Adsorption of Fe and Pb from Aqueous Solution using Coconut Shell Activated Carbon

The wastewater produced by numerous industrial processes has seriously contaminated the ecosystem. Due to its excellent adaptability and low cost, adsorption is a potential pollutant remediation technology. Different agricultural wastes were used for the adsorption procedure because of their loose and porous structures and included active groups like carboxyl and hydroxyl, which aid in the binding of pollutants. An alternative agricultural by-product that can remove heavy metals is coconut shell. The coconut shell was activated by carbonization for two hours at a temperature of 600°C, followed by impregnation with zinc chloride in a ratio of 1:2 (zinc chloride: adsorbent). The agitation speed, pH, starting concentration, adsorbent mass, and contact time varied throughout the optimization studies on removing Fe and Pb. According to the findings, the adsorption equilibrium of both heavy metals was reached after 240 minutes. Initial concentration, initial pH, and agitation speed were the three elements that contributed to heavy metal removal. The maximum adsorption was demonstrated at pH 7 for Fe and pH 11 for Pb, where the highest adsorption capacities were 9.67 and 10.04, respectively. The results show that the second-order model best expressed the kinetic data for heavy metals adsorption and adsorption. The isotherm data, with R2 values of 0.9981 for Fe and 0.9962 for Pb, demonstrated the compatibility of the Freundlich model with isotherm models. Using FTIR, the chemical properties of activated carbon changed both before and after the adsorption process, vanishing and forming a new peak.