Synthesis, Characterisation, and Evaluation of Zeolite Materials for Cadmium (Cd²⁺) Sequestration in Water Treatment

Abstract

Cadmium (Cd²⁺) is a toxic heavy metal often found in industrial wastewater, creating significant hazards for water systems and human health. In this study, we synthesized zeolite materials from low-cost precursors using hydrothermal processing. We characterized the materials using XRD, SEM, and BET surface analysis (though FTIR offered limited structural data). The resulting zeolites showed distinct crystalline frameworks, higher surface area, and plenty of cation-exchange sites. In batch tests, we achieved cadmium removal rates over 90% by optimizing pH and contact time. The data fit best with the Langmuir isotherm and pseudo-second-order kinetic models, pointing to monolayer chemisorption as the primary mechanism. Additionally, regeneration tests showed the material held up well after several cycles. These findings suggest that synthesized zeolites are a viable, cost-effective option for capturing cadmium in water treatment.