Removal of heavy metals from drinking water through agri-food bioadsorbents

This research experiment explores the feasibility of employing agro-industrial residues, specifically pig hair and rice husk, as bioadsorbents for the removal of heavy metals from contaminated water. Controlled laboratory experiments, supported by spectroscopic analyses, were conducted to evaluate their effectiveness as a sustainable, low-cost, and environmentally responsible alternative to conventional treatment technologies. The research objectives are threefold: (i) to determine the bioadsorptive capacity of both materials against selected metal species; (ii) to identify optimal experimental conditions, including variations in pH, initial concentration, and contact time, and to characterise the mechanisms governing the adsorption processes; and (iii) to propose an approach based on low-cost, widely available resources with potential application in decentralised small-scale water treatment systems. The preliminary results obtained indicate that both agro-industrial residues exhibit a significant capacity to remove Cr⁶⁺ and Al³⁺ from aqueous solutions. In this regard, pig hair has demonstrated higher efficiency (85% compared to 65% in the case of rice husk). On the other hand, the main limitation lies in the exclusive use of synthetic water, which necessitates validation under real water matrices. Future applicability could materialise in modular, adaptable treatment solutions, particularly relevant for industries discharging metallic effluents and for rural communities with technological constraints.