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Cadmium (Cd) and Lead (Pb) from industrial wastewater can bioaccumulate in the living organisms of water bodies, posing serious threats to human health. Therefore, efficient remediation of heavy metal ions of Cd (II) and Pb (II) in aqueous media is necessary for public health and environmental sustainability. In the present study, water stable Zirconium (Zr) based metal organic frameworks (MOFs) with SO 3 H functionalization were synthesized by solvothermal method and used first time for the adsorption of Cd (II) and Pb (II). Synthesis of UiO-66-SO 3 H, nano-sized (<100 nm) MOFs, was confirmed by FTIR, XRD, FESEM and BET. Effects of contact time, pH and temperature were investigated for adsorption of Cd (II) and Pb (II) onto SO 3 H-functionalized Zr-MOFs. The UiO-66-SO 3 H displayed notable rejections of 97% and 88% towards Cd (II) and Pb (II), respectively, after 160 min at 25 °C and pH (6) with an initial concentration of 1000 mg/L. Adsorption capacities of Cd (II) and Pb (II) were achieved as 194.9154 (mg/g) and 176.6879 (mg/g), respectively, at an initial concentration of 1000 mg/L. The Pseudo second-order kinetic model fitted well with linear regression (R 2 ) of value 1. The mechanism was confirmed mainly as a chemisorption and coordination interaction between sulfone group (-SO 3 H) and metal ions Cd (IIa) and Pb (II). These results may support effective adsorption and can be studied further to enrich and recycle other heavy metals from wastewater., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Environmental remediation of heavy metals from wastewater is becoming popular area in the field of membrane technology. Heavy metals are toxic in nature and have ability to bioaccumulate in water bodies. In current study, zirconium-based metal organic frameworks (MOFs), that is, UiO-66 and UiO-66-SO 3 H with a mean diameter of 200 nm were synthesized and intercalated into polyethersulfone (PES) substrate to fabricate thin-film nanocomposite (TFN) membranes via an interfacial polymerization (IP) method. TFN membranes exhibit higher selectivity and permeability as compared to thin-film composite (TFC) membranes for heavy metals, such as cadmium (Cd) and mercury (Hg). Zirconium-based MOFs are highly stable in water and due to smaller pore size enhanced hydrophilicity of TFN membranes. In addition, TFN membrane with functionalized MOF (UiO-66-SO 3 H) performed best as compared to TFC and TFN with UiO-66 MOF. The effect of loading of different weight percentages (wt%) of both MOFs for TFN membranes was also investigated. The TFN membranes with loading (0.2 wt%) of UiO-66-SO 3 H displayed highest permeability of 9.57 LMH/bar and notable rejections of 90% and 87.7% toward Cd and Hg, respectively. To our best understanding, it is the first study of intercalating functionalized UiO-66-SO 3 H in TFC membranes by IP and their application on heavy metals especially Cd and Hg., (© 2021 Wiley Periodicals LLC.)

The green macroalgae present in freshwater ecosystems have attracted a great attention of the world scientists for removal of heavy metals from wastewater. In this mesocosm study, the uptake rates of heavy metals such as cadmium (Cd), nickel (Ni), chromium (Cr), and lead (Pb) by Oedogonium westi (O. westti) were measured. The equilibrium adsorption capabilities of O. westti were different for Cd, Ni, Cr, and Pb (0.974, 0.418, 0.620, and 0.261 mgg(-1), respectively) at 18 °C and pH 5.0. Furthermore, the removal efficiencies for Cd, Cr, Ni and Pb were observed from 55-95%, 61-93%, 59-89%, and 61-96%, respectively. The highest removal efficiency was observed for Cd and Cr from aqueous solution at acidic pH and low initial metal concentrations. However, the removal efficiencies of Ni and Pb were higher at high pH and high concentrations of metals in aqueous solution. The results summarized that O. westti is a suitable candidate for removal of selected toxic heavy metals from the aqueous solutions.