Document Type : Original Article
Authors
1
Expert of Khorasan Razavi Mininhouse
2
Mining Group of Samin Bayhaq Company, Mashhad, Iran
3
Department of Environmental Engineering, Civil Engineering Faculty, Babol Noshirvani University of
Abstract
The escalating issue of heavy metal contamination in industrial effluents, particularly from Iran's burgeoning petrochemical and metallurgical sectors, necessitates the development of cost-effective and sustainable remediation technologies. This study investigates the potential of natural and modified minerals sourced from significant Iranian deposits for the adsorptive removal of heavy metals from synthetic industrial wastewater. Clinoptilolite-rich zeolite from Semnan Province and vermiculite from Gilan Province were subjected to a novel blended modification, combining acid (H₂SO₄) and surfactant (CTAB) treatments to create a multi-functional adsorbent. The performance of these materials was evaluated for the removal of Cr(III), Cr(VI), Cu(II), Ni(II), Cd(II), Pb(II), and Zn(II) ions from an initial concentration of 10 mg/L for each metal. Batch adsorption experiments were conducted by varying key parameters, including adsorbent concentration (10 g/L), pH (4, 6, 8), and the ratio of natural to modified minerals. Characterization using XRD, FTIR, and BET analysis confirmed structural and surface chemical changes post-modification, leading to enhanced surface area and active site availability. Results demonstrated that modified vermiculite was exceptionally effective, achieving removal efficiencies exceeding 98% for Pb(II) and Cr(VI) under optimal conditions (pH 6, 60:40 a cost-effective 60:40 natural-to-modified mineral ratio). Modified zeolite also showed significant removal capabilities, particularly for Cu(II) and Zn(II). Kinetic studies indicated rapid initial adsorption, with equilibrium reached within 60-90 minutes for most metals. Multiple regression analysis yielded robust predictive models (R² > 0.97) for the tested parameter space, linking final pollutant concentrations to variables such as removal percentage and mineral adsorption capacity. This research highlights the immense potential of locally sourced, geochemically characterized Iranian minerals as a sustainable solution for industrial wastewater treatment, offering a practical pathway to mitigate environmental pollution and support circular-economy principles in the region, while acknowledging the need for further validation under more complex, competitive conditions.
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