P-32 powdered activated carbon detoxifies potentially toxic elements in the Kumasi Abattoir Ghana effluent

Industrial activities, particularly from abattoirs without effluent treatment facilities, threaten ecosystems, releasing a spectrum of potentially toxic elements (PTEs) into the environment. With a defunct wastewater treatment plant (WTP), exploring a low-cost but efficacious and eco-friendly adsorbent for the Kumasi Abattoir Ghana (KAG) effluent treatment is warranted. The study is the first attempt to utilize activated carbon (AC), such as the P-32 Powdered AC (PAC) brand, to detoxify PTEs—Cadmium (Cd), Copper (Cu), Zinc (Zn), Iron (Fe), and Lead (Pb)—in Ghana’s abattoir effluent. The adsorbent was manufactured and supplied by the Climate/Environmental Research and Technology (CLERET) Laboratory, one of the Research and Development (R&D) departments of Explore Scientific Innovations (ESI) Ltd., Ghana, using palm nutshell wastes as precursor. The study systematically evaluated the efficiency and adsorption prowess using incremental masses of 0.5, 1.0, 1.5, 2.0, and 2.5 g of the adsorbent/100 ml effluent, with three replicates per experimental unit in one cycle application of the adsorbent. The PTE concentrations were determined using standard methods before and after applying the adsorbent. Three adsorption isotherm models Langmuir, Freundlich, and Elovich, were applied to investigate the adsorption mechanisms governing the PTEs. The model performance was evaluated using R2 and Root Mean Squared Error (RMSE) metrics. The findings unveiled varied percentage removal efficiencies (% Rs), with Zn exhibiting the highest (79.64 %) at 2.5 g and Cd the least (7.8 %) at 0.5 g, of the carbon. The Freundlich isotherm emerged as the most robust model, consistently exhibiting the highest coefficient of determination (R2) with the lowest RSME values. Fe and Cd had the highest and lowest adsorption capacity (Kf) of 0.181 and 0.001, respectively. The Freundlich exponent (nf) values were within the favorability range of 1–10. The PTE adsorptions were physical rather than chemical. P-32 PAC provided a promising avenue for abattoir effluent management.