Recent advances in liquid fuel production from plastic waste via pyrolysis: Emphasis on polyolefins and polystyrene.

The management of plastic waste (PW) has become an indispensable worldwide issue because of the enhanced accumulation and environmental impacts of these waste materials. Thermo-catalytic pyrolysis has been proposed as an emerging technology for the valorization of PW into value-added liquid fuels. This review provides a comprehensive investigation of the latest advances in thermo-catalytic pyrolysis of PW for liquid fuel generation, by emphasizing polyethylene, polypropylene, and polystyrene. To this end, the current strategies of PW management are summarized. The various parameters affecting the thermal pyrolysis of PW (e.g., temperature, residence time, heating rate, pyrolysis medium, and plastic type) are discussed, highlighting their significant influence on feed reactivity, product yield, and carbon number distribution of the pyrolysis process. Optimizing these parameters in the pyrolysis process can ensure highly efficient energy recovery from PW. In comparison with non-catalytic PW pyrolysis, catalytic pyrolysis of PW is considered by discussing mechanisms, reaction pathways, and the performance of various catalysts. It is established that the introduction of either acid or base catalysts shifts PW pyrolysis from the conventional free radical mechanism towards the carbonium ion mechanism, altering its kinetics and pathways. This review also provides an overview of PW pyrolysis practicality for scaling up by describing techno-economic challenges and opportunities, environmental considerations, and presenting future outlooks in this field. Overall, via investigation of the recent research findings, this paper offers valuable insights into the potential of thermo-catalytic pyrolysis as an emerging strategy for PW management and the production of liquid fuels, while also highlighting avenues for further exploration and development.

Schiff base-functionalized metal-organic frameworks as an efficient adsorbent for the decontamination of heavy metal ions in water.

Adsorptive removal of heavy metal ions from water is an energy- and cost-effective water decontamination technology. Schiff base functionalities can be incorporated into the pore cages of metal-organic frameworks (MOFs) via direct synthesis, post-synthetic modification, and composite formation. Such incorporation can efficiently enhance the interactions between the MOF adsorbent and target heavy metal ions to promote the selective adsorption of the latter. Accordingly, Schiff base-functionalized MOFs have great potential to selectively remove a particular metal ion from the aqueous solutions in the presence of coexisting (interfering) metal ions through the binding sites within their pore cages. Schiff base-functionalized MOFs can bind divalent metal ions (e.g., Pb(II), Co(II), Cu(II), Cd (II), and Hg (II)) more strongly than trivalent metal ions (e.g., Cr(III)). The adsorption capacity range of Schiff base-functionalized MOFs for divalent ions is thus much more broad (22.4-713 mg g-1) than that of trivalent metal ions (118-127 mg g-1). To evaluate the adsorption performance between different adsorbents, the two parameters (i.e., adsorption capacity and partition coefficient (PC)) are derived and used for comparison. Further, the possible interactions between the Schiff base sites and the target heavy metal ions are discussed to help understand the associated removal mechanisms. This review delivers actionable knowledge for developing Schiff-base functionalized MOFs toward the adsorptive removal of heavy metal ions in water in line with their performance evaluation and associated removal mechanisms. Finally, this review highlights the challenges and forthcoming research and development needs of Schiff base-functionalized MOFs for diverse fields of operations.

Effects of Ni/Al2O3 catalyst treatment condition on thermocatalytic conversion of spent disposable wipes.

Municipal solid waste (MSW) management is an essential municipal service. Proper waste treatment is an important part of the waste management. Thermocatalytic waste upcycling has recently gained great interest and attention as a method to extract value from waste, which potentially substitutes traditional waste treatment methods. This study aims at demonstrating the potential for thermocatalytic waste upcycling using spent disposable wipes as an MSW surrogate. Two different Ni/Al2O3 catalysts were prepared, treated under two different atmospheres (N2 and CO2). The catalyst treated in N2 (Ni/Al2O3-N2) exhibited a higher surface metallic Ni site than the catalyst treated in CO2 (Ni/Al2O3-CO2). The use of the Ni/Al2O3-N2 increased the yield of gas pyrolysate and decreased the yield of byproduct (e.g., wax), compared with no catalyst and the Ni/Al2O3-CO2. In particular, the Ni/Al2O3-N2 catalyst affected the generation of gaseous hydrogen (H2) by increasing the H2 yield by up to 102% in comparison with the other thermocatalytic systems. The highest H2 yield obtained with the Ni/Al2O3-N2 was attributed to the most surface metallic Ni sites. However, the Ni/Al2O3-N2 catalyst led to char having a lower higher heating value than the other catalysts due to its lowest carbon content. The results indicated that the reduction treatment environment for Ni/Al2O3 catalyst influences thermocatalytic conversion product yields of spent disposable wipes, including enhanced H2 production. Electronic Supplementary Material: Supplementary material is available in the online version of this article at 10.1007/s11814-023-1461-8.

A new brain-cutting device and ultraviolet resin-mounted human brain slices as a teaching adjunct for neuroanatomy education.

Although the level of neuroscience research is rapidly developing with the introduction of new technologies, the method of neuroanatomy education remains at the traditional level and requires improvement to meet the needs of educators and trainees. We developed a new three-dimensional (3D) printed device (human brain-cutting mold, HBCM) for creating human brain slices; moreover, we demonstrated a simple method for creating semi-permanent ultraviolet (UV) resin-mounted brain slice specimens for neuroanatomy education. We obtained brain slices of uniform thickness (3 mm) through the HBCM; the resultant brain slices were optimal for assessing morphological details of the human brain. Furthermore, we used an agar-embedding method for brain-slicing with the HBCM, which minimized geometrical distortions of the brain slices. Also, we prepared semi-permanent brain serial specimens using an acrylic brain slice frame and UV-curable resin, which was highly compatible with moist bio-specimens. During UV resin curing, neither air bubble formation nor color change occurred. The resultant UV resin-mounted brain slices produced definite coronal sections with high transparency and morphological accuracy. We also performed 3D modeling by stacking brain slice images that differentiated the cortical area and nine subcortical regions via manual segmentation. This method could be a reliable alternative for displaying high-quality human brain slices and would be helpful for students and trainee to understand anatomical orientation from 2D images to 3D structures. Also, this may present an innovative approach for preparing and preserving coronal sections of the normal or pathological human brain.

Carbon dioxide-mediated thermochemical conversion of banner waste using cobalt oxide catalyst as a strategy for plastic waste treatment.

In this study, the effects of CO2 thermochemical agent and a metal oxide catalyst (Co3O4) on thermochemical banner waste conversion were explored. The results revealed that compared to the non-catalytic conversion of banner waste under N2 environment, the conversion under CO2 yielded more non-condensable gases owing to an enhanced thermal cracking of volatiles. In addition, the CO and CH4 yields at >700 °C in CO2 increased considerably owing to the reverse water-gas shift reaction and CO2 methanation. The CO2 agent reduced the yields of condensables (e.g., benzoic acids, phthalic acids, esters, biphenyls, fluorenes) and decomposition residue (e.g., char and wax), which could be attributed to the enhancement of the thermal cracking of volatiles evolved during the banner waste conversion by CO2 and the C-H and O-H bonds present in the feedstock. In addition, the Co3O4 catalyst promoted the decarboxylation reaction under N2 environment, whereas it promoted the methanation and reverse water-gas shift reaction under CO2. This indicates that compared to the non-catalytic CO2-assisted banner waste conversion, the use of CO2 for the conversion of banner waste in the presence of Co3O4 significantly increased the yields of CH4 and CO. Furthermore, Co3O4 promoted the thermal cracking of polyester bond, thus decreasing the yields of long-chain chemical compounds. In addition, the simultaneous use of Co3O4 catalyst and CO2 agent minimized the formation of char and wax. For all cases (N2 versus CO2, non-catalytic versus catalytic), an increase in temperature enhanced the total permanent gas yield and decreased the yields of condensables, char, and wax. The findings of this study revealed the importance of the synergistic use of Co3O4 catalyst and CO2 agent for the plastic waste upcycling, such as banner waste.

Progress in pre-treatment and extraction of organic and inorganic pollutants by layered double hydroxide for trace-level analysis.

Continuous release of pollutants into the environment poses serious threats to environmental sustainability and human health. For trace-level analysis of pollutants, layered double hydroxide (LDH) is an attractive option to impart enhanced sorption capability and sensitivity toward pollutants because of its unique layered structure, tunable interior architecture, high anion-exchange capacities, and high porosity (e.g., Zn/Cr LDH/DABCO-IL, Ni/Al LDH, CS-Ni/Fe LDH, SDS-Fe3O4@SiO2@Mg-Al LDH, Boeh/Mg/Al LDH/pC, and Fe@NiAl LDH). In concert with the well-defined analytical methodologies (e.g., HPLC and GC), the LDH materials can be employed to detect trace-level targets (e.g., as low as âˆ¼ 20 fg/L for phenols) in aqueous environments. This review highlights LDH as a promising material for pre-treatment of a variety of organic and inorganic target pollutants in complex real matrices. Challenges and future requirements for research into LDH-based analytical methods are also discussed.

Plant-based remediation of air pollution: A review.

Humans face threats from air pollutants present in both indoor and outdoor environments. The emerging role of plants in remediating the atmospheric environment is now being actively investigated as a possible solution for this problem. Foliar surfaces of plants (e.g., the leaves of cotton) can absorb a variety of airborne pollutants (e.g., formaldehyde, benzene, trimethylamine, and xylene), thereby reducing their concentrations in indoor environments. Recently, theoretical and experimental studies have been conducted to offer better insights into the interactions between plants and the surrounding air. In our research, an overview on the role of plants in reducing air pollution (often referred to as phytoremediation) is provided based on a comprehensive literature survey. The major issues for plant-based research for the reduction of air pollution in both outdoor and indoor environments are discussed in depth along with future challenges. Analysis of the existing data confirms the effectiveness of phytoremediation in terms of the absorption and purification of pollutants (e.g., by the leaves and roots of plants and trees), while being controlled by different variables (e.g., pore characteristics and planting patterns). Although most lab-scale studies have shown that plants can effectively absorb pollutants, it is important for such studies to reflect the real-world conditions, especially with the influence of human activities. Under such conditions, pollutants are to be replenished continually while the plant surface area to ambient atmosphere volume ratio vastly decreases (e.g., relative to lab-based experiments). The replication of such experimental conditions is the key challenge in this field of research. This review is expected to offer valuable insights into the innate ability of various plants in removing diverse pollutants (such as formaldehyde, benzene, and particulate matter) under different environmental settings.

Metal oxide and carbon nanomaterial based membranes for reverse osmosis and membrane distillation: A comparative review.

Commercial membranes typically suffer from fouling and wetting during membrane distillation (MD). In contrast, reverse osmosis (RO) can be subject to the fouling issue if applied for highly saline feed solutions containing foulants (e.g., organics, oils, and surfactants). Among the diverse treatment options, the nanomaterial-based membranes have recently gained great interest due to their advantageous properties (e.g., enhanced flux and roughness, better pore size distribution, and higher conductivity). This review focuses on recent advances in the mechanical properties, anti-fouling capabilities, salt rejection, and economic viability of metal oxide (SiO2, TiO2, and ZnO) and carbon nanomaterial (graphene oxide/carbon nanotube)-based membranes. Current challenges in applying nanomaterial-based membranes are also discussed. The study further describes the preparation methods, mechanisms, commercial applications, and economical feasibility of metal oxide- and carbon nanomaterial-based membrane technologies.

COVID-19 mask waste to energy via thermochemical pathway: Effect of Co-Feeding food waste.

In this study, co-pyrolysis of single-use face mask (for the protection against COVID-19) and food waste was investigated for the purpose of energy and resource valorization of the waste materials. To this end, disposable face mask (a piece of personal protective equipment) was pyrolyzed to produce fuel-range chemicals. The pyrolytic gas evolved from the pyrolysis of the single-use face mask consisted primarily of non-condensable permanent hydrocarbons such as CH4, C2H4, C2H6, C3H6, and C3H8. An increase in pyrolysis temperature enhanced the non-condensable hydrocarbon yields. The pyrolytic gas had a HHV of >40 MJ kg-1. In addition, hydrocarbons with wider carbon number ranges (e.g., gasoline-, jet fuel-, diesel-, and motor oil-range hydrocarbons) were produced in the pyrolysis of the disposable face mask. The yields of the gasoline-, jet fuel-, and diesel-range hydrocarbons obtained from the single-use mask were highest at 973 K. The pyrolysis of the single-use face mask yielded 14.7 wt% gasoline-, 18.4 wt% jet fuel-, 34.1 wt% diesel-, and 18.1 wt% motor oil-range hydrocarbons. No solid char was produced via the pyrolysis of the disposable face mask. The addition of food waste to the pyrolysis feedstock led to the formation of char, but the presence of the single-use face mask did not affect the properties and energy content of the char. More H2 and less hydrocarbons were produced by co-feeding food waste in the pyrolysis of the disposable face mask. The results of this study can contribute to thermochemical management and utilization of everyday waste as a source of energy.

Effect of eggshell- and homo-type Ni/Al2O3 catalysts on the pyrolysis of food waste under CO2 atmosphere.

This study highlights the potential of pyrolysis of food waste (FW) with Ni-based catalysts under CO2 atmosphere as an environmentally benign disposal technique. FW was pyrolyzed with homo-type Ni/Al2O3 (Ni-HO) or eggshell-type Ni/Al2O3 (Ni-EG) catalysts under flowing CO2 (50 mL/min) at temperatures from 500 to 700 °C for 1 h. A higher gas yield (42.05 wt%) and a lower condensable yield (36.28 wt%) were achieved for catalytic pyrolysis with Ni-EG than with Ni-HO (34.94 wt% and 40.06 wt%, respectively). In particular, the maximum volumetric content of H2 (21.48%) and CO (28.43%) and the lowest content of C2-C4 (19.22%) were obtained using the Ni-EG. The formation of cyclic species (e.g., benzene derivatives) in bio-oil was also effectively suppressed (24.87%) when the Ni-EG catalyst and CO2 medium were concurrently utilized for the FW pyrolysis. Accordingly, the simultaneous use of the Ni-EG catalyst and CO2 contributed to altering the carbon distribution of the pyrolytic products from condensable species to value-added gaseous products by facilitating ring-opening reactions and free radical mechanisms. This study should suggest that CO2-assisted catalytic pyrolysis over the Ni-EG catalyst would be an eco-friendly and sustainable strategy for disposal of FW which also provides a clean and high-quality source of energy.

Biochar as a catalytic material for the production of 1,4-butanediol and tetrahydrofuran from furan.

Biomass valorization is emerging as a new trend for the synthesis of materials for various environmental applications. In this connection, a biochar resulting from pyrolysis of rice straw was employed as a catalytic material for the conversion of hemicellulose-derived furan into value-added platform chemicals such as 1,4-butanediol (1,4-BD) and tetrahydrofuran (THF). The biochar was used as catalyst support of bifunctional Ru-Re catalyst. Two different catalysts were prepared: a conventional activated carbon (AC)-supported Ru-Re catalyst (Ru-Re/AC) and a biochar-supported Ru-Re catalyst (Ru-Re/biochar). The Ru-Re/biochar had a different form of Re species from the Ru-Re/AC, resulting in different reducibility. The difference of reducibility between the two was attributed to alkali metal present in the biochar such as potassium. The Ru-Re/biochar had a 17 times lower metal dispersion on the surface than the Ru-Re/AC, ascribed to a lower surface area of the biochar than the AC. Catalytic activities of the catalysts with regard to reaction rate per available surface active site for transforming furan to 1,4-BD and THF were measured. The Ru-Re/AC was 3 times less active than the Ru-Re/biochar. This study not only provides a way to efficiently use biomass both for environmental catalysts and for feedstock of producing value-added platform chemicals, but also shows potential of biochar for the replacement of typical catalysts employed in biorefinery.

Sustainable production of alkyl esters via thermal process in the presence of carbon black.

In this study, it is introduced a sustainable synthetic route of alkyl esters, considered value-added industrial chemicals and fuels, from volatile fatty acids (VFAs) that can potentially be generated from organic waste. In the presence of a porous carbon material, the thermally induced reaction could be conducted under an initial pressure of 1 atm. Even though the reaction was finished within <10 s, they gave a high yield of target products: the conversion of six VFAs into their corresponding methyl esters which can be further converted into gasoline alternatives with >90 wt% yields. The carbon black showed better performance for both reactions than other commercially available porous material such as silica. This work suggests that carbon is a good option of being used as a porous material for thermal esterification to produce renewable alternative chemicals from waste-derived feedstocks.

Acid-treated waste red mud as an efficient catalyst for catalytic fast copyrolysis of lignin and polyproylene and ozone-catalytic conversion of toluene.

In this study, red mud (RM), a highly alkaline waste generated from alumina production industries, was used as a catalytic material for both fast copyrolysis of organosolv lignin (OL) and polypropylene (PP) and toluene removal under ozone at room temperature. The RM was pretreated with HCl to investigate the effect of alkalinity. In the catalytic fast copyrolysis of the OL and PP, the acid-treated RM (HRM) produced more aromatics, phenolics, and light olefins (C3 to C5) but less oxygenates and heavy olefins (C6 to C46) than the RM. The difference in pyrolytic performance between the RM and HRM was likely attributed to the concentrated Fe2O3 species in the HRM catalyst. In addition, more efficient toluene removal was observed over MnOx/HRM than over MnOx/RM owing to the large Brunauer-Emmett-Teller surface area, high amounts of Al and Fe, and optimal Mn3+/Mn4+ ratio. This study demonstrates that the RM, an industrial waste, can be reused as an effective catalytic material for not only biofuel production but also pollutant removal.

CO2-mediated chicken manure biochar manipulation for biodiesel production.

This study employs chicken manure as a feedstock to produce different forms of energy to abate environmental burdens. To achieve ultimate carbon management, the possible utilization of CO2 during pyrolysis of chicken manure was fundamentally investigated. The roles of CO2 in pyrolysis of chicken manure include enhanced thermal cracking and shifting of the carbon distribution via reaction between volatile organic compounds and CO2. The identified roles induced by CO2 were catalytically enhanced because of the inorganic content in the feedstock. The morphology of biochar created from the chicken manure pyrolysis was significantly affected by CO2. For example, a well-developed pore structure was observed in the biochar developed under a CO2 environment; this biochar was used as an effective porous material for biodiesel synthesis.

Preparation and evaluation of a porous molecularly imprinted polymer for selective recognition of the antiepileptic drug carbamazepine.

A novel and porous molecularly imprinted polymer (PMIP) was synthesized and used as a solid-phase extraction adsorbent for preconcentration of carbamazepine (CBZ) prior to its quantitation by high-performance liquid chromatography (HPLC) in various sample forms (e.g., drinking water, river water, hospital wastewater, and pharmaceuticals). PMIP-CBZ was applied to a polymerization process in which polystyrene spheres were coated with a silica layer. Removal of polystyrene spheres and formation of porous silica facilitated the recovery of CBZ (99.4%) during the extraction process. Site accessibility to the surface of PMIP-CBZ increased the density of high-recognition sites. PMIP-CBZ was characterized by Fourier-transform infrared spectroscopy and scanning electron microscopy. The key variables influencing the extraction efficiency of PMIP (e.g., adsorbent loading, eluent type, eluent volume, reusability of the adsorbent, and cross-reactivity) were optimized. The optimized protocol was successfully employed to quantify CBZ with limit of detection and limit of quantification as 0.082 and 0.270 ng/mL, respectively (linear detection range: 0.5-250 ng/mL and a relative standard deviation:  < 5%). Use of the PMIP adsorbent resulted in a sensitive and stable method for efficiently quantitation of CBZ from various real sample matrices.

Biodegradation of methylene blue dye in a batch and continuous mode using biochar as packing media.

Bacterial species for metabolizing dye molecules were isolated from dye rich water bodies. The best microbial species for such an application was selected amongst the isolated bacterial populations by conducting methylene blue (MB) batch degradation studies with the bacterial strains using NaCl-yeast as a nutrient medium. The most suitable bacterial species was Alcaligenes faecalis (A. faecalis) according to 16S rDNA sequencing. Process parameters were optimized and under the optimum conditions (e.g., inoculum size of 3 mL, temperature of 30 °C, 150 ppm, and time of 5 days), 96.2% of MB was removed. Furthermore, the effectiveness for the separation of MB combining bio-film with biochar was measured by a bio-sorption method in a packed bed bioreactor (PBBR) in which microbes was immobilized. The maximum MB removal efficiencies, when tested with 50 ppm dye using batch reactors containing free A. faecalis cells and the same cells immobilized on the biochar surface, were found to be 81.5% and 89.1%, respectively. The PBBR operated in continuous recycle mode at high dye concentration of 500 ppm provided 87.0% removal of MB through second-order kinetics over 10 days. The % removal was found in the order of PBBR>Immobilized batch>Free cell. The standalone biochar batch adsorption of MB can be described well by the pseudo-second order kinetics (R2 ≥ 0.978), indicating the major contribution of electron exchange-based valence forces in the sorption of MB onto the biochar surface. The Langmuir isotherm suggested a maximum monolayer adsorption capacity of 4.69 mg g-1 at 40 °C which was very close to experimentally calculated value (4.97 mg g-1). Moreover, the Casuarina seed biochar was reusable 5 times.

Analysis of fatty acids in mouse tissue via in situ transmethylation with biochar.

Lipid derivatization technology-mediated fatty acid profiling studies have been suggested to dissect the contents of lipids in white fat and brown fat tissue. The focus of this study is to profile fatty acid lipidomics in brown adipose tissue and white adipose tissue of mice by derivatizing their lipids into fatty acid methyl esters via in situ transmethylation using a rice husk-derived biochar as porous media. The in situ transmethylation using biochar is advantageous in biological analysis because there was no loss of samples inevitably occurring in the loss of lipid in solvent extraction and purification steps.

A critical review of ferrate(VI)-based remediation of soil and groundwater.

Over the past few decades, diverse chemicals and materials such as mono- and bimetallic nanoparticles, metal oxides, and zeolites have been used for soil and groundwater remediation. Ferrate (FeVIO42-) has been widely employed due to its high-valent iron (VI) oxo compound with high oxidation/reduction potentials. Ferrate has received attention for wide environmental applications including water purification and sewage sludge treatment. Ferrate provides great potential for diverse environmental applications without any environmental problems. Therefore, this paper provides comprehensive information on the recent progress on the use of (FeVIO42-) as a green material for use in sustainable treatment processes, especially for soil and water remediation. We reviewed diverse synthesis recipes for ferrates (FeVIO42-) and their associated physicochemical properties as oxidants, coagulants, and disinfectants for the elimination of a diverse range of chemical and biological species from water/wastewater samples. A summary of the eco-sustainable performance of ferrate(VI) in water remediation is also provided and the future of ferrate(VI) is discussed in this review.

Production of high-octane gasoline via hydrodeoxygenation of sorbitol over palladium-based bimetallic catalysts.

A methodology for the synthesis of gasoline-range fuels from carbon neutral resources is introduced. Sorbitol, a sugar-based compound, was employed as a raw material because the compound is readily obtained from cellulose. Gasoline-range hydrocarbons were produced via hydrodeoxygenation (HDO) on zirconium phosphate-supported Pd-bimetallic (Pt-Pd, Ru-Pd, Ni-Pd, Fe-Pd, Co-Pd, W-Pd) catalysts. Among the tested catalysts, the bimetallic W-Pd/ZrP catalyst exhibited the highest yield of gasoline products, peaking at ∼70%. However, with the bimetallic Fe-Pd and Co-Pd catalysts, high-octane gasoline products were made (research octane number (RON) of the products was higher than 100). The Fe-Pd catalyst also showed the highest initial activity for the HDO of sorbitol. This study demonstrates that HDO in the Pd-system is a promising option to produce high-quality gasoline-range hydrocarbons from lignocellulosic biomass.

Post-Traumatic Chylous Wrist Effusion: A Case Report.

Chylous joint effusion is a rare condition characterized by the presence of a milky, viscous synovial fluid with abnormal lipid concentrations. The thorax is the most common site of involvement. Only a handful of cases have been reported in the field of orthopedic surgery and even fewer have been reported involving uncommon locations such as the knee. Treatment of chylous joint effusion may require surgical intervention along with the use of somatostatin or octreotide and a low-fat diet. We present herein a case of post-traumatic chylous effusion in the wrist treated with surgical incision and drainage, octreotide, and a low-fat diet. There have been few reports of chylous effusion in the knee; however, to our knowledge, this is the first report of post-traumatic chylous effusion in the wrist.