Synthesis of biodiesel from non-edible (Brachychiton populneus) oil in the presence of nickel oxide nanocatalyst: Parametric and optimisation studies

Hazardous waste management (Buxus papillosa) investment for the prosperity of environment and circular economy: Response surface methodology-based simulation

Dealing with the current defaults of environmental toxicity, heating, waste management, and economic crises, exploration of novel non-edible, toxic, and waste feedstock for renewable biodiesel synthesis is the need of the hour. The present study is concerned with Buxus papillosa with seeds oil concentration (45% w/w), a promising biodiesel feedstock encountering environmental defaults and waste management; in addition, this research performed simulation based-response surface methodology (RSM) for Buxus papillosa bio-diesel. Synthesis and application of novel Phyto-nanocatalyst bimetallic oxide with Buxus papillosa fruit capsule aqueous extract was advantageous during transesterification. Characterization of sodium/potassium oxide Phyto-nanocatalyst confirmed 23.5 nm nano-size and enhanced catalytic activity. Other characterizing tools are FTIR, DRS, XRD, Zeta potential, SEM, and EDX. Methyl ester formation was authenticated by FTIR, GC-MS, and NMR. A maximum 97% yield was obtained at optimized conditions i.e., methanol ratio to oil (8:1), catalyst amount (0.37 wt%), reaction duration (180 min), and temperature of 80 °C. The reusability of novel sodium/potassium oxide was checked for six reactions. Buxus papillosa fuel properties were within the international restrictions of fuel. The sulphur content of 0.00090% signified the environmental remedial nature of Buxus papillosa methyl esters and it is a highly recommendable species for biodiesel production at large scale due to a t huge number of seeds production and vast distribution.

Risk assessment of toxic and hazardous metals in paddy agroecosystem by biochar-for bio-membrane applications

Toxic and carcinogenic metal (loid)s, such arsenic (As) and cadmium (Cd), found in contaminated paddy soils pose a serious danger to environmental sustainability. Their geochemical activities are complex, making it difficult to manage their contamination. Rice grown in Cd and As-polluted soils ends up in people's bellies, where it can cause cancer, anemia, and the deadly itai sickness. Solving this issue calls for research into eco-friendly and cost-effective remediation technology to lower rice's As and Cd levels. This research delves deeply into the origins of As and Cd in paddy soils, as well as their mobility, bioavailability, and uptake mechanisms by rice plants. It also examines the current methods and reactors used to lower As and Cd contamination in rice. Iron-modified biochar (Fe-BC) is a promising technology for reducing As and Cd toxicity in rice, improving soil health, and boosting rice's nutritional value. Biochar's physiochemical characteristics are enhanced by the addition of iron, making it a potent adsorbent for As and Cd ions. In conclusion, Fe-BC's biomembrane properties make them an attractive option for remediating As- and Cd-contaminated paddy soils. More efficient mitigation measures, including the use of biomembrane technology, can be developed when sustainable agriculture practices are combined with these technologies.

Methyl esters synthesis from Luffa cylindrica seeds oil using green copper oxide nanoparticle catalyst in membrane reactor

This study investigates the potential role of Juglans sp. root extract-mediated copper oxide nanoparticles of Luffa cylindrica seed oil (LCSO) into methyl esters. The synthesized green nanoparticle was characterized by Energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), and Scanning electron microscopy (SEM) spectroscopies to find out the crystalline size (40 nm), surface morphology (rod shape), particle size (80-85 nm), and chemical composition (Cu = 80.25% & O = 19.75%), accordingly. The optimized protocol for the transesterification reaction was adjusted as oil to methanol molar ratio (1:7), copper oxide nano-catalyst concentration (0.2 wt %), and temperature (90 °C) corresponding to the maximum methyl esters yield of 95%. The synthesized methyl esters were characterized by GC-MS, 1H NMR, 13C NMR, and FT-IR studies to know and identify the chemical composition of newly synthesized Lufa biodiesel. The fuel properties of Luffa cylindrica seed oil biofuel were checked and compared with the American Biodiesel standards (ASTM) (D6751-10). Finally, it is commendable to use biodiesel made from wild, uncultivated, and non-edible Lufa cylindrica to promote and adopt a cleaner and sustainable energy method. The acceptance and implementation of the green energy method may result in favourable environmental effects, which in turn may lead to better societal and economic development.

Methanol production and purification via membrane-based technology: Recent advancements, challenges, and the way forward

Industrail revolution on the back of fossil fuels has costed humanity higher temperatures on the planet due to ever-growing concentration of CO₂ emissions in Earth's atmosphere. To tackle global warming demand for renewable energy sources continues to increase. Along renewables, there has been a growing interest in converting carbon dioxide to methanol, which can be used as a fuel or a feedstock for producing chemicals. The current review study provides a comprehensive overview of the recent advancements, challenges, and future prospects of methanol production and purification via membrane-based technology. Traditional downstream processes for methanol production, such as distillation and absorption, have several drawbacks, including high energy consumption and environmental concerns. In comparison to conventional technologies, membrane-based separation techniques have emerged as a promising alternative for producing and purifying methanol. The review highlights recent developments in membrane-based methanol production and purification technology, including using novel membrane materials such as ceramic, polymeric, and mixed matrix membranes. Additionally, integrating photocatalytic processes with membrane separation has been investigated to improve the conversion of carbon dioxide to methanol. Despite the potential benefits of membrane-based systems, several challenges need to be addressed. Membrane fouling and scaling are significant issues that can reduce the efficiency and lifespan of the membranes. Furthermore, the cost-effectiveness of membrane-based systems compared to traditional methods is a critical consideration that must be evaluated. In conclusion, the review provides insights into the current state of membrane-based technology for methanol production and purification and identifies areas for future research. The development of high-performance membranes and the optimization of membrane-based processes are crucial for improving the efficiency and cost-effectiveness of this technology and for advancing the goal of sustainable energy production.

Membrane reactor for production of biodiesel from nonedible seed oil of Trachyspermum ammi using heterogenous green nanocatalyst of manganese oxide

Conventional homogeneous-based catalyzed transesterification for the production of biodiesel can be replaced with a membrane reactor that has an immobilized heterogeneous catalyst. Combining reaction with separation while utilizing membranes with a certain pore size might boost conversion process. this investigation to study the effectiveness of membrane reactor in combination with heterogeneous green nano catalysis of MnO2. Techniques such as XRD, EDX, FTIR, SEM, and TGA were used to characterize the synthesized MnO2 nano catalyst. The highest conversion of around 94% Trachyspermum ammi oil was obtained by MnO2. The optimum process variables for maximum conversion were catalyst loading of 0.26 (wt.%), 8:1 M ratio, 90 °C reaction temperature, and time 120 min. The green nano catalyst of MnO2 was reusable up to five cycles with minimum loss in conversion rate of about 75% in the fifth cycle. Nuclear magnetic resonance validated the synthesis of methyl esters. It was concluded that membrane reactor a promising technique to efficiently transesterify triglycerides into methyl esters and enable process intensification uses MnO2 as a catalyst.

Synthesis, characterization and adsorption behavior of modified cellulose nanocrystals towards different cationic dyes

Green and efficient removal of polluted materials are essential for the sustainability of a clean and green environment. Nanomaterials, particularly cellulose nanocrystals (CNCs), are abundant in nature and can be extracted from various sources, including cotton, rice, wheat, and plants. CNCs are renewable biomass materials with a high concentration of polar functional groups. This study used succinic anhydride to modify the surface of native cellulose nanocrystals (NCNCs). Succinic anhydride has been frequently used in adhesives and sealant chemicals for a long time, and here, it is evaluated for dye removal performance. The morphology and modification of CNCs studied using FTIR, TGA & DTG, XRD, SEM, AFM, and TEM. The ability of modified cellulose nanocrystals (MCNCs) to adsorb cationic golden yellow dye and methylene blue dye was investigated. The MCNCs exhibited high adsorption affinity for the two different cationic dyes. The maximum adsorption efficiency of NCNCs and MCNCs towards the cationic dye was 0.009 and 0.156 wt%. The investigation for adhesive properties is based on the strength and toughness of MCNCs. MCNCs demonstrated improved tensile strength (2350 MPa) and modulus (13.9 MPa) using E-51 epoxy system and a curing agent compared to 3 wt% composites. This research lays the groundwork for environmentally friendly fabrication and consumption in the industrial sector.

Synthesis of bioinspired sorbent and their exploitation for methylene blue remediation

In this research article, novel starch phosphate grafted polyvinyl imidazole (StP-g-PIMDZs) was synthesized. Firstly, a phosphate group was attached to starch polymer via a phosphorylation reaction. Next, 1-vinyl imidazole (VIMDZ) was grafted on the backbone of starch phosphate (StP) through a free radical polymerization reaction. The synthesis of these modified starches was confirmed by 1H NMR, 31P NMR and FT-IR techniques. The grafting of vinyl imidazole onto StP diminished the crystallinity. Due to the insertion of the aromatic imidazole ring, the StP-g-PIMDZs demonstrated greater thermal stability. The StP and StP-g-PIMDZs were used as sorbents for the adsorption of methylene blue dye (MBD) from the model solution. The maximum removal percentage for starch, StP, StP-g-PIMDZ 1, StP-g-PIMDZ 2 and StP-g-PIMDZ 3 was found to be 60.6%, 66.7%, 74.2%, 85.3 and 95.4%, respectively. The Pseudo second order kinetic model and Langmuir adsorption isotherm were best suited to the experimental data with R2 = 0.999 and 0.99, respectively. Additionally, the thermodynamic parameters showed that the adsorption process was feasible, spontaneous, endothermic and favored chemi-sorption mechanism.

Membrane-processed honey samples for pollen characterization with health benefits

Better processing techniques must be utilized widely due to the rising demand for honey. The most common honey processing techniques are applied to melissopalynomorphs to check the quality and quantity of valuable honey using microporous ultrafiltration membranes. It is essential to have the ability to selectively filter out sugars from honey using ultrafiltration. This study authenticated 24 honey samples using membrane reactors ultrafiltration protocol to describe the pollen spectrum of dominant vegetation. The purpose of this study was also to explore nutritional benefits as well as the active phytochemical constituents of honey samples. Honey samples were collected and labeled Acacia, Eucalyptus, and Ziziphus species based on plant resources provided by local beekeepers. A variety of honeybee flora was collected around the apiaries between 2020 and 2021. Honey analysis revealed that the pollen extraction of 24 bee foraging species belonging to 14 families. The honey membrane technology verified the identities of honey and nectar sources. Also, pollen identified using honey ultrafiltration membranes revealed dominant resources: Acacia spp. (69%), Eucalyptus spp. (52%) and Ziziphus spp. Honey filtration using a membrane technology classified 14 samples as unifloral, represented by six dominant pollen types. The absolute pollen count in the honey sample revealed that 58.33% (n = 14) belong to Maurizio's class I. Scanning ultrasculpturing showed diverse exine patterns: reticulate, psilate, scabrate-verrucate, scabrate-gemmate, granulate, perforate, microechinate, microreticulate, and regulate to fossulate for correct identification of honey pollen types. Honey ultrafiltration should be utilized to validate the botanical sources of honey and trace their biogeographic authenticity. Thus, it is imperative to look at the alternative useful method to identify the botanical origin of filtered honey. It is critical to separate honey from adulteration by a standardized protocol. Membrane technology has yielded significant outcomes in the purification of honey.

Graphene loaded TiO2 submicron spheres scattering layer for efficient dye-sensitized solar cell

Dye-Sensitized Solar Cells (DSSCs) have attracted great attention due to environmentally friendly low-cost processing, excellent working ability in diffuse light, and potential to meet the power demands of future buildings due the true class of building integrated photovoltaics (BIPV). Nevertheless, DSSCs have relatively low photoconversion efficiency (PCE) due to multiple issues. Several strategies have been employed to enhance its PCE. For instance, bi-layered structure of photoelectrode i.e., mesoporous TiO₂ transparent layer with top scattering layer was introduced which scatter light inside on large angles improves the harvesting ability of photoelectrode thus enhanced PCE. However, scattering layer is composed of aggregated small particles which offer sluggish electron transport due to multiple grain boundaries, consequently, unwanted recombination reaction which leads to poor PCE. This issue has been addressed for transparent layer immensely but ignored for scattering layer. Mostly for scattering layer in previous studies novel structures have been proposed to enhance scattering properties and dye adsorption only. Therefore, in this study for the first time presenting dual functional graphene/TiO₂ scattering layer in which solvent exfoliated graphene is incorporated in TiO₂ submicron spheres which enhanced electron transport properties, while submicron spheres scatter light effectively. Scattering and electron transport characteristics of DSSCs are thoroughly investigated with the function of graphene loading. Electrochemical impedance spectroscopy (EIS) has revealed that diffusion coefficient length and coefficient and conductivity attained maximum value at 0.01 wt%. while other important parameters such as electron lifetime and electron density in conduction band have been improved till 0.020 wt% graphene loading. However, results indicated that with 0.01 w% graphene 33% higher PCE was achieved than without scattering layer and 13% higher than scattering layer without graphene. The depraving in PCE at >0.01 wt% graphene despite of excellent electron transport improvement is attributed to the loss of diffuse reflectance and higher optical absorption by graphene.

Hydrophobic ammonium based ionic liquids for efficient extraction of textile dyes from aqueous media: Extraction study and antibacterial evaluation

Alizarin red S (ARS) extraction from aqueous medium was carried out using hydrophobic ionic liquids (ILs) containing trioctylammonium cation paired with 4-tert-butylbenzoate ([TOA][Butbenz] (IL1), 4-phenylbutanoate ([TOA][PheBut] (IL2), 3-4-dimethylbenzoate ([TOA][DMbenz] (IL3), naphthoate, ([TOA][Naph]) (IL4), salicylate ([TOA][Sali]) (IL5) and nonanedioate ([TOA]2[Nona]) (IL6). The findings demonstrated that all of the tested ILs were efficient for extracting ARS, however, [TOA]2[Nona] was more effective than others. For the extraction of ARS from the aqueous phase, the effects of various parameters including the initial pH of the dye solution, contact time, ILs to dye volume ratio (VIL:VW), dye concentration, temperature, and salt effect were investigated. The spontaneity of the liquid-liquid extraction of ARS from the aqueous phase to the IL phase was confirmed by thermodynamic parameters. More than 90% of the ARS was extracted from the aqueous phase to the IL phase throughout all experiments. Interaction of selected IL with dyes were confirmed using FTIR analysis. The standard bacterial strains of Escherichia coli (E. coli) ATCC BAA-2471 (gram negative) and Methicillin-resistant Staphylococcus (MRSA) ATCC 43300 (gram positive) were used for evaluating antibacterial activity. The lower dose (250 ppm), the ILs1, 2, 3, 4, 5, and 6 inhibited 0.40, 1.50, 6.50, 1.50, 2.50, and 0.50 mm growth of E. coli, and 4.0, 2.0, 16.50, 0.40, 5.0, and 3.50 mm growth of MRSA, respectively. The experimental findings confirmed that the present ILs can be utilized as an effective solvent for ARS and other dyes extraction from aqueous media.

Comparative study of ZIF-8-materials for removal of hazardous compounds using physio-chemical remediation techniques

The inherent toxicity, mutagenicity and carcinogenicity of dyes that are discharged into aquatic ecosystems, harming the health of humans and animals. ZIF-8 based composites are regarded as good adsorbents for the breakdown of dyes in order to remove or degrade them. In the course of this research, metal-organic framework materials known as ZIF-8 and its two stable composites, ZIF-8/BiCoO₃ (MZBC) and ZIF-8/BiYO₃ (MZBY), were produced via a hydrothermal process and solvothermal process, respectively, for the dangerous Congo red (CR) dye removal from the solution in water using adsorption method. According to the findings, the most significant amount of CR dye that could be adsorbed is onto MZBC, followed by MZBY and ZIF-8. The pseudo-second-order kinetic model was used effectively to match the data for adsorption behavior and was confirmed using the Langmuir isotherm equation. There is a possibility that the pH and amount of adsorbent might influence the adsorption behavior of the adsorbents. According to the experiment results, the technique featured an endothermic adsorption reaction that spontaneously occurred. The higher adsorption capability of MZBC is because of the large surface area. This results in strong interactions between the functional groups on the surface of MZBC and CR dye molecules. In addition to the electrostatic connection between functional group Zn-O-H on the surface of ZIF-8 in MZBC and the -NH₂ or SO₃ functional group areas in CR molecules, it also includes the strong π-π interaction of biphenyl rings.

Plant-soil-microbe interactions in maintaining ecosystem stability and coordinated turnover under changing environmental conditions

Ecosystem functions directly depend upon biophysical as well as biogeochemical reactions occurring at the soil-microbe-plant interface. Environment is considered as a major driver of any ecosystem and for the distributions of living organisms. Any changes in climate may potentially alter the composition of communities i.e., plants, soil microbes and the interactions between them. Since the impacts of global climate change are not short-term, it is indispensable to appraise its effects on different life forms including soil-microbe-plant interactions. This article highlights the crucial role that microbial communities play in interacting with plants under environmental disturbances, especially thermal and water stress. We reviewed that in response to the environmental changes, actions and reactions of plants and microbes vary markedly within an ecosystem. Changes in environment and climate like warming, CO₂ elevation, and moisture deficiency impact plant and microbial performance, their diversity and ultimately community structure. Plant and soil feedbacks also affect interacting species and modify community composition. The interactive relationship between plants and soil microbes is critically important for structuring terrestrial ecosystems. The anticipated climate change is aggravating the living conditions for soil microbes and plants. The environmental insecurity and complications are not short-term and limited to any particular type of organism. We have appraised effects of climate change on the soil inhabiting microbes and plants in a broader prospect. This article highlights the unique qualities of tripartite interaction between plant-soil-microbe under climate change.

Coupling of carboxymethyl starch with 2-carboxyethyl acrylate: A new sorbent for the wastewater remediation of methylene blue

Textile and printing industries play a vital role in the economy of any country. But the effluents of these industries, which contain toxic Methylene Blue (MB) dye when mixed with fresh water, make it unfit for human health and aquatic life. For the removal of MB, different adsorbents were used, but they were expensive, non-biodegradable or less effective. In this research, novel carboxymethyl starch grafted poly 2-carboxyethyl acrylate (CM-St-g-P2CEtA) was synthesized by reacting carboxymethyl starch with 2-carboxyethyl acrylate. The reaction followed a free radical polymerization mechanism. The structure and properties of CM-St-g-P2CEtA were investigated by advanced analytical techniques. The CM-St-g-P2CEtA was employed for the remediation of Methylene Blue (MB) dye from wastewater. The removal percentage (%R) of MB was checked under different parameters, like different pH levels, different initial concentrations of dye, different adsorbent doses, and different contact times. The results obtained during the experiment were subjected to different adsorption and kinetic models. In the kinetic investigation, the experimental results were best represented by the pseudo-second-order kinetic model due to its high R² value of 0.999. Similarly, with a regression coefficient (R²) value of 0.947, the Langmuir adsorption isotherm was best represented by the experimental results. The Langmuir adsorption model showed that MB dye was adsorbed on the surface of CM-St-g-P2CEtA in a monolayer pattern. The pseudo 2nd order kinetic model suggested that the adsorption process favored chemisorption mechanism. The CM-St-g-P2CEtA showed maximum percentage removal efficiency (%R) of 99.3% for MB dye.

Ni modified distillation waste derived heterogeneous catalyst utilized for the production of glycerol carbonate from a biodiesel by-product glycerol: Optimization and green metric studies

Biodiesel prices could be made competitive with petrol-diesel prices by valorizing its by-product glycerol. Glycerol carbonate can be derived from glycerol and is one of the widely needed chemical having high price and its extensive application in different industrial purposes. Glycerol carbonate can be synthesized via many routes; among them catalytic route gives promising activity and selectivity towards glycerol carbonate. For the first time, Ni modified distillation waste (CaO) derived heterogeneous catalyst Ni/CaO (NDW) was synthesized and utilized for the conversion of glycerol (Gl) to glycerol carbonate (GC). The catalyst's physicochemical properties were studied by performing TGA-DSC, XRD, FT-IR, SEM- EDAX, HRTEM, and basicity through Hammet indicator. Through NDW, solvent-free synthesis of glycerol carbonate was achieved using glycerol and dimethyl carbonate (DMC) as reactants upon conventional heating (90 °C). The validation of the synthesized product was performed through proton and carbon NMR analysis. In addition to this, HR-MS was performed to check the composition of the product formed. A plausible mechanism for the transesterification of glycerol (Gl) to glycerol carbonate (GC) was also designed. Higher conversion (99.2%) and selectivity (95%) towards glycerol carbonate (GC) were achieved at mild reaction conditions, viz., 1:3 M ratio of glycerol to DMC, reaction temperature 90 °C, reaction duration of 90 min with catalyst dose of 300 mg. The green metric parameters were also calculated to show that the overall process is sustainable and the environment benign.

Transformation of waste seed biomass of Cordia myxa into valuable bioenergy through membrane bioreactor using green nanoparticles of indium oxide

Depletion of non-renewable fuel has obliged researchers to seek out sustainable and environmentally friendly alternatives. Membranes have proven to be an effective technique in biofuel production for reaction, purification, and separation, with the ability to use both porous and non-porous membranes. It is demonstrated that a membrane-based sustainable and green production can result in a high degree of process intensification, whereas the recovery and repurposing of catalysts and alcohol are anticipated to increase the process economics. Therefore, in this study sustainable biodiesel was synthesized from inedible seed oil (37 wt%) of Cordia myxa using a membrane reactor. Transesterification was catalyzed by heterogenous nano-catalyst of indium oxide prepared with leaf extract of Boerhavia diffusa. Highest biodiesel yield of 95 wt% was achieved at methanol to oil molar ratio of 7:1, catalyst load 0.8 wt%, temperature 82.5 °C and time 180 min In₂O₃ nanoparticles exhibited reusability up to five successive transesterification rounds. The production of methyl esters was confirmed using Fourier-transform infrared spectroscopy and Nuclear Magnetic Resonance. The predominant fatty acid methyl ester detected in the biodiesel was 5, 8-octadecenoic acid. Biodiesel fuel qualities were determined to be comparable to worldwide ASTM D-6571 and EN-14214 standards. Finally, it was concluded that membrane technology can result in a highly intensified reaction process while efficient recovery of both nano catalysts and methanol increases the economics of transesterification and lead to sustainable production.

Energy, exergy, economic, environment, exergo-environment based assessment of amine-based hybrid solvents for natural gas sweetening

Natural gas is the cleanest form of fossil fuel that needs to be purified from CO₂ and H₂S to diminish harmful emissions and provide feasible processing. The conventional chemical and physical solvents used for this purpose have many drawbacks, including corrosion, solvent loss, high energy requirement, and the formation of toxic compounds, which ultimately disrupt the process and affect the environment. Hybrid solvents have lately been researched to cater to these liabilities and enhance process economics. This study screened eight solvents based on CO₂ selectivity viscosity, absorption enthalpy, corrosivity, working capacity, specific heat, and vapor pressure. From the screened solvents, ten cases of hybrid solvents are simulated and optimized on Aspen HYSYS®. Furthermore, 5Es (Energy, Exergy, Economic, Environmental, and Exergy-environmental) analyses were performed on optimized cases, and results were compared with the base case, MEA (30 wt%). The hybrid blend of Sulfolane and MDEA with weight percentages of 6% and 24%, respectively, showed the highest energy savings of 20% concerning the base case. In addition, it offered 93% savings in exergy destruction and 17.26% in the total operating cost of the process. It is also promising to the environment due to reduced entropy sent to the ecosystem and controlled CO₂ emissions. Therefore, the blend of Sulfolane and MDEA is proposed to Supersede the conventional solvent MEA for the natural gas sweetening process.

Catalytic Hydrothermal Liquefaction of Brachychiton populneus Biomass for the Production of High-Value Bio-Crude

The current study focused on the heterogenous catalytic hydrothermal liquefaction (HTL) of Brachychiton populneus biomass seed, using Ni as hydrogenation catalyst and Fe as active hydrogen producer. The activity of Ni metal and of Ni/Al2O3 in the HTL of seed (BS) and of a mixture of seed and shell (BM) was studied. To establish the best operating process conditions, the influence of variation of temperature and reaction time on the product yields was also examined. The highest bio-crude yields of 57.18% and 48.23% for BS and BM, respectively, were obtained at 330 °C and 10 min of reaction time, in the presence of Ni/Al2O3 as catalyst and Fe as hydrogen donor. Elemental analysis results showed that at these operative conditions, an increase of the higher heating value (HHV) from 25.14 MJ/kg to 38.04 MJ/kg and from 17.71 MJ/kg to 31.72 MJ/kg was obtained for BS and BM biomass, respectively, when the combination of Fe and Ni/Al2O3 was used. Gas chromatography–mass spectrometry (GC-MS) and Fourier transform infrared spectroscopy (FT-IR), used to determine the oils’ chemical compositions, showed that the combined presence of Fe and Ni/Al2O3 favored the hydrodeoxygenation of the fatty acids into hydrocarbons, indeed their amount increased to ≈20% for both biomasses used. These results demonstrate that the obtained bio-crude has the capacity to be a source of synthetic fuels and chemical feedstock.

Comparison of constructed wetland performance coupled with aeration and tubesettler for pharmaceutical compound removal from hospital wastewater

Pharmaceutical compounds being able to alter, retard, and enhance metabolism has gained attention in recent time as emerging pollutant. However, hospitals which are part of every urban landscape have yet to gain attention in terms of its hospital wastewater treatment to inhibit pharmaceutical compounds from reaching environment. Hence this study evaluated performance of constructed wetland in combination with tubesettler and aeration based on removal efficiency and ecological risk assessment (HQ). The removal efficiency of constructed wetland with plantation was higher by 31% (paracetamol), 102% (ibuprofen), 46%, (carbamazepine), 57% (lorazepam), 54% (erythromycin), 31% (ciprofloxacin) and 20% (simvastatin) against constructed wetland without plantation. Constructed wetland with aeration efficiency increased for paracetamol, ibuprofen, carbamazepine, lorazepam, erythromycin, ciprofloxacin, and simvastatin removal efficiency were higher by 58%, 130%, 52%, 79%, 107%, 57%, and 29% respectively. In constructed wetland with plantation, removal efficiency was higher by 20% (paracetamol), 13% (ibuprofen), 4% (carbamazepine), 14% (lorazepam), 34% (erythromycin), 19% (ciprofloxacin) and 7% (simvastatin). High ecological risk was observed for algae, invertebrate and fish with hazard quotient values in range of 2.5-484, 10-631 and 1-78 respectively. This study concludes that if space is the limitation at hospitals aeration with constructed wetland can be adopted. If space is available, constructed wetland with tubesettler is suitable, economic and environmentally friendly option. Future research works can focus on evaluating other processes combination with constructed wetland.

Incorporation of Nanocatalysts for the Production of Bio-Oil from Staphylea holocarpa Wood

Biomass has been recognized as the most common source of renewable energy. In recent years, researchers have paved the way for a search for suitable biomass resources to replace traditional fossil fuel energy and provide high energy output. Although there are plenty of studies of biomass as good biomaterials, there is little detailed information about Staphylea holocarpa wood (S. holocarpa) as a potential bio-oil material. The purpose of this study is to explore the potential of S. holocarpa wood as a bio-oil. Nanocatalyst cobalt (II) oxide (Co₃O₄) and Nickel (II) oxide (NiO) were used to improve the production of bio-oil from S. holocarpa wood. The preparation of biofuels and the extraction of bioactive drugs were performed by the rapid gasification of nanocatalysts. The result indicated that the abundant chemical components detected in the S. holocarpa wood extract could be used in biomedicine, cosmetics, and biofuels, and have a broad industrial application prospect. In addition, nanocatalyst cobalt tetraoxide (Co₃O₄) could improve the catalytic cracking of S. holocarpa wood and generate more bioactive molecules at high temperature, which is conducive to the utilization and development of S. holocarpa wood as biomass. This is the first time that S. holocarpa wood was used in combination with nanocatalysts. In the future, nanocatalysts can be used to solve the problem of sustainable development of biological resources.

Membrane based reactors for sustainable treatment of Coronopus didymus L. by developing Iodine doped potassium oxide Catalyst under Dynamic conditions

Green nano-technology together with the availability of eco-friendly and alternative sources are the promising candidates to combat environment deteriorations and energy clutches globally. The current work focuses on the synthesis and application of newly synthesized nano catalyst of Iodine doped Potassium oxide I (K₂O) for producing sustainable biodiesel from novel non-edible seed oils of Coronopus didymus L. using membrane based contactor to avoid emulsification and phase separation issues. Highest biodiesel yield (97.03%) was obtained under optimum conditions of 12:1 methanol to oil ratio, reaction temperature of 65 °C for 150 min with the 1.0 wt% catalyst concentration. The lately synthesized, environment friendly and recyclable Iodine doped Potassium oxide K (IO)₂ catalyst was synthesized via chemical method followed by characterization via advanced techniques including EDX, XRD, FTIR and SEM analysis. The catalyst was proved to be stable and efficient with the reusability of five times in transesterification reaction. These analysis have reported the sustainability, stability and good quality of biodiesel from seed oil of Coronopus didymus L. using efficient Iodine doped potassium oxide catalyst. Thus, non-edible, environment friendly and novel Coronopus didymus L. seeds and their extracted oil along with Iodine doped potassium oxide catalyst seems to be highly affective, sustainable and better alternative source to the future biodiesel industry. Also, by altering the reaction equilibrium and lowering the purification phases of the process, these studies show the potential of coupling transesterification and a membrane contactor.

Biodiesel Production Using Wild Apricot (Prunus aitchisonii) Seed Oil via Heterogeneous Catalysts

We confined the formation and characterization of heterogenous nano-catalysts and then used them to produce biodiesel from the novel non-edible seed oil of Prunus aitchisonii. P. aitchisonii seeds’ oil content was extracted at about 52.4 ± 3% with 0.77% FFA. Three different heterogenous nano-catalysts—calcined (CPC), KPC, and KOH-activated P. aitchisonii cake Titanium Dioxide (TiO₂)—were synthesized using calcination and precipitation methods. The mentioned catalysts were characterized through XRD, SEM, and EDX to inspect their crystallin dimension, shape, and arrangement. Titanium dioxide has morphological dimensions so that the average particle size ranges from 49–60 nm. The result shows that the crystal structure of TiO₂ is tetragonal (Anatase). The surface morphology of CPC illustrated that the roughness of the surface was increased after calcination, many macropores and hollow cavities appeared, and the external structure became very porous. These changes in morphology may increase the catalytic efficiency of CPC than non-calcined Prunus aitchisonii oil cake. The fuel belonging to PAOB stood according to the series suggested by ASTM criteria. All the characterization reports that P. aitchisonii is a novel and efficient potential source of biodiesel as a green energy source.

Non-edible plant seeds of Acacia farnesiana as a new and effective source for biofuel production

Currently, the energy crisis is a hot topic for researchers because we are facing serious problems due to overpopulation and natural energy sources are vanishing day-by-day. To overcome the energy crisis, biofuel production from non-edible plant seeds is the best solution for the present era. In the present study, we select the non-edible seeds of Acacia farnesiana for biofuel production from different areas of Pakistan with better oil production results. Different kinds of analytical method, like the American Standard for Testing and Materials and techniques like Fourier transform infra-red spectroscopy, nuclear magnetic resonance spectroscopy, gas chromatography, and inductively coupled plasma optical emission spectrometry, were used to evaluate the chemical compositions. The maximum oil extraction rate (23%) was produced by petroleum ether. Potassium hydroxide exhibited the best conversion result of 96% fatty acid methyl ester. The transesterification method was used for the preparation of fatty acid methyl ester (96%) using potassium hydroxide and methanol. The viscosity and density of Acacia farnesiana seed oil biodiesel was comparable to American Standard for Testing Material biodiesel standards. By using gas chromatography-mass spectrometry, five fatty acids were detected comprising palmitic acid (6.85%), stearic acid (2.36%), oleic acid (12.13%), linoleic acid (46.85%), and α-linolenic acid (1.23%). This study concludes that Acacia farnesiana seed oil biodiesel could be an intriguing raw material for yielding Acacia farnesiana seed oil methyl ester as an alternative fuel source.

Currently, the energy crisis is a hot topic for researchers because we are facing serious problems due to overpopulation and natural energy sources are vanishing day-by-day.

Efficient removal of ibuprofen and ofloxacin pharmaceuticals using biofilm reactors for hospital wastewater treatment

Hospital wastewater is harmful to the environment and human health due to its complex chemical composition and high potency towards becoming a source of disease outbreaks. Due to these complexities, its treatment is neither efficient nor cost-effective. It is a challenging issue that requires immediate attention. This effort focuses on the treatment of hospital wastewater (HWW) by removing two selected drugs, namely ibuprofen (IBU) and ofloxacin (OFX) using individual biological treatment methods, such as moving bed biofilm reactors (MBBR) and physicochemical treatment, such as ozonation and peroxane process. The both methods are compared to find the best method overall based on effectiveness and removal efficiency. The optimal removal for ozone dosing range was nitrate (9.00% and 62.00%), biological oxygen demand (BOD) (92.00% and 64.00%), and chemical oxygen demand (COD) (96.00% and 92.00%) that required at least 10 min to reach considerable degradation. The MBBR process assured a better performance for ibuprofen removal, overall. The IBU and OFX removal was found to be 14.32-96.00% at a higher COD value and 11.33-94.00% at a lower COD value due to its biodegradation. This work strives to pave the way forward to build an HWW treatment technology using integrated MBBR processes for better efficiency and cost-effectiveness.

Fe-zeolite catalyst for ozonation of pulp and paper wastewater for sustainable water resources

The pulp and paper industry consumes enormous quality of freshwater, leading to wastewater. It must be treated to remove pollutants, particularly residual dyestuffs, before releasing them to water bodies to avoid adverse environmental effects. The traditional wastewater treatment methods used for the pulp and paper industry are less efficient in colour and chemical oxygen demand (COD) removal. The current study is aimed at developing a novel catalyst for the catalytic ozonation of pulp and paper wastewater with better colour and COD removal for sustainable resources of clean water. The proposed catalyst is impregnated by iron on natural zeolites. Various parameters such as catalyst dose, pH, ozone dose, initial COD concentration, and reaction time are studied and optimized. The performance was evaluated by comparing the results with the single ozonation process (SOP) and catalytic ozonation process (COP). The highest COD and colour reduction efficiencies have been achieved, i.e., 71%, and 88% at a natural pH of 6.8. The proposed process achieved higher COD and colour efficiencies than the single ozonation process and catalytic ozonation process using raw zeolites. The improvement in efficiencies are 23% and 29% for SOP and 17% and 19% for COP, respectively. Hence, the results proposed the sustainability and applicability of COP to treat paper and pulp sector effluent.

Seed nano-priming with Zinc Oxide nanoparticles in rice mitigates drought and enhances agronomic profile

All cereal crops, particularly rice are perpetually affected due to drastic climatic changes which triggers different stressors resulting in food shortage scenarios across the globe. In modern era, application of nanotechnology holds the pledge in combating the climate change mediated environmental stressors through nanomaterials such as pesticides, nano-biosensors, nano-clays and nano-seed priming technologies. Current study is a part of experiment conducted to comprehend the behaviour of rice plants raised from Zinc Oxide nanoparticles (ZnONPs) primed seeds under the water shortage environment. The seed priming treatment concentrations included 0, 5, 10, 15, 25 and 50 ppm. In the experimental results an increase in plant height, total chlorophyll contents, plant fresh and dry weights was obtained by use of seed priming with ZnONPs. The study results proved that seed priming with 25ppm of ZnONPs increased seed and straw yield with value of 85.333 and 123.333, respectively under water deficit environment. The analysis depicted that 25 ppm has been found more suitable for increasing the 1000 paddy weight of rice plants under both well irrigated and water shortage conditions. Seed priming with ZnONPs results in 53% reduction in MDA contents of water stressed rice plants Drought stress leads to reduction in plant height by 31%, plant fresh weight by 22% and plant dry weight by 28%. Seed priming treatments imparted in current study show significance increase in plant biomass. Priming with ZnONPs further enhances the levels of proline amino acid facilitating the plant to combat water shortage stress. A further elevation in activities of SOD, CAT and POD takes place in rice plants raised from ZnONPs primed seeds by 11%, 13% and 38%, respectively. An elevation in activities of antioxidant enzymes was found and the levels of oxidative stress indicators decreased upon seed priming with ZnONPs. Furthermore the yield characteristics such as panicle length, number of tillers, paddy yield and straw yield of the rice plants raised through ZnONPs primed seeds enhanced. The ZnONPs at concentration of 25 ppm proved optimum in alleviating drought induced damages. It can be inferred that seed pre conditioning with ZnONPs is helpful in increasing yield attributes under the water shortage environment.

Biodiesel synthesis from Prunus bokhariensis non-edible seed oil by using green silver oxide nanocatalyst

The present work investigates the proficiency of green silver oxide nanocatalyst synthesised from Monotheca buxifolia (Falc.) Dcne. leaves extract, and their application for biodiesel synthesis from novel Prunus bokhariensis seed oil (non-edible). The seed oil content of 55% and FFA content of 0.80 mg KOH/g were reported. Several analytical tools (EDX, FT-IR, SEM and XRD) were used to characterise the Ag₂O nanocatalyst. Maximum (89%) FAME yield of the PBSOB (Prunus bokhariensis seed oil biodiesel) was achieved at ambient transesterification conditions i.e. 3.5 wt% nanocatalyst loading, 2.5 h reaction time, 130 °C of reaction temperature and 12:1 alcohol to oil ratio. The synthesised PBSOB was additionally characterised by analytical methods like, GC-MS and FT-IR. The different aspects of fuel were identified i.e. flash point (84 °C), kinematic viscosity (4.01 cSt @ 40 °C), sulphur content (0.0003 wt %), density (0.853 kg/L) and acid number (0.167 mg KOH/g). All the above properties were verified and agreed well with biodiesel international standards (European Union (14214), China GB/T (20828) and ASTM (6751, 951). In general, Prunus bokhariensis seed oil and Ag₂O nanocatalyst seem to be remarkably active, cheap and stable candidates for the biodiesel industry in future.

Synthesis and catalytic properties of calcium oxide obtained from organic ash over a titanium nanocatalyst for biodiesel production from dairy scum

The fatty acid methyl ester (FAME) production from dairy effluent scum as a sustainable energy source using CaO obtained from organic ash over titanium dioxide nanoparticles (TNPs) as the transesterification nano-catalyst has been studied. The physical and chemical properties of the synthesized catalysts were characterized, and the effect of different experimental factors on the biodiesel yield was studied. It was revealed that the CaO-TiO₂ nano-catalyst displayed bifunctional properties, has both basic and acid phases, and leads to various effects on the catalyst activity in the transesterification process. These bifunctional properties are critical for achieving simultaneous transesterification of dairy scum oil feedstock. According to the reaction results, the catalyst without and with a low ratio of TNPs showed a low catalytic activity. In contrast, the 3Ca-3Ti nano-catalyst had the highest catalytic activity and a strong potential for reusability, producing a maximum biodiesel yield of 97.2% for a 3 wt% catalyst, 1:20 oil to methanol molar ratio for the dairy scum, and a reaction temperature of 70 °C for a period of 120 min under a 300 kPa pressure. The physical properties of the produced biodiesel are within the EN14214 standards.

Phyllosilicate derived catalysts for efficient conversion of lignocellulosic derived biomass to biodiesel: A review

The efforts have been made to review phyllosilicate derived (clay-based) heterogeneous catalysts for biodiesel production via lignocellulose derived feedstocks. These catalysts have many practical and potential applications in green catalysis. Phyllosilicate derived heterogeneous catalysts (modified via any of these approaches like acid activated clays, ion exchanged clays and layered double hydroxides) exhibits excellent catalytic activity for producing cost effective and high yield biodiesel. The combination of different protocols (intercalated catalysts, ion exchanged catalysts, acidic activated clay catalysts, clay-supported catalysts, composites and hybrids, pillared interlayer clay catalysts, and hierarchically structured catalysts) was implemented so as to achieve the synergetic effects (acidic-basic) in resultant material (catalyst) for efficient conversion of lignocellulose derived feedstock (non-edible oils) to biodiesel. Utilisation of these Phyllosilicate derived catalysts will pave path for future researchers to investigate the cost-effective, accessible and improved approaches in synthesising novel catalysts that could be used for converting lignocellulosic biomass to eco-friendly biodiesel.

Constructed sediment microbial fuel cell for treatment of fat, oil, grease (FOG) trap effluent: Role of anode and cathode chamber amendment, electrode selection, and scalability

For wastewater treatment, sediment microbial fuel cells (SMFCs) have advantages over traditional microbial fuel cells in cost (due to their membrane-less structure) and operation (less intensive maintenance). Nevertheless, the technical obstacles of SMFCs include their high internal electrical resistance due to sediment in the anode chamber and slow oxygen reduction reaction (ORR) in the cathode chamber, which is responsible for their low power density (PD) (0.2-50 mW/m²). This study evaluated several SMFC improvements, including anode and cathode chamber amendment, electrode selection, and scaling the chamber size up to obtain optimally constructed single-chamber SMFCs to treat fat, oil, and grease (FOG) trap effluent. The chemical oxygen demand (COD) removal efficiency, PD, and electrical energy conversion efficiency concerning theoretically available chemical energy from FOG trap effluent treatment (%EC^WW) were examined. Packing biochar in the anode chamber reduced its electrical resistance by 5.76 times, but the improvement in PD was trivial. Substantial improvement occurred when packing the cathode chamber with activated carbon (AC), which presumably catalyzed the ORR, yielding a maximum PD of 109.39 mW/m², 959 times greater than without AC in the cathode chamber. This SMFC configuration resulted in a COD removal efficiency of 85.80 % and a %EC^WW of 99.74 % in 30 days. Furthermore, using the most appropriate electrode pair and chamber volume increased the maximum PD to 1787.26 mW/m², around 1.7 times greater than the maximum PD by SMFCs reported thus far. This optimally constructed SMFC is low cost and applicable for household wastewater treatment.

Implication of scanning electron microscopy as a tool for identification of novel, nonedible oil seeds for biodiesel production

Biodiesel is a promising, bio-based, renewable, nontoxic, environment friendly, and alternative fuel for petroleum derived fuels which helps to reduce dependency on conventional fossil fuels. In this study, six novel, nonedible seed oil producing feedstock were explored for their potential for sustainable production of biodiesel. It is very important to correctly identify oil yielding plant species. Scanning electron microscopy (SEM) was used as reliable tool for authentic identification of oil yielding seeds. Macromorphological characters of seeds were studied with light microscopy (LM). Outcomes of LM of seeds exposed distinctive variation in seed size from 16.3 to 3.2 mm in length and 12.4 to 0.9 mm in width, shape varied from oval to triangular, and color from black to light brown. Oil content of nonedible seed ranged from 25 to 30% (w/w). Free fatty acid content of seed oil varied from 0.32 to 2.5 mg KOH/g. Moreover, ultra structural study of seeds via SEM showed variation in surface sculpturing, cell arrangement, cell shape, periclinal wall shape, margins, protuberances, and anticlinal wall shape. Surface sculpturing varied from rugged, reticulate, varrucose, papillate, and striate. Periclinal wall arrangements confirmed variation from rough, wavy, raised, depressed, smooth, and elevated whereas, anticlinal walls pattern showed variation from profuse undulating, smooth, raised, grooved, deep, curved, and depressed. It was concluded that SEM could be a latent and advanced technique in unveiling hidden micromorphological characters of nonedible oil yielding seeds which delivers valuable information to researchers and indigenous people for precise and authentic identification and recognition.

Scanning electron microscopy as a tool for authentication of biodiesel synthesis from Linum usitatissimum seed oil

Utilization of renewable and alternative energy feedstocks such as nonedible seeds oil to deal with the increasing energy crises and related ecological concerns have gained the attention of researchers. Biodiesel is an efficient and renewable substitute for diesel engine. This work investigates the potential of inexpensive nonedible seed oil of Linum usitatissimum to synthesize biodiesel using iron sulfate green nanocatalyst through the process of transesterification. Flax seed contains about 37.5% oil content estimated through Soxhlet apparatus. Light microscopy revealed that seed size varies from 3.0 to 6.0 cm in length, 2.0 to 3.3 cm in width, and 0.7 to 1.0 mm in diameter. Color of seed varied from yellow to brown. Characterization of biodiesel is performed through GC-MS and FTIR. Scanning electron microscopy was carried out to study the morphological features of seed coat. Catalyst was characterized by scanning electron microscopy, energy diffraction X-ray, and X-ray diffraction. The diffraction peaks of Fe₃ O₄ green nanoparticles were found to be in 2θ values, 30.24°, 35.62°, 38.26°, 49.56°, 57.12°, and 62.78°. Fuel properties of biodiesel are also determined and compared with ASTM standards. Linum usitatissimum biodiesel has density 0.8722 (15°C kg/L), kinetic viscosity 5.45 (40°C cSt), flash point (90°C), pour point (-13°C), cloud point (-9°C), sulfur (0.0432% wt), and total acid number (0.245 mg KOH/g). It is concluded that L. usitatissimum seed oil is a highly potential source for biodiesel production to cope with the challenge of present energy demand.

Transition metal oxide (NiO, CuO, ZnO)-doped calcium oxide catalysts derived from eggshells for the transesterification of refined waste cooking oil

This paper reports the synthesis of new transition metal oxide-modified CaO catalysts derived from eggshells for the transesterification of refined waste cooking oil. CaO is a well-known base catalyst for transesterification. However, its moderate basicity and low surface area have restricted its catalytic performance. Therefore, a new attempt was made to modify the CaO catalyst with transition metal oxides, including Ni, Cu and Zn oxides, via simple wetness impregnation method. The catalytic performance of the resulting modified CaO-based catalysts was evaluated through the transesterification reaction using refined waste cooking oil. The results showed that the NiO/CaO(10 : 90)(ES) catalyst calcined at 700 °C, demonstrated being highly potential as a catalyst. It gave the highest biodiesel production (97.3%) at the optimum conditions of 1 : 18 oil-to-methanol molar ratio, 6 wt% catalyst loading and 180 minutes reaction time as verified by response surface methodology (RSM). The high catalytic activity of NiO/CaO(10 : 90)(ES)(700 °C) was attributed to its high basicity (8.5867 mmol g⁻¹) and relatively large surface area (7.1 m² g⁻¹). The acid value and free fatty acids of the biodiesel produced under optimal process conditions followed the EN 14214 and ASTM D6751 limit with 0.17 mg KOH per g (AV) and 0.09 mg KOH per g (FFA), respectively.

This paper reports the synthesis of new transition metal oxide-modified CaO catalysts derived from eggshells for the transesterification of refined waste cooking oil.