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The current study focuses on the synthesis of Cerium oxide (CeO2) nanocatalyst via Tragacanth Gum (TG) using the wet impregnation method and its application for sustainable biodiesel production from a novel, non-edible Descurainia sophia (L.) Webb ex Prantl seed oil. The D. sophia seed oil has higher oil content (36 wt%) and free fatty acid (FFA) value (0.6 mg KOH/g). Innovative analytical methods, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy, were used to characterize the newly synthesized, environmentally friendly, and recyclable CeO2-TG phytonanocatalyst (FT-IR). The results show that the CeO2-TG phytonanocatalyst was 22 nm in diameter with a spherical shape outer morphology, while the inner structure was hexagonal. Due to low FFA content, the D. sophia seed oil was pretreated and transesterified via a single step. Using varying parameters, the optimized process variables were determined via Response Surface Methodology (RSM). The optimum process values were 8:1 methanol to oil molar ratio, 0.3 wt% catalyst concentration, 90 °C temperature, and reaction time of 210 min with 98% biodiesel yield. The recently created phytonanocatalyst was reliable and effective, with three times reusability in the transesterification reaction. Thin layer chromatography (TLC), FT-IR, gas chromatography–mass spectroscopy (GCMS), and Nuclear magnetic resonance (NMR) analyses were used to characterize the synthesized biodiesel. Physico-chemical properties of D. sophia biodiesel, i.e., Kinematic viscosity (4.23 mm2/s), density (0.800 kg/m3), pour point (−7 °C), cloud point (−12 °C), and flash point (73.5 °C) agree well with international biodiesel standards (ASTM-6751, 951), (EU-14214), and China (GB/T 20828) standards. The results show that the synthesized nanocatalyst demonstrated remarkable stability, indicating a bright future for industrial biodiesel production from low-cost feedstock. [ABSTRACT FROM AUTHOR]

Highlights: Brassica juncea (L.) Czern. seeds contain 30% oil content and 0.43 mg KOH/g FFA content. Ni-TG nano-catalyst was synthesized through a wet impregnation route. The Ni-TG nano-catalyst has a crystalline size of 39.29 nm with a semispherical and ovoid shape. 0.3 wt% catalyst concentration, 6:1 methanol to oil ratio at 90 °C for 120 min yielded 93% of Brassica juncea (L.) Czern. biodiesel. In the current study, a novel green nano-catalyst from Tragacanth gum (TG) was synthesized and used for sustainable biodiesel production from Brassica juncea (L.) Czern. seed oil. Brassica juncea (L.) Czern contains 30% oil on dry basis and free fatty acid content of 0.43 mg KOH/g. Physiochemical characterization of a newly synthesized nano-catalyst was performed by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), Transmission Electron Microscopy (TEM), and Fourier Transform Infrared Spectroscopy (FT-IR) analysis. The XRD results showed an average crystalline size of 39.29 nm. TEM analysis showed the cluster form of NiSO4 nanoparticles with a size range from 30–50.5 nm. SEM analysis of the catalyst showed semispherical and ovoid shapes with surface agglomeration. The synthesized catalyst was recovered and re-used in four repeated transesterification cycles. Maximum biodiesel yield (93%) was accomplished at 6:1 methanol to oil molar ratio, catalyst concentration of 0.3 wt%, at 90 °C for 120 min at 600 rpm using Response Surface Methodology (RSM) coupled with central composite design (CCD). Brassica juncea (L.) Czern. biodiesel was characterized by Thin Layer Chromatography (TLC), FT-IR, Nuclear Magnetic Resonance (NMR) (1H, 13C), and Gas Chromatography-Mass Spectroscopy (GCMS) analytical techniques. The major fatty acid methyl esters were 16-Octadecenoic acid and 9-Octadecenoic acid methyl ester. The fuel properties, i.e., flash point (97 °C), density (825 kg/m3 at 40 °C), kinematic viscosity (4.66 mm2/s), pour point (–10 °C), cloud point (–14 °C), sulfur content (66 wt.%), and total acid number (182 mg KOH/g) were according to the International biodiesel standards. The reaction kinetic parameters were determined, and all the reactions followed Pseudo first-order kinetics. It was concluded that non-edible Brassica juncea (L.) Czern. seed oil is one of the sustainable candidates for the future biofuel industry using a cleaner, reusable, and highly active Ni-modified TG nano-catalyst. [ABSTRACT FROM AUTHOR]

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‐SO3H 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‐SO3H) 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‐SO3H 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‐SO3H in TFC membranes by IP and their application on heavy metals especially Cd and Hg. [ABSTRACT FROM AUTHOR]

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) byOedogonium westi(O. westti) were measured. The equilibrium adsorption capabilities ofO. westtiwere 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. [ABSTRACT FROM PUBLISHER]

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.)