Activation strategy-driven performance of coconut shell-based activated carbon for arsenic decontamination

Arsenic contamination in groundwater poses a serious threat to human health, and this has necessitated the formulation of a sustainable solution to arsenic contamination. The scholars prepared coconut shell-derived activated carbons using three chemical activationer strategies which comprised of H3PO4, KOH, and ZnCl2 and then examined the materials to extract arsenate [As(V)] and arsenite [As(III)] out of water. KOH-activated carbon (AC-KOH) was one of the ready-prepared adsorbents and the one with the best physicochemical properties and adsorption capabilities. Under ideal testing conditions, the batch adsorption tests recorded a higher than 95% removal efficiency of As(V) and higher than 90% removal efficiency of As(III). The maximum adsorption capacity of AC-KOH reached 61.7 mg g^-1 through isotherm modeling, which showed that this method exceeded all other activation methods. The adsorption process followed a pseudo-second-order model, which demonstrated that the main interaction mechanism involved chemisorption. The regeneration tests demonstrated that the system maintained consistent operation results throughout several adsorption and desorption cycles. The tests showed that AC-KOH effectively removed arsenic from real groundwater samples to levels below the WHO guideline value of 10 µg L^-1, which demonstrates its potential as a sustainable adsorbent for laboratory-scale arsenic remediation.