“Removal of Heavy Metals from Drinking Water Using Low-Cost Adsorbents and Chemical Methods: A Comparative Environmental Chemistry Study”

Abstract

Heavy metal contamination in drinking water has become a major environmental and public health concern due to the toxic, persistent, and non-biodegradable nature of metals such as lead (Pb), cadmium (Cd), arsenic (As), and mercury (Hg).
Lead is known for its neurotoxic effects, particularly impairing cognitive development in children, while cadmium primarily affects renal function and causes bone demineralization. Arsenic, commonly found in groundwater, is a well-established carcinogen associated with skin, lung, and bladder cancers, whereas mercury, especially in its organic forms, severely damages the central nervous system and leads to neurological disorders.
The increasing presence of these metals in water resources is mainly attributed to industrial discharge, mining operations, agricultural activities, and improper waste disposal.
The present study focuses on the removal of these hazardous metals from drinking water through a comparative evaluation of low-cost adsorption techniques and conventional chemical treatment methods.
Low-cost adsorbents such as biochar, rice husk, activated carbon, and clay minerals have gained considerable attention due to their high surface area, porous structure, and the presence of functional groups capable of binding metal ions through mechanisms such as ion exchange and surface complexation.
On the other hand, chemical methods including precipitation, coagulation–flocculation, ion exchange, and redox processes offer rapid and effective removal, particularly in large-scale water treatment systems, although they are often associated with higher costs and secondary sludge generation.
Comparative analysis indicates that while chemical methods ensure faster removal efficiency, adsorption-based approaches provide a more sustainable, cost-effective, and environmentally friendly solution, especially for rural and resource-limited areas. Furthermore, the integration of both approaches offers a promising strategy for improving overall treatment performance.
This study highlights the need for developing efficient, affordable, and scalable technologies to ensure safe drinking water and reduce the adverse impacts of heavy metal contamination.