This study examined the potential of waste tea as an adsorbent for the removal of Pb2+, Cu2+, 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 °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 Cu2+, 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.

The present study was aimed to analyze the influence of industrial and agricultural wastes on quality ofKosi river water, Rampur, UP, India. The results of the present study revealed pH values of between 7.2 and 6.3 (neutral to slightly acidic), the electrical conductivity between 129.4 μs/cmto399.3 μs/cm. The maximum EC value was observed at S5 in spring season. The turbidity of each was 0.4 to 7.067 NTU. The highest turbidity observed at S5 in winters. Total hardness of 73 (mg/L) and 506.33 (mg/L) were evident at S4 and S7 sites respectively. The BOD values ranged from 10.5 (mg/L) at S4 to 137.4 (mg/L) at S5. Higher BOD values at each site are reflecting the great extent of pollution. The minimum COD recorded at S3 (32.60 mg/L) however maximum recorded at S5 (168.65 mg/L). The results of the heavy metals showed a significant increase in the concentration of Pb, Zn, Cu, Hg and As at S5 as compared to the other sites. The As concentration was 0.04, 0.08, 0.85, 0.72 and 0.71 at S2, S3, S5, S6, and S7 respectively. These values were higher than the value of Arsenic as per WHO guidelines.The average concentration of Zn obtained was 0.05, 0.786, 0.413, 0.06, 3.26,0.97 and 0.53 mg/L at S1, S2, S3, S4, S5, S6, and S7 respectively. The highest value of Zn was recorded at S5 (SDP) as compared to other sites. Only at S5 the zinc content is exceeding the normal value. The copper content found to be lower (1.0 mg/Ll) than permissible value according to WHO. The Cu concentration was 0.01, 0.06 0.01 at S4, S5 and S6 respectively, at S1,S2, S3 and S7 zero. The changed physicochemical parameters and occurrence of heavy metal ions indicated a significant level of pollution in Kosi River.

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