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In this study, a sustainable NH2-MIL-101(Al) is synthesized and subjected to characterization for cryogenic CO2 adsorption, isotherms, and thermodynamic study. The morphology revealed a highly porous surface. The XRD showed that NH2-MIL-101(Al) was crystalline. The NH2-MIL-101(Al) decomposes at a temperature (>500 °C) indicating excellent thermal stability. The BET investigation revealed the specific surface area of 2530 m2/g and the pore volume of 1.32 cm3/g. The CO2 adsorption capacity was found to be 9.55 wt% to 2.31 wt% within the investigated temperature range. The isotherms revealed the availability of adsorption sites with favorable adsorption at lower temperatures indicating the thermodynamically controlled process. The thermodynamics showed that the process is non-spontaneous, endothermic, with fewer disorders, chemisorption. Finally, the breakthrough time of NH2-MIL-101(Al) is 31.25% more than spherical glass beads. The CO2 captured by the particles was 2.29 kg m-3. The CO2 capture using glass packing was 121% less than NH2-MIL-101(Al) under similar conditions of temperature and pressure.
Composite membranes typically used for gas separation are susceptible to interfacial voids and CO2 plasticization which adversely affects the gas permeation performance. This paper evaluates routes towards the enhancement of CO2 permeation performance and CO2 plasticization resistance of composite membranes using non-stoichiometric ZIF-62 MOF glass and cellulose acetate (CA). Single and mixed gas permeation results, obtained with CO2 and CH4, demonstrate that the presence of ZIF-62 glass in CA polymer enhanced the CO2 permeability and CO2/CH4 ideal selectivity from 15.8 to 84.8 Barrer and 12.2-35.3, respectively. The composite membrane loaded with 8 wt% of ZIF-62 glass showed the highest CO2 permeability and CO2/CH4 ideal selectivity of 84.8 Barrer and 35.3, which were 436.7% and 189.3% higher compared to the pristine CA membrane, respectively. A CO2 plasticization pressure of 26 bar was achieved for the composite membranes, which is 160% higher compared to the pristine CA membranes, at about 10 bar. The mechanisms for the materials stabilization and greater separation performance were attributed to higher pore size (7.3 Å) and significant CO2 adsorption on the unsaturated metal nodes followed by metal cites electrostatic interaction with CO2. These findings confirm the potential of ZIF-62 glass materials as promising materials solutions towards the design of composite membranes for CO2 separation at industrial scale.
In the present research work, a comprehensive tool for cumulative ecotoxicological impact assessment of ionic liquids (ILs) to aquatic life has been constructed. Using the probabilistic tool, impact of individual ILs to a group of aquatic species is assessed by chemical toxicity distributions (CTDs). The impact of group of ILs to individual aquatic species is assessed by species sensitivity distributions (SSDs). Acute toxicity data of imidazolium ILs with chloride (Cl-), bromide (Br-), tetrafluoroborate (BF4-), and hexafluorophosphate (PF6-) anions are used in CTD and SSD. Allowable concentrations for a group of Imidazolium ILs with the same mode of action (SMOA) to five aquatic species; Daphnia magna, Vibrio fischeri, Algae, Zebrafish, and Escherichia coli are estimated by CTDs. It has been concluded that 1-Butyl-3-methylimidazolium chloride (BMIMCl) possess the lowest risk at an acceptable risk value of 750 × 10-5 mmol/L which is 12% less than that of OMIMCl. Furthermore, the sensitivities towards the aquatic species reveal that from the studied ILs, BMIMBF4 with an acceptable risk value of 3200 × 10-5 mmol/L is the most suitable IL towards the selected aquatic species. Hence, current work provides cumulative allowable concentrations and acceptable risk values for ILs which release to aquatic compartment of ecosystem.
This study analyzes the impact of ASEAN's goal of achieving carbon neutrality by 2050 on climate change and coastal ecosystems by examining carbon emissions and energy usage from 2019 to 2050 using different scenarios to reduce emissions and meet global temperature goals. This research proposes strategies to reduce carbon emissions and mitigate climate change effects on coastal ecosystems, focusing on evaluating CO2 emissions from ASEAN's coastal shipping sector. Geospatial data was used to analyze ship activity and develop carbon neutrality strategies. Various sources are used to gather data, including the Maritime Portal, exact Earth AIS, FASA and GFW. This study finds that container ships emitted 13.7 × 106 t of CO2 in 2019, with the transportation sector contributing 3.8% of the total greenhouse gas in 2020. Without regulations, CO2 emissions could increase fourfold by 2050. The study recommends implementing policies such as adopting clean fuels, energy efficiency standards and fuel-related regulations to reduce CO2 emissions by 65-80% by 2050. It also emphasizes the importance of cleaner technologies, regulatory considerations and collaboration, which would have positive implications for coastal ecosystems. This study is beneficial to professionals in the maritime and shipping industries, policy makers, environmental consultants, sustainability specialists, and international organizations.
Carbon capture technologies are becoming increasingly crucial in addressing global climate change issues by lowering CO2 emissions from industrial and power generation activities. Post-combustion carbon capture, which uses membranes instead of adsorbents, has emerged as one of promising and environmentally friendly approaches among these technologies. The operation of membrane technology is based on the premise of selectively separating CO2 from flue gas emissions. This provides a number of different benefits, including improved energy efficiency and decreased costs of operation. Because of its adaptability to changing conditions and its low impact on the surrounding ecosystem, it is an appealing choice for a diverse array of uses. However, there are still issues to be resolved, such as those pertaining to establishing a high selectivity, membrane degradation, and the costs of the necessary materials. In this article, we evaluate and explore the prospective applications and roles of membrane technologies to control climate change by post-combustion carbon capturing. The primary proposition suggests that the utilization of membrane-based carbon capture has the potential to make a substantial impact in mitigating CO2 emissions originating from industrial and power production activities. This is due to its heightened ability to selectively absorb carbon, better efficiency in energy consumption, and its flexibility to various applications. The forthcoming challenges and potential associated with the application of membranes in post-carbon capture are also discussed.
This study reports the application of hydrated lime for the effective adsorption of the heavy mercury metal from the aqueous phase solutions. Initially, hydrated lime was subjected to structural characterization and thermal stability analysis. The FT-IR spectrum analysis revealed that the existence of the O-H bonds as a confirmation of hydrated lime formation. Subsequently, the XRD powder-based analysis demonstrated that most of the hydrated lime is pure crystalline material known as Portlandite while a small amount of calcite is also present in the structure of the hydrated lime. The thermal stability analysis revealed that the hydrated lime is highly thermally stable under harsh conditions without decomposing at higher temperatures up to 500 °C. Furthermore, the hydrated lime was subjected to the selective adsorption of heavy metal mercury to investigate the potential influence of the adsorbent particle size and loading on adsorption capacity. The results demonstrated that the decrease in the adsorbent particle size leads to the improvement in the mercury adsorption attributing to the rise in specific surface area. The enhancement in the loading of the adsorbent resulted in a reduction in mercury adsorption directing to the fact that already adsorbed metal ions onto the adsorbent surface lead to hindrance for the adsorption of other ions of heavy metal. These results lead to a significant impact on modern in inventing different adsorbents with promising water treatment efficiency for more industrial applications and the related recovery of mercury.
The work aimed to study the potential in producing a system with high microalgal protein recovery and separation by utilizing a one-step or integrated downstream process. This in turn enables green biorefinery of protein, contributing to circular bioeconomy whereby less energy, labor, and cost are required for the process. By utilizing electric three phase partitioning flotation system, high protein recovery yield, R of 99.42 ± 0.52% and high separation efficiency, E of 52.72 ± 0.40% system was developed. Scaling up also showed high protein recovery yield with R value of 89.13 ± 1.56%. Total processing duration (extraction, separation, and purification) was also significantly reduced to 10 min. This system showed remarkable potential in reducing processing time, alternatively cost of production, benefiting microalgal downstream processing. Concisely, through this system, microalgal bioprocessing will no longer be complex allowing a wide array of potentials for further studies in this field.
The present study defines a novel green method for the synthesis of the nickel oxide nanocatalyst by using an aqueous latex extract of the Ficus elastic. The catalyst was examined for the conversion of novel Brachychiton populneus seed oil (BPSO) into biodiesel. The Brachychiton populneus seeds have a higher oil content (41 wt%) and free fatty acid value (3.8 mg KOH/g). The synthesised green nanocatalyst was examined by the Fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-Ray (EDX) spectroscopy, X-Ray diffraction (XRD) spectroscopy and scanning electron microscopy (SEM). The obtained results show that the synthesised green nanocatalyst was 22-26 nm in diameter and spherical-cubic in shape with a higher rate of catalytic efficiency. It was utilised further for the conversion of BPSO into biofuel. Due to the high free fatty acid value, the biodiesel was synthesised by the two-step process, i.e., pretreatment of the BPSO by means of acid esterification and then followed by the transesterification reaction. The acidic catalyst (H2SO4) was used for the pretreatment of BPSO. The optimum condition for the transesterification of the pretreated BPSO was 1:9 of oil-methanol molar ratio, 2.5 wt % of prepared nanocatalyst concentration and 85 °C of reaction temperature corresponding to the highest biodiesel yield of 97.5 wt%. The synthesised biodiesel was analysed by the FT-IR and GC-MS technique to determine the chemical composition of fatty acid methyl esters. Fuel properties of Brachychiton populneus seed oil biodiesel (BPSOB) were also examined, compared, and it falls in the prescribed range of ASTM standards.
This study presents an extended thermodynamic and phenomenological combined model to mitigate the environmental hazardous acid gas over composite membranes. The model has been applied to an acid gas such as carbon dioxide (CO2) for its permeation through polyetherimide incorporated montmorillonite (Mt) nanoparticles hollow fiber asymmetric composite membranes. The well-established non-equilibrium lattice fluid (NELF) model for penetrating low molecular weight penetrant in a glassy polyetherimide (PEI) was extended to incorporate the other important polymer/filler system features such as tortuosity in acid gas diffusion pathways resulted from layered filler aspect ratio and concentration. The model mentioned above predicts the behavior of acid gas in PEI-Mt composite membranes based on thermodynamic characteristics of CO2 and PEI and tortuosity due to Mt. The calculated results are compared to experimentally determined values of CO2 permeability through PEI-Mt composite asymmetric hollow fiber membranes at varying transmembrane pressures and Mt concentrations. A reasonable agreement was found between the model predicted behavior and experimentally determined data in terms of CO2 solubility, Mt concentration and aspect ratio were calculated based on average absolute relative error (%AARE). The proposed modified model efficiently predicts the CO2 permeance across MMMs up to 3 wt% Mt loadings and 6 bar pressure with ± 10%AARE.
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.
In hemodialysis process, membrane serves as a barrier between blood and the dialysate. The barrier when contacted by blood accompanied activation of coagulation, immunity, and cellular passageways. In the recent years, hemodialysis membrane's biocompatibility has become a issue which leads to reduce the performance during the separation process. In previous work, we developed and evaluated a cellulose-based membrane blended with polyaziridine or polyetyleneimine in formic acid for hydrophilicity, pure water flux, surface morphology, and permeation efficiency. Biocompatibility was accessed, by conducting cellular viability and cellular attachments tests. In this study, the membrane compared to a non-treated control, and cell viability revealed active and growing cell cultures after 14 days. During the cellular attachment experiment, cell cultures attached to the fabricated membrane simulated the formation of cell junctions, proving that the membrane is non-toxic and biocompatible. CA + PEI + FA membrane tested with a blood mimic fluid having density identical to renal patient's blood. The BSA concentration in the feed solution was the same as that in the blood of the renal patient. The results revealed that the CA + PEI + FA membrane was able to reject 99% bovine serum albumin (BSA) and 69.6% urea. Therefore, from biocompatibility and blood mimic fluid testing, it is confirmed that the CA + PEI + FA membrane is the finest implant for dialysis applications.
One of the most significant chemical operations in the past century was the Haber-Bosch catalytic synthesis of ammonia, a fertilizer vital to human life. Many catalysts are developed for effective route of ammonia synthesis. The major challenges are to reduce temperature and pressure of process and to improve conversion of reactants produce green ammonia. The present review, briefly discusses the evolution of ammonia synthesis and current advances in nanocatalyst development. There are promising new ammonia synthesis catalysts of different morphology as well as magnetic nanoparticles and nanowires that could replace conventional Fused-Fe and Promoted-Ru catalysts in existing ammonia synthesis plants. These magnetic nanocatalyst could be basis for the production of magnetically induced one-step green ammonia and urea synthesis processes in future.
Biomedical waste from healthcare activities poses a higher hazard of infection and damage than other types of trash. The main objective of the study was to assess the awareness knowledge and practices of biomedical waste management (BMWM) among health care professionals in the health care units. The cross-sectional study was carried out to access the awareness, knowledge and practices of health care professionals for BMWM. Using a qualitative approach, the study was escorted in two Apex hospitals i.e. the Allied Hospital and the District Head Quarter Hospital, Faisalabad, Pakistan from August 5, 2019 to October 15, 2019. More than 90% of respondents knew the phrase BMWM, but just 35.4% had awareness about biomedical waste regulations. About 71.6% of the respondents were familiar with biomedical waste's color-coding segregation. The study concludes gap in the awareness, knowledge and practices for BMWM. The sanitary workers of the hospitals had no knowledge about BMWM and the BMWM/healthcare waste management rule 2005 established in Pakistan due to the lack of training regarding waste management and the segregation process. Some of the staff members were aware of the BMWM practices under the rules and regulations of Pakistan but were unable to implement at their work place. It is necessary to dispose of the biomedical waste according to the established terms and conditions of BMWM rules (2005) of Pakistan. Weak structure of BMWM was observed at the study sites due to the lack of training, liabilities and absence of penalties against improper biomedical waste disposal as violation of the rules and regulations. It's a dire need of the time to consider the biomedical waste as hazardous waste and make policies for its safe disposal and ensure the implementation of the policies in all the medical centers of Pakistan.
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.
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.
The International Maritime Organization has set a goal to achieve a 50% reduction of total annual greenhouse gas emission related to the international shipping by 2050 compared to the 2008 baseline emissions. Malaysia government has taken an initiative to investigate the assessment (cost-effectiveness) of this International Maritime Organization's short-term measure on Malaysian-registered domestic ships although this measure is only for international merchant ship. To achieve this, this paper collected the ship's data from the shipowners from 25 sample ships. Engine power limitation is the most cost-effective option, but low power limits can lead to substantially increased sailing times. Based on cost-efficiency analysis, it creates for the purpose of compliance with the operational carbon intensity indicator. It found that even if it is possible to bring an asset back into service, it may not be possible to do so in a manner that generates a profit or complies with applicable regulations. In these situations, it may be more prudent to scrap the asset rather than run the risk of having it become a stranded asset. This is especially true for older tankers. Alternatives with lengthy payback periods are not desirable for the domestic tanker fleet that is already in operation.
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.
Cellulose is the most abundant polysaccharide on earth. It has a large number of desirable properties. Its low toxicity makes it more useful for a variety of applications. Nowadays, its composites are used in most engineering fields. Composite consists of a polymer matrix and use as a reinforcing material. By reducing the cost of traditional fibers, it has an increasing demand for environment-friendly purposes. The use of these types of composites is inherent in moisture absorption with hindered natural fibers. This determines the reduction of polymer composite material. By appropriate chemical surface treatment of cellulose composite materials, the effect could be diminished. The most modern and advanced techniques and methods for the preparation of cellulose and polymer composites are discussed here. Cellulosic composites show a reinforcing effect on the polymer matrix as pointed out by mechanical characterization. Researchers tried their hard work to study different ways of converting various agricultural by-products into useful eco-friendly polymer composites for sustainable production. Cellulose plays building blocks, that are critical for polymer products and their engineering applications. The most common method used to prepare composites is in-situ polymerization. This help to increase the yields of cellulosic composites with a significant enhancement in thermal stability and mechanical properties. Recently, cellulose composites used as enhancing the incorporation of inorganic materials in multi-functional properties. Furthermore, we have summarized in this review the potential applications of cellulose composites in different fields like packaging, aerogels, hydrogels, and fibers.
The potential of new trimetallic (Ce, Cu, La) loaded montmorillonite clay catalyst for synthesizing biodiesel using novel non-edible Celastrus paniculatus Willd seed oil via two-step transesterification reaction has been reported along with catalyst characterization. Transesterification reaction was optimized and maximum biodiesel yield of 89.42% achieved under optimal operating reaction states like; 1:12 oil to methanol ratio, 3.5% of catalyst amount, 120 °C of reaction temperature for 3 h. The predicted and experimental biodiesel yields under these reaction conditions were 89.42 and 89.40%, which showing less than 0.05% variation. Additionally, optimum biodiesel yield can be predicted by drawing 3D surface plots and 2D contour plots using MINITAB 17 software. For the characterization of the obtained biodiesel, analysis including the GC/MS, FT-IR, 1H NMR and 13C NMR were applied. The fuel properties of obtained biodiesel agrees well with the different European Union (EU-14214), China (GB/T 20828), and American (ASTM-951, 6751) standards.