Activated Green Tamarind Pulp (AGTP) as an efficient adsorbent for removal of Pb2+, Cu2+, Zn2+ & Ni2+ from contaminated water

Activated Green Tamarind Pulp (AGTP) was explored as a cost-effective, eco-friendly adsorbent to remove Pb2+, Cu2+, Zn2+, and Ni2+ ions from contaminated water. Given the environmental significance of heavy metal remediation, this study aimed to assess the efficacy of various AGTP formulations under diverse conditions affecting adsorption properties, including adsorbent dose, solution pH, shaking time, shaking speed, temperature, and particle size. The investigation encompassed a comprehensive evaluation of Pb2+, Cu2+, Zn2+, and Ni2+ adsorption on AGTP, considering different isotherms and kinetics. Additionally, we employed SEM, XRD, FTIR, and TGA to characterize AGTP before and after adsorption, providing a comprehensive understanding of its adsorption behavior. The experimental data revealed a fitting to the Langmuir isotherm for equilibrium adsorption and a pseudo-second-order model for the adsorption process. Thermodynamic parameters (ΔH°, ΔS°, ΔG°) indicated that AGTP-mediated adsorption of all these heavy metal ions was applicable, spontaneous, and endothermic. Under optimized conditions, AGTP demonstrated maximum elimination efficiencies of 98.14 %, 85.30 %, 94.98 %, and 93.05 % for Pb2+, Cu2+, Zn2+, and Ni2+ ions, respectively. This study underscores AGTP as a promising solution for environmentally conscious and efficient removal of heavy metal pollutants from water sources.