Potential of valourized Moringa oleifera seed waste modified with activated carbon for toxic metals decontamination in conventional water treatment

Reducing the cost of adsorbents employed in contaminant removal during water treatment is vital to achieving sustainable clean water. Hence, two composites of commercial activated carbon (AC) and defatted Moringa oleifera (MS) seedcake biomass waste were prepared in ratio of 1:1 and 1:2, and named ACMS-1 and ACMS-2, respectively. Cursory adsorption experiments showed that the composites exhibited better average maximum sorption efficiencies of ≈135, 1990 and 169% for As(III), Cd(II) and Pb(II), respectively, than the pristine AC and MS. The adsorption rates of all contaminants on both composites were high within the initial 60 min of commencing the experiment with almost 50% of the total adsorption occurring. The composites were reusable and lost ≤25% of their initial adsorption capacity after the three cycles. The composites exhibited enhanced properties and better durability than several low-cost biomasses, cheaper than commercial AC, and easier to handle than raw biomass.