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Ionogel is an emerging hybrid material where the ionic liquid is immobilized within polymer matrix. Interesting combination of properties has permitted wide applications of ionogel. In this study, a well-known method, sol-gel is used to synthesize ionogel. However, it is intended to identify the optimum concentration of ionic liquid within ionogel which endows the ionogel with the best electrochemical performance. By varying the concentration of ionic liquid, the appearance of ionogel is compared. FTIR is performed to understand the structural changes that occur in ionogel. Linear Sweep Voltammetry is performed to study the electrochemical stability of ionogel.

A limited experimental work was on multi-walled carbon nanotube (MWCNT)—water nanofluid with surfactant in the solar parabolic collector at low volume concentrations. At high-volume concentrated nanofluid, the pressure drop was more due to an increase in the viscosity of the working fluid and an increase in the nanoparticle cost; hence it is not economical. This report attempted to use Sodium Dodecyl Benzene Sulfonate (SDBS) surfactant in the low-volume concentrated MWCNT-water nanofluid to establish effective heat transfer in solar parabolic collector applications. The stable MWCNT-water nanofluid was prepared at 0.0158, 0.0238, and 0.0317 volume concentrations. The experiments were conducted from 10:00 to 16:00 at 6, 6.5 and 7 L/min flow rates concerning ASHRAE Standards. At the 7 L/min flow rate of the working fluid, having a minimum temperature difference between the working fluid and absorber tube leads to better heat transfer. The increased volume concentration of MWCNT in the water enhances the surface area interaction between water and MWCNT nanoparticles. This results in maximum solar parabolic collector efficiency at 0.0317 vol% with a 7 L/min flow rate and 10–11% higher than the distilled water.

Contamination of water resources by industrial effluents containing heavy metal ions and management of solid waste from agricultural and food industries is a serious issue. This study presents the valorization of waste walnut shells as an effective and environment-friendly biosorbent for sequestrating Cr(VI) from aqueous media. The native walnut shell powder (NWP) was chemically modified with alkali (AWP) and citric acid (CWP) to obtain modified biosorbents with abundant availability of pores as active centers, as confirmed by BET analysis. During batch adsorption studies, the process parameters for Cr(VI) adsorption were optimized at pH 2.0. The adsorption data were fitted to isotherm and kinetic models to compute various adsorption parameters. The adsorption pattern of Cr(VI) was well explained by the Langmuir model suggesting the adsorbate monolayer formation on the surface of the biosorbents. The maximum adsorption capacity, qm, for Cr(VI) was achieved for CWP (75.26 mg/g), followed by AWP (69.56 mg/g) and NWP (64.82 mg/g). Treatment with sodium hydroxide and citric acid improved the adsorption efficiency of the biosorbent by 4.5 and 8.2%, respectively. The endothermic and spontaneous adsorption was observed to trail the pseudo-second-order kinetics under optimized process parameters. Thus, the chemically modified walnut shell powder can be an eco-friendly adsorbent for Cr(VI) from aqueous solutions.

The use of solar energy is one of the most prominent strategies for addressing the present energy management challenges. Solar energy is used in numerous residential sectors through flat plate solar collectors. The thermal efficiency of flat plate solar collectors is improved when conventional heat transfer fluids are replaced with nanofluids because they offer superior thermo-physical properties to conventional heat transfer fluids. Concentrated chemicals are utilized in nanofluids' conventional synthesis techniques, which produce hazardous toxic bi-products. The present research investigates the effects of novel green covalently functionalized gallic acid-treated multiwall carbon nanotubes-water nanofluid on the performance of flat plate solar collectors. GAMWCNTs are highly stable in the base fluid, according to stability analysis techniques, including ultraviolet–visible spectroscopy and zeta potential. Experimental evaluation shows that the thermo-physical properties of nanofluid are better than those of base fluid deionized water. The energy, exergy and economic analysis are performed using 0.025%, 0.065% and 0.1% weight concentrations of GAMWCNT-water at varying mass flow rates 0.010, 0.0144, 0.0188 kg/s. The introduction of GAMWCNT nanofluid enhanced the thermal performance of flat plate solar collectors in terms of energy and exergy efficiency. There is an enhancement in efficiency with the rise in heat flux, mass flow rate and weight concentration, but a decline is seen as inlet temperature increases. As per experimental findings, the highest improvement in energy efficiency is 30.88% for a 0.1% weight concentration of GAMWCNT nanofluid at 0.0188 kg/s compared to the base fluid. The collector's exergy efficiency increases with the rise in weight concentration while it decreases with an increase in flow rate. The highest exergy efficiency is achieved at 0.1% GAMWCNT concentration and 0.010 kg/s mass flow rate. GAMWCNT nanofluids have higher values for friction factor compared to the base fluid. There is a small increment in relative pumping power with increasing weight concentration of nanofluid. Performance index values of more than 1 are achieved for all GAMWCNT concentrations. When the solar thermal collector is operated at 0.0188 kg/s and 0.1% weight concentration of GAMWCNT nanofluid, the highest size reduction, 27.59%, is achieved as compared to a flat plate solar collector with water as a heat transfer fluid.

The concept of green chemistry has attracted attention due to the green synthesis and ecofriendly nature of the compounds leading to the green and sustainable chemical industries and processes. Chitosan is an ecofriendly material, which is biodegradable, non-toxic, and biocompatible. It has the potential to be modified into biofilms for various applications such as biomedical, packaging, and pharmaceutical fields. Nevertheless, some poor properties of chitosan restrict its wide applications. The incorporation of nanocellulose fillers into chitosan matrix can enhance the mechanical and thermal properties of chitosan. Cellulose nanomaterials can be achieved through chemical and mechanical modifications. The common type of nanocellulose are cellulose nanofibers (CNFs), cellulose nano-whiskers (CNWs), tunicate CNCs (t-CNCs), algae cellulose particles (AC) and bacterial cellulose particles (BC). Nanocellulose are applied as the reinforcement fillers in various polymer matrices such as polysaccharides, proteins, lipids, polylactic acid etc. Deep eutectic solvents (DES) are relatively novel green solvents, which can be applied in various fields. DES are widely applied in metal processing, polymer processing and synthesis. Even though there are not much studies available on DES for synthesis of nanocomposite films; however they are used as eco-friendly solvents in manufacturing processes. This study reviews the discovery, structure, properties of chitosan and cellulose, their derivatives and applications. In addition, the paper also discusses the properties of DES and their applications.

The demand for the development of high-performance and eco-friendly nanocomposites is soaring up. This is because of their desired mechanical, thermal, electrical, magnetic, catalytic, and optical properties and their ecofriendly development. The diversity of nanocomposites has introduced them to a wide variety of applications such as drug delivery, biosensors, bone regeneration, solar cells, super capacitors, fuel cells, automobiles etc. The nanocomposites are deemed competing materials for the sustainable development, this is because of their ecofriendly behavior and value addition. This manuscript reviews the status of the silicon enhanced nanocomposites, various classes of nanocomposites such as ceramic based matrix nanocomposites, metal-based matrix nanocomposites, Polymer based matrix nanocomposites, etc. advanced green polymer-based nanocomposites and sustainable nanofillers for nanocomposites. The applications of nanocomposites in various sectors such as energy, automobiles, packaging, biomedical, environment and safety have been critically reviewed.

Synthesis of hybrid nanomaterials in the lab-scale frequently involves complex processing and often is not able to be adopted in the industry without major enhancements for its commercial production. This research is focused on a convenient route for the fabrication of chitosan-supported magnetically recoverable carbon bio-nanocomposites by functionalizing magnetic nanoparticles on chitosan and renewable carbon material using solvothermal carbonization co-precipitation (STCC). This process can be adopted in large-scale synthesis with minimum enhancements. The nanocomposites produced using STCC offered excellent features including porous and ultrafine nanostructure, stable mechanical, and chemical properties. From the analysis of variance (ANOVA), the temperature has been found to be the most influential factor for both magnetic nanocomposite and bio-oil yield. The highest porosity for nanocomposites was observed with water-based synthesis at 260 °C at 194.62 m2/g. However, water/ethanol (50:50) at 260 °C yielded 6.67% and 8.01% more bio-oil and having 5.35% and 3.49% higher heating value as compared to that of bio-oil produced using water and ethanol.

The presence of metal with microwave irradiation has always invited controversial arguments as the metal will catch on fire easily. But interestingly, researchers found that arc discharge phenomena provide a promising way for molecule cracking to synthesize nanomaterials. This study developed a single-step yet affordable synthesis approach that combines microwave heating and arcing in transforming crude palm oil into magnetic nanocarbon (MNC), which can be considered a new alternative for the palm oil sectors. It involves synthesizing the medium at a partial inert condition with constant coiled stainless steel metal wire (dielectric media) and ferrocene (catalyst). This approach successfully demonstrates heating at a temperature ranging from 190.9 to 472.0 °C with different synthesis times (10–20 min). The produced MNC shows formations of spheres with average sizes of 20.38–31.04 nm, mesoporous structure (SBET: 14.83–151.95 m2/g), and high content of fixed carbon (52.79–71.24wt%), and the ratio of the D and G bands (ID/IG) is 0.98–0.99. The formation of new peaks in the FTIR spectra (522.29–588.48 cm−1) supports the appearance of the FeO compounds from the ferrocene. The magnetometer shows high magnetization saturation (22.32–26.84 emu/g) in ferromagnetic materials. The application of the MNC in wastewater treatment has been demonstrated by evaluating their adsorbent capability with Methylene Blue (MB) adsorption test at a different concentrations varying between 5 and 20 ppm. The MNC produced at synthesis time (20 min) shows the highest adsorption efficiency (10.36 mg/g) compared to others, with 87.79% removal of MB dye. As a result, the value for Langmuir is not promising compared to Freundlich, with R2 being around 0.80, 0.98, and 0.99 for MNC synthesized at 10 min (MNC10), 15 min (MNC15), and 20 min (MNC20), respectively. Hence, the adsorption system is in a heterogeneous condition. The microwave-assisted arcing thereby presents a promising approach to transforming CPO into MNC that could remove the hazardous dye.

To date, the development of renewable fuels has become a normal phenomenon to solve the problem of diesel fuel emissions and the scarcity of fossil fuels. Biodiesel production has some limitations, such as two-step processes requiring high free fatty acids (FFAs), oil feedstocks and gum formation. Hydrotreated vegetable oil (HVO) is a newly developed international renewable diesel that uses renewable feedstocks via the hydrotreatment process. Unlike FAME, FFAs percentage doesn't affect the HVO production and sustains a higher yield. The improved characteristics of HVO, such as a higher cetane value, better cold flow properties, lower emissions and excellent oxidation stability for storage, stand out from FAME biodiesel. Moreover, HVO is a hydrocarbon without oxygen content, but FAME is an ester with 11% oxygen content which makes it differ in oxidation stability. Waste sludge palm oil (SPO), an abundant non-edible industrial waste, was reused and selected as the feedstock for HVO production. Techno-economical and energy analyses were conducted for HVO production using Aspen HYSYS with a plant capacity of 25,000 kg/h. Alternatively, hydrogen has been recycled to reduce the hydrogen feed. With a capital investment of RM 65.86 million and an annual production cost of RM 332.56 million, the base case of the SPO-HVO production process was more desirable after consideration of all economic indicators and HVO purity. The base case of SPO-HVO production could achieve a return on investment (ROI) of 89.03% with a payback period (PBP) of 1.68 years. The SPO-HVO production in this study has observed a reduction in the primary greenhouse gas, carbon dioxide (CO

Mg–Al–Zn alloys are widely preferred in many applications by considering their excellent properties of high stiffness-to-weight ratio, lightweight, high strength-to-weight ratio, low density, castability, high-temperature mechanical properties, machinability, high corrosion resistance, and great damping. Improving the properties of such alloys is challenging due to their hexagonal crystal structure and other alloying limitations. This study aims to synthesize Mg–Al–Zn alloy by incorporating the alloying elements 8.3 wt% Al, 0.35 wt% Zn on pure magnesium (Control specimen). Then synthesize Mg–Al–Zn/BN/B4C hybrid composite by reinforcing B4C at three weight proportions (3 wt%, 6 wt%, 9 wt%) along with constant solid lubricant BN (3 wt%) through a stir casting process. The hybrid composite samples were characterized and compared with the performances of the control specimen. The results reveal that 9 wt% B4C reinforced samples outperformed through recording the improvement of tensile strength by 28.94%, compressive strength by 37.89%, yield strength by 74.63%, and hardness by 14.91% than the control specimen. Apart from this, it has reduced the corrosion area (37.81%) and noticed negligible changes in density (increased by 0.03%) and porosity (decreased by 0.01%) than the control specimen. The samples were characterized using SEM, XRD, and EDAX apparatus.

Almost a billion people, especially in developing countries, need safe water. Several studies in India show that most drinking water sources have high coliform counts. Standard quality control is needed. This study was conducted in rural parts of South Kashmir in the Western Himalaya from February to January, 2020–2022. Water samples were taken from the river from upstream to downstream using standard water sampling techniques. The purpose of this study was to investigate the detection and molecular identification of coliforms in drinking water and the chemical water quality associated with coliform-contaminated drinking water, which summarises river water pollution. The results showed significant variation in water quality measures, indicating increased pollution levels downstream. In all seasons, the highest coliform count was recorded at Sangam (downstream) of the river. In the summer season at Sangam it was recorded (72.2600 cfu 106/l) and no coliform count was found at Kongwaton (upper stream) during the winter season near the source of the Veshaw river. In all seasons, the highest values of water quality parameters (pH 6.847, EC 71.620 dS/m, BOD 1.120 mg/l, and COD 24.637 mg/l) were recorded at Sangam (downstream) of the river during the summer season. In the winter season at Kongwaton, the lowest values of water quality parameters were pH 8.947, EC 253.680 dS/m, BOD 4.963 mg/l, and COD 51.440 mg/l. The existence of coliforms in water indicates current faecal contamination and determines the presence of disease-causing pathogens. The goal of this work is to examine the level of total coliform contamination, coliform species identification, and chemical water quality properties of drinking water and its associated factors, which implies the pollution level in the river. Total DNA was collected and sequenced for 16S rDNA and metagenomics. Universal primers were used to amplify the bacterial 16S rRNA. Using BLAST, the amplified 16S rRNA gene sequence was matched to the NCBI database. A metagenomic study found 27 species that had different relative abundances. These species include E. coli, Escherichia fergusonii, Escherichia albertii, Klebsiella grimontii, and Shigella dysenteriae. This study is thought to be the first to discriminate against E. fergusonii, Escherichia albertii, Klebsiella grimontii, and Shigella dysenteriae from E. coli and to report on E. fergusonii and E. albertii, Klebsiella grimontii, and Shigella dysenteriae in the river Veshaw water sources in Kulgam, Western Himalaya.

Emerging pollutants (EPs) in the environment have become a significant source of pollution and cause of serious concern for the ecosystem and human health. Although during the recent decades, extensive research has been performed worldwide for the detection and analysis of EPs, continuous refinement, and development of specific analytical techniques; a great number of undetected EPs still need to be investigated in different components of the ecosystem and biological tissues. Therefore, this chapter provides extensive reviews of several emerging pollutants reported around the globe along with their physiochemical properties and potential ecological impacts. Moreover, formulated legislations and policy regulations for the monitoring of EPs are also discussed in this chapter.

Nanotechnology has many advantages, and its applications are spread to every field, from engineering to medicine and space to agriculture. Owing to the immense advantages of nano-size particles, nano-based materials are widely applied in wastewater treatment. These nanomaterials are developed and utilized in different sizes, shapes, and chemical compositions. These nanomaterials are characterized by their unique physical, chemical and biological properties. Besides the immense benefits of nanomaterials, they also have few environmental implications. This chapter presents the pros and cons of nanomaterials and their implications on the environment. Further, the effect of various nanomaterials on the aquatic environment, including the behaviour and toxicity on the aquatic ecosystem, is discussed. Finally, future directions to minimize the toxic effect of nanomaterials on the aquatic ecosystem and the need for improvement in the nanomaterials are presented.&nbsp

Oil spills are a major contributor to water contamination, which sets off a significant impact on the environment, biodiversity, and economy. Efficient removal of oil spills is needed for the protection of marine species as well as the environment. Conventional approaches are not efficient enough for oil-water separation; therefore, effective strategies and efficient removal techniques (and materials) must be developed to restore the contaminated marine to its normal ecology. Several research studies have shown that nanotechnology provides efficient features to clean up these oil spills from the water using magnetic nanomaterials, particularly carbon/polymer-based magnetic nanocomposites. Surface modification of these nanomaterials via different techniques render them with salient innovative features. The present review discusses the advantages and limitations of conventional and advanced techniques for the oil spills removal from wastewater. Furthermore, the synthesis of magnetic nanocomposites, their utilization in oil-water separation, and adsorption mechanisms are discussed. Finally, the advancement and future perspectives of magnetic nanocomposites (particularly of carbon and polymer-based magnetic nanocomposites) in environmental remediation are presented.

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.