Synthesis of zeolite from clays for the removal of arsenic from groundwater

Resumen

This study focuses on the synthesis of zeolites from Pucará clay for the removal of arsenic from groundwater in Chuñuhuayo, Moquegua, Peru. The raw material was initially characterized chemically and physically, determining its silicon dioxide (SiO₂) and aluminum oxide (Al₂O₃) content to predict the type of zeolite that could be obtained. The synthesis was performed via a hydrothermal process, varying temperature, activation time, and NaOH concentration as key factors. The zeolites were evaluated for their cation exchange capacity, with the highest value of 180 meq/100g achieved at 100°C, using 3M NaOH for 8 hours. Morphological and crystalline characterization confirmed the formation of analcime- and phillipsite-type zeolites. Subsequently, these zeolites were applied to groundwater containing 38.4 µg/L of arsenic, significantly exceeding the 10 µg/L limit established by the WHO. Adsorption tests in batch systems demonstrated an arsenic removal efficiency of 96.9% within 50 minutes of contact under magnetic stirring conditions. These findings underscore the potential of zeolites synthesized from local clays as low-cost, efficient materials for arsenic remediation in contaminated groundwater