This dataset contains barium concentration and stable isotope ratio measurements of the adsorbed and dissolved phases associated with batch laboratory adsorption-desorption reactions using common environmental mineral adsorbents (clay minerals: kaolinite & montmorillonite, iron-oxyhydroxides: goethite and ferrihydrite) and surface waters (river water, groundwater and seawater). The experiments systematically changed several variables (reaction duration, adsorbent concentration, water type and the pre-experiment adsorbent cleaning procedure). Barium concentration and stable isotope ratio measurements of the adsorbed and dissolved phases from two Himalayan rivers (Saptakoshi River and Sunkoshi River) are also provided.