundamental resource for evaluating the effectiveness of natural mineral-based approaches for remediating co-contaminated waters.