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The advancement of eco-friendly technology in the construction sector has been improving rapidly in the last few years. As a result, multiple building materials were developed, enhanced, and proposed as replacements for some traditional materials. One notable example presents geopolymer as a substitute for ordinary Portland concrete (OPC). The manufacturing process of (OPC) generates CO2 emissions and a high energy demand, both of which contribute to ozone depletion and global warming. The implementation of geopolymer concrete (GPC) technology in the construction sector provides a path to more sustainable growth and a cleaner environment. This is due to geopolymer concrete's ability to reduce environmental pollutants and reduce the construction industry's carbon footprint. This is achieved through its unique composition, which typically involves industrial byproducts like fly ash or slag. These materials, rich in silicon and aluminum, react with alkaline solutions to form a binding gel, bypassing the need for the high-energy clinker production required in OPC. The use of such byproducts not only reduces CO2 emissions but also contributes to waste minimization. Additionally, geopolymer offers extra advantages compared to OPC, including improved mechanical strength, enhanced durability, and good stability in acidic and alkaline settings. Such properties make GPC particularly suitable for a range of construction environments, from industrial applications to infrastructure projects exposed to harsh conditions. This paper comprehensively reviews the different characteristics of geopolymers, which include their composition, compressive strength, durability, and curing methods. Furthermore, the environmental impacts related to the manufacturing of geopolymer materials were evaluated through the life-cycle assessment method. The result demonstrated that geopolymer concrete maintains positive environmental impacts due to the fact that it produces fewer carbon dioxide CO2 emissions compared to OPC concrete during its manufacturing; however, geopolymer concrete had some minor negative environmental impacts, including abiotic depletion, human toxicity, freshwater ecotoxicity, terrestrial ecotoxicity, and acidification. These are important considerations for ongoing research aimed at further improving the sustainability of geopolymer concrete. Moreover, it was determined that silicate content, curing temperature, and the proportion of alkaline solution to binder are the major factors significantly influencing the compressive strength of geopolymer concrete. The advancement of geopolymer technology represents not just a stride toward more sustainable construction practices but also paves the way for innovative approaches in the field of building materials. [ABSTRACT FROM AUTHOR]

Considering the risk associated with exposure to benzene and toluene in water resources, researchers have been motivated to conduct studies to remove them from aqueous solutions. Thus, by performing the present study, the potential of Fe3O4/zeolite imidazolate framework nanoparticles (Fe3O4@ZIF-8) was evaluated for the adsorption of benzene and toluene. Accordingly, the solution pH, Fe3O4@ZIF-8 dosage, mixing time, concentration of benzene and toluene, and temperature, were the parameters considered for conducting the batch experiments, for which their effect on adsorption efficiency was evaluated. Our conducted experiments introduced the neutral pH as the best pH range to obtain the maximum removal. Fitting the adsorption data into the various models revealed the aptness of the Langmuir isotherm equation in describing experimental information and highest adsorption capacity; for benzene it was 129.4, 134.2, 137.3, and 148.2 mg g−1, but for toluene it was 118.4, 125.2, 129.6, and 133.1 mg g−1, for temperature 20, 30, 40, and 50 °C, respectively. Using obtained optimal conditions, the adsorption efficiencies of benzene and toluene were obtained to be 98.4% and 93.1%, respectively. Kinetic studies showed acceptable coefficients for PSO kinetics and confirmed its suitability. Also, the recyclability results showed that for six consecutive periods of the adsorption-desorption process, the percentage of removal decreased by only 6% for benzene and toluene. Moreover, calculating thermodynamic parameter changes for benzene and toluene removal confirmed the favorability and spontaneity of the studied process and its endothermic nature. Considering the above findings, Fe3O4@ZIF-8 was found to be an operative adsorbent for removing pollutants. [ABSTRACT FROM AUTHOR]

In the present study, the adsorption behavior of ciprofloxacin (CIP) from aqueous solution onto MWCNTs/Al2O3 was studied using batch experiments. Physical characterization of MWCNTs/Al2O3 was determined by SEM, XRD, and BET. The effective parameters investigated included: initial CIP concentration, contact time, MWCNTs/Al2O3 mass, and temperature. Based on experimental results and correlation coefficients, the rate of CIP adsorption followed the pseudo-second-model kinetics. Complete compatibility of the adsorption isotherm process was achieved with the Langmuir model, and the maximum adsorption capacity reached 41.73 mg/g under the optimized conditions (pH = 7, MWCNTs/Al2O3 dose = 1.2 g/L, contact time = 60 min, initial concentration = 10 mg/L, and temperature= 45 °C). The adsorption capacities based on the Langmuir model at different temperatures, 273, 288, 303, and 318 K, were equal to 72.18, 75.92, 79.65, and 83.47 mg/g, respectively. The determined parameters of the thermodynamic studies demonstrated the endothermic and spontaneous nature of the biosorption. The mean free energy was estimated from D–R isotherm model to be 0.316–0.707 KJ/mol, which clearly proved that the adsorption experiment followed a physical process. The data suggest that MWCNTs/Al2O3 could be used as a highly effective adsorbent material with a high capacity for the removal of antibiotics from water and wastewater. [ABSTRACT FROM AUTHOR]

• First food waste study at a university campus in Qatar. • Mixture of large-scale catering services and specialized franchise food outlets. • The per person food waste generation exceeds the highest globally reported rates. • Overproduction is the main driver for food wastage resulting from food display. • Highlights the possible scale of issue at cafeterias and need for caterer education. Food waste is a pressing issue that imposes economic, social and environmental impacts on both developing and developed countries. This study analyzes quantitatively and qualitatively the generated food waste at various food outlets of a university campus in Qatar. It is a fundamental step to manage the issue of food waste from educational institutes. The investigation comprised four stages: screening, sampling, surveying, and synthesis. Food waste generation at the sampled locations was estimated at 329.5 kg/day or 80 t/year. Based on per sales estimates, total food waste was 980 g/sale and 757 g/sale at the student male and female housing complexes, respectively, equating to roughly one wasted meal for each sold meal. The majority of this waste was avoidable waste and the root cause for the excessive food waste generation was overproduction rather than consumer wastage. The study found that the main food provider, who primarily serves buffet style meals, lacks the proper tools to measure food waste generated at their cafeterias. Past experience was the primary tool to support the company's demand management estimation which has proven unsuccessful and highlights the need to not only educate the consumer but also food providers. Possible treatments routes are discussed based on food waste characterization findings. [ABSTRACT FROM AUTHOR]

• Study evaluates generation from biomass gasification. • Syngas is used within poly-generation systems to generate sustainable fuels. • The article considers recycling of multiple sources of biomass to generate syngas. • A new poly-generation process to produce urea, liquids fuels and power is proposed. • A novel hybrid environmental and economic optimisation methodology is proposed. The production of renewable chemicals and fuels is driving modern society towards a type of sustainable development which involves a decreasing dependency on fossil fuels and the minimisation of waste. Biomass, a waste by-product from the urban environment, is a carbon dioxide neutral organic fuel that can potentially serve as a feedstock for the production of sustainable power and heat. Gasification is preferred over the other thermal conversion options for biomass processing whereby the product synthesis gas can be utilised to power generators/turbines and generate clean energy, ammonia and methanol. Incidentally, efficient and economically sound biomass driven supply chains can be integrated into an existing petrochemical infrastructure. Moreover, the potential production volumes of fuels and green chemicals can also be increased by the addition of multiple biomass sources, thereby creating potential positive scale effects. This study proposes a new poly-generation process that utilises multiple sources of biomass feedstock to produce high quality urea, methanol, Fisher-Tropsch liquids and power. Four flowsheet configurations are simulated using Aspen Plus software and the built-in capabilities of the activated analysis using Aspen Process Economic Analyzer and Aspen Energy Analyzer to perform the economic, energy and environmental impact calculations. The results demonstrate that the methanol production technique is the most economic process pathway with a net profit of approximately $0.035 per kg of biomass input, whilst the urea process pathway presents the lowest environmental impact solution with approximately 0.71 kg of CO 2 -e per kg of biomass input. These results are relative and can be analysed from different perspectives based on the market demand of the products and their applications and local need. For instance, considering at the economic and environmental indicators relative to the production capacity, production of liquid fuels achieve net profits of approximately $0.27 per kg of product, whilst urea production demonstrates the lowest environmental emissions of approximately 3.93 kg of CO 2 -e per kg of product. [ABSTRACT FROM AUTHOR]

Graphical abstract Graphical abstract demonstrating the complexation of acacia gum with lead in water and the removal of the complexed AG/lead by membrane filtration. Highlights • Acacia gum (AG) was used as novel & cheap agent for lead removal from water. • Effect of AG dosage, pH, and contact time on lead removal was studied. • Lead removal of 99.9% achieved with AG followed by membrane filtration. • The possible mechanism of lead chelating with AG was discussed. Abstract In this work, for the first time, the use of AG as a natural, widely available and cheap material to enhance the removal of lead from contaminated water using polymer-enhanced membrane filtration (PEMF) has been carried out. In this technique, heavy metal ions are chelated with high molecular weight water-soluble polymers with following rejection of the formed polymer-metal complexes with the wide-porous and high flux polymer membranes. Acacia gum (AG) is a natural gum, which is collected from the hardened sap of some species of the acacia tree. The surface area particle sizes, zeta potential and elemental composition of AG were evaluated using BET, FE-SEM, zeta potential analyzer, EDS and XPS methods. The effect of AG dosage, lead concentration, feed pH, and contact time on lead-AG complex formation has been studied. The highest binding capacity of AG was about 12.2 mg/g when 1000 ppm AG was added to 35 ppm lead solution at pH 7. It was found that, with a dosage of 1000 mg/L of AG at pH 7, successful lead removal efficiencies of 97.5%, 98.3% and 99.9% were achieved using microfiltration polytetrafluoroethylene (PTFE), 30 kDa and 3 kDa molecular weight cut-off ultrafiltration cellulose membranes, respectively. The possible mechanism of lead removal with AG has been discussed. The obtained data have shown that AG can be used as a safe and cheap chelating agent for lead removal from water. [ABSTRACT FROM AUTHOR]

Recycling low-end, one-time-use plastics—such as low-density polyethylene (LDPE)—is of paramount importance to combat plastic pollution and promote sustainability in the modern green economy. This study valorizes LDPE waste by transforming it into 3D oleophilic swellable thin films through a process involving dissolution, phase separation, and extraction. These films are subsequently layered using a customized polypropylene (PP) based nonwoven fabric separator and securely sealed in a zigzag pattern. The zigzag-shaped seal enhances the adhesion of pollutants to the sorbent by providing wire curvatures that increase retention time and uptake capacity. As a result, the sorbent exhibits impressive oil uptake capacities, with immediate and equilibrium values of 120 g/g and 85 g/g, respectively. Notably, the as-prepared sorbent demonstrates low water retention and high selectivity for oil, outperforming commercially available oil sorbents. The unique design involving a 3D-film structure, superposed films, and a zigzag-shaped seal offers a sustainable and value-added solution to the issues of LDPE waste and oil spills on water surfaces. [ABSTRACT FROM AUTHOR]

Sorbent pads and films have been commonly used for environmental remediation purposes, but designing their internal structure to optimize access to the entire volume while ensuring cost-effectiveness, ease of fabrication, sufficient strength, and reusability remains challenging. Herein, we report a trimodal sorbent film from recycled polypropylene (PP) with micropores, macro-voids, and sponge-like 3D cavities, developed through selective dissolution, thermally induced phase separation, and annealing. The sorbent has hundreds of cavities per cm2 that are capable of swelling up to twenty-five times its thickness, allowing for super-fast saturation kinetics (within 30 s) and maximum oil sorption (97 g/g). The sorption mechanism follows a pseudo-second-order kinetic model. Moreover, the sorbent is easily compressible, and its structure is retained during oil sorption, desorption, and resorption, resulting in 96.5% reuse efficiency. The oil recovery process involves manually squeezing the film, making the cleanup process efficient with no chemical treatment required. The sorbent film possesses high porosity for effective sorption with sufficient tensile strength for practical applications. Our integrated technique results in a strengthened porous polymeric structure that can be tailored according to end-use applications. This study provides a sustainable solution for waste management that offers versatility in its functionality. [ABSTRACT FROM AUTHOR]

Inorganic membrane science and technology is an attractive field of membrane separation technology, which has been dominated by polymer membranes. Recently, the inorganic membrane has been undergoing rapid development and innovation. Inorganic membranes have the advantage of resisting harsh chemical cleaning, high temperature and wear resistance, high chemical stability, long lifetime, and autoclavable. All of these outstanding properties made inorganic membranes good candidates to be used for water treatment and desalination applications. This paper is a state of the art review on the synthesis, development, and application of different inorganic membranes for water and wastewater treatment. The inorganic membranes reviewed in this paper include liquid membranes, dynamic membranes, various ceramic membranes, carbon based membranes, silica membranes, and zeolite membranes. A brief description of the different synthesis routes for the development of inorganic membranes for application in water industry is given and each synthesis rout is critically reviewed and compared. Thereafter, the recent studies on different application of inorganic membrane and their properties for water treatment and desalination in literature are critically summarized. It was reported that inorganic membranes despite their high synthesis cost, showed very promising results with high flux, full salt rejection, and very low or no fouling. [ABSTRACT FROM AUTHOR]

This study presents the copyrolysis of three biomasses (date pits, cow manure, and coffee waste) and explores the potential of utilizing natural waste catalysts—seashell (SS) and cuttlebone (CB)—to improve the kinetics and thermodynamics of the process. Mixing the feeds led to positive synergistic effects, particularly at a heating rate of 10 K/min or higher. By employing three model-free kinetic methods, the estimated activation energy (Ea) was lower for the ternary feed than the single feeds, and 20 wt.% of the feed with SS and CB catalysts was added. The Ea reduced from 162 kJ/mol for the ternary feed by 25.6% (~121 kJ/mol) and 21.6% (154 kJ/mol) in the presence of SS and CB, respectively. The thermodynamic parameters were positive for all the noncatalytic feeds, resulting in endothermic, nonspontaneous reactions and increased disorder or randomness. Catalysts influenced the thermodynamic parameters, making the process more energy efficient. The results are the utilization of cheap, eco-friendly feeds and catalysts for sustainable energy production using copyrolysis. [ABSTRACT FROM AUTHOR]

Natural product waste treatment and the removal of harmful dyes from water by adsorption are two of the crucial environmental issues at present. Traditional adsorbents are often not capable in removing detrimental dyes from wastewater due to their hydrophilic nature and because they form strong bonds with water molecules, and therefore they remain in the dissolved state in water. Consequently, new and effective sorbents are required to reduce the cost of wastewater treatment as well as to mitigate the health problems caused by water pollution contaminants. In this study, the adsorption behaviour of methyl orange, MO, dye on chitosan bead-like materials was investigated as a function of shaking time, contact time, adsorbent dosage, initial MO concentration, temperature and solution pH. The structural and chemical properties of chitosan bead-like materials were studied using several techniques including SEM, BET, XRD and FTIR. The adsorption process of methyl orange by chitosan bead materials was well described by the Langmuir isotherm model for the uptake capacity and followed by the pseudo-second-order kinetic model to describe the rate processes. Under the optimal conditions, the maximum removal rate (98.9%) and adsorption capacity (12.46 mg/g) of chitosan bead-like materials were higher than those of other previous reports; their removal rate for methyl orange was still up to 87.2% after three regenerative cycles. Hence, this chitosan bead-like materials are very promising materials for wastewater treatment. [ABSTRACT FROM AUTHOR]

Haematite (Fe2O3) loaded on graphitic carbon nitride (g-C3N4) was synthesised as a new photocatalyst by hydrothermal method, and its photocatalytic activity was evaluated for the degradation of ciprofloxacin (CIP) from aqueous solutions. Structural properties determined by scanning electron microscope (SEM), X-ray powder diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR) showed that Fe2O3 nanoparticles were successfully prepared and a good interaction occurred between g-C3N4 and Fe2O3. The g-C3N4/Fe2O3/UV system showed higher degradation efficiencies than UV and g-C3N4/Fe2O3 alone. The maximum removal of CIP (100%) and TOC (93.86%) was achieved at pH of 7, photocatalytic dosage of 0.3 g/L, radiation intensity of 36 W, and reaction time of 60 min. The rate of degradation of CIP was investigated by first-order kinetic and its constant rate confirmed the influence of factors. Trapping experiments showed that hole (h+), hydroxyl radical (•OH) and superoxide radical (O2•-) were involved in photodegradation of CIP, however, h+ and •OH plays major role in the degradation of the target pollutant. The excellent stability and recyclability of g-C3N4/Fe2O3 was confirmed by five consecutive reaction cycles. The energy consumption of the system for different concentrations of CIP (10–50 mg/L) was in the range of 9–44.02 kWh/m3, which emphasises that the g-C3N4/Fe2O3/UV process is energy-efficient. The BOD5/COD rate showed that the photocatalytic process can degrade CIP into degradable compounds. The presence of NH4+, NO3− and F− anions in the treated effluent indicates that CIP is well mineralised. Toxicity experiments performed by Escherichia coli (E. coli) and Enterococcus faecalis (E. faecalis) culture suggested the applicability of the g-C3N4/Fe2O3/UV process as a promising and effective technology for treatment of CIP-containing solution. [ABSTRACT FROM AUTHOR]

MXene as two dimensional (2-D) Titanium (III) Carbide (II) (Ti 3 C 2 T x ) nanosheets was synthesized and processed by etching bulk MAX phase Titanium (III) Aluminium Carbide (II) (Ti 3 AlC 2 ) powders in HF solution. This material demonstrated an extraordinary efficiency for the removal of barium from synthetic produced/co-produced water. The synthesized nanosheet was characterized using field emission scanning electron microscopy (FE-SEM), the Brunauer, Emmett and Teller (BET) nitrogen surface area adsorption, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), particle size analysis and zeta potential. The effect of adsorption parameters such as adsorbent dosage, contact time, and initial barium concentration were investigated and the optimum parameters for maximum removal of barium have been investigated. The experimental adsorption equilibrium data were correlated by the Langmuir and Freundlich isotherms, while the sorption energy was calculated using Dubinin-Radushkevich (D-R) model. The kinetic data were analyzed using two kinetic models. Optimization of process variables including shaking speed, contact time, pH, and amount of MXene has been performed to determine the maximum adsorption capacity of barium from water. MXene has a combination of unique properties such as a large number of available active sites, hydrophilic surface, highly negative surface charge, chemical stability, reasonable surface area, and the possibility of cations intercalating through its layers. MXene showed a large sorption capacity, fast kinetics, enormous trace barium removal, and reversible adsorption properties which offer an efficient removal performance of barium with a capacity of 9.3 mg/g and removal efficiency reaching up to 100% under optimized conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • A hybrid biorefinery is developed for jet biofuel production. • The system provides a unique integration of technologies, streams, and heat. • The system accommodates multiple biomass from different solid and liquid categories. • A 22% reduction in jet fuel price is achieved as compared to the conventional Jet-A. • A 41% mitigation of associated emissions is attained relative to Jet-A. Jet biofuel (JBF) is identified as an essential solution to mitigate the carbon footprint of the aviation sector. Since aeroplanes rely solely on liquid fuels, the development of pathways that generates JBF as a major product has become crucial. Thus far, seven pathways to produce JBF have been developed and certified over the past decade. Each of these pathways accommodates a specific type of biomass. However, the availability, sustainability and feasibility of feedstocks to fulfil the growing demand on jet fuel remains an issue. As such, this study presents a holistic approach for the design of a state-of-the-art hybrid biorefinery that accommodates multiple biomass feedstocks across different categories including energy crops (i.e., Jatropha energy crop), dry biomass (i.e., municipal solid waste) and wet biomass (i.e., livestock manure). A Qatar-based industrial scale biorefinery was modelled in Aspen Plus® considering a pre-defined geospatial distribution of biomass and the optimal biorefinery site in the country. The hybrid system integrated advanced technologies such as hydroprocessing, Fischer-Tropsch, gasification, dry-reforming and hydrothermal liquefaction. While biomass optimal insertion streams were evaluated using a prediction model. Besides, intensive materials, heat, water and power integrations were performed to maximise JBF production, mitigate its environmental impact and control its cost. The system generated 328, 94 and 44 million litres of JBF, gasoline and diesel, respectively. Produced JBF was characterised and found to comply with all international standards. The generated JBF can substitute 15.3 % of Qatar's jet fuel needs, while it can power around one third of its fleet considering a maximum allowable jet biofuel blend of 50 %. The proposed model achieved a minimum selling price of JBF at 0.43 $/kg, which is 22 % lower than the market price of conventional Jet-A fuel (2019). In addition, the environmental analysis of the model indicated a 41 % mitigation in greenhouse gas emissions achieved by JBF throughout its lifecycle, relative to Jet-A fuel. [ABSTRACT FROM AUTHOR]

Oil removal from water is a highly important area due to the large production rate of emulsified oil in water, which is considered one of the major pollutants, having a negative effect on human health, environment and wildlife. In this study, we have reported the application of high quality carbon nanotube bundles produced by an injected vertical chemical vapor deposition (IV-CVD) reactor for oil removal. High quality, bundles, super hydrophobic, and high aspect ratio carbon nanotubes were produced. The average diameters of the produced CNTs ranged from 20 to 50 nm while their lengths ranged from 300 to 500 μm. Two types of CNTs namely, P-CNTs and C-CNTs, (Produced CNTs from the IV-CVD reactor and commercial CNTs) were used for oil removal from water. For the first time, thermogravimetric analysis (TGA) was conducted to measure maximum oil uptake using CNT and it was found that P-CNT can take oil up to 17 times their weight. The effect of adsorbent dosage, contact time, and agitation speed were examined on the oil spill clean-up efficiency using batch sorption experiments. Higher efficiency with almost 97% removal was achieved using P-CNTs compared to 87% removal using C-CNTs. [ABSTRACT FROM AUTHOR]

Jatropha curcas L. (JCL) is one of the most prominent energy crops due to its superior agronomical traits, where it can grow in non-arable lands and harsh climates with minimal water requirements. A significant number of studies were published on the utilisation of JCL for biofuel production, whereas there are no studies on its use in greenbelt (GB) or windbreak technologies reported thus far. Meanwhile, a few approaches on the delineation of greenbelts to fight desertification in the arid regions exist in literature. This study presents a novel approach to delineate a multipurpose energy-greenbelt using JCL crop for biofuel production, as well as to preserve the soil and enhance air quality, thereby helping to combat desertification and sand-dust storms (SDS). The methodology is demonstrated using a case study in the state of Qatar for the diversification of its renewable energy resources. Moreover, Qatar is also suffering from land degradation due to erosion factors and desert creep. A multi-dimensional approach is proposed for this purpose using satellite and meteorological data to initially select the optimal plantation sites that potentially contribute to the highest possible biofuel yield. The spatial analysis was carried out using the analytical hierarchy process (AHP) technique for multi-criteria decision making in the geographic information system (ArcGIS). In addition, the Landsat and MODIS satellite imagery were utilised in combination with historical records from the weather stations to evaluate the patterns of SDS, land degradation and urban expansion, to best define optimal GB pathway. COMSOL Multiphysics software was subsequently employed to evaluate the performance of Jatropha -GB and determine its optimal density. The different solutions for GB delineation spans 166.6–227.8 km length and (6 × 6 m) of field density. It is expected that the economic and environmental benefits from the derived GB configuration include: (a) protection of up to 87% of Qatar farms against further deterioration; (b) yield of up to 36 M gallon of green liquid fuels; (c) capture of 0.33 M tonnes of CO 2 per 1 km GB-depth annually; and (d) provide a better air quality for around 95% of the Qatar population. [Display omitted] • Jatropha curcas is proposed for establishing a greenbelt to combat desertification. • Dust storms patterns are defined using a novel combination of satellite and meteorological data. • Greenbelt was delineated considering agronomical, environmental, and social aspects. • Defined greenbelt provides protection to 87% of Qatar's farms and 95% of population. • Greenbelt of 1 km-depth generates 36 M gallons of fuels and capture 0.3 M tonnes of CO 2. [ABSTRACT FROM AUTHOR]

Selective sorption of oil using plastic waste is presented. Plastic solid waste constitutes 15% of total municipal solid waste produced across the world and is mostly either discarded in landfills or incinerated. On the other hand, pollution caused by oil spill in aquatic locations is a serious environmental concern, and several sorbents have so far been proposed to address oil spill and plastic waste problems simultaneously by converting waste into oil sorbent. However, most of the sorbents have drawbacks of either high water uptake or low oil uptake capacity. In this study, we have synthesized oil sorbent using waste plastic bottles made up of high-density polyethylene with high selectivity and high oil uptake capacity. Mechanical properties and %crystallinity using differential scanning calorimetry were also determined to provide useful insight about the as prepared sorbent. © 2016 Curtin University of Technology and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Due to growing concerns about carbon emissions, using zero-carbon fuels has become an interesting alternative to overcome this problem. The NH 3 (70%)-H 2 (30%) fuel blend is an innovative fuel example that has the potential to replace conventional hydrocarbon fuels. Studies on the NH 3 (70%)-H 2 (30%) fuel blend have shown its superior combustion performance and its effect on enhancing cycle efficiency compared to other compositions of the NH 3 –H 2 blends. However, without calibrating ammonia plants and simply mixing portions of the produced pure ammonia to hydrogen at the desired molar fraction essentially requires coupling ammonia plants with other hydrogen-producing plants, leading to potential difficulties in commercializing the unused (as fuel in the NH 3 –H 2 /air gas turbines) hydrogen portions from the hydrogen-producing plan. Therefore, in this paper, as an attempt to utilize the existing ammonia production infrastructure and facility without acquiring major changes that could lead to resisting the adoption of the NH 3 (70%)-H 2 (30%) fuel blend, the independent parameters of a conventional ammonia plant have been calibrated, and the reactors have been sized to provide a continuous supply of the NH 3 (70%)-H 2 (30%) fuel blend with the exact molar fraction to run a power plant. Calibrating of the ammonia plant has been performed using an ASPEN PLUS model. • A recalibrated ammonia plant to produce the NH3(70%)-H2(30%) fuel blend. • A reduced ammonia plant to produce the NH3(70%)-H2(30%) fuel blend. • Identifying the sensitivities of the reduced ammonia plant. • Utilizing the existing facilities of ammonia plants to produce carbon-free fuel. [ABSTRACT FROM AUTHOR]

The availability of agricultural wastewater in arid climes limits the possibility of exploiting purple non‐sulfur bacteria (PNSB) to recover aqua‐feed bioproducts. Thus, this study examines the feasibility of recovering such bioproducts using fuel‐synthesis process water (FSPW) as a feedstock. Experiments were performed under varying light conditions. The results revealed that PNSB cultured in the zero‐nitrogen feedstock had over 40 % protein content, contained substantial lipids and pigments, and reduced FSPW organics by over 70 %. The light intensity significantly impacted biomass constituents and treatment efficiency. The results are promising for the potential development of a circular economy to convert FSPW to aqua‐feed. [ABSTRACT FROM AUTHOR]

Highlights: [•] Fractional Theoretical Capacity measure was proposed for isotherm model selection. [•] Using error analysis statistics alone may lead to wrong isotherm model selection. [•] The sorption system for all dyes was heterogeneous based on the Toth model. [•] Fractal dimension can be determined based on the theoretical sorption capacity. [•] The sorbent (GAC) surface was smooth according to the fractal dimension parameter. [Copyright &y& Elsevier]

[Display omitted] • The sonophotocatalytic degradation of the acid blue 113 (AB113) dye is examined. • MWCNTs/CoFe 2 O 4 catalyst was prepared by the solvothermal co-precipitation method. • Biodegradability, mineralization, and toxicity tests were conducted. • MWCNTs/CoFe 2 O 4 acts as an efficacious catalytic agent of high reusability value. • Under optimum conditions, 100% degradation efficiency of AB113 dye was achieved. Complete degradation of acid blue 113 (AB113) dye was successfully achieved by using the sonophotocatalytic process with CoFe 2 O 4 nanoparticles loaded on multi-walled carbon nanotubes (MWCNTs/CoFe 2 O 4), as a novel catalyst. The catalyst used was synthesized using the solvothermal co-precipitation method. First, the characteristic parameters of the synthesized catalyst were evaluated using advanced analyses of Field Emission Scanning Electron Microscopy (FESEM), X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), Energy-Dispersive X-Ray Spectroscopy (EDX), Thermogravimetric (TGA), Vibrating Sample Magnetometry (VSM), and Fourier Transform Infrared Spectroscopy (FTIR). The results of the sonophotocatalytic degradation experiments showed that the optimum parameters for 100% AB113 removal were: AB113 concentration = 25 mg/L, pH = 3, MWCNTs/CoFe 2 O 4 dose = 0.4 g/L, reaction time = 40 min, intensity of UV light = 36 W, and intensity of ultrasonic waves = 50 kHz. To identify the utility of using MWCNTs/CoFe 2 O 4 as a catalyst, the degradation efficiencies of AB113, resulting from the sonophotocatalytic process, were compared with those determined from other similar treatment processes, that is, adsorption, photolysis, sonolysis, and sonocatalytic and photocatalytic processes, where the sonophotocatalytic process was found to be the most efficient one. Catalyst recycling was performed in eight degradation–regeneration cycles, whereas, a total reduction of 9% was observed in removal efficiency after the 8th cycle. The results showed that the AB113 dye, which was a non-biodegradable contaminant, became almost a biodegradable compound after subjection to sonophotocatalytic treatment. The results also demonstrated a high mineralization rate of the applied treatment method. In addition, a toxicity test was performed using Daphna Magna, and the results indicated a low toxicity of the AB113 dye effluent. The results of this study clarified that the sonophotocatalytic process system using MWCNTs/CoFe 2 O 4 could be a feasible and cost-effective system for degrading dyes, for example, AB113. [ABSTRACT FROM AUTHOR]

Pyrolysis has gained significant attention due to its generation of value-added products from waste feeds in an environmentally friendly manner. The primary purpose of this study is to understand the effect of different particle sizes of biomass wastes – date stones (DS), cow manure (CM), and spent coffee grounds (SCG) – to understand better and design a biomass pyrolysis system. Thermogravimetric analysis of four different sizes of DS, SCG, and CM (range 1 mm to 125 μm) and a mixed sample (for each feed) was conducted at a heating rate of 10K/min from room temperature to 1173.15 K at inert conditions and employed model-based Coats–Redfern equations to understand the kinetic and thermodynamic parameters of the pyrolysis process. All the particle sizes except 355–125 μm for DS and SCG have the best-fit reaction mechanism of Ginstling-Brounshtein (D4). Both activation energy and pre-exponential factor decreased from 18.78 to 5.57 kJ/mol and 1.16 E+10 to 1.48 E+08 with reducing particle sizes. The onset degradation temperature, activation energy, change in enthalpy, and entropy decrease with particle sizes. The product formation is favored for all feeds and particle sizes, as the difference between the enthalpy and activation energies (Ea) is below 10 kJ/mol. As a result of their substantially lower activation energies and better reaction thermodynamics, mixed and smaller particle-sized biomass are favored. [ABSTRACT FROM AUTHOR]

Abstract: A large volume of the waste produced across the world is composed of polymers from plastic wastes such as polyethylene (HDPE or LDPE), polypropylene (PP), and polyethylene terephthalate (PET) amongst others. For years, researchers have been looking for various ways to overcome the problems of such large quantities of waste plastics. On the other hand, carbon nanotubes (CNTs) are materials with extraordinary physical and chemical properties which often have energy- and resource-intensive production processes. In recent years, some researchers have suggested the idea of using plastic polymers as the carbonaceous feed of CNT production. The studies undertaking such a feat are rather scattered. This review paper is the first of its kind reporting, compiling and reviewing these various processes. The production of multi-walled carbon nanotubes (MWCNTs) from plastic polymers is seen to be satisfactorily achievable through a variety of different catalytic and thermal methods in autoclaves, quartz tube reactors, muffle furnaces, fluidized beds, amongst others. Still, much work needs to be done regarding the further investigation of the numerous parameters influencing production yields and qualities. For example, differences in results are seen in varying operating conditions, experimental setups, catalysts, and virgin or waste plastics being used as feeds. The area of producing CNTs from plastic wastes is still very open for further research, and seems as a promising route for both waste reduction, and the synthesis of value-added products such as carbon nanotubes. [Copyright &y& Elsevier]

Abstract: The adsorptive removal of toxic para-chlorophenol using activated carbon adsorption columns is a proven effective engineering process. This paper examined the possibility to stratify an adsorbent bed into layers, in order to enhance the adsorption process performance in terms of increased column service time and adsorbent bed saturation. Four different types of fixed-bed adsorption columns are used and compared under the same operating conditions, but with the variation of column geometry and activated carbon particle size stratification. The Type 3 column – a cylindrical column with particle stratification packing, is found to be the most efficient choice, as the extent of column service time and adsorbent bed saturation are the largest. This could eventually decrease the frequency of adsorbent replacement/regeneration and hence reduce the operating cost of the fixed-bed adsorption process. The Homogeneous Surface Diffusion Model (HSDM) was applied successfully to describe the dynamic adsorption of para-chlorophenol onto Filtrasorb 400 (F400) activated carbon in different types of columns. The Redlich-Peterson isotherm model equation, an experimentally derived external mass transfer correlation and a constant surface diffusivity are used in the HSDM. The optimised surface diffusivity of para-chlorophenol is found to be 1.20E-8 cm2/s, which is in good agreement with other phenolics/F400 carbon diffusing systems in literature. [Copyright &y& Elsevier]

Abstract: The rates of adsorption of cadmium, copper and zinc ions onto bone char have been studied in three single component systems using an agitated batch adsorber. The effects of initial metal ion solution concentration and bone char mass have been studied. The capacities of the three metals on bone char are 0.477, 0.709 and 0.505 mmolg−1 for cadmium, copper and zinc respectively which are much higher than most other adsorbents reported in the literature for these three metals. In order to model the experimental concentration decay curves, a film-surface diffusion equation proposed by Crank (1979) has been solved. The model results correlate the experimental better than a previously applied film-pore diffusion model. However, the results indicate that the surface diffusion coefficient was a variable function of initial metal ion concentration. The surface diffusivities vary from 3.00×10−9 to 8.80×10−9 cm2 s−1, 2.11×10−9 cm2 s−1 to 5.4×10−9 cm2 s−1 and 3.10×10−9 to 8.49×10−9 cm2 s−1 for cadmium, copper and zinc respectively, for metal ion solution concentrations of 2.10–5.40 mmoldm−3. [Copyright &y& Elsevier]

Abstract: The sorption of cadmium, copper and zinc from aqueous solutions onto bone char has been studied in both single and binary multi-component systems. Equilibrium experimental studies have been performed to determine the sorption capacity of bone char for each metal ion. The isotherm results have been analysed using single and multi-component equilibrium models. The rate of sorption of the metal ions onto bone char has been studied using an agitated batch adsorber. The concentration versus time decay curves have been measured and a number of mass transfer models have been developed and tested based on diffusion controlled sorption. The results of the equilibrium and rate studies are presented and discussed in the paper. The possible mechanisms of metal sorption are also discussed. Finally a series of fixed bed column studies have been performed and analysed using a diffusion mass transport model. The experimental results show a displacement effect for the binary metal ion breakthrough curves. [Copyright &y& Elsevier]

Three solutions to the film surface diffusion mass transport model are discussed. The solutions are based on the homogenous surface diffusion model (HSDM) and are compared using three different adsorption systems. The mass transport solutions include a Crank–Nicholson implicit finite difference method, a semi-analytical solution method and a Cartesian collocation method. The three solutions are compared for accuracy, stability, convergence and computation CPU time.The experimental systems used two adsorbents, activated carbon, a mainly microporous material, and sorbsil silica, a mainly macroporous material. Two categories of adsorbates were selected for the study, phenol, a relatively small organic molecule, which does not ionise, and basic dyes, larger organic structures, which exist as ionisable salts. A range of initial adsorbate concentrations were studied. The range of material types and experimental conditions selected should be sufficient to test and compare the three models under a variety of conditions. [Copyright &y& Elsevier]

The present review discusses the current views on methods to minimise dioxins, namely polychlorinated dibenzodioxins (PCDDs) and dibenzofurans (PCDFs), formation in MSW incineration systems. The structure of this group of compounds is discussed initially and then the toxic equivalence scale is presented for the most common isomers and congeners in the dioxin family. The current status on dioxin limits imposed in various countries and by various organisations is presented. A detailed analysis of the theories leading to dioxin formation in MSW incineration is given, since, this has been one of the most controversial areas of dioxin chemistry for the past 20 years.Three dioxin formation theories were considered possible for a long time; (i) from PCDD/PCDFs originally present in the furnace feedstock; (ii) from precursor compounds (foundation formatting molecules which could react rapidly with other groups in the system to form dioxins) in the MSW feed; (iii) from de novo synthesis of smaller, relatively innocuous chemical molecules combining together to form the dioxins. Methods (ii) and (iii) are based on heterogeneously catalysed reactions. Some researchers are considering possible homogeneous thermal reaction formation of dioxin.This review demonstrates that with the advanced modern MSW combustion systems, option (i) is a most unlikely route and also methods (ii) and (iii) are quite feasible. Based on thermodynamic and kinetic data in the literature, the rate and extent of the formation of dioxins and their precursors by certain mechanisms can definitely be contributing to routes (ii) and (iii). Since even the most advanced MSW combustion systems do not produce complete combustion, predominantly because of inadequate feed preparation and turbulence, some de novo synthesis of precursors can also take place.These ‘de novo precursors’ could be carried through the combustion unit adsorbed or absorbed on particulate material such as soot and dust, but also these precursors could be formed during the cooling process by heterogeneous catalytic reactions and go on to form dioxins. The maximum rate of formation of PCDD/PCDFs from both sources lies in the temperature range 300–400 °C. This knowledge of formation rates and mechanisms provides the basis of designing combustion systems. A two stage approach is adopted; firstly, system design to achieve complete combustion and minimise formation; secondly, end-of-pipe treatment systems to remove dioxins.In the first case, combustion temperature should be above 1000 °C, combustion residence time should be greater than 1 s, combustion chamber turbulence should be represented by a Reynolds number greater than 50,000, good MSW feed preparation and controlled feed rate are also critical. In the second category, very rapid gas cooling from 400 to 250 °C should be achieved, semi-dry lime scrubbing and bag filtration coupled with activated carbon injection adsorption as end-of-pipe treatments can all play a role in prevention or minimisation of dioxins in the final flue gas emission to the atmosphere. [Copyright &y& Elsevier]

Traditional bulk adsorbents, employed for the removal of dyes and metal ions, often face the drawback of requiring an additional filtration system to separate the filtrate from the adsorbent. In this study, we address this limitation by embedding the adsorbent into the polymer matrix through a process involving dissolution–dispersion, spin-casting, and heat-stretching. Selective dissolution and dispersion facilitate the integration of the adsorbent into the polymer matrix. Meanwhile, spin-casting ensures the formation of a uniform and thin film structure, whereas heat-induced stretching produces a porous matrix with a reduced water contact angle. The adsorbent selectively captures dye molecules, while the porous structure contributes to water permeability. We utilized inexpensive and readily available materials, such as waste polyethylene and calcium carbonate, to fabricate membranes for the removal of methylene blue dye. The effects of various parameters, such as polymer-adsorbent ratio, initial dye concentration, and annealing temperature, were investigated. Equilibrium data were fitted to Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherms. The equilibrium data were best represented by the Langmuir isotherm, with maximum adsorption capacity of 35 mg/g and 43 mg/g at 25 °C and 45 °C, respectively. The membranes can be regenerated and recycled with a 97% dye removal efficiency. The study aims to present a template for adsorbent-embedded polymeric membranes for dye removal, in which adsorbent can be tailored to enhance adsorption capacity and efficiency. [ABSTRACT FROM AUTHOR]

• Literature review of phosphate removal by modified and unmodified biochars. • Desorption studies and direct use of phosphate laden biochars were considered. • Adsorption mechanism, effect of coexisting ions and thermodynamics were outlined. • Modified biochars demonstrated significant enhancement in phosphate sorption capacity. • Research challenges of phosphate removal by biochars have been identified. In the last decade, biochar (BC) has attracted significant attention for the removal of pollutants from aqueous solutions. Biochar exhibits many distinctive characteristics that make it an attractive adsorbent due to its availability, low manufacturing cost and compelling surface properties. This review presents a comprehensive summary of BC's application in phosphate remediation. Adsorption isotherm, kinetics, experimental conditions and the effect of different adsorption parameters on phosphate removal are outlined. The adsorption mechanisms, effect of coexisting ions, desorption studies and reuse of exhausted BCs are also considered. The results demonstrate that unmodified BCs possess low phosphate sorption capacity with the exception of BCs with high minerals content. As such, engineered BCs by decoration with different elements have been shown to alter the surface characteristics of the adsorbents such as surface charge, surface area, pore diameter, pore volume and the surface functional groups. Therefore, the phosphate sorption capacity of modified BCs has been significantly improved compared to unmodified adsorbents. Magnesium, aluminum, calcium and lanthanum were of significant interests for BC decoration due to their high affinity toward phosphate ions. Iron has been also widely used in BC composites for increasing the adsorption capacity of phosphate, in addition to providing an opportunity for magnetic recovery of the adsorbent. Based on this review, future research for BC applications in terms of phosphate removal is also discussed. [ABSTRACT FROM AUTHOR]

• Whole-fruit of Jatropha curcas is processed into jet fuel in novel integrated system. • The System implements 5 integration techniques to enhance jet fuel yield and cost. • 49 wt% of Jatropha fruit is converted into liquid fuels, with 65% jet fuel selectivity. • An increment of 88% of jet fuel yield is obtained by utilising the whole-fruit. • A minimum selling price of 0.445 $/kg of jet fuel is achieved below market price. The production of 'Jet Biofuel' has been identified as a promising strategy to mitigate the carbon footprint of the aviation sector. During the past decade, the commercial production of Jet Biofuel has attracted the attention of airline companies and governments across the globe. However, achieving a competitive production cost and sustainable Jet Biofuel remains a challenge. In this regard, various feedstocks have been tested for this purpose, where the vast majority have not complied with sustainability and feasibility expectations. Although not fully utilised in the Jet Biofuel industry, Jatropha curcas has emerged as one of the most promising feedstocks for Jet Biofuel production, since it is non-edible and is able to grow in non-arable lands with minimal water and energy requirements. This study presents a novel integrated pathway that utilises all parts of Jatropha fruit to produce a cost-effective Jet Biofuel using conventional hydroprocess, gasification, Fischer-Tropsch and reforming technologies. Different integration techniques are employed, including waste valorisation, by-products incorporation, as well as water, heat and power integration. The effect of various operating parameters on the products' characteristics and yields has been evaluated. The model is validated against literature experimental data and demonstrates promising results. Whereby, 49 wt% of Jatropha fruit is converted into liquid fuels, with a Jet Biofuel selectivity of 65%, which represents an increment of almost 88% of Jet Biofuel yield compared to processing Jatropha oil alone. Furthermore, the system developed is power and water self-sufficient. The proposed pathway significantly lowers the production cost of Jet Biofuel below the market price of conventional Jet-A fuel for the base year of analysis, achieving a minimum selling price of 0.445 $/kg. [ABSTRACT FROM AUTHOR]

The ability of chitosan, prepared from waste prawn shell, to sorb copper (II) ions from aqueous solutions has been studied. Equilibrium studies show that chitosan has a maximum sorption capacity for copper ions of about 40mg/g chitosan. The mass transport characteristics have been investigated by monitoring the kinetics in an agitated batch adsorber. An external mass transfer coefficient and an intraparticle diffusion rate parameter have been determined for a number of system variables including agitation, initial copper ion concentration, chitosan mass, chitosan particle size and solution temperature. [ABSTRACT FROM PUBLISHER]

Carbon emissions from the aviation sector are expected to double during the coming three decades as the sector expands rapidly. Besides, the fluctuation of conventional fuel prices continues to obstruct the establishment of stable commercial strategies for the airlines. Meanwhile, Jet Biofuel (JBF) has been identified as a reliable alternative to conventional Jet-A fuel. Amongst the tested promising feedstocks for JBF production, Jatropha oil has gained growing attention and is believed to play a key role in the JBF industry. Though, no in-depth reviews on Jatropha JBF are found in literature, it is believed that there is a need to evaluate Jatropha as feedstock for JBF production after over 10 years of intensive research. Therefore, this article presents a comprehensive state-of-the-art review of Jatropha JBF production. The article offers a thorough review of the hydroprocessing of Jatropha by investigating its optimum operating conditions, recent catalyst application developments, the feasibility of JBF, its performance and environmental impact. This study concludes that Jatropha JBF production by hydroprocessing can achieve up to a 75% reduction in greenhouse gas emissions relative to Jet-A. While Jatropha JBF can be produced with a levelised cost as low as $0.6/kg. The main challenges facing Jatropha JBF industry has been identified to be the availability of feedstock and achieving a competitively priced JBF. As such, alternative routes to utilise the remaining parts of the Jatropha fruit into JBF production are proposed to reduce the land footprint, enhance JBF yield and minimise its selling price. The proposed pathways are expected to achieve a significant fuel yield increment of 24–89% as compared to utilising Jatropha oil alone, which remain to be evaluated in terms of technical and economic aspects. Image 1 • JBF production from Jatropha , its feasibility, performance and LCA are investigated. • Jatropha JBF production cost varies ($ 0.6–1.6/kg) based on process specifications. • Jatropha JBF can achieve up to 75% reduction in GHG emissions relative to Jet-A. • Pathways for Jatropha whole-fruit utilisation in JBF production are proposed. • Fuel yield increment of 24–89% can be achieved via the different proposed pathways. [ABSTRACT FROM AUTHOR]

• Hydrogen rich syngas can be produced from gasified waste biomass. • Optimum feedstock blending options are utilised to maximise hydrogen production. • A hybrid environmental and economic optimisation methodology is implemented. • Steam gasification demonstrates excellence in providing hydrogen-rich syngas. • Date pits indicates high potential in maximising the hydrogen content in syngas. Concerns related to global warming and the depletion of fossil fuels have propelled the global community to explore alternative renewable energy sources. Biomass is a nonconventional and renewable energy resource that can potentially be utilised for the production of sustainable heat and power. The thermal gasification process is an effective biomass conversion and utilisation method producing syngas as the product gas. This study details a biomass gasification process and subsequent optimisation, considering multiple parameters, including the type of feedstock and gasifying agent (gasifier) to maximise hydrogen production. Aspen Plus software is used to develop three agent-based biomass gasification models considering the characteristics of certain materials from Qatar built environment. The ultimate goal of the study is to optimise the gasification processes to yield different biomass blending options satisfying the maximisation of hydrogen generation through different scenarios. The capabilities of the built-in activated analysis package using Aspen Energy Analyser and Aspen Process Economic Analyser are utilised to evaluate the environmental and economic perspectives. The results demonstrate the excellence of steam-only biomass gasification in providing profitable and cleaner products. The yield of hydrogen production from blending of biomass feedstock achieved a high fraction of 5.23% with the steam-only gasification, while the yield increased from 1.63% to 5.22% for the oxygen/steam gasification when maximising the hydrogen fraction. Moreover, the selective limiting of biomass capacity enhances the quality of syngas through enriching the hydrogen production and lowers the need for subsequent adjustment and the manipulation of gasifying agent quantity and operating energy. [ABSTRACT FROM AUTHOR]

• The study evaluates generation of sustainable products from biomass gasification. • Two types of gasifying medium; oxygen and steam, are compared. • The article considers recycling of a blended feed of multiple biomass sources. • Aspen plus is utilised to simulate and integrate the different processes. • Poly-generation of Fisher-Tropsch liquids, methanol, urea and power is considered. Economically, fossil fuels remain the main source of energy despite their high emissions of greenhouse gases. However, biomass, a renewable fuel with CO 2 neutrality, has experienced widespread attention as a potential contributor to sustainable development of the energy sector. Gasification is an important thermochemical process that converts biomass feedstock into H 2 -rich combustible gases, which are favoured by wide downstream applications. The use of pure steam or oxygen as a gasifying agent is preferred to increase the yield of combustible gases. Consequently, hydrogen is utilised as an important intermediary in the generation of value-added products such as urea, fuels and power. This study compares the biomass gasification using oxygen-only and steam-only gasifying agents. Moreover, the study examines a poly-generation system that consumes biomass feedstock of multiple sources to produce high grade Fisher-Tropsch liquids, methanol, urea, and power. To achieve this aim, four Aspen Plus simulation flowsheets are developed considering both gasifiying agents and compared utilising the built-in economic and environmental capabilities. The results obtained from the economic and environmental evaluation demonstrate the excellence of steam-only biomass gasification in providing profitable and cleaner products. The methanol production using steam gasification is the most economical solution with a net profit per input of $0.12 per kg of biomass input and the lowest emissions pathway with 0.68 kg of CO 2 -e per biomass input. The relative nature of the results can offer diverse perspectives depending on the market situation of the products. Consequently, analysing the results relative to production capacity, power generation using steam gasification achieves a net profit approximated at $0.80 per kg of product, whilst methanol production using steam gasification remains the lowest environmental impact solution with 2.32 kg of CO 2 -e per output product. [ABSTRACT FROM AUTHOR]

The presence of traces of heavy metals in wastewater causes adverse health effects on humans and the ecosystem. Adsorption is a low cost and eco-friendly method for the removal of low concentrations of heavy metals from wastewater streams. Over the past several years, graphene-based materials have been researched as exceptional adsorbents. In this review, the applications of graphene oxide (GO), reduce graphene oxide (rGO), and graphene-based nanocomposites (GNCs) for the removal of various metals are analyzed. Firstly, the common synthesis routes for GO, rGO, and GNCs are discussed. Secondly, the available literature on the adsorption of heavy metals including arsenic, lead, cadmium, nickel, mercury, chromium and copper using graphene-based materials are reviewed and analyzed. The adsorption isotherms, kinetics, capacity, and removal efficiency for each metal on different graphene materials, as well as the effects of the synthesis method and the adsorption process conditions on the recyclability of the graphene materials, are discussed. Finally, future perspectives and trends in the field are also highlighted. [ABSTRACT FROM AUTHOR]

Considering changes in the global climate, there is an impetus to diversify away from fossil fuels as part of efforts to reduce greenhouse gas emissions. Biomass, as a source of energy, has the potential to generate sustainable power and fuels and contribute towards a cleaner future. In fact, the utilisation of biomass as a carbon dioxide neutral organic source in an integrated system generates valuable products, and reduces waste and the consumption of non-renewable resources. Gasification, the preferred option for converting biomass to combustible gas, provides higher electrical efficiencies than combustion, whereby the syngas generated from the gasification process can be utilised to generate clean energy. In addition, syngas can be utilised for the production of ammonia and methanol thus reducing their respective dependencies on natural gas. This study will detail an optimised biomass gasification process considering multiple parameters, including the thermodynamic operating conditions, the type of gasifier (gasifying agent) and feedstock. Fundamentally, this study considers the process pathways for the recycling of multiple sources of biomass to generate high energy syngas from the available biomass options when used in combination as blends or individually. To achieve this aim, an Aspen Plus simulation model is developed for four different biomass agent-based gasification techniques using the biomass characteristics of certain Qatar biomass materials, which include date pits, manure and sewage sludge. Outcomes of the study included an optimisation of the gasification processes to yield different blending options of the biomass feedstock satisfying the downstream operations of power and fuels production. The results demonstrate the domination of date pits for two of the considered configurations with over 99% w/w date pit feed composition. Moreover, the sensitivity analysis conducted on the different configurations highlighted specific optimum operation points in terms of temperature, pressure, and oxygen and steam feed ratios. The hydrogen content in the generated syngas, considered important for the downstream production, yields a peak at approximately 850 °C and 1 bar with a modified equivalence ratio of approximately 2.5, and a ratio of oxygen supplied by an air-steam combination of approximately 0.6. The process can be further optimised by considering trade-offs between product purity or yield, profit, operating efficiency, quality of raw materials blends, and carbon footprint. • Biomass as a source of energy has the potential to generate sustainable products. • Syngas is an important intermediary in the production of power, fuels and chemicals. • Different pathways for recycling of multiple biomass sources are evaluated. • Optimum biomass feedstock blending options are determined. • The effect of changing key gasification performance parameters is analysed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Plastic waste valorization into water filtration membranes with a trimodal structure. • Acid-catalyzed oxidation enhances the hydrophilicity, improving water flow rates. • The macrovoids allows efficient water passage while cavities serve as oil reservoirs. • Membranes recycle for 10 cycles, maintaining 84 – 94 % oil–water separation efficiency. Polyolefin waste is among the most generated yet least recycled. Despite its potential as a feedstock of superhydrophobic membranes for organic solvent filtration, it remains a challenge to achieve high selectivity and permeability for viscous oils. In this study, we valorized polyolefin waste into trimodal water filtration membranes through acid-catalyzed oxidation and a void inducer. This approach enabled the creation of membranes with exceptional wettability and strength, characterized by a combination of micropores, macrovoids (30 – 70 µm), and cavities (150 – 200 µm). The acid-catalyzed oxidation introduced oxygen moieties into the membrane structure, resulting in a reduced water contact angle, improved hydrophilicity, and increased permeability. The micropores facilitated capillary action, macrovoids enabled efficient water passage, and cavities acted as oil reservoirs, for optimal oil–water separation. Various membranes were synthesized using low-density and high-density polyethylene (PE), polypropylene (PP), and their blend. The obtained results were compared with commercial membranes, revealing a flow rate of 43 ml/min, a retention capacity of 261 mg, and an oil removal efficiency ranging from 84 – 94 %. Furthermore, the membranes exhibited recyclability, demonstrating stability over at least 10 cycles. This hybrid process transforms plastic waste into trimodal water filtration membranes, achieving a balance between superoleophilicity and hydrophilicity. [ABSTRACT FROM AUTHOR]

• Integration of biomass gasification with power devices was reviewed for clean electricity generation. • The electrical efficiency ranges from 40% to 60% for SOFC-gasification systems. • The overall electrical efficiency is approximately 60–90% for integrated systems using CHP. • The technical maturity of biomass gasification systems with all approaches was analyzed. • The pros and cons, as well as the current status of each configuration, were analyzed. The integration of biomass based gasification with power systems can enable carbon neutral electricity. This study examines the power generation process from syngas derived from biomass gasification using syngas generators, gas and steam turbines, and combined heat and power (CHP). The efficiency of electricity generation using syngas in a combustion engine ranges from approximately 20 % to 35 %. It is considered cost-effective due to its ability to tolerate syngas with impurities. Conversely, the use of steam and gas turbines also falls within this efficiency range, ranging from 20 to 35 %, although, in specific instances, efficiencies up to 50 % have been reported. The integrated CHP system enhances the overall system efficiency, achieving levels as high as 90 %, whereas it is within the range of 40–60 % without CHP. This review also evaluates the potential for clean electricity generation through the integration of fuel cells (FC) with the gasification system, specifically, the solid oxide fuel cell (SOFC) by considering both experimental and modelling studies. The electrical efficiency of power production using SOFC falls within the range of 30–60 % using syngas derived from a gasification system. However, for hydrogen, higher efficiencies up to 90 % have been observed. The power generation is approximately 0.85kWel using syngas produced from gasification of one kg biomass/h. The power generation capacity is normally in the range of 200 kW to 2 MW. Moreover, Technology readiness level (TRL) for these technologies, with a particular focus on FC technology is also analysed. Finally, this review examines the current state of the art, challenges, and future prospects of technologies. [ABSTRACT FROM AUTHOR]

The global pollution crisis arising from the accumulation of plastic in landfills and the environment necessitates addressing plastic waste issues. Notably, polypropylene (PP) waste accounts for 20% of total plastic waste and holds promise for hydrophobic applications in the realm of recycling. Herein, the transparent and non-transparent superhydrophobic films made from waste PP are reported. A hierarchical structure with protrusions is induced through spin-casting and thermally induced phase separation. The films had a water contact angle of 159° and could vary in thickness, strength, roughness, and hydrophobicity depending on end-user requirements. The Bode plot indicated enhanced corrosion resistance in the superhydrophobic films. Antibacterial trials with Escherichia coli and Staphylococcus aureus microbial solutions showed that the superhydrophobic film had a significantly lower rate of colony-forming units compared to both the transparent surface and the control blank sample. Moreover, a life cycle assessment revealed that the film production resulted in a 62% lower embodied energy and 34% lower carbon footprint compared to virgin PP pellets sourced from petroleum. These films exhibit distinctiveness with their dual functionality as coatings and freestanding films. Unlike conventional coatings that require chemical application onto the substrate, these films can be mechanically applied using adhesive tapes on a variety of surfaces. Overall, the effective recycling of waste PP into versatile superhydrophobic films not only reduces environmental impact but also paves the way for a more sustainable and eco-friendly future. [Display omitted] • Waste PP is transformed into superhydrophobic films—transparent and non-transparent. • Films are suitable for weather resistance and self-cleaning applications. • Films demonstrate improved corrosion resistance compared to bare carbon steel. • Reduced microbial growth in films makes them suitable for antibacterial use. • Films show lower embodied energy and fewer carbon emissions than virgin PP pellets. [ABSTRACT FROM AUTHOR]

The objective of the study is to investigate the potential of carbide-derived carbon (CDC) for the adsorptive removal of nonionic t-octylphenoxy poly ethoxy ethanol (TX-100), anionic sodium dodecylbenzene sulfonate (SDBS) and cationic 1-hexadecylpyridinium bromide (HDPB) surfactants from water. The CDC was characterized using TEM, SEM, FTIR, BET, EDS, XPS methods and zeta potential measurements. The effects of adsorption parameters included initial surfactant concentration, contact time, temperature, and pH of the feed solution were evaluated. The adsorption capacity and mechanism were determined by modeling the isotherm, kinetic and thermodynamic data. The kinetics results demonstrated that the adsorption of the surfactant by CDC obeys the pseudo 2nd order model. The thermodynamic results have shown that surfactants adsorption by CDC is an endothermic and spontaneous process. The Sips model agreed with the adsorption isotherm data of SDBS with R2 of 0.987, while both Freundlich and Redlich-Peterson models comply well with adsorption data for TX-100 and HDPB. The hydrophobic and electrostatic interactions were found the dominant mechanisms of the adsorption of the surfactant by CDC. The adsorption capacities of CDC were found to be 442.4, 462.0 and 578.4 mg/g for SDBS, HDPB and TX-100, respectively. [ABSTRACT FROM AUTHOR]

This study deals with removing crude oil droplets from colloidal oil in water emulsions. The target was the development of efficient adsorbents for the tertiary treatment of industrial-produced water (PW). The novel adsorbent was designed from recycled low-density polyethylene (LDPE) powder grafted by the cationic polymer. The cationic polymer was synthesized directly on the LDPE surface by plasma-induced radical polymerization. A positively charged adsorbent was chosen due to the negative character of oily droplets to enhance separation efficiency in treating oil-water emulsions. The separation was performed in both batch and filtration modes. Absorption/adsorption uptake capacities showed a sigmoidal S-shape that was analyzed using the Sips model and compared with the newly developed empirical model. Both models showed a remarkable coincidence in the description of experimental data. The separation efficiency of the novel adsorbent was also tested in a filtration mode mimicking a commonly used deep-bed filtration technology. The comparison of the separation efficiency for various sorbents indicated a supreme performance of novel adsorbent. This study demonstrates the potential of a relatively cheap, prepared commodity-based adsorbent for the purification of emulsified oily polluted water in both batch and filtration configurations. This study also contributes to the recycling of polyethylene waste because LDPE attracts meager interest in recycled LLDPE due to many obstacles to reusing LDPE waste for its reprocessing as packaging materials. [ABSTRACT FROM AUTHOR]

• Green diesel consumption is forcasted to grow 3% per annum until 2030. • Deoxygenation technology is widely applied in green diesel production. • Zeolites are promising catalysts with high potential for DO. • Reusability studies are important for assessing the stability and performance of catalysts. • The costs associated with green diesel production should be thoroughly investigated. Worldwide consumption of energy produced from fossil fuels is forecasted to grow. This trend leads to both environmental pollution and the depletion of fossil fuel resources. Green diesel is a suitable candidate to substitute petroleum based-diesel due to its plentiful raw materials, non-polluting production process, and cost-effectiveness. Green diesel production is seen as simple, efficient, and relatively clean process. Deoxygenation (DO) is crowned as the best available technology to produce green diesel from palm fatty acid distillate (a side product of palm oil production) and other oils using heterogeneous catalysts such as zeolites. The capability of catalysts can be improved by optimizing operating parameters, treating and modifying catalysts and with the use of nano-sized catalytic materials. These activities contribute to stronger and more active Bronsted-Lewis acid-base sites and enlarged crystallite sizes, which improve the DO efficiency, selectivity, and reusability, to produce high-grade green diesel with less oxygen content. [ABSTRACT FROM AUTHOR]

Targeting tumour metabolism through glucose transporters is an attractive approach. However, the role these transporters play through interaction with other signalling proteins is not yet defined. The glucose transporter SLC2A3 (GLUT3) is a member of the solute carrier transporter proteins. GLUT3 has a high affinity for D-glucose and regulates glucose uptake in the neurons, as well as other tissues. Herein, we show that GLUT3 is involved in the uptake of arsenite, and its level is regulated by peroxiredoxin 1 (PRDX1). In the absence of PRDX1, GLUT3 mRNA and protein expression levels are low, but they are increased upon arsenite treatment, correlating with an increased uptake of glucose. The downregulation of GLUT3 by siRNA or deletion of the gene by CRISPR cas-9 confers resistance to arsenite. Additionally, the overexpression of GLUT3 sensitises the cells to arsenite. We further show that GLUT3 interacts with PRDX1, and it forms nuclear foci, which are redistributed upon arsenite exposure, as revealed by immunofluorescence analysis. We propose that GLUT3 plays a role in mediating the uptake of arsenite into cells, and its homeostatic and redox states are tightly regulated by PRDX1. As such, GLUT3 and PRDX1 are likely to be novel targets for arsenite-based cancer therapy. [ABSTRACT FROM AUTHOR]

In light of resource depletion, energy scarcity, and toxic waste management, gasification is regarded as a viable waste-to-energy conversion method. Moreover, the Gasifier-Engine-Genest combo provides a suitable alternative for distributed electric power, waste conversion, and alleviating electricity scarcity. Despite an abundance of research report, it is not usually acknowledged as a viable alternative to traditional energy sources. Thus, to promote Gasification, efficient technology is required to maximize the yield of syngas with clean and improved calorific value. Furthermore, there is a void in the prior study that summarises the various types of biomasses and their pre-treatment, as well as the progression of conventional gasification to advanced gasification for the improvement of syngas quality and respective critical applications. Moreover, this is necessary in order to organise the conditions and biomass for gasification, which are many and frequently scattered in the literature. Hence, this study summarises the detailed review of recent novel concepts development over conventional techniques of biomass gasification. Recent reports on feed material properties of diverse biomass, as well as pre-treatment employing biomass torrefaction for gasification, are presented in this paper in order to evaluate their potential. In addition, a literature review of the various categories of gasification, the gasification processes, and the impact of technology on the quality of syngas, power generation and distribution were reported. In conclusion, it is proposed that enhanced gasification technology be employed to implement sustainable development in order to reduce the existing reliance on non-renewable energy sources. [ABSTRACT FROM AUTHOR]

Renewable fuel generation and reducing reliance on fossil fuels are essential components of sustainable development. Manufacturing and use of petrochemicals are such an important economic pillar of contemporary civilisation. Therefore, there is a strong incentive to allocate alternative production pathways in order to conserve scarce resources. In order to minimise global emissions, it is also necessary to utilise environment wastes to generate value-added goods. This study demonstrates the sustainability assessment of various biomass gasification utilisation strategies developed through the poly-generation process. The superstructure network, which consists of different biomass feedstock (sources) and prospective uses (sinks) among the various gasification alternatives (pools), is examined to find the most cost-effective and ecologically beneficial production routes. Superstructure optimisation aids decisions on biomass feedstock mixing and subsequent utilisation, while taking both economic and environmental concerns into account. The results indicated the importance of biomass feedstock blending in enhancing the profitability of the process and lowering the requirement of gasifying agents. The findings indicated the domination of the power generation technique at 95.9% for oxygen gasification and methanol production for both oxygen/steam and steam-only gasification options at 92.5% when economic objective is considered. However, when the environmental objective is considered, urea generation turned to dominate the utilisation allocation at 94.9% for oxygen gasification, and methanol dominated the allocation at 92.5% for oxygen/steam and steam-only gasification options. Nevertheless, when both objectives are considered concurrently, urea dominated the strategies in all scenarios with a varying allocation of 38%–95%. The former solution maximiser the net profit at 0.124 $/kg biomass, and minimised net emissions at 0.58 kg CO 2 /kg biomass. Additionally, the study highlights the excellence of steam-only gasification over oxygen/steam and oxygen-only gasification options in delivering value-added products with higher profits and lower emissions. [ABSTRACT FROM AUTHOR]

The use of Polypropylene PP in disposable items such as face masks, gloves, and personal protective equipment has increased exponentially during and after the COVID-19 pandemic, contributing significantly to microplastics and nanoplastics in the environment. Upcycling of waste PP provides a useful alternative to traditional thermal and mechanical recycling techniques. It transforms waste PP into useful products, minimizing its impact on the environment. Herein, we synthesized an oil-sorbent pouch using waste PP, which comprises superposed microporous and fibrous thin films of PP using spin coating. The pouch exhibited super-fast uptake kinetics and reached its saturation in fewer than five minutes with a high oil uptake value of 85 g/g. Moreover, it displayed high reusability and was found to be effective in absorbing oil up to seven times when mechanically squeezed between each cycle, demonstrating robust oil-sorption capabilities. This approach offers a potential solution for managing plastic waste while promoting a circular economy. [ABSTRACT FROM AUTHOR]

A new hybrid method of utilizing Evidential Reasoning (ER) approach and Geographic Information System (GIS) was applied to find the optimum location of a Combined Heat and Power (CHP) incineration plant in Guilan province. According to guidelines and prevailing conditions, thirteen criteria were analyzed and divided to three main sections of environmental, social and economic categories. Most of the data in the study were obtained from local organizations and satellite images. To weight the criteria, evidential reasoning was applied to aggregate the decision-makers' opinions, and to find the potential sites; spatial analysis was done through the GIS. The result of suitability analysis indicates that about 0.07 % of total area of Guilan province is "the most suitable" region for the incineration plant and 0.05 %, 0.07 %, 2.77%, and 97.04 % are in the class of "suitable", "relatively suitable", "least suitable" and "limited". The areas with an area of larger than 40,000 m2 which is the necessary area for a 9 MW incineration plant were classified as alternatives for incineration CHP plant locations (A 1 -A 7). All the locations were investigated to be near rural areas, which might bring inevitable harm to the adjacent communities. Also, the low amount of "most suitable region" and "suitable region" foster a sense of concerns, which should be addressed by applying a sustainable approach for preserving the environment. The techno-economic analysis presented in this study indicates that the project is not economically beneficial at all. [ABSTRACT FROM AUTHOR]

Graphical abstract Effect of the concentration of the diesel–water emulsion on zeta potential. Optical images of emulsion with different diesel concentration are shown in inset. Highlights • Two graphene nanosorbents were prepared and used for oil emulsion adsorption. • Oil uptake rates achieved 90% oil uptake in less than 10 min. • Maximum oil capacities were 1554 and 805 mg/g for TRG and GNP, respectively. • Studies were performed under different saline conditions. • Fixed bed column studies and adsorbent regeneration are reported. Abstract The application of thermally reduced graphene (TRG) and graphene nanoplatelets (GNP) for the removal of emulsified and dissolved oil from oil–water emulsions has been investigated under different process parameters; namely, initial oil concentration, adsorbent dosage and salinity. Batch equilibrium studies have been performed at low oil concentrations (25–200 ppm), achieving an adsorption capacity = 1550 mg oil/g for TRG and 805 mg oil/g for GNP. Batch kinetic studies were performed to assess the rate of removal and over 90% removal was achieved in less than 10 min. Fixed bed column adsorption studies obtained bed capacities of 1100 mg oil/g for TRG and 850 mg oil/g for GNP. Regeneration studies revealed that both adsorbents could still adsorb over 94% of the full bed capacity after three adsorption–regeneration cycles. Increasing the emulsion salinity up to 20,000 ppm NaCl enhanced the adsorption capacities and removal efficiency, but further increases in salinity had no additional effect on capacity. [ABSTRACT FROM AUTHOR]

Environmental pollution caused by plastic waste and oil spills has emerged as a major concern in recent years. Consequently, there has been a growing interest in exploring innovative solutions to address these challenges. Herein, we report a method to upcycle polyolefins-based plastic waste by converting it into a bimodal super-oleophilic sorbent using dissolution, spin-coating, and annealing techniques. The resulting sorbent possesses an extensive network of pores and cavities with a size range from 0.5 to 5 µm and 150–200 µm, respectively, with an average of 600 cavities per cm2. Each cavity can swell up to twenty times the thickness of the sorbent, exhibiting sponge-like behavior. The sorbent had an oil uptake capacity of 70–140 g/g, depending on the type of sorbate and dripping time. Moreover, the sorbent can be mechanically or manually squeezed to recover the sorbed oil. Our integrated methodology provides a promising approach to upcycling plastic waste as an abundant source of value-added materials. [Display omitted] • Polyolefins, which make up 60% of plastic waste, were used to produce a super-sorbent for oil and organic removal from water. • The super-sorbent has pores and cavities, with an oil uptake capacity of 70–140 g/g. • Each cavity can swell up to twenty times the thickness of the sorbent, exhibiting sponge-like behavior. • The sorbent can be squeezed mechanically or manually to recover the sorbed oil, with at least 97% efficiency. • This technique can lead to greater utilization of plastic waste as a source of value-added materials. [ABSTRACT FROM AUTHOR]