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In-depth explorations into spinels have produced noteworthy findings in the realm of research, owing to remarkable advancements across various applications, including photocatalysis, dye degradation, sensors, and batteries. Presently, extensive research is centered on the photocatalytic capabilities of spinel. In the realm of wastewater decontamination, the efficacy of MFe 2 O 4 spinel ferrites and their binary nanocomposites as cost-effective, stable, and biocompatible photocatalysts. Leveraging the exceptional magnetic properties of MFe 2 O 4 , facile catalyst separation is ensured. This review has prominence on enforcing spinel-based nanomaterials in wastewater treatment, environmental remediation, and hydrogen generation. The chemical, physical, size, and shape-dependent properties are highlighted to improve the photocatalytic performance of the spinels. This article has comprehensively discussed the emphasis on different types of spinel-based materials with organic pollutants. These materials are critical in photocatalytic activity because of their expansive surface area, reusable nature, supreme charge transfer, and high magnetization properties. Different approaches used to form nano-spinels are thoroughly discussed based on their applications. Spinel materials are cost-effective and practical renewable energy materials that can easily replace the current commercial energy materials by improving their properties for various environmental aspects, specifically in green energy production. [ABSTRACT FROM AUTHOR]

The world is facing water crises because freshwater scarcity has become a global issue due to rapid population growth, resulting in the need for more industries, agriculture, and domestic sectors. Therefore, it is challenging for scientists and environmental engineers to treat wastewater with cost-effective treatment techniques. As compared to conventional processes (physical, chemical, and biological), advanced oxidation processes (AOP) play an essential role in the removal of wastewater contaminants, with the help of a powerful hydroxyl (OH•) through oxidation reactions. This review study investigates the critical role of O 3 -based Advanced Oxidation Processes (AOPs) in tackling the complex difficulties of wastewater treatment. Effective treatment methods are critical, with wastewater originating from various sources, including industrial activity, pharmaceutical manufacturing, agriculture, and a wide range of toxins. O 3 -based AOPs appear to be powerful therapies capable of degrading a wide range of pollutants, including stubborn organics, medicines, and pesticides, reducing environmental and human health risks. This review sheds light on their efficacy in wastewater treatment by explaining the underlying reaction mechanisms and applications of several O 3 -based AOP processes, such as O 3 , O 3 /UV, and O 3 /H 2 O 2. Ozone, a powerful oxidizing agent, stimulates the breakdown of complex chemical molecules by oxidation processes, which are aided further by synergistic combinations with ultraviolet (UV) radiation or hydrogen peroxide (H 2 O 2). Notably, while ozonation alone may not always produce the best outcomes, it acts as an essential pretreatment step prior to traditional treatments, increasing total treatment efficiency. Furthermore, O 3 -based AOPs' transformational capacity to convert organic chemicals into simpler, more stable inorganic forms with little sludge creation emphasizes its sustainability and environmental benefits. This study sheds light on the processes, uses, and benefits of O 3 -based AOPs, presenting practical solutions for sustainable water management and environmental protection. It is a valuable resource for academics, engineers, and politicians looking for new ways to combat wastewater contamination and protect water resources. [Display omitted] • The treatment efficiency is higher for ozone-based AOP methods illustrated. • The numerous ozone-based reaction mechanisms and applications of AOP are discussed. • The merged techniques are economically advantageous to various methods narrated. [ABSTRACT FROM AUTHOR]

Biodiesel is one of the ideal options, considering it is a renewable, biodegradable, non-toxic, environmentally friendly fuel with low pollutant emission. However, biodiesel encounters challenges, mostly connected to its high manufacturing costs, that hinder its continued development and advancement. Focusing on more affordable and environmentally friendly inputs, such as suitable and abundant feedstock and efficient catalysts, is crucial. This paper aims to summarize the literature on biodiesel production and life cycle assessment (LCA) studies, critically review the catalyst and oil feedstock employed, and the findings of the LCAs, focusing on spotting prospective low-cost feedstock sources. Furthermore, an overview of recent LCA-related works applied in various biodiesel processes incorporating various catalysts and oil feedstock was evaluated. The application of LCA and its environmental impacts in biodiesel production was discussed and summarised in table form. The importance of using a sustainable and favorable approach could result in cost-efficient biodiesel production. Additionally, the advantages and limitations of the LCA in biodiesel production have been discussed. Last, the status and challenges of LCA in biodiesel production are covered. The findings of using cheaper feedstock are expected to inspire future studies and help industry professionals develop sustainable biodiesel production. • A comprehensive review of LCA framework and biodiesel process technologies were covered. • LCA of biodiesel production using various catalysts and oil feedstock was reviewed. • Challenges and status were discussed for sustainable biodiesel production. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Lipase enzyme extracted from Porcine Pancreas was immobilized onto the GO. • Comparison of the immobilized enzymes performance and free enzymes. • Adsorption isotherm and kinetic studies. • The enzyme activity, and reusability of the immobilized Lipase. Immobilization of enzymes improves their stability, performance, reusability, and recovery. This study investigated the removal of Azo dyes from industrial wastewater effluent using immobilized Lipase enzyme on Graphene Oxide (GO) in batch mode. The Lipase enzyme extracted from Porcine Pancreas was immobilized onto the GO via adsorption, where the enzymes are attached to the support by intermolecular forces. This study aims to investigate the immobilization efficiency of Lipase on the GO and determine the effect of parameters such as Lipase concentration, pH, and temperature on the enzyme activity. The results showed that the enzyme activity increased with the Lipase concentration, pH and temperature until an optimum point was achieved. The saturation of support surface pores causes the loss of enzyme activity due to the excessive Lipase enzyme, structural deformation of the support surface and enzyme denaturation due to extreme pH and temperature. The immobilized Lipase activity and free Lipase activity were compared. The optimum Lipase concentration is 6 mg/mL, with the greatest immobilization efficiency and highest enzyme activity. Besides, the optimum pH for the highest immobilized Lipase activity is 8.0, and the optimum temperature is 40 °C. The characterization results confirmed the immobilization of the Lipase enzyme. Adsorption isotherm and kinetic studies are also carried out to investigate the dye removal performances. The highest Azo dye removal efficiency obtained is 89.47% at 240 min of contact time and 5 mg/L of initial dye concentration. Further, the reusability of the immobilized Lipase was also investigated and found that the immobilized Lipase can be reused up to four cycles. Thus, the adsorption of dyes through immobilized lipase on GO can significantly impact various industrial sectors. [ABSTRACT FROM AUTHOR]

This study aims to investigate the thermal conductivity, viscosity and thermal degradation of naphthenic-based mineral oil, palm oil methyl ester (POME) and its blend. Mineral oil and POME were mixed at various mass ratios (70:30, 80:20 and 90:10) via homogenisation for 10 min at 25,000 RPM. The thermo-physical properties of oil studied were thermal conductivity, viscosity, density, flash point and thermal degradation. Results indicated enhancement in thermal conductivity with an increase in temperature. The highest enhancement (0.185 W mK−1) was observed for the 70:30 blend ratio at 80 °C. The viscosity decreased as temperature increased, whereby POME resulted in lower values (2.3 mPa.s) than mineral oil (4.3 mPa.s) at 80 °C. Density also showed a decreasing trend with temperature with no significant difference between POME and mineral oil. However, POME (175.5 °C) resulted in a higher flash point compared to mineral oil (146.5 °C), resulting in the enhanced flashpoint of blend oils. Blend oil with a 70:30 ratio resulted in the highest thermal degradation of 274.56 °C in the air environment. Oxidation induction time (OIT) decreased with temperature from 160–180 °C where mineral oil resulted in higher induction time than POME. The results proved improvement in properties of mineral oil blend with POME, which can enhance the system performance and faster heat dissipation. [ABSTRACT FROM AUTHOR]

Owing to the high toxicity of cerium toward living organisms, it is necessary to remove cerium from aqueous solutions. In this regard, the extraction of cerium (Ce (III)) from nitrate media by Cyanex 572 under different operating conditions was examined in this study. The effect of contact time, pH, extractant concentration, and nitrate ion concentration were investigated to characterize the extraction behavior of cerium and based on these outcomes, an extraction mechanism was suggested. The analysis of infrared spectra of Cyanex 572 before and after the extraction of cerium indicated that cerium extraction was performed via a cation-exchange mechanism. Then, the predictive models based on intelligent techniques [artificial neural network (ANN) and hybrid neural-genetic algorithm (GA-ANN)] were developed to predict the cerium extraction efficiency. The GA-ANN model provided better predictions that resulted higher R2 and lower MSE compared to ANN model for predicting the extraction efficiency of cerium by Cyanex 572. The interactive effects of each process variable on cerium extraction were also investigated systematically. pH was the most influential parameter on cerium extraction, followed by extractant concentration, nitrate ion concentration and contact time. Finally, the separation of cerium from other rare earth elements like La (III), Nd (III), Pr (III), and Y (III) was conducted and observed that the present system provides a better separation of cerium from rare heavy earth than light rare earths. [ABSTRACT FROM AUTHOR]

Wastewater consisting of different pharmaceuticals and drug residues is quite challenging to treat and dispose of. This situation poses a significant impact on the health aspect of humans and other biotic organisms in the environment. The main concern of hospital wastewater (HWW) is the resistivity towards treatment using the different conventional methods. For the treatment of HWW, this study was performed using an electro bioreactor using hospital wastewater. The electro reduction overcomes the effect of toxic elements in hospital wastewater, and biodegradation removes organic matter and nutrients from wastewater. This study investigated electro bioreactor performance for treating hospital wastewater connected with tubesettler. The parameters of chemical oxygen demand, nitrate, and phosphate concentration were analyzed to evaluate an influent and effluent from electro bioreactor and tubesettler. Also, Kinetic modelling for chemical oxygen demand, nitrate, and phosphate removal was done. The chemical oxygen demand was reduced by 76% in electro bioreactor, and 31% in tubesettler, 84%. The nitrate and phosphate were reduced within permissible discharge limits with a final effluent concentration of 1.4 mg L−1 and 3 mg L−1. Further studies are required to assess the impact of pharmaceutical compounds in hospital wastewater on the system's performance. [ABSTRACT FROM AUTHOR]

We studied polylactic acid (PLA) nanocomposite reinforced with graphene nanoplatelets (GNP)/Nanohydroxyapatite (NHA) hybrid prepared using the melt-mixing technique. Before mixing with the GNP, NHA was surface modified using 3-aminopropyl triethoxysilane (APTES). The surface-modified NHA (mNHA) loading was constant at 5wt% while varying the GNP loading from 0.01–0.1wt%. Results show with 0.01 wt% GNP, the impact strength of the PLA/mNHA/GNP nanocomposite increased, tensile strength decreased, thermal stability, and viscoelastic properties improved significantly compared to neat PLA and PLA/mNHA. The FESEM images show the agglomeration of mNHA/GNP hybrid at higher loading (>0.05 wt%), leading to the deterioration of PLA/mNHA/GNP nanocomposite properties. [ABSTRACT FROM AUTHOR]

Biodiesel has recently gained popularity as an alternative biofuel to substitute fossil fuel. Utilization of magnetic biochar catalyst (MBC) in biodiesel production can enhance the catalyst separation process. In this research, MBC was synthesized from oil palm waste such as palm kernel shell (PKS), oil palm frond (OFP), and empty fruit bunch (EFB). Biodiesel production parameters were studied using the Central Composite Design-based Response Surface Method. Based on the characterization results, EFB is the most suitable palm lignocellulosic biomass for MBC synthesis. The MBC has a BET surface area of 44.42 m2 g−1, an average acid density value of 3.85 mmol g−1, and a σ s value of 3.19 Am2 kg−1. MBC synthesis is at its optimal by using 1.5 M FeCl 3 ·6H 2 O solution, 800 °C carbonization temperature, and 2.5 M H 2 SO 4. The optimized transesterification parameters are: catalyst loading of 10.25 wt%, methanol to oil molar ratio of 28, 70 °C, and 8 h gave a maximum fatty acid methyl ester yield of 91.50 %. After five cycles, the yield dropped to 67.37 %. Biodiesel production is reported to be the pseudo-irreversible first-order kinetic with an activation energy of 29.20 kJ mol−1. The physicochemical characterization showed the biodiesel has met the ASTM D6751 standard. [ABSTRACT FROM AUTHOR]

The stress of pharmaceutical and personal care products (PPCPs) discharging to water bodies and the environment due to increased industrialization has reduced the availability of clean water. This poses a potential health hazard to animals and human life because water contamination is a great issue to the climate, plants, humans, and aquatic habitats. Pharmaceutical compounds are quantified in concentrations ranging from ng/Lto μg/L in aquatic environments worldwide. According to (Alsubih et al., 2022), the concentrations of carbamazepine, sulfamethoxazole, Lutvastatin, ciprofloxacin, and lorazepam were 616–906 ng/L, 16,532–21635 ng/L, 694–2068 ng/L, 734–1178 ng/L, and 2742–3775 ng/L respectively. Protecting and preserving our environment must be well-driven by all sectors to sustain development. Various methods have been utilized to eliminate the emerging pollutants, such as adsorption and biological and advanced oxidation processes. These methods have their benefits and drawbacks in the removal of pharmaceuticals. Successful wastewater treatment can save the water bodies; integrating green initiatives into the main purposes of actor firms, combined with continually periodic awareness of the current and potential implications of environmental/water pollution, will play a major role in water conservation. This article reviews key publications on the adsorption, biological, and advanced oxidation processes used to remove pharmaceutical products from the aquatic environment. It also sheds light on the pharmaceutical adsorption capability of adsorption, biological and advanced oxidation methods, and their efficacy in pharmaceutical concentration removal. A research gap has been identified for researchers to explore in order to eliminate the problem associated with pharmaceutical wastes. Therefore, future study should focus on combining advanced oxidation and adsorption processes for an excellent way to eliminate pharmaceutical products, even at low concentrations. Biological processes should focus on ideal circumstances and microbial processes that enable the simultaneous removal of pharmaceutical compounds and the effects of diverse environments on removal efficiency. • Pharmaceuticals and their reactions in water are referred to as emergent organic pollutants, and they are becoming a global concern. • The frequent presence of pharmaceuticals and personal care items in the environment and wastewater has becomes major concerns due to it adverse effect. • The major purpose of this research is to give an in-depth compilation and discussion of pharmaceutical removal treatment solutions, including methods for detecting and removing pharmaceutical substances from water sources. • The pharmaceutical adsorption capabilities of adsorption, biological, and advanced oxidation technologies, as well as their usefulness in pharmaceutical concentration removal, are investigated in this work. [ABSTRACT FROM AUTHOR]

In this work, the effect of ionic liquid (IL) pretreatment on the pyrolytic behavior of lignite was analyzed by examining reactivity, kinetic, and thermodynamic parameters. Pretreatment of lignite with 1-butyl-3-methylimidazolium methyl sulfate ([Bmim][MeSO4]) was carried out at 150°C and 30 min followed by thermal analysis under an inert environment, at a constant ramp rate of 20°C/min. Ten Coats–Redfern (CR) models were applied to the TGA data to evaluate kinetic and thermodynamic parameters. IL-treated lignite increased volatile matter from 46.39% to 57.81% and reduced ash from 21.71% to 8.50%. DTG profiles indicated that [Bmim][MeSO4] accelerated the thermal degradation of lignite by breaking the hydrogen bonding structure of coal, which was statistically confirmed by a higher average rate of thermal degradation, mean relative reactivity (Rm), pyrolysis factor (PF), and lower activation energy (Eα) than untreated lignite. This study shows that [Bmim][MeSO4] could be an attractive eco-friendly pretreatment solvent for the thermochemical conversion of lignite. [ABSTRACT FROM AUTHOR]

[Display omitted] • MOFs in presence of co-catalyst TBABr are attractive for cycloaddition of CO 2 to epoxides. • Photocatalytic activity of MOFs is enhanced by implantation of atoms, semiconductors, photosensitizers etc. • The product selectivity depends on active metal nodes/clusters, ligands, visible-light absorption, conductivity, efficient charge separation etc. • The application of MOFs has been proven for efficient synthesis of formate, formic acid, alcohols, carbon monoxide, methane etc. Abundant CO 2 emissions from industries and the transportation sector cause an alarming threat to the planet due to overwhelming concerns over CO 2 induced climate change. To resolve this tremendous environmental pollution, the long-term solution for CO 2 mitigation exists in the conversion of CO 2 into value-added products through catalysis. Among several catalysts, metal organic frameworks (MOFs) are one of the remarkable candidates for CO 2 conversion into fuels and chemicals. The MOFs are molded with robust structures, high porosity, high potential of CO 2 adsorption, maximum atom utilization due to high dispersion and isolation of active sites of MOFs, tunability of the metal nodes, organic ligands, etc. MOFs have been implemented for several CO 2 conversion processes such as cycloaddition of CO 2 to epoxides, photocatalytic CO 2 reduction, electrocatalytic CO 2 reduction, hydrogenation, and others. These processes convert CO 2 into products like cyclic carbonates, alkyl formate, formic acid, ethanol, methanol, methane, CO, and others. This study strived to explain elaborately the formation of fuels and chemicals through different catalytic processes using MOFs. Detailed reaction conditions, catalyst chemistry, reaction mechanisms, and formation rates for alkyl formate, formic acid, methanol, ethanol, CO, and methane have been critically analyzed in present study. [ABSTRACT FROM AUTHOR]

Pollution problems are increasingly becoming e a priority issue from both scientific and technological points of view. The dispersion and frequency of pollutants in the environment are on the rise, leading to the emergence have been increasing, including of a new class of contaminants that not only impact the environment but also pose risks to people's health. Therefore, developing new methods for identifying and quantifying these pollutants classified as emerging contaminants is imperative. These methods enable regulatory actions that effectively minimize their adverse effects to take steps to regulate and reduce their impact. On the other hand, these new contaminants represent a challenge for current technologies to be adapted to control and remove emerging contaminants and involve innovative, eco-friendly, and sustainable remediation technologies. There is a vast amount of information collected in this review on emerging pollutants, comparing the identification and quantification methods, the technologies applied for their control and remediation, and the policies and regulations necessary for their operation and application. In addition, This review will deal with different aspects of emerging contaminants, their origin, nature, detection, and treatment concerning water and wastewater. [Display omitted] • CECs can be toxic to all kinds of organisms if exposed for a prolonged duration • Proper protocol needs to followed to accurately measure low concentration of CECs • HPLC and GC are the most commonly used instruments to detect CECs • Biological processes are low-cost treatment processes but gives low removal of CECs • AOPs are ecofriendly technologies that can provide a high removal efficiency of CECs [ABSTRACT FROM AUTHOR]

Currently, substances have been detected that have always been present but have long been unnoticed; among these substances called emerging pollutants are pharmaceuticals, pesticides, cosmetics, cleaning, and personal care products, among others. Membrane Bioreactor (MBR) technology has gained extensive popularity in enhancing the treatment and reutilization of wastewater. It exhibits efficiencies ranging from 40 to 79 % for treating high organic loads such as dairy wastewater while achieving impressive rates of up to 90 % for effectively removing emerging contaminants. However, traditional MBRs with ultrafiltration or porous microfiltration membranes are not intended to remove hazardous micropollutants from water, which are constantly present in trace concentrations and can adversely affect terrestrial and aquatic ecosystems. Several effective techniques have been used to remove hazardous micropollutants from water, especially for hydrophilic and resistant chemicals. These tactics consist mainly of improving the operating environment, using high-retention membranes instead of porous membranes, adding functional materials to the bioreactor, and including additional procedures for effluent treatment. To ensure almost complete removal of micropollutants, the MBR can be complemented with effluent treatment, recently the use of high retention membranes, hybrid MBR-nanofiltration systems, or other processes such as electrocoagulation or advanced oxidation (AOP) have been reported. Nevertheless, additional investigation is required to assess these strategies' technical and economic viability, particularly regarding real-time effectiveness. This evaluation is crucial for identifying the most appropriate techniques for industrial applications. • Emerging membrane technology for micropollutant removal was narrated. • Membrane Bioreactor (MBR) technology for hazardous pollutant removal was illustrated. • Advanced hybrid treatment for micropollutants removal was discussed. • Advanced integrated technique for micropollutant from wastewater was elaborated. [ABSTRACT FROM AUTHOR]

Graphene – a carbon nanomaterial has gained huge research interest due to its intriguing and extraordinary properties such as large surface area, excellent electrical conductivity, ultra-thinness, high electron mobility, and superior mechanical strength. The combination of graphene with other inorganic nanoparticles can significantly boost its physiochemical properties and hence, opens up new frontiers of its utilization. Grapheneis significantly exploited for the energy storage systems due to its great potential for electrochemical energy storage. However, the experimental electrochemical performance of graphene is still far away from the theoretical facts. This study critically evaluated the existing synthesis routes for the production of graphene, graphene-based composites and their utilization in the energy storage applications. Furthermore, the techno-economic analysis of the synthesis methods was undertaken to determine the best routes in terms of sustainability for commercial graphene production. Lastly, the fundamental understanding of graphene growth mechanisms and the overall intricacies of the synthesis processes were highlighted and the possible way forward is proposed. Therefore, in the quest for the development of effective alternative yet sustainable energy storage devices; it is hoped that this research will give useful insights to researchers and key players in the electronics industry. [ABSTRACT FROM AUTHOR]

Electrochemical stability of energy storage devices is one of their major concerns. Polymeric binders are generally used to enhance the stability of the electrode, but the electrochemical performance of the device is compromised due to the poor conductivity of the binders. Herein, 3D binder-free electrode based on nickel oxide deposited on graphene (G-NiO) was fabricated by a simple two-step method. First, graphene was deposited on nickel foam via atmospheric pressure chemical vapour deposition followed by electrodeposition of NiO. The structural and morphological analyses of the fabricated G-NiO electrode were conducted through Raman spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and energy dispersive X-ray spectroscopy (EDS). XRD and Raman results confirmed the successful growth of high-quality graphene on nickel foam. FESEM images revealed the sheet and urchin-like morphology of the graphene and NiO, respectively. The electrochemical performance of the fabricated electrode was evaluated through cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS) in aqueous solution at room temperature. The G-NiO binder-free electrode exhibited a specific capacity of ≈ 243 C g−1 at 3 mV s−1 in a three-electrode cell. A two-electrode configuration of G-NiO//activated charcoal was fabricated to form a hybrid device (supercapattery) that operated in a stable potential window of 1.4 V. The energy density and power density of the asymmetric device measured at a current density of 0.2 A g−1 were estimated to be 47.3 W h kg−1 and 140 W kg−1, respectively. Additionally, the fabricated supercapattery showed high cyclic stability with 98.7% retention of specific capacity after 5,000 cycles. Thus, the proposed fabrication technique is highly suitable for large scale production of highly stable and binder-free electrodes for electrochemical energy storage devices. [ABSTRACT FROM AUTHOR]

Abstract This paper evaluates the feasibility of using fusion waste chicken and fish bones as the reusable and low cost solid catalyst for synthesis of biodiesel from used cooking oil via two-step transesterification. A catalyst characterization of the prepared fusion waste chicken and fish bones catalyst was made in order to study their catalytic performance through various techniques such as Scanning Electron Microscopy (SEM), Brunauer–Emmett–Teller (BET), Particle Size Analysis (PSA), Thermal Gravimetric Analysis (TGA), Fourier Transform Infrared spectra (FTIR), Carbon Dioxide-Temperature Programmed Desorption (TPD-CO 2) and X-Ray Diffraction (XRD). The used cooking oil transesterification was optimized using a response surface methodology (RSM) based on five level three variables central composite design (CCD). The RSM results revealed that the optimal operational condition for the transesterification has defined as: catalyst loading, 1.98%w/v, reaction temperature, 65 °C and time, 1.54 h, whereas the alcohol/oil molar ratio, 10:1 is a fixed variable in this study. The actual biodiesel yield of 89.5% was achieved under the predicted optimal conditions and fulfilled the ASTM D6751 biodiesel fuel standards. The promising features of the chicken and fish bones catalyst are inexpensive, easily obtained, simple work-up, simple recovery, reusability without significant drop in catalytic activity for up to four consecutive runs. Highlights • Waste chicken and fish bone were utilized for biodiesel production as solid catalyst. • RSM was implemented to optimize the transesterification process. • The prepared catalyst was reusable without significant loss in its activity. • Maximum 89.5% yield at 1.98%w/v catalyst and alcohol/oil ratio of 10:1 at 65 °C in 1.54 h. [ABSTRACT FROM AUTHOR]

The newly set up power plant has been committed to fulfilling the power supply demand of the world. Therefore, optimizing operating variables within constraints of varying power demand becomes necessary. The research aims to identify and optimize several parameters influencing the performance and efficiency of a 660 MW supercritical power plant at different operating conditions, such as steam temperature, pressure, feedwater flow rate, and fuel consumption. Ultimately, the research aims to contribute to developing sustainable and environmentally friendly power generation technologies. The present study covers the multi-objective optimization of a 660 MW capacity fossil fuel-fired SUPP. The overall plant efficiency, cost of electricity, and exergetic efficiency are taken as objective functions. The Particle Swarm Optimization (PSO) technique and a semi-empirical model of energy, economic, and exergy analysis of fossil fuel-fired SUPP have been employed. The varying power outputs, coal calorific value, amount of coal consumption, inlet temperature, and pressure conditions of turbines set are decision variables taken for the study. The parametric study was carried out with the variation in plant load and mass of coal consumption concerning the variation of the objective function. The lower temperature at the inlet of the low-pressure turbine is preferred for lowing the cost of electricity. The maximum value of plant efficiency of 41.643% and exergy efficiency of 39.834% with a minimum cost of electricity of 3.1456 INR/Unit have been evaluated using multi-objective PSO. The outcome of the present study is that the optimized value of decision variables will reduce the dependency on high-grade coal from an energy, exergy, and economic point of view. The outcome of the present study will explore the scope for future researchers and engineers. • Parametric and multi-objective optimization of supercritical power plant. • Metaheuristic approach Particle Swarm Optimization is preferred. • The increase in plant and exergy efficiency reduces the cost of electricity. • Integration of semi-imperial thermodynamic model with multi-objective optimization. [ABSTRACT FROM AUTHOR]

We aimed to evaluate the possible effects of the application of zinc oxide nanoparticles [ZnO NPs; 68.96 ± 33.71 nm; at 100 and 500 mg/kg in a soil mixture of the Typic Dystrophic Red Latosol type and sand (2:1 ratio)] in the cultivation of Panicum maximum (until 125 days), using different biomarkers in addition to evaluating the uptake of Zn by the plants. Furthermore, we assessed the possible transfer of ZnO NPs from P. maximum leaves to zebrafish and their potential. Plants cultivated in substrates with ZnO NPs at 500 mg/kg showed reduced germination rate and growth. However, at 100 mg/kg, plants showed higher biomass and productivity, associated with higher Zn uptake, without inducing oxidative and nitrosative stress. Zinc content in zebrafish was not associated with ingesting leaves of P. maximum cultivated in substrate containing ZnCl 2 or ZnO NPs or with genotoxic, mutagenic, and biochemical effects. In conclusion, ZnO NPs (at 100 mg/kg) are promising in the cultivation of P. maximum , and their ingestion by zebrafish did not cause changes in the evaluated biomarkers. However, we recommend that studies with other animal models be conducted to comprehensively assess the ecotoxicological hazard associated with applying ZnO NPs in soil. [Display omitted] • Substrate enriched with ZnO NPs (at 100 mg/kg) showed higher biomass and productivity. • Higher Zn uptake in leaves and roots was observed in P. maximum grown on substrates enriched with ZnO NPs. • Redox imbalance and nitrosative stress were not evidenced in plants. • Zn content in zebrafish was not associated with ingestion of leaves of P. maximum cultivars in substrate containing NPs. • Zebrafish-fed leaves of P. maximum showed no genotoxic, mutagenic, or biochemical changes. [ABSTRACT FROM AUTHOR]

Bacterial strains belonging to Citrobacter spp. were reported to produce polysaccharides consisting of N-acetylglucosamine and glucosamine like chitosan, with high flocculation activity. In this work, the flocculation dewatering performance of activated sludge conditioned by a novel cationic chitosan-like bioflocculant (BF) named BF01314, produced from Citrobacter youngae GTC 01314, was evaluated under the influences of flocculant dosage, pH, and temperature. At BF dosage as low as 0.5 kg/t DS, the sludge dewaterability was significantly enhanced in comparison to the raw (untreated) sludge, featuring well-flocculated characteristic (reduction in CST from 22.0 s to 9.4 s) and good sludge filterability with reduced resistance (reduction in SRF by one order from 7.42 × 1011 to 9.59 × 1010 m/kg) and increased compactness of sludge (increase in CSC from 15.2 to 23.2%). Besides, the BF demonstrated comparable high sludge dewatering performance within the pH range between 2 and 8, and temperature range between 25 °C and 80 °C. Comparison between the BF, the pristine chitosan and the commercial cationic copolymer MF 7861 demonstrated equivalent performance with enhanced dewaterability at the dosage between 2.0 and 3.0 kg/t DS. Besides, the BF demonstrated strong flocculation activity (>99%) when added to the sludge suspension using moderate to high flocculation speeds (100–200 rpm) with at least 3-min mixing time. The BF's reaction in sludge flocculation was best fitted with a pseudo first-order kinetic model. Electrostatic charge patching and polymer bridging mechanisms are believed to be the dominant mechanistic phenomena during the BF's sludge conditioning process (coagulation-flocculation). • BF01314 performs equivalent to commercial biopolymers in sludge dewatering. • Excellent dewatering performance between pH 2–8 and temperature 25–80 °C. • Sludge flocculation reaction was best fitted with pseudo first–order kinetic model. • Flocculation by BF01314 is preceded by electrostatic charge patching. [ABSTRACT FROM AUTHOR]

• Encapsulated ionic liquids are now used for CO 2 capture applications due to hybrid characteristics of materials and ionic liquids. • Various methods can be used for the synthesis of the encapsulated ionic liquids. • The spherical morphology of encapsulated ionic liquids is observed in most cases. • Aprotic Heterocyclic Anion (AHA) like ionic liquids are suited for the maximum absorption of CO 2 performance. • The encapsulated ionic liquids overcome the problems of low absorption rate and difficulties in solvent regeneration. Ionic liquids (ILs) are well-known for their carbon dioxide (CO 2) capture properties. The impregnation or encapsulation of various materials attracts applications for CO 2 capture due to the hybrid characteristics of materials and ILs. ILs on their own are faced with the problem of high viscosity; however, their diluted use onto materials significantly reduces this problem. The low CO 2 absorption rate and difficulties in solvent regeneration can also be overcome by using encapsulated ionic liquid (ENIL) systems. Currently, studies on CO 2 capture using ENILs are still limited to the basic absorption behavior of the absorbent. This review aims to comprehensively evaluate the most recent literature available on ENILs for CO 2 capture including preparation of ENILs, characterization, thier reaction kinetics, CO 2 solubility, CO 2 selectivity and regeneration studies. The manuscript also discusses the current research challenges, opportunities, and future prospects in the applications of ENILs for CO 2 capture. [ABSTRACT FROM AUTHOR]

• Sonochemistry as an advanced oxidation process. • Mechanism of remediation/disinfection of microbial hazards in polluted water. • Types and comparison of sonochemical reactors for remediation. • Energy and economic aspects. • Challenges and recommendations for future studies. Water is one of the major sources that spread human diseases through contamination with bacteria and other pathogenic microorganisms. This review focuses on microbial hazards as they are often present in water and wastewater and cause various human diseases. Among the currently used disinfection methods, sonochemical reactors (SCRs) that produce free radicals combined with advanced oxidation processes (AOPs) have received significant attention from the scientific community. Also, this review discussed various types of cavitation reactors, such as acoustic cavitation reactors (ACRs) utilizing ultrasonic energy (UE), which had been widely employed, involving AOPs for treating contaminated waters. Besides ACRs, hydrodynamic cavitation reactors (HCRs) also effectively destroy and deactivate microorganisms to varying degrees. Cavitation is the fundamental phenomenon responsible for initiating many sonochemical reactions in liquids. Bacterial degradation occurs mainly due to the thinning of microbial membranes, local warming, and the generation of free radicals due to cavitation. Over the years, although extensive investigations have focused on the antimicrobial effects of UE (ultrasonic energy), the primary mechanism underlying the cavitation effects in the disinfection process, inactivation of microbes, and chemical reactions involved are still poorly understood. Therefore, studies under different conditions often lead to inconsistent results. This review investigates and compares other mechanisms and performances from greener and environmentally friendly sonochemical techniques to the remediation of microbial hazards associated with water and wastewater. Finally, the energy aspects, challenges, and recommendations for future perspectives have been provided. [ABSTRACT FROM AUTHOR]

[Display omitted] • An overview of the MXene-based photocatalysts' synthesis chemical and physical routes has been discussed. • MXene Surface terminating groups significantly impacted the photodegradation activity of MXene-based composites. • MXene's significance throughout the utilization of photocatalysis was highlighted. • Problems and opportunities for MXenes research in the future have been described. In recent years, MXene has attracted significant interest in the photocatalysis because of its novel physical and chemical characteristics, including uniform planer structure, strong metallic conductivity, effective functional groups and plenty of derivatives. Compared to other photocatalysts for the photocatalytic degradation of various contaminants, MXene-based photocatalysts possess excellent photodegradation performance and long-term stability. MXene is widely used as a photocatalyst for the photodegradation of organic compounds and CO 2 conversion into value-added products to remediate the environment. MXene-based composites possess superb photodegradation activity compared to the pristine MXene because it lacks the active sites and porous structure compared to MXene-based composites. For example, the NiFe/MXene nanocomposite has ability to degrade the targeted the organic contaminants 4 and 6.72 times higher than the pristine MXene and NiFe, respectively. MXene and their derivatives are invaluable photocatalysts because of their widespread accessibility, inexpensiveness, non-irritating nature, and excellent photocatalytic performance. The active functional groups present on the surface of MXene have a viable impact on the photodegradation performance. This study reports the recent investigations on the photodegradation capability of MXene-based photocatalysts. The physiochemical characteristics of MXene have been discussed briefly for an extensive understanding of the activity of MXene-based photocatalysts. The strength of MXene-based photocatalysts for the photodegradation of organic compounds and CO 2 conversion into value-added products, physical and chemical synthesis routes of MXene preparation are reviewed. Finally, the future work and challenges faced by MXene-based photocatalysts are presented. [ABSTRACT FROM AUTHOR]

Aerogel based on reduced graphene oxide was synthesized using supercritical methods of drying the hydrogel in isopropanol. The synthesis technique involves the deposition of iron hydroxides on graphene layers, then their reduction in supercritical isopropyl alcohol to iron oxides (Fe 3 O 4 and γ-Fe 2 O 3). Results revealed that synthesized adsorbents Graphene aerogel (GA) and GA/Fe show excellent high gravimetric methane adsorption with an achievable capacity of 2.5 g/g and 3.6 g/g, respectively, in the pressure range of 0.5–10 MPa and 298 K, which is more than seven times higher than the requirements established by the US Department of Energy for the gravimetric capacity of a porous material for methane storage. However, at high gravimetric absorption, the volume absorption was 104 m3 (STP)/m3 and 102 m3 (STP)/m3 for (GA) and (GA/Fe), respectively. It should be noted that the performance characteristics of aerogels, in general, are comparable to adsorbents of other classes. A generalized flow-chart for obtaining the graphene aerogel. [Display omitted] [ABSTRACT FROM AUTHOR]

Aerogel based on reduced graphene oxide was synthesized using supercritical methods of drying the hydrogel in isopropanol. The synthesis technique involves the deposition of iron hydroxides on graphene layers, then their reduction in supercritical isopropyl alcohol to iron oxides (Fe 3 O 4 and γ-Fe 2 O 3). Results revealed that synthesized adsorbents Graphene aerogel (GA) and GA/Fe show excellent high gravimetric methane adsorption with an achievable capacity of 2.5 g/g and 3.6 g/g, respectively, in the pressure range of 0.5–10 MPa and 298 K, which is more than seven times higher than the requirements established by the US Department of Energy for the gravimetric capacity of a porous material for methane storage. However, at high gravimetric absorption, the volume absorption was 104 m3 (STP)/m3 and 102 m3 (STP)/m3 for (GA) and (GA/Fe), respectively. It should be noted that the performance characteristics of aerogels, in general, are comparable to adsorbents of other classes. A generalized flow-chart for obtaining the graphene aerogel. [Display omitted] [ABSTRACT FROM AUTHOR]

The present work proposes an ultrasound (US) assisted electro-Fenton (EF) process for eliminating penicillin G (PNG) and ciprofloxacin (CIP) from aqueous solutions and the process was further optimized by response surface methodology (RSM)- Box-Behnken design (BBD). The impact of pH, hydrogen peroxide (H 2 O 2) concentration, applied voltage, initial pollutant concentration, and operating time were studied. The capability application of the electro-Fenton (EF) and US processes was compared separately and in combination under the optimum conditions of pH of 4, a voltage of 15 V, the initial antibiotic concentration of 20.7 mg/L, H 2 O 2 concentration of 0.8 mg/L, and the operating time of 75 min. The removal efficiency of PNG and CIP using the sono-electro-Fenton (SEF) process, as the results revealed, was approximately 96% and 98%, respectively. The experiments on two scavengers demonstrated that ⦁OH contributes significantly to the CIP and PNG degradation by SEF, whereas ⦁O− 2 corresponds to only a negligible amount. The total organic carbon (TOC) and chemical oxygen demand (COD) analyses were used to assess the mineralization of CIP and PNG. The efficiency of COD and TOC removal was reached at 73.25% and 62.5% for CIP under optimized operating circumstances, and at 61.52% and 72% for PNG, respectively. These findings indicate that a sufficient rate of mineralization was obtained by SEF treatment for the mentioned pollutants. The reaction kinetics of CIP and PNG degradation by the SEF process were found to follow a pseudo-first-order kinetic model. In addition, the human health risk assessment of natural water containing CIP and PNG that was purified by US, EF, and SEF processes was done for the first time. According to the findings, the non-carcinogenic risk (HQ) caused by drinking purified water by all three systems was calculated in the acceptable range. Thus, SEF is a proper system to remove various antibiotics in potable water and reduces their human health risks. [Display omitted] • More than 96% of studied antibiotics were removed by sono-electro-Fenton. • Based on Box–Behnken design, pH was the most vital factor for antibiotics removal. • The antibiotics degradation by the process followed a pseudo-first-order model. • By increasing time, the antibiotics were more mineralized and biodegraded. • The water source treated by the system had no non-carcinogenic risk to consumers. [ABSTRACT FROM AUTHOR]

[Display omitted] • The removal of Hg from environmental water by advanced oxidation processes. • The removal of Hg from environmental water by adsorption. • Thermodynamic molecular modelling and simulation of Hg adsorption. • Hg adsorption mechanism, kinetics and column adsorption studies. • Regeneration and reusability studies. The review discusses the removal of mercury (Hg) from wastewater by advanced oxidation processes (AOPs) and adsorption. The Hg adsorption in batch and column method was described, and the mechanism was explained, followed by the equilibrium and kinetic modelling. Furthermore, thermodynamic molecular modelling and simulation of Hg adsorption were discussed. The results showed that the removal of Hg from the aqueous solution by AOPs was successfully applied. Some of the future perspectives include enhancing the efficiency of the AOPs for the removal of Hg. The efficiency of available technologies for the removal of heavy metals in general and Hg in particular, depend on three criteria, namely efficacy, cost, suitability, and conditions of application. Langmuir and Freundlich isotherm models are best-fit and also pseudo second order kinetic model. [ABSTRACT FROM AUTHOR]

In this study, nano pumice (NP) and a cationic surfactant (hexadecyltrimethylammonium-chloride (HDTMA.Cl)) treated nano pumice (HMNP) were used for humic acid (HA) adsorption from an aqueous solution. The adsorption process was modeled and optimized using Response surface methodology-central composite design (RSM-CCD) and Artificial neural networks- Genetic algorithm (ANN-GA). The results show that the ANN model outperforms the RSM-CCD model in terms of response prediction. Optimization results based on the RSM-CCD approach proposed pH 3, adsorbent dose 3 g L−1, reaction time 60 min, and initial HA concentration 5 mg L−1 as optimal points of the variables, to reach the maximum adsorption efficiency of 100% and 65.4% by HMNP and NP adsorbents. The maximal adsorption capacity of NP was 1.21 mg g−1, while that of HMNP was 27.34 mg g−1. The optimal points of process parameters by the ANN-GA method are in accordance with the values suggested by the RSM-CCD method. In isotherm studies, Langmuir model was found to be the best-fitted model for both adsorbent with R2 = 0.97 for NP and 0.992 for HMNP, and also among three different kinetic models which were assessed, Pseudo-second-order model with R2 = 0.9989 for HMNP and R2 = 0.9957 for NP were the best-fitted models for HA removal. Thermodynamic studies indicated that the HA adsorption process by both of the adsorbents is endothermic and the nature of HMNP was found spontaneous while for NP was non-spontaneous. The value of ΔH for both adsorbents was in the range of 34–36.8 kJ mol−1 so the process is clarified as chemical–physical adsorption. The reusability test revealed that the adsorption effectiveness of HMNP drops from 100% to 82.4% after 10 consecutive recycles. The influence of interfacing anions indicated that the adsorption efficiency drops from 100% to 95.4% when the anions were added to the reaction solution. [Display omitted] • NP and a cationic surfactant (HDTMA.Cl))-treated Nano pumice (HMNP). • The adsorption process was modeled and optimized by RSM-CCD and ANN-GA. • The maximum adsorption efficiency of 100% by HMNP adsorbent. • Co-existing anions drop the adsorption efficiency from 100% to 95.4%. [ABSTRACT FROM AUTHOR]

• Tribological performance of the non-aqueous miscible lubricants is reviewed. • Vegetable oils as a sustainable and environmentally friendly lubricant is explored. • Nanolubricants based on ionic liquids (ILs) are presented. • Nanolubricants for high-temperature applications. This review presents the literature review on the recent research on the tribological performance of non-water miscible lubricants. First, the paper reviewed the tribological properties of vegetable oil, blend oil, synthetic oil and ionic liquid. Aside from that, the tribological performance of lubricants with ionic liquids (ILs) and nanoparticles is being studied. According to the findings, more research should be conducted into oil-miscible ILs for mineral, vegetable oils and nanolubricant. The review has also explained the dispersion stability, viscosity and viscosity index, thermal conductivity, thermal-oxidative stability and tribological performance of nanolubricant. Finally, future recommendations on lubricant research are also discussed. [ABSTRACT FROM AUTHOR]

Endotoxins as the outer membrane of most Gram-Negative Bacteria (GNB) and typical toxic biochemical produced by microorganisms are identified as one of the emerging pollutants. These microbial by-products are harmful compounds that can be present in various environments including air, water, soil, and other ecosystems which were discussed in detail in this review. Environmental and occupational exposure caused by endotoxin occurs in water and wastewater treatment plants, industrial plants, farming, waste recovery, and composting facilities. Even though the health risk related to endotoxin injection in intravenous and dialysis are well identified, the harmful effects of ingestion, inhalation, and other way of exposure are not well quantified and there is insufficient information on the potential health risks of endotoxins exposure in water environments, and another exposure. Because of limited studies, the outbreaks of diseases related to endotoxins in the various source of exposure not been well documented. Endotoxin removal from different environments are investigated in this review. The results of various studies have shown that conventional treatment methods have been unable to remove endotoxins from water and wastewater, therefore, monitoring the effectiveness of these processes in controlling this contaminant and also using the appropriate removal method is essential. However, management of water and wastewater treatment processes and the use of advanced processes such as Advanced Oxidation Processes (AOPs) can be effective in monitoring and reducing endotoxin levels during water and wastewater treatment. One of the limitations of endotoxin monitoring is the lack of sufficient information to develop monitoring levels. In addition, the lack of guidelines and methods of controlling them at high levels may cause irreparable disaster. [Display omitted] • Endotoxins produced by bacteria are identified as one of the emerging pollutants in environment. • The exposure route, environmental and health risks in different environments are reviewed. • The concentration of endotoxin in bio-aerosols and processes of water and wastewater treatment are reviewed. • The removal and inactivation of endotoxins by different treatment processes were compared. [ABSTRACT FROM AUTHOR]

Microbial desalination cell (MDC) is an emerging bio-electrochemical system technology used for wastewater decontamination, seawater desalination, and co-energy production. MDCs can be used alone in combination with various water treatment technologies, which may synergize the process of water purification. Efforts are being made for the scale-up of the technology. However, several challenges need to be answered before the up-gradation of the technology to a large scale. This manuscript provides a thorough chronological-founded assessment that encompasses technological challenges for the scale-up of the MDCs. Furthermore, a detailed analysis has been provided on how various technologies help MDCs in efficient and economical wastewater treatment. Some integrated technologies include traditional anaerobic digestion, reverse osmosis, electrodialysis, etc. Various MDC arrangements for their parametric evaluation, such as process conditions, bacteriological impacts, and possible power generation outputs with different anodic materials, have been discussed. Suggestions have also been put forward that can help large-scale MDC development. [Display omitted] • Microbial desalination cells (MDCs) are evaluated as a promising technology for power generation. • Advances in membranes, cell design and hybrid systems for MDCs are discussed. • The microbial desalination cell (MDC) can treat wastewater, produce electricity and desalinate seawater. • Recent progress and developments of microbial desalination has been evaluated. • Various types of microbial desalination also discussed. [ABSTRACT FROM AUTHOR]

• Efficiency of new generation adsorbents and their adsorption capacities. • Equilibrium isotherms and kinetic modelling for fluoride adsorption. • Thermodynamic studies for adsorption of fluoride onto novel adsorbents. • Molecular modelling and simulation. • Knowledge gap and future perspectives. Water is essential for life and is threatened by the pollution and contamination generated by human activity and industries. Fluoride contamination of water is a serious problem in the world. The review article highlights on new generation adsorbents including carbon-based adsorbents, nano-adsorbents, bio-sorbents, inorganic materials, modified and composite adsorbents for purification of fluoride from water. It was indicated from the review that a Zinc oxide nanoparticles is the best adsorbents for the removal of fluoride from aqueous media, with a capacity adsorption (q max) of 100 mg/g. The f l u o r i d e uptake best-fit both the Langmuir and Freundlich isotherm models as well as a pseudo second order kinetic model. A wide range of values for the thermodynamic parameters (both negative and positive) were reported for fluoride across different studies. Kinetic and thermodynamic, molecular modelling and simulations, knowledge gaps and future prospects are also presented. [ABSTRACT FROM AUTHOR]

[Display omitted] • The adsorption of Cr (VI) on MOF-5 functionalized with amino groups. • Linear and nonlinear isotherms, kinetic models, and thermodynamic analysis. • Influence of coexisting ion species on the adsorption efficiency. • Thermodynamic studies revealed that adsorption nature is spontaneous and endothermic. • Maximum adsorption capacity of 78.6 mg/g was achieved. In the past decades, an extensive effort has been devoted to remove Hexavalent chromium H(Cr (VI)) from industrial effluents, owning to its great health concerns to humans and the environment. Recently, Metal organic framework (MOFs) adsorbents draws more attention of researchers to remove contaminants from aqueous environments in the recent years. In the present study, solvothermal method was employed to fabricate MOF-5 that was examined for Cr (VI) adsorption from water matrices. XRD, FESEM, EDS, FTIR and BET analyses were utilized to characterize MOF-5. The influence of some independent parameters on MOF-5 performance in Cr (VI) adsorption was explored in a batch mode system. It was found that the uptake rate of Cr (VI) is significantly affected by initial pH of solution; the maximum adsorption rate is favored by acidic pH. Also, the adsorption efficiency shows a direct relationship with contact time and adsorbent dose, and an indirect relation with initial Cr (VI) concentration. The adoption process was modeled and optimized successfully by two approach of response surface methodology and artificial neutral network approaches; both models indicated an accuracy of predictions by determining error distribution and statistical significance and a good fit to experimental data. The experimental data showed a superior agreement with linear and nonlinear Langmuir isotherm, as compared with the other isotherm models, and pseudo-second-order kinetic better described Cr (VI) adsorption data by MOF-5, compared to the other kinetic models. The maximum absorption capacity was 78.12 mg/g. Thermodynamic studies revealed that adsorption is spontaneous and endothermic process. The findings claimed the great reusability and high stability of MOF-5; adsorption efficiency decreased only by 92.4% after ten recycles. The interfering anions affected negatively on the adsorption efficiency in the order of phosphate > sulfate > chloride > nitrate. The present study provides valuable and good information for Cr (VI) adsorption on MOF-5 in water matrices. [ABSTRACT FROM AUTHOR]

This study aims to optimize the fabrication parameters of nickel‑iron phosphate (NiFe-P) electrode to achieve a high areal capacity electrode for supercapattery. The fabrication of binder-free NiFe-P electrode on nickel foam (NF) employs a one-step hydrothermal synthesis method. Further, central composite design (CCD) under the response surface methodology (RSM) is used to optimize the electrode's performance. The factors evaluated are synthesis temperature (60 to 180 °C), time (6 to 24 h), and the molar ratio of precursor solution (1:3, 1:1, 3:1 of Fe: Ni), whereas the response is the areal capacity of NiFe-P electrode at the scan rate of 3 mV/s in a standard three-electrode cell system. The optimal temperature, time, and molar ratio (Fe:Ni) are determined to be 100 °C, 14 h, and 3:1, respectively. The model is confirmed within the confidence interval and prediction as well as comparable with a 10% percentage error between the experimental and predicted specific capacity. The specific capacity of the optimized electrode is 446 C/g at a scan rate of 3 mV/s using cyclic voltammetry (CV) and 413.75 C/g at a current density of 1 A/g in 1 M KOH using a standard three-electrode cell system. Supercapattery is fabricated by combining NiFe-P and activated carbon electrodes (NiFe-P//AC) as positive and negative electrodes, respectively, to evaluate the two-electrode cell system. The results show the maximum power density of NiFe-P//AC supercapattery is 2250 W/kg at an energy density of 45.6 Wh/kg. Furthermore, the NiFe-P//AC supercapattery demonstrated excellent stability and coulombic efficiency by retaining 87.6% and 98.7% of the initial specific capacity values and coulombic efficiency, respectively. • Binder-free NiFe-P electrode was prepared using hydrothermal synthesis. • The fabrication parameters of the electrode were optimized using DOE. • The electrochemical performance of the electrodes was investigated. • Maximum power density of NiFe-P//AC supercapattery is 2250 W/kg at an energy density of 45.6 Wh/kg. • NiFe-P//AC supercapattery retained 87.6% and 98.7% of the initial specific capacity values and coulombic efficiency. [ABSTRACT FROM AUTHOR]

Waste tea powder (WTP)/poly(lactic acid) (PLA) biocomposites were prepared using a Brabender Plastograph mixer and RAY-RAN injection moulding machine. The effect of WTP loadings (0–50 wt %) and NaOH mercerisation on the properties of WTP/PLA biocomposites were investigated. The WTP/PLA biocomposites were then subjected to electron beam irradiation to elucidate the biocomposites' radiation compatibility. The infrared spectrum of untreated and treated WTP were obtained using Fourier Transform Infrared Spectroscopy (FTIR). The results show mercerisation of WTP facilitated its dispersion, as observed under scanning electron microscopy (SEM). The biocomposite's mechanical and thermal properties were obtained using a tensile test, Izod impact test, and thermogravimetric analysis (TGA). A decreasing trend for both tensile and impact tests with increasing WTP loading regardless of NaOH mercerisation was observed. However, the tensile strength of the irradiated biocomposite samples was not significantly affected. Moreover, the thermal stability of the biocomposites was improved with mercerisation but not affected by the irradiation process. Biocomposites with 50% mercerised WTP loading showed the highest equilibrium water absorption. Studies reveal that WTP/PLA biocomposites show radiation stability at low dosages of electron beam irradiation (20 and 40 kGy), which is beneficial for food and medical packaging applications. At higher doses, it appears that the WTP/PLA biocomposites undergo predominantly radiation-induced degradation. • Biocomposites were prepared using waste tea powder and poly(lactic acid). • Effect of WTP loading and irradiation dose on biocomposites properties were studied. • Increasing WTP loading decreased both tensile and impact properties. • Tensile strength of the irradiated biocomposite samples were not significantly affected. • Thermal stability of the biocomposites were not affected by the irradiation. [ABSTRACT FROM AUTHOR]

We studied the reinforcing effects of treated and untreated nanohydroxyapatite (NHA) on poly-lactic acid (PLA). The NHA surface was treated with three different types of chemicals; 3-aminopropyl triethoxysilane (APTES), sodium n-dodecyl sulfate (SDS) and polyethylenimine (PEI). The nanocomposite samples were prepared using melt mixing techniques by blending 5 wt% untreated NHA and 5 wt% surface-treated NHA (mNHA). Based on the FESEM images, the interfacial adhesion between the mNHA filler and PLA matrix was improved upon surface treatment in the order of mNHA (APTES) > mNHA (SDS) > mNHA (PEI). As a result, the PLA-5wt%mNHA (APTES) nanocomposite showed increased viscoelastic properties such as storage modulus, damping parameter, and creep permanent deformation compared to pure PLA. Similarly, PLA-5wt%mNHA (APTES) thermal properties improved, attaining higher Tc and Tm than pure PLA, reflecting the enhanced nucleating effect of the mNHA (APTES) filler. [ABSTRACT FROM AUTHOR]

Hazardous contamination of water is a major hurdle in the provision of usable and drinkable water to the world. Innovative, economic, renewable and environment friendly technologies are need of the hour for wastewater treatment. Several technologies such as ion-exchange, co-precipitation, adsorption, membrane separation, oxidation, biochemical processes etc. are being researched to encourage the wastewater treatment. Among these technologies, the adsorption is being considered as a promising approach owing to its short route. To adsorb the pollutants, different types of adsorbents are synthesized and utilized for wastewater treatment. The bio-adsorbents (BAs) from waste biomass sources are renewable, sustainable, economical, and ecofriendly for wastewater treatment. Among other biomass waste sources, fruit-based biomass wastes are on rise due to global food and fruit demand. The utilization of fruit wastes for the development of BAs have received high attention due to their low cost, rich in bio cellulose and abundance. Herein, we report a comprehensive review on the fruit waste derived bio-adsorbents for wastewater treatment. The manuscript includes synthesis, characterizations, and utilization of fruit waste derived bio-adsorbents for removal of various water contaminants. Characteristics, adsorption capacities, isotherms and adsorption kinetics of various bio-adsorbents and influence of parameters on adsorption is provided and critically analyzed. [Display omitted] • Waste fruit derived bio-adsorbents are competing candidates for wastewater treatment. • Pseudo second order rate equation dominates adsorption kinetics using bio-adsorbents. • In several cases Langmuir isotherm better fits the adsorption behavior. • Fruit waste utilization can bridge water-energy-food nexus gap. • Challenges on commercialization of fruit waste derived bio-adsorbents need to be addressed. [ABSTRACT FROM AUTHOR]

Herein, a one-step fabrication of three-dimensional (3D) binder-free graphene-nickel foam (G-Ni) electrode via atmospheric pressure chemical vapour deposition (APCVD) is reported. Graphene thin films were deposited on nickel foam under isobaric conditions in an inert environment. The process parameters such as temperature, time, and the gas flow rate were statistically optimised using design of experiment (DOE) to maximise the yield of graphene. The structural and morphological properties of the fabricated graphene electrode were investigated through X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FESEM), and energy dispersive X-ray spectroscopy (EDS). The electrochemical investigations were conducted through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements. The results confirmed few-layered graphene with good surface morphology, high purity, and crystallinity of a binder-free electrode. The statistical analysis revealed that the optimal graphene electrode fabrication conditions were 900 °C, 10 min, and 100 sccm, respectively. Moreover, the regressed model and experimental results for the graphene growth were determined to be 3.93 mg/cm2, and 4.01 mg/cm2, respectively. Electrochemically, a specific capacitance value of 62.07 F/g was recorded at a scan rate of 3 mV/s showing an excellent performance of the fabricated 3D graphene electrode for energy storage applications. • 3D binder-free graphene electrode exhibits excellent properties. • Rapid and cost-effective fabricating of binder-free electrode • Remarkable electrochemical performance (specific capacitance of 62.07 F/g) • Potential electrode candidate for enhanced electrochemical performance [ABSTRACT FROM AUTHOR]

Physical and thermodynamic properties of physical or chemical solvents are of utmost importance for mass and heat transfer calculations, process design and solvent regeneration. In recent times, machine learning has attracted interest for applications in several fields of engineering sciences. The ionic liquid 1-Butyl-3-methylimidazolium hexafluorophosphate [Bmim][PF6] is an emerging solvent for CO 2 capture. In this study, three Gaussian process regression (GPR) models - the Matern 5/2 GPR model, rational quadratic GPR model, squared exponential GPR model - and one support vector machine (SVM) model (the nonlinear SVM)– are developed for predicting CO 2 solubility, density, viscosity and molar heat capacity of [Bmim][PF6]. Detailed statistics of each model and comparative analyses between the models and their predicted results with experimental results is highlighted. • In this study rational quadratic GPR, squared exponential GPR and nonlinear SVM models are applied. • The models predicted CO 2 solubility, density, viscosity, and molar heat capacities of [Bmim][PF6]. • Matern 5/2 GPR has the minimal error percentage compared to other models in predicting CO 2 solubility in [Bmim][PF6]. • In most of the models, the error percentage in predicting molar heat capacities of [Bmim][PF6] less than 1. [ABSTRACT FROM AUTHOR]

Vulcanized rubber, due to its superior mechanical properties, has long been used in various industries, especially automotive. The rubber industry has evolved and expanded over the years to meet the increasing global demands for tires. Today tires consist of about 19% natural rubber and 24% synthetic rubber, while plastic polymer and metal, filler and additives make up the rest. Over 1.6 billion new tires are produced annually and around 1 billion waste tires are generated. Tires are extensively designed with several complex processes to make them virtually indestructible. Since tire rubber does not decompose easily, their disposal at the end of service life creates a monumental environmental impact. However, waste tire rubber (WTR) consist of valuable rubber hydrocarbon, making its recovery or regeneration highly desirable. The conventional recovery method of WTR tends to produce undesirable products due to the destruction of the polymeric chain and exponentially degenerates the vulcanizates' physical properties. Since then, multiple devulcanization processes were introduced to effectively and selectively cleave vulcanizate's crosslinks while retaining the polymeric networks. Different devulcanization methods such as chemical, mechanical, irradiation, biological and their combinations that have been explored until now are reviewed here. Besides, an overview of the latest development of devulcanization by ionic liquids and deep eutectic solvents are also described. While such devulcanization technique provides new sustainability pathway(s) for WTR, the generated devulcanizate also possesses comparable physical properties to that of virgin products. This further opens the possibility of novel circular economic opportunities worldwide. • Waste vulcanizates disposal is a global sustainability and industrial challenge. • Chemical, mechanical, microwave, ultrasonic are typical reclamation methods. • Greener technologies promote value-added product generation from waste. • Ultrasonic treatment with green devulcanizing agent enhances devulcanization efficiency. [ABSTRACT FROM AUTHOR]

In this study, NiO was electrodeposited on a 3D graphene electrode to produce a nanocomposite with enhanced electrochemical properties. The electrodeposition process parameters such as electrolyte concentration, deposition time, and deposition potential were statistically optimised using response surface methodology. The statistical analysis showed that the optimal electrodeposition conditions to be 0.3 M, 10 min, and -1.2 V for electrolyte concentration, deposition time, and deposition potential, respectively. Furthermore, the predicted model and experimental results for the specific capacity of G-NiO were determined to be 240.91 C/g and 240.58 C/g at 3 mV/s. The results show that the electrochemical deposition technique can be employed as a fast and reliable synthesis route to develop graphene-based metal oxide nanocomposites. The structural and morphological properties were determined by XRD and FESEM studies. The electrochemical measurements revealed the excellent electrochemical performance of 3D graphene NiO composite (G-NiO) for energy storage applications. • Process optimisation study for the electrodeposition of NiO. • G-NiO binder-free electrode exhibits excellent electrochemical properties. • High specific capacity (240.58 C/g) of G-NiO electrode. • Rapid fabrication and eco-friendly of binder-free electrode. [ABSTRACT FROM AUTHOR]

The recent implication of circular economy in Australia spurred the demand for waste material utilization for value-added product generations on a commercial scale. Therefore, this experimental study emphasized on agricultural waste biomass, rice husk (RH) as potential feedstock to produce valuable products. Rice husk biochar (RB) was obtained at temperature: 180 °C, pressure: 70 bar, reaction time: 20 min with water via hydrothermal carbonization (HTC), and the obtained biochar yield was 57.9%. Enhancement of zeta potential value from − 30.1 to − 10.6 mV in RB presented the higher suspension stability, and improvement of surface area and porosity in RB demonstrated the wastewater adsorption capacity. Along with that, an increase of crystallinity in RB, 60.5%, also indicates the enhancement of the catalytic performance of the material significantly more favorable to improve the adsorption efficiency of transitional compounds. In contrast, an increase of the atomic O/C ratio in RB, 0.51 delineated high breakdown of the cellulosic component, which is favorable for biofuel purpose. 13.98% SiO2 reduction in RB confirmed ash content minimization and better quality of fuel properties. Therefore, the rice husk biochar through HTC can be considered a suitable material for further application to treat wastewater and generate bioenergy. [ABSTRACT FROM AUTHOR]

Deep eutectic solvent (DES) has been projected as a possible alternative for toxic organic solvents and has gained increasing attention from scientific community as well as industries. The most beneficial aspect of DES is its tuneable properties. In the current work, highly stable novel ammonium-based ternary deep eutectic solvents (TDESs) were synthesized by combining hydrogen bond donor (HBD) and hydrogen bond acceptors (HBAs) at variable molar ratios. Ethyl ammonium chloride (EAC), and zinc (II) chloride (ZnCl 2) were selected as the HBAs, whereas glycerol (Gly) was the HBD. Their thermophysical properties namely, melting point, degradation temperature, density, viscosity, acidity, miscibility, refractivity and electrical conductivity were measured respectively. Additionally, the correlation (Arrhenius or linear regression) between the physical properties as a function of temperature was also studied and presented. The results show an increase in electrical conductivity and decrease in pH, density, dynamic and kinematic viscosities of TDESs with increasing temperature. Unlabelled Image • Thermophysical properties of Ethylammonium Chloride-Glycerol-ZnCl 2 TDESs are reported • Electrical conductivity of TDESs increases with increasing temperature. • pH, density and viscosity of TDESs decreases with increasing temperature. • Molar ratio of TDESs affected their thermophysical properties. • Correlation between physical properties as a function of temperature is presented. [ABSTRACT FROM AUTHOR]

This study aims to optimize the parameters in thermo-sonic devulcanisation of ground rubber tyre (GRT) with the help of three novel ternary deep eutectic solvents (TDESs). Ultrasonic frequency and time were varied between 37 and 80 kHz and 25–60 min, respectively. Whereas, heating temperature and time intervals were ranged from 25 to 200 °C and 0–60 min. Through one factor at a time (OFAT) analysis and response surface methodology (RSM) software modelling, the study shows that 37 kHz sonication for 60 min and thermal treatment at 180 °C for 55 min were the optimum conditions, resulting in 75% devulcanisation (%Dvul). At these conditions, devulcanisates were further analysed by thermogravimetric analyser (TGA), Fourier transform infrared spectroscopy (FTIR), swelling behaviour and Horikx curve to verify the occurrence of devulcanisation. These additional analyses verify that the intensity of sulphur bridges reduced and negligible changes in degradation temperature as well as the amount of main chain scission were experienced. These evidences demonstrate selective scission of sulphur-bridges as well as the high potential that polymeric properties were being retained compared to typical reclamation process. Unlabelled Image • TDES with a high number of α-Hs showed greater GRT devulcanisation. • 1 h sonication and heating at 180 °C for 55 min was optimum for devulcanisation. • Di-ethyl-ammonium chloride-based TDES gave the best response. [ABSTRACT FROM AUTHOR]

• Low temperature molten salt was synthesized for thermal energy storage. • Graphene doped low temperature molten salt shows enhancement in heat capacity and thermal conductivity. • No Alteration in thermal stability before and after doping graphene in molten salt. • Good prediction of heat capacity and thermal conductivity by various models except Nan's model. Enhancement of heat capacity and thermal conductivity with the dispersion of graphene nanoparticles into low-temperature eutectic salt was investigated. Three different nanoparticle concentrations (0.01, 0.05 & 0.1 wt. %) were dispersed into a eutectic salt mixture composed of 5.66% NaNO 3 , 21.25% KNO 3 , 24.75% Ca(NO 3) 2 , 41% CsNO 3 , & 7.34% LiNO 3 by weight. The results show that the graphene doping resulted in enhanced heat capacity ranging from 5 to 13%, whereas thermal conductivity increased marginally by ˜3%, with respect to graphene concentration. Various theoretical models were tested to predict the thermal conductivity and heat capacity of the graphene-doped eutectic salt. The Maxwell and Hamilton-Crosser thermal conductivity models showed good agreement with experimental results, with a deviation of ±3%, while Nan's thermal conductivity model over-predicted the thermal conductivity value. The conventional heat capacity equation fits well with the experimental data, with deviation <14%. [ABSTRACT FROM AUTHOR]

In this study, a cost-effective thermoelectric generator was developed from recycled carbon fibre (RCF) composites incorporated with multi-walled carbon nanotubes (MWCNT) doped bismuth telluride (Bi 2 Te 3) and bismuth sulphide (Bi 2 S 3). A facile approach utilising hot compression and brushing was used to prepare a cost-effective inorganic RCF thermoelectric composite with varying content of MWCNT ranging from 0.05 to 0.20 wt%. This work investigated the effect of doping MWCNT in Bi 2 Te 3 and Bi 2 S 3 matrix and its corresponding effect on thermoelectric, morphological, structural and thermal properties of RCF thermoelectric composite. The thermoelectric properties of RCF composites were optimised at 0.10 wt % (1.044 μW K−2m−1) and 0.15 wt% (0.849 μW K−2m−1) of MWCNT for doped Bi 2 Te 3 and Bi 2 S 3 respectively. The addition of MWCNT reduced the difference in power factor between RCF-Bi 2 Te 3 and RCF-Bi 2 S 3 from 52% to 19%. The presence of MWCNT in the Bi 2 S 3 matrix overcame the high resistivity of Bi 2 S 3 and improved its thermoelectric properties as MWCNT provided a conductive pathway for efficient electron transfer. Thus, MWCNT doped Bi 2 S 3 RCF composites is an alternative to telluride free thermoelectric generators. Image 1 [ABSTRACT FROM AUTHOR]