Industrial activities release large amounts of chromium into the environment, raising serious concerns about water safety and human health. Among its different forms, hexavalent chromium (Cr (VI)) is highly toxic and carcinogenic. This study explores the potential of untreated natural clay as a low-cost, environmentally friendly adsorbent for removing Cr (VI) from aqueous solutions. Batch adsorption experiments assessed the effects of contact time, initial concentration, temperature, pH, and agitation speed. The results demonstrated rapid adsorption, reaching equilibrium within 20 minutes. Adsorption efficiency increased in acidic conditions and at higher temperatures, indicating favorable and endothermic behavior. Isotherm analysis showed that the Freundlich model better describes the adsorption process, implying adsorption on a heterogeneous surface. These findings highlight the potential of untreated natural clay as an effective and sustainable material for water treatment, especially in regions lacking access to advanced purification technologies.
BOULEDROUA et al. (Wed,) studied this question.