Hard water, caused by excessive concentrations of calcium and magnesium ions, leads to scaling, reduced efficiency of appliances, and health concerns. Conventional treatment methods such as ion exchange and chemical precipitation are often expensive and environmentally harmful. This paper explores eco-friendly alternatives using coconut shell–derived activated carbon and bentonite clay as sustainable adsorbents. These natural materials demonstrate significant adsorption capacity for hardness ions, offering low-cost, accessible, and environmentally benign water treatment solutions. The societal impact includes improved access to clean water, reduced environmental pollution, and economic benefits for rural communities.
Reddy et al. (Thu,) studied this question.