Search

In this study, the new lanthanum sulfide nanoparticle (La 2 S 3) was synthesized and incorporated onto magnetic graphene oxide (MGO) sheets surface to produce potential adsorbent (MGO@LaS) for efficient removal of lead ions (Pb2+) from wastewater. The synthesized MGO@LaS adsorbent was characterized using Fourier transform infrared spectroscopy, field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. The effective parameters on the adsorption process including solution pH (~5), adsorbent dosage (20 mg), contact time (40 min), initial Pb2+ concentration and temperature were studied. The removal efficiency was obtained >95% for lead ions at pH 5 with 20 mg adsorbent. To validate the adsorption rate and mechanism, the kinetic and thermodynamic models were studied based on experimental data. The Langmuir isotherm model was best fitted to initial equilibrium concentration with a maximum adsorption capacity of 123.46 mg/g. This indicated a monolayer adsorption pattern for Pb2+ ions over MGO@LaS. The pseudo-second-order as the kinetic model was best fitted to describe the adsorption rate due to high R2 > 0.999 as compared first-order. A thermodynamic model suggested a chemisorption and physisorption adsorption mechanism for Pb2+ ions uptake into MGO@LaS at different temperatures; ΔG° < −5.99 kJ mol−1 at 20 °C and ΔG° −18.2 kJ mol−1 at 45 °C. The obtained results showed that the novel nanocomposite (MGO@LaS) can be used as an alternative adsorbent in wastewater treatment. • Lanthanum sulfide nanoparticles were synthesized and decorated on magnetic graphene oxide. • The MGO@LaS nanocomposite applied for removal of lead ions (Pb2+) from wastewater. • The isotherm model provided monolayer adsorption for lead ions with an adsorption capacity of 123.46 mg/g. [ABSTRACT FROM AUTHOR]

A novel adsorbent was developed based on nitrile functionalized calix [4]arene grafted onto magnetic graphene oxide (N-Calix-MGO) for remediation of arsenic (III) ions from aqueous media. The nanocomposite was characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The effective parameters on adsorption efficiency such as pH, adsorbent dosage, contact time, initial concentration, and temperature were studied. The adsorption process was provided with a high removal efficiency up to (90%) at pH 6 which followed by IUPAC Type II pattern. The mathematical models of kinetics and isotherm validated the experimental process. The adsorption kinetic is followed pseudo-first-order model with R2 > 0.9. The adsorption equilibrium was well fitted on the Freundlich model (R2 ∼ 0.96) as compared Langmuir model (R2 ∼ 0.75). Hence, the Freundlich model suggested a multilayer sorption pattern with a physisorption mechanism for arsenic (III) uptake ono developed nanocomposite with a sorption capacity of 67 mg/g for arsenic. The Gibbs free energy (ΔG° < −20 kJ/mol) showed As(III) uptake ono N-Calix-MGO nanocomposite was the physical adsorption mechanism. • A novel magnetic graphene oxide supported nitrile calix [4]arene was developed. • CN-Calix-MGO was used for removal of arsenic (III) ions from water samples. • The highest removal efficiency (90%) was obtained at pH 6. • A sorption capacity of 67 mg/g obtained with referring to Langmuier adsorption model. [ABSTRACT FROM AUTHOR]

• The heterogeneous nanocatalyst used for conversion of waste frying oil to biodiesel. • The biodiesel yield was 94% at a temperature of 60 °C in 90 min using nanocatalyst. • The binary functionality for nanocatalyst as Brønsted acid–base sites was obtained. • FAMEs yield decreased to 86% after four cycles. The magnetic graphene oxide (GO) supported with heterogeneous ternary mixed metal oxide (MMO) was used as nanocatalyst to enhance the conversion of waste frying oil (WFO) triglycerides to biodiesel via esterification process. In this regard, acidic MGO was modified with three basic metal cations of cerium, zirconium, and strontium oxides to produce heterogeneous MGO@MMO nanocatalyst. The nanocatalyst was characterized by FESEM, TEM, EDX and FTIR. The influence of different parameters such as catalyst material ratio, methanol to oil ratio, contact time, and reaction temperature was studied. Based on the results of effecting parameters, the MGO@MMO nanocatalyst converted WFO to biodiesel with a yield 94%, a reaction time of 90 min, methanol to oil ratio (8:1), and a temperature of 60 °C. Esterification mechanism indicated the MGO@MMO nanocatalyst having both binary Brønsted acid–base sites that increased the conversion yields as compared to MGO and MMO at low temperatures. [ABSTRACT FROM AUTHOR]

In this study, the MGO@SnO as a new nanocatalyst with diverse chemical/physical properties was generated by the combination of graphene oxide covered with magnetic iron oxide (MGO) and tin oxide (SnO(x)) nanoparticles used for biodiesel production from soybean oil. Before GC-FID analysis, the nanostructured MGO@SnO was successfully employed to transesterify soybean oil to FAMEs (biodiesel). The proposed material was characterized using Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometer (EDX), X-ray diffraction (XRD), and vibrating sample magnetometer (VSM). Given the acidic-alkaline nature of the proposed catalyst, it has a strong probability of creating carbocation ions to attack with methanol and subsequently converting the triglycerides to methyl ester (FAMEs). In further experiments, it was found that the ideal reaction parameters were a ratio of MGO to SnO of 1:0.5, a molar ratio of soybean oil to methanol (MeOH) of 1:10, a reaction period of 180 min, and a reaction temperature of 120 °C. Furthermore, the MGO@SnO catalyst demonstrated adequate catalytic performance (>88 %) for transforming the triglycerides of soybean oil to FAMEs (biodiesel) as compared to pure SnO NPs (74 %) and plain MGO (69 %) at similar conditions. [ABSTRACT FROM AUTHOR]

Waste cooking oil (WCO) is a potential and low-cost source for biodiesel production which has been used widely. In this study, novel nanocatalyst (GO@ZrO 2 –SrO) was synthesized via co-precipitation method by the combination of both potential graphene oxide and bimetal zirconium/strontium oxide nanoparticles. The proposed nanocomposite showed a promising ability as a heterogeneous catalyst for the transesterification of WCO to produce FAMEs as biodiesel. The FTIR, SEM/EDX and XRD were used for the characterization of nanocatalyst to evaluate the surface functional groups, nanostructure/elements and crystallinity, respectively. The effective parameters on the transesterification FAMEs yield including oil to alcohol ratio, reaction time, and reaction temperature were studied. Based on the results, the maximum FAMEs yield of 91% was obtained in the conditions of the material ratio of 1:0.5 (w/w) of GO:ZrO 2 –SrO, oil to methanol ratio (1:4), the reaction time of 90 min and the temperature of 120 °C. Therefore, this study showed that GO@ZrO 2 –SrO can be used as an alternative potential heterogeneous catalyst to produce biodiesel from WCO. • Biodiesel production from graphene oxide doped metal oxide nanoparticles catalyst. • The nanocatalyst was validated and characterized with FTIR, SEM/EDX and XRD. • The catalyst ability reduced after fourth run due to the loss of active sites. • The maximum biodiesel yield of 91% was obtained. [ABSTRACT FROM AUTHOR]

• Double-layered bimetal titanium-zirconium oxide nanoparticles incorporated magnetic graphene oxide. • The microreactor supported novel nanocomposite used for the transesterification of UCO to biodiesel. • The microreactor based nanocatalyst provided a conversion rate of 99.32% in 3 min. • The microreactor effectively assisted the transesterification reaction of UCO using heterogeneous nanocatalyst. The application of novel heterogeneous catalyst materials with unique physicochemical properties for the production of biodiesel can increase the sustainability of the process. In this study, a novel heterogeneous nanocatalyst (NCT) was developed and improved using a microreactor for biodiesel production from used cooking oil (UCO). The NCT was developed based on double-layered bimetal titanium-zirconium oxide nanoparticles (NPs) incorporated over magnetic graphene oxide (ZrO 2 -TiO 2 @MGO) using a simple hydrothermal method. The physiochemical morphology of newly developed NCT materials of ZrO 2 -TiO 2 NPs and ZrO 2 -TiO 2 @MGO was investigated using FESEM, FTIR, VSM, XRD, and EDX. The effects of several independent variables, including residence duration (60–180 s), oil/methanol molar ratio (1–3), and catalyst concentration (1–5 wt.%) on biodiesel production yield were optimized. The optimum reaction conditions in the microreactor-intensified transesterification process were the ZrO 2 -TiO 2 @MGO concentration of 4.75 wt.% (oil-based), reaction duration of 180 s, and oil/ methanol ratio of 2.33. The designed microreactor-assisted ZrO 2 -TiO 2 @MGO provided a conversion rate of 99.32%. Consequently, the results revealed that the microreactor effectively shortens the transesterification time while producing a high rate of biodiesel. [Display omitted] [ABSTRACT FROM AUTHOR]

This research used titanium oxide-coated magnetic Fe 3 O 4 nanoparticles doped graphene oxide (MTiGO) and modified with Candida antarctica Lipase B (CALB) enzyme. The MTiGO@CALB nanocomposite is a novel biocatalyst for transesterifying triglycerides to fatty acid methyl esters (FAMEs) from waste cooking oil. tThe physicochemical characteristics of the proposed biocatalyst were determined via FTIR, VSM, XRD, SEM, and EDS techniques. The maximum immobilization efficiencies and activity recovery of immobilized enzymes were obtained at 89% and 75% in the following operating condition: lipase concentration of 2.0 mg/mL, pH of 7.0, immobilization temperature of 35 °C, and immobilization time of 4 h. Various effective parameters on biodiesel were stated, and according to the revealed data, the maximum yield of biodiesel via the transesterification process was achieved at 92%, at a reaction temperature of 45 °C, catalyst quantity of 4 wt%, aa reaction duration of 40 h, and methanol to molar oil ratio of 5:1 These findings indicated that the provided bio-nanocomposite has a high potential for producing biodiesel as an efficient heterogeneous biocatalyst. • Candida Antarctica Lipase B (CALB) was immobilized on ternary oxide incorporated titanium oxide. • The maximum enzyme immobilization and activity recovery were obtained at 89% and 75%, respectively. • The biocatalyst (MTiGO@CALB) was applied to produce biodiesel from highly acidic WCO. • The maximum yield of biodiesel (FAMEs) was 92%, at a reaction temperature of 45 °C. [ABSTRACT FROM AUTHOR]

Pesticides are a large group of pristine organic contaminants, which are widely discharged into environmental water due to agricultural activities. Hence, extraction, determination, and removal of pesticides from water resources are necessary for human health. In this study, novel adsorbent was developed based on three-dimensional magnetic graphene coated with gold nanoparticles (3D-MG@AuNPs) for extraction of chlorpyrifos, dicrotophos, fenitrothion, and piperophos as four specific organophosphorus pesticides (OPPs) from wastewater and tap water samples. The proposed nanocomposite was characterized; FTIR and EDX are performed for the expected functional groups and elemental analysis, SEM showed the unique and spherical AuNPs are well dispersed over graphene sheets. In this investigation, the important parameters that have effect on the extraction efficiency, including the desorbing solvent, desorbing solvent volume, vortex time, the extraction time, adsorbent dosage, pH of sample solutions, and salt effect were evaluated. In conclusion, the measured amounts of the chosen OPPs were determined using the gas chromatography microelectron capture (μECD-GC) method. Limits of quantification (S/N ratio of 10) and detection (S/N ratio of 3) were attained at concentrations of 0.26–0.43 μg.L−1 and 0.08–0.14 μg.L−1, respectively. According to the results of the investigations, the synthesized 3D-MG@AuNPs did not require any complicated sample preparation methods; therefore, it is a very good choice for solid magnetic phase extraction studies. [Display omitted] • 3D-MG@AuNPs was used for removal of organophosphate pesticides. • The effecting parameters for removal of pesticides were evaluated. • With a high reusability, the nanoparticles worked after 25 times extraction. • The LOD (0.08–0.14 μg L−1) and LOQ (0.26–0.43 μg L−1) was achieved. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biomass conversion through phytoremediation process of tannery effluent. • Effective volarization of Azolla using nanocatalyst. • Transesterification for the production of biodiesel using Graphene oxide nanocatalyst. • Reliable and cost effective method of biodiesel production. A circular bioeconomy is concerned with environmental sustainability and waste valorization. Utilization of leftovers and trashes while elevating the value of biomass through the cascade is receiving greater attention in recent years. Biomass is expected to play a significant role in fixing global alternative fuel ambitions. Azolla, a type of macroalgae which grows very quickly, is employed to develop a self-sustaining Azolla biorefinery model. Tannery effluents are treated using the phytoremediation approach, and the algal oil extracted from the cultivated Azolla is employed to produce bio-diesel as an alternative energy source. Biodiesel is produced via the transesterification technique. N 2 sorption isotherms, scanning electron microscopy (SEM), FT-IR, and X-ray diffraction studies are used to evaluate the catalyst. The IR spectral analysis with the absorption bands corresponding to alkyl and ester stretching and bending modes of vibrations confirm biodiesel production. The reaction mechanism involved in the conversion process is proposed, and the process parameters such as the reaction temperature, oil-to-methanol molar ratio, and catalyst quantity are optimized. The results show that a catalyst loading of 2 % (by weight) and a molar ratio of 1:9 produce a high biodiesel yield with GO as the catalyst at temperatures between 60 and 65 °C. Its ability to catalyze allowed for numerous cycles of repetitive use. The results show that employing GO as a catalyst to trans esterify Azolla oil to biodiesel is cost-effective and reliable. [ABSTRACT FROM AUTHOR]

The current study presents a viable and straightforward method for synthesizing titanium lanthanum three oxide nanoparticles (TiLa) and their decoration onto the ferrous graphene oxide sheets to produce FeGO-TiLa as efficient magnetic adsorbent. Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and vibration sample magnetometer (VSM) were used to evaluate the physical and chemical properties of the produced nanocomposites. The FeGO-TiLa was used to enhance the removal of lead ions from aqueous solution. The FeGO-TiLa nanocomposite exhibited a much higher removal efficiency (93%) for lead ions than pure TiLa nanoparticles (81%) and magnetic graphene oxide (74%). The influence of FeGO-TiLa dosage, contact time, solution pH, solution temperature, and starting quantity on the lead ions was evaluated and adjusted. The investigations demonstrated that a pH 6 with 40 mg adsorbent resulted in >91% removal of lead ions at ambient temperature after 120 min. Isotherm models were used to analyze experimental results, and Langmuir model fitted the data well as compared Freundlich model with a maximum adsorption capacity of 109.89 mg g−1. Kinetic and studies are performed the lead adsorption over FeGO-TiLa follow pseudo-second-order rate. Langmuir and Free energy suggested the lead ions uptake with FeGO-TiLa was monolayer and physical adsorption mechnaism, respectively. Finally, the FeGO-TiLa nanocompoiste can be used as an alternative adsorbent for water remediation. [Display omitted] • Novel titanium lanthanum oxide nanoparticles doped iron graphene oxide was used. • The FeGO-TiLa as magnetic adsorbent was used to enhance the removal of lead from water. • The FeGO-TiLa had a higher removal (93%) for lead than pure LaTiO3 (81%). • Langmuir suggested the lead ions uptake with FeGO-TiLa was a monolayer. [ABSTRACT FROM AUTHOR]

The current study presents a viable and straightforward method for synthesizing titanium lanthanum three oxide nanoparticles (TiLa) and their decoration onto the ferrous graphene oxide sheets to produce FeGO-TiLa as efficient magnetic adsorbent. Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and vibration sample magnetometer (VSM) were used to evaluate the physical and chemical properties of the produced nanocomposites. The FeGO-TiLa was used to enhance the removal of lead ions from aqueous solution. The FeGO-TiLa nanocomposite exhibited a much higher removal efficiency (93%) for lead ions than pure TiLa nanoparticles (81%) and magnetic graphene oxide (74%). The influence of FeGO-TiLa dosage, contact time, solution pH, solution temperature, and starting quantity on the lead ions was evaluated and adjusted. The investigations demonstrated that a pH 6 with 40 mg adsorbent resulted in >91% removal of lead ions at ambient temperature after 120 min. Isotherm models were used to analyze experimental results, and Langmuir model fitted the data well as compared Freundlich model with a maximum adsorption capacity of 109.89 mg g−1. Kinetic and studies are performed the lead adsorption over FeGO-TiLa follow pseudo-second-order rate. Langmuir and Free energy suggested the lead ions uptake with FeGO-TiLa was monolayer and physical adsorption mechnaism, respectively. Finally, the FeGO-TiLa nanocompoiste can be used as an alternative adsorbent for water remediation. [Display omitted] • Novel titanium lanthanum oxide nanoparticles doped iron graphene oxide was used. • The FeGO-TiLa as magnetic adsorbent was used to enhance the removal of lead from water. • The FeGO-TiLa had a higher removal (93%) for lead than pure LaTiO3 (81%). • Langmuir suggested the lead ions uptake with FeGO-TiLa was a monolayer. [ABSTRACT FROM AUTHOR]

The present study developed and evaluated nano-adsorbents based on zirconium oxide and graphene oxide (ZrO 2 /GO) as a novel adsorbent for the efficient removal of ammonia from industrial effluents. Fourier transform infrared (FTIR) spectroscopy, Field Emission Scanning Electron Microscope, Energy-dispersive X-ray Spectroscopy, and X-ray diffraction were used to evaluate and identify the novel adsorbent in terms of morphology, crystallography, and chemical composition. The pH (7), adsorbent quantities (20 mg), adsorbent contact time (30 min) with the sample, and initial ammonia concentration were all tuned for ammonia uptake. To validate ammonia adsorption on the ZrO 2 /GO adsorbent, several kinetic models and adsorption isotherms were also utilized. The results showed that the kinetics of ammonia adsorption are of the pseudo-second order due to high R 2 (>0.99) value as compared first-order (R 2 = 0.52). The chemical behavior and equilibrium isotherm were analyzed using the isotherm models and Langmuir model provided high R 2 (>0.98) as compared Freundlich (>0.96). Hence, yielding a maximum uniform equilibrium adsorption capacity of 84.47 mg g−1. The presence of functional groups on the surface of graphene oxide and ZrO 2 nanoparticles, which interact efficiently with ammonia species and provide an efficient surface for good ammonia removal, is most likely to be responsible. • Zirconium oxide and graphene oxide (ZrO 2 /GO) were synthesized as nanocomposite. • The highest ammonia removal was of 90.11 mg/g using ZrO 2 /GO adsorbent. • A high regression coefficient of 0.998, was obtained by using quasi-second order. [ABSTRACT FROM AUTHOR]