Effectiveness of Activated Bentonite as an Adsorbent for Zinc and Lead Ions

Heavy metal contamination in water resources cause a serious threat to environmental and health in urban area. Zinc and lead are the most common toxic heavy metals that do not break naturally and can cause long-term health problem to communities. Addressing these issues requires a low-cost, effective, and consistent solution for wastewater treatment. This study investigates the efficiency of bentonite clay—specifically raw and thermally activated forms—as an adsorbent for removing zinc (Zn²⁺) and lead (Pb²⁺) ions from aqueous solutions. Three types of bentonites were tested: raw (RB), activated at 300°C (AB300), and activated at 400°C (AB400). Adsorption experiments were conducted using a magnetic stirrer process, with 50 ppm of heavy metal solutions and bentonite doses ranging from 0.5 g to 1.1 g. Stirring durations were set at 30 and 60 minutes. Removal efficiency was determined using Inductively Coupled Plasma (ICP) analysis. The results showed that thermal activation significantly enhanced bentonite’s adsorption performance, particularly at 400°C. For lead removal at 60 minutes and 1.1 g dosage, activated bentonite at 400°C achieved a peak removal efficiency of 99.6%. Similarly, zinc removal reached 75.9% under the same conditions. These findings show the potential of using thermally activated bentonite as a sustainable and economically practical solution for industrial and municipal wastewater treatment. This approach offers strong commercialization chances due to its local availability, low processing cost and high effectiveness especially for regions seeking affordable water purification technologies aligned with environmental protection goals.