This study assessed the effectiveness of calcium carbonate and clinoptilolite zeolite in removing copper ions from synthetic copper sulfate wastewater. Atomic absorption analysis was used to evaluate the performance of both adsorbents at a copper concentration of 300 mg/L at room temperature. The research focused on the impact of contact time and adsorbent dosage on the adsorption process. The results demonstrated that increasing the adsorbent dosage initially led to a significant rise in copper ion removal. However, the improvement in removal efficiency diminished beyond a dosage of 0.9 g/L. Under optimized conditions (0.3 g/L adsorbent dosage and 120 min contact time), calcium carbonate achieved a removal efficiency of 95.82%, while clinoptilolite reached 82.49%. Kinetic analysis revealed that the adsorption mechanism aligned with a pseudo-second-order model. This suggests that the rate-limiting step may involve valence forces or electron transfer between the metal ions and the adsorbent material. Brunauer-Emmett-Teller analysis revealed that the specific surface area of the clinoptilolite was 13.631 m2/g. The findings suggest that both calcium carbonate and clinoptilolite are effective and readily available adsorbents for removing copper ions from aqueous solutions, with calcium carbonate exhibiting a slightly higher removal efficiency under the tested conditions. Calcium carbonate and clinoptilolite offer the advantages of being low-cost and readily available, making them promising candidates for wastewater treatment.
