Efficient Removal of Pb <sup>2+,</sup> Cu <sup>2+</sup> and Zn <sup>2+</sup> by Waste Tea‐Derived Cost‐Effective Bioadsorbent
Ummul Khair Fatma, Gulrez Nizami, Shakir Ahamad, Mohd Kamil Hussain
Abstract
Abstract This study examined the potential of waste tea as an adsorbent for the removal of Pb 2+ , Cu 2+, and Zn 2+ 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 °C), and particle size (300–710 μm), 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+, and Zn 2+ . 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 Pb 2+ , Cu 2+ , and Zn 2+ 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 Pb 2+ , 73.22 % of Cu 2+ , and 88.37 % of Zn 2+ ions from aqueous solutions.