Efficient Removal of Pb2+, Cu2+ and Zn2+ by Waste Tea-Derived Cost-Effective Bioadsorbent

This study examined the potential of waste tea as an adsorbent for the removal of Pb2+, Cu-2+,Cu- and Zn2+ ions from contaminated water. The study analyzed the effect of various factors, including adsorbent dose (1-6 g), NaOH concentration (0.5-1.5 %), pH (3-8), shaking time (1-4 h), shaking speed (220 rpm and 320 rpm), temperature (25-50 & DEG;C), and particle size (300-710 & mu;m), on the adsorption of ions on waste tea. The experiment's findings revealed that the removal of Pb+2 with a waste tea-derived adsorbent was more significant than that of Cu-2+,Cu- and Zn2+. Instrumental techniques such as FTIR, SEM, XRD, TGA, and ICPMS were used to characterize the adsorbent. Additionally, Langmuir, Freundlich, and Temkin isotherm models were employed to explain the equilibrium isotherm data of Pb2+, Cu2+, and Zn2+ ions. Furthermore, the adsorption kinetics data for these heavy metal ions were found to fit a pseudo-second-order model. The study found waste tea to be a low-cost, eco-friendly, and easily obtainable natural adsorbent for eliminating heavy metal ions from aqueous solutions. Additionally, the study showed that waste tea was effective in removing 98.43 % of Pb2+, 73.22 % of Cu2+, and 88.37 % of Zn2+ ions from aqueous solutions.