Surviving chlorinated waters: bleaching sensitivity and persistence of free-living amoebae.

Recent advancements in membrane technologies and disinfection methods have enhanced drinking water quality significantly. However, microorganisms, including free-living amoebae (FLA), persist and pose potential threats to humans. FLA are linked to severe neuro-ophthalmic infections and serve as hosts of pathogenic bacteria. This study examined FLA presence in chlorinated and ultrafiltration drinking water and evaluated chlorine's disinfectant. Of 115 water samples, 21 tested positive for Acanthamoeba sp., Allovahlkampfia sp., and Vermamoeba vermiformis, originating from chlorinated sources. FLA trophozoites withstand temperatures up to 37 °C, while the cysts tolerate heat shocks of 60-70 °C. Trophozoites are susceptible to 5 mg L-1 chlorine, but cysts remain viable at concentrations up to 10 mg L-1. FLAs' survival in chlorinated waters is attributed to high cyst tolerance and lower residual chlorine concentrations. These findings highlight the need for ultrafiltration or enhanced chlorination protocols to ensure safer drinking water.

Production of biodiesel via esterification of coffee waste-derived bio-oil using sulfonated catalysts.

Catalytic esterification of acid-rich coffee waste-derived bio-oil was performed using sulfonated metal oxide catalysts (Al2O3, MgO, ZrO2, and TiO2) and ethanol to produce fatty acid alkyl esters. The potential of the sulfonated catalysts for esterification decreased in the following order: Ti-SO4 > Zr-SO4 > Al-SO4 > Mg-SO4. Particularly, Ti-SO4 and Zr-SO4 resulted in 91.2 % (peak area %) and 85.2 % esters, respectively. This is attributed to the contributions of well-dispersed Brønsted acid sites created by -SO3H functional groups, additional Lewis acid sites formed by Ti and Zr oxides, and their appropriate pore size. Compared with HCl and H3PO4, the use of H2SO4 for TiO2 treatment significantly enhanced ester formation. When using Ti-SO4, increasing the catalyst-to-feedstock ratio (1/2 âˆ¼ 1/10) significantly increased the esters' selectivity (38.7 %∼94.7 %). Ethanol utilization caused a superior selectivity for esters than methanol, while the increasing temperature favored ester production. This study proposes an eco-friendly and practical method for biodiesel generation.

Fractional condensation of bio-oil vapors from pyrolysis of various sawdust wastes in a bench-scale bubbling fluidized bed reactor.

The use of lignocellulosic waste as an energy source for substituting fossil fuels has attracted lots of attention, and pyrolysis has been established as an effective technology for this purpose. However, the utilization of bio-oil derived from non-catalytic pyrolysis faces certain constraints, making it impractical for direct application in advanced sectors. This study has focused on overcoming these challenges by employing fractional condensation of pyrolytic vapors at distinct temperatures. The potential of five types of sawdust for producing high-quality bio-oil through pyrolysis conducted with a bench-scale bubbling fluidized bed reactor was investigated for the first time. The highest yield of bio-oil (61.94 wt%) was produced using sample 3 (damaged timber). Remarkably, phenolic compounds were majorly gathered in the 1st and 2nd condensers at temperatures of 200 °C and 150 °C, respectively, attributing to their higher boiling points. Whereas, carboxylic acid, ketones, and furans were mainly collected in the 3rd (-5 °C) and 4th (-20 °C) condensers, having high water content in the range of 35.33%-65.09%. The separation of acidic nature compounds such as acetic acid in the 3rd and 4th was evidenced by its low pH in the range of 4-5, while the pH of liquid collected in the 1st and 2nd condensers exhibited higher pH (6-7). The well-separated bio-oil derived from biomass pyrolysis facilitates its wide usage in various applications, proposing a unique approach toward carbon neutrality. In particular, achieving efficient separation of phenolic compounds in bio-oil is important, as these compounds can undergo further upgrading to generate hydrocarbons and diesel fuel.

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.

Enhanced mono-aromatics production by the CH4-assisted pyrolysis of microalgae using Zn-based HZSM-5 catalysts.

This study presents the catalytic pyrolysis of microalgae, Chlorella vulgaris (C. vulgaris), using pure CH4 and H2-rich gas evolved from CH4 decomposition on three different HZSM-5 catalysts loaded with Zn, Ga, and Pt, aimed specifically at producing high-value mono-aromatics such as benzene, toluene, ethylbenzene, and xylene (BTEX). In comparison with that for the typical inert N2 environment, a pure CH4 environment increased the bio-oil yield from 32.4 wt% to 37.4 wt% probably due to hydrogen and methyl radical insertion in the bio-oil components. Furthermore, the addition of bimetals further increased bio-oil yield. For example, ZnPtHZ led to a bio-oil yield of 47.7 wt% in pure CH4. ZnGaHZ resulted in the maximum BTEX yield (6.68 wt%), which could be explained by CH4 activation, co-aromatization, and hydrodeoxygenation. The BTEX yield could be further increased to 7.62 wt% when pyrolysis was conducted in H2-rich gas evolved from CH4 decomposition over ZnGaHZ, as rates of aromatization and hydrodeoxygenation were relatively high under this condition. This study experimentally validated that the combination of ZnGaHZ and CH4 decomposition synergistically increases BTEX production using C. vulgaris.

Investigating catalytic oxidative desulfurization of model fuel using hollow PW12/TiO2@MgCO3 and performance optimization via box-behnken design.

A facile and eco-friendly synthesis of PW12/TiO2@MgCO3 hollow tubes (PW12·âˆ¼· H3[PW12O40] = polyoxometalate) using a soluble and reusable MgCO3·3H2O micro-rods template was reported for the first time. The resultant hollow tubes were characterized by Fourier transform infrared spectroscopy (FT-IR), UV-visible spectroscopy, powder X-ray diffraction (PXRD), energy-dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM), which indicated that the [PW12O40]3- structure remained intact within the hollow tubes. Furthermore, the specific surface area (88.982 m2/g) and average pore size (2.6 nm) of the PW12/TiO2@MgCO3 hollow tubes were calculated using the Brunauer-Emmett-Teller (BET) analysis. This study explored the catalytic performance of PW12/TiO2@MgCO3 hollow tubes using a three-level Box-Behnken design (BBD), through which optimization curves were designed. The desulfurization of model fuel using hollow tubes was optimally performed when the catalyst dose, time, temperature, and oxidant/sulfur (O/S) were 20-80 gm, 80-120 min, 25-80 °C and 3-8 molar ratio, respectively. These results were further processed, and the experiments were replicated twenty-nine times using a model based on two quadratic polynomials to create a response surface methodology (RSM). This permits a mathematical correlation linking the desulfurization and experimental parameters. The optimal performance of reaction mixture was evaluated to be 80 mg for catalyst concentration, 25 °C of temperature, reaction time of 100 min, and 5.5 for oxidant/sulfur molar ratio from 20 mL of octane simulation oil containing 350 ppm dibenzothiophene (DBT). The predicted desulfurization rate of the model fuel under these optimal conditions was 95.3%. The correspondence between the experimental results and predicted values was verified based on regression analysis, with an R2 value greater than 0.99. These hollow tubes could be used for their desulfurization properties ten times a row without significantly reducing catalytic activity.

Relevance Index Regional Variation by Each Disease and Its Essential Medical Field: A Retrospective Data Analysis From 2016-2020 in Korea.

BACKGROUND: To precisely build a healthcare delivery system at regional levels, local patients' healthcare service utilization patterns must be examined. Hence, this study utilized trend analysis of the relevance index of each disease of each essential medical service field at the municipal and provincial levels. METHODS: This study analyzed customized databases released by the National Health Insurance Service from 2016-2020. Diseases defined in the Korean National Burden of Disease (KNBD) study were categorized into the following essential medical service fields: trauma care, cardiocerebrovascular, maternal and neonatal, mental health, infection, cancer, older adults' care and rehabilitation, and others. Relevance index, the percentage of medical service utilization in a region by the residents of that region relative to their total medical service utilization, was examined by region (17 municipal and provincial regions) and disease area. The relevance index was determined based on the number of patients and the total out-of-pocket expenses. RESULT: Eight of the 17 regions showed over a 90.0% relevance index in the infection area. In the cancer area, 14 regions (not including Seoul, Daegu, and Busan) had a relevance index lower than 75.0%. Throughout the analysis period (2016-2020), there were no significant variations in the relevance index. Diseases such as bone and connective tissue cancer (39.0%), neural tube defects (16.7%), and autism (57.1%) had low relevance index in the essential medical service fields. In all 17 regions, the relevance index of inpatients was lower than that of outpatients, and that for out-of-pocket expenses was lower than that based on the number of patients. CONCLUSION: The relevance index of major diseases of each essential medical service field calculated in this study can provide good indicators for monitoring the level of an independent regional healthcare delivery system.

H2 generation from steam gasification of swine manure over nickel-loaded perovskite oxides catalysts.

In this study, nickel-loaded perovskite oxides catalysts were synthesized via the impregnation of 10%Ni on XTiO3 (X = Ce, Sr, La, Ba, Ca, and Fe) supports and employed in the catalytic steam gasification of swine manure to produce H2-rich syngas for the first time. The synthesized catalysts were characterized using BET, H2-TPR, XRD, HR-TEM, and EDX analysis. Briefly, using perovskite supports resulted in the production of ultrafine catalyst nanoparticles with a uniform dispersion of Ni particles. According to the catalytic activity test, the gas yield showed the increment as 10% Ni/LaTiO3 < 10% Ni/FeTiO3 < 10% Ni/CeTiO3 < 10% Ni/BaTiO3 < 10% Ni/SrTiO3 < 10% Ni/CaTiO3. Meanwhile, zero coke formation was achieved due to the oxygen mobility of prepared catalysts. Also, the increase in the H2 production for the applied catalysts was in the sequence as 10% Ni/CeTiO3 < 10% Ni/FeTiO3 < 10% Ni/LaTiO3 < 10% Ni/BaTiO3 < 10% Ni/SrTiO3 < 10% Ni/CaTiO3. The maximum H2 selectivity (∼48 vol%) obtained by10% Ni/CaTiO3 was probably due to the synergistic effect of Ni and Ti on enhancing the water-gas shift reaction, and Ca on creating the maximum oxygen mobility compared to other alkaline earth metals doped at the A place of perovskite. Overall, this study provides a suitable solution for enhanced H2 production through steam gasification of swine manure along with suggesting the appropriate supports to prevent Ni deactivation by lowering coke formation at the same time.

Templating agent-mediated Cobalt oxide encapsulated in Mesoporous silica as an efficient oxone activator for elimination of toxic anionic azo dye in water: Mechanistic and DFT-assisted investigations.

While Azorubin S (AZRS) is extensively used as a reddish anionic azo dye for textiles and an alimentary colorant in food, AZRS is mutagenic/carcinogenic, and it shall be removed from dye-containing wastewaters. In view of advantages of SO4•--related chemical oxidation technology, oxone (KHSO5) would an ideal source of SO4•- for degrading AZRS, and heterogeneous Co3O4-based catalysts is required and shall be developed for activating oxone. Herein, a facile protocol is proposed for fabricating mesoporous silica (MS)-confined Co3O4 by a templating agent-mediated dry-grinding procedure. As the templating agent retained inside the ordered pores of MS (before calcination) would facilitate insertion and dispersion of Co ions into pores, the resulting Co3O4 nanoparticles (NPs) would be grown and confined within the pores of MS after calcination, affording Co@MS. On the contrary, another analogue, Co/MS, is also prepared using the similar protocol without the templating agent-mediated introduction of Co, but Co3O4 NPs seriously aggregate as clusters on MS. Therefore, Co@MS outperforms Co/MS for activating oxone to eliminate AZRS. Co@MS shows a noticeably lower activation energy of AZRS elimination than the existing catalysts, revealing its advantage over the reported catalysts. Moreover, the mechanistic investigation of AZRS elimination by Co@MS-activated oxone has been also elucidated for identifying the presence of SO4•‒, •OH, and 1O2 in AZRS degradation using scavengers, electron paramagnetic resonance spectroscopy, and semi-quantification. The AZRS decomposition pathway is also investigated and unveiled in details via the DFT calculation. These results validate that Co@MS appears as a superior catalyst of oxone activation for AZRS degradation.

BET Inhibitors Target the SCLC-N Subtype of Small-Cell Lung Cancer by Blocking NEUROD1 Transactivation.

Small-cell lung cancer (SCLC) is a recalcitrant malignancy that urgently needs new therapies. Four master transcription factors (ASCL1, NEUROD1, POU2F3, and YAP1) have been identified in SCLC, and each defines the transcriptome landscape of one molecular subtype. However, these master transcription factors have not been found directly druggable. We hypothesized that blocking their transcriptional coactivator(s) could provide an alternative approach to target these master transcription factors. Here, we identify that BET proteins physically interact with NEUROD1 and function as transcriptional coactivators. Using CRISPR knockout and ChIP-seq, we demonstrate that NEUROD1 plays a critical role in defining the landscapes of BET proteins in the SCLC genome. Blocking BET proteins by inhibitors led to broad suppression of the NEUROD1-target genes, especially those associated with superenhancers, resulting in the inhibition of SCLC growth in vitro and in vivo. LSAMP, a membrane protein in the IgLON family, was identified as one of the NEUROD1-target genes mediating BET inhibitor sensitivity in SCLC. Altogether, our study reveals that BET proteins are essential in regulating NEUROD1 transactivation and are promising targets in SCLC-N subtype tumors. IMPLICATIONS: Our findings suggest that targeting transcriptional coactivators could be a novel approach to blocking the master transcription factors in SCLC for therapeutic purposes.

Household food waste conversion to biohydrogen via steam gasification over copper and nickel-loaded SBA-15 catalysts.

Household food waste (FW) was converted into biohydrogen-rich gas via steam gasification over Ni and bimetallic Ni (Cu-Ni and Co-Ni) catalysts supported on mesoporous SBA-15. The effect of catalyst method on steam gasification efficiency of each catalyst was investigated using incipient wetness impregnation, deposition precipitation, and ethylenediaminetetraacetic acid metal complex impregnation methods. H2-TPR confirmed the synergistic interaction of the dopants (Co and Cu) and Ni. Furthermore, XRD and HR-TEM revealed that the size of the Ni particle varied depending on the method of catalyst synthesis, confirming the formation of solid solutions in Co- or Cu-doped Ni/SBA-15 catalysts due to dopant insertion into the Ni. Notably, the exceptional activity of the Cu-Ni/SBA-15-EMC catalyst in FW steam gasification was attributed to the fine distribution of the concise Ni nanoparticles (9 nm), which resulted in the highest hydrogen selectivity (62 vol%), gas yield (73.6 wt%). Likewise, Cu-Ni solid solution decreased coke to 0.08 wt%.

Removal of oxytetracycline from water by liquid-phase plasma process with an iron precipitated TiO2 photocatalyst.

This study developed a new water treatment method using liquid-phase plasma (LPP) process that can decompose oxytetracycline (OTC) remaining in the aquatic environment. Relatedly, the OTC causes damage to the human body and cannot be removed by traditional water treatment methods. The study also prepared Fe/TiO2 photocatalyst responding to visible light using the LPP process. In particular, the OTC decomposition efficiency of the LPP process improved by more than 10% with the use of the Fe/TiO2 photocatalyst as compared to that of the one with the use of bare TiO2 photocatalyst. Further, the optimal LPP process parameters and Fe/TiO2 photocatalyst amount in the LPP process for OTC decomposition were established in the study. Finally, the degradation pathway of the OTC in the LPP process was found based on the five intermediates of the LPP reaction that were detected by the liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) analysis. In particular, the decomposition pathway was estimated to be involving the mineralization of the OTC through demethylation, deamination, dehydration, and ring cleavage.

A review on activated carbon modifications for the treatment of wastewater containing anionic dyes.

Polluted water resources, particularly those polluted with industrial effluents' dyes, are carcinogenic and hence pose a severe threat to sustainable and longstanding worldwide development. Meanwhile, adsorption is a promising process for polluted/wastewater treatment. In particular, activated carbon (AC) is popular among various wastewater treatment adsorbents, especially in the organic contaminants' remediation in wastewater. Hence, the AC's synthesis from degradable and non-degradable resources, the carbon activation involved in the AC synthesis, and the AC's modification to cutting-edge and effective materials have been modern-research targets in recent years. Likewise, the main research focuses worldwide have been the salient AC characteristics, such as its surface chemistry, porosity, and enhanced surface area. Notably, various modified-AC synthesis methods have been employed to enhance the AC's potential for improved contaminants-removal. Hence, we critically analyze the different modified ACs (with enhanced (surface) functional groups and textural properties) of their capacity to remove different-natured anionic dyes in wastewater. We also discuss the corresponding AC modification techniques, the factors affecting the AC properties, and the modifying agents' influence on the AC's morphological/adsorptive properties. Finally, the AC research of future interest has been proposed by identifying the current AC research gaps, especially related to the AC's application in wastewater treatment.

Production of valuable chemicals through the catalytic pyrolysis of harmful oil sludge over metal-loaded HZSM-5 catalysts.

This research studied the catalytic pyrolysis of oil sludge (OS) over metal-loaded HZSM-5 catalysts, an eco-friendly and cost-effective technology to produce value-added aromatics such as benzene, toluene, ethylbenzene, and xylene (BTEXs). In particular, it evaluated the respective effects of the experimental parameters: the type and amount of the metal loaded, the reaction temperature, and the OS/catalyst ratio, on the BTEXs yield sequentially to achieve optimum conditions. This evaluation showed that the highest yields of the BTEXs (6.61 wt%) and other aromatics were achieved when Ni was incorporated into the HZSM-5 (Ni/HZSM-5) followed by the corresponding yields of Ga/HZSM-5 and Fe/HZSM-5, due to a better distribution of Ni on the support surface and an enhanced acidity strength of this catalyst. Further, increase in Ni loading (up to 10 wt% Ni/HZSM-5) increased the BTEXs yield to 13.48 wt%. However, the excessive Ni loading (15 wt% Ni/HZSM-5) resulted in a reduced BTEXs yield due to the blockage of the zeolite channels. Next, an increase in the reaction temperature from 500 °C to 600 °C increased the yield of the BTEXs and other aromatics. However, a further increase in the reaction temperature to 650 °C decreased slightly their yield because of the stimulating secondary reactions at high temperatures. The increase of catalyst amount (OS/catalyst of 1/3) also maximized the BTEXs yield (30.50 wt%).

Ultrasound process-enhanced removal of the toxic disinfection by-product bromate from water by aluminum: A comparative study.

As bromate removal and reduction can be also achieved using metals, aluminum (Al) appears as the most promising one for reduction of bromate because Al is abundant element and exhibits a high reduction power. Reactions between bromate and Al shall be even enhanced through ultrasound (US) process because US can facilitate mass transfer on liquid/solid interfaces and clean surfaces via generating microscale turbulence to facilitate reactions. Therefore, the aim of this study is for the first time to investigate the effect of US on bromate removal by Al metal. Specifically, Al particle would be treated by HCl to afford HCl-treated Al (HCTAL), which is capable of removing bromate and even reducing it to bromide. Such a mechanism is also validated by density function theory calculation through determining adsorption energy as -152.8 kJ/mole, and oxygen atoms of bromate would be extracted and reacted with Al atoms, releasing bromide ion. US not only facilitated bromate removal by further increasing removal capacity under the acidic condition but also suppressed the inhibitive effect from basicity at relatively high pH. The spent HCTAL could still remove bromate and convert it to bromide after regeneration. These features indicate that US considerably enhances bromate removal by Al. PRACTITIONER POINTS: Bromate removed by Al is elucidated by DFT calculation with Eabsorption = -152.8 kJ/mole. Oxygen atoms of bromate are extracted and reacted with Al atoms, releasing bromide ion. A higher power of ultrasound would substantially enhance bromate removal efficiency. Ultrasound also suppresses the inhibitive effect from basicity at relatively high pH. With ultrasound, the interference of co-existing anions on bromate removal is lessened.

Production of value-added hydrochar from single-mode microwave hydrothermal carbonization of oil palm waste for de-chlorination of domestic water.

A huge amount of palm waste generated daily represents a problematic high-moisture waste to be disposed of, yet it also represents a promising biomass resource to be transformed into a value-added product. A single-mode microwave hydrothermal carbonization process incorporating steam purging was developed and utilised to convert high-moisture palm waste into hydrochar over a range of process temperatures from 150 to 300 °C. The microwave hydrothermal carbonization recorded a shorter process duration (10 min) and prevented the occurrence of hot spots within the reactor. The resulting hydrochar showed up to 94.3 wt% of mass yield, 69.2 wt% of fixed carbon, and 412.3 m2/g of surface area. The subsequent application of the hydrochar in de-chlorination of domestic water demonstrated an impressive removal performance of up to 98.9% of free chlorine, exhibiting 435 min of breakthrough time, and 40.0 mg/g of bed capacity in continuous column operation. The results show great promise of microwave hydrothermal carbonization as a desirable approach to produce desirable hydrochar for de-chlorination application.

Catalytic cracking of polystyrene pyrolysis oil: Effect of Nb2O5 and NiO/Nb2O5 catalyst on the liquid product composition.

The catalytic cracking of polystyrene pyrolysis oil was investigated over a Nb2O5 and a NiO/Nb2O5 catalyst in a fixed bed reactor. First, the pyrolysis of two different polystyrene feedstock (polystyrene foam and polystyrene pellet) was carried out in a semi-batch reactor, and the resulting polystyrene pellets pyrolysis oil was selected for catalytic cracking reaction because of its high liquid yield (85%). Catalytic cracking experiments were then performed at different temperatures (350-500 °C) using Nb2O5 or NiO/Nb2O5 catalyst. Gas chromatography-mass spectrometry analysis of liquid product obtained from the catalytic cracking process showed that the dimers in the pyrolysis oil were converted to monomers during the catalytic cracking process. The catalytic cracking results also showed that the NiO/Nb2O5 catalyst (having slightly higher acidic sites) had slightly higher activity for monomer conversion than the Nb2O5 catalyst (having less acidic sites). X-ray diffraction, transmission electron microscopy, pyridine Fourier transform infrared spectroscopy, NH3 Temperature Programmed Desorption and X-ray photoelectron spectroscopy were used to characterize the catalyst. The highest catalytic cracking activity was observed at 400 °C with the Nb2O5 catalyst with 4% toluene, 6% ethylbenzene, approximately 50% styrene, 13% α-methyl styrene, and only 6% of dimers in the liquid oil. The increase in temperature positively affected the yield of gases during catalytic cracking process.

Nanoneedle-Assembled Copper/Cobalt sulfides on nickel foam as an enhanced 3D hierarchical catalyst to activate monopersulfate for Rhodamine b degradation.

While metal oxides are conventionally proposed for activating monopersulfate (MPS) to degrade refractory contaminants, metal sulfides have recently gained increased attention for MPS activation because these sulfides exhibit more reactive redox characteristics to enhance the catalytic activation of MPS. The present study attempts to develop a novel material comprised of metal sulfides with 3D hierarchical nanostructures to activate MPS. Specifically, a 3D hierarchically structured catalyst was fabricated by growing CuCo-layered double hydroxide (LDH) on nickel foam (NF), followed by direct sulfurization, affording Cu/CoS@NF (CCSNF). CCSNF could exhibit a unique morphology of floral bunches comprised of nano-needles, residing on the NF surfaces. Compared with its precursor, CuCo-LDH@NF, oxide analogue, and CuCo2O4@NF, CCSNF possessed superior physical and chemical properties, including larger surface area and pore volume, higher current density, and lower charge transfer resistance. These features render CCSNF a much more effective catalyst than CuCo-LDH@NF and CuCo2O4@NF for activating MPS to degrade Rhodamine B (RB). In particular, RB degradation by CCSNF-activated MPS required an activation energy only 26.8 kJ/mol, which is much lower than the reported values. The activation mechanism and degradation pathway of RB degradation by CCSNF-activated MPS were investigated and validated through experimental evidences and density function theory calculations.

Suppression of the hazardous substances in catalytically upgraded bio-heavy oil as a precautious measure for clean air pollution controls.

Bio-heavy oil (BHO) is a renewable fuel, but its efficient use is problematic because its combustion may emit hazardous air pollutants (e.g., polycyclic aromatic hydrocarbon (PAH) compounds, NOx, and SOx). Herein, catalytic fast pyrolysis over HZSM-5 zeolite was applied to upgrading BHO to drop-in fuel-range hydrocarbons with reduced contents of hazardous species such as PAH compounds and N- and S-containing species (NOx and SOx precursors). The effects of HZSM-5 desilication and linear low-density polyethylene (LLDPE) addition to the feedstock on hydrocarbon production were explored. The apparent activation energy for the thermal decomposition of BHO was up to 37.5% lowered by desilicated HZSM-5 (DeHZSM-5) compared with HZSM-5. Co-pyrolyzing LLDPE with BHO increased the content of drop-in fuel-range hydrocarbons and decreased the content of PAH compounds. The DeHZSM-5 was effective in producing drop-in fuel-range hydrocarbons from a mixture of BHO and LLDPE and suppressing the formation of N- and S-containing species and PAH compounds. The DeHZSM-5 enhanced the hydrocarbon production by up to 58.5% because of its enhanced porosity and high acid site density compared to its parent HZSM-5. This study experimentally validated that BHO can be upgraded to less hazardous fuel via catalytic fast co-pyrolysis with LLDPE over DeHZSM-5.

Hydrogen-rich gas production via steam gasification of food waste over basic oxides (MgO/CaO/SrO) promoted-Ni/Al2O3 catalysts.

Food waste, a renewable resource, was converted to H2-rich gas via a catalytic steam gasification process. The effects of basic oxides (MgO, CaO, and SrO) with 10 wt% Ni/Al2O3 on the gasification properties of food waste were investigated using a U-shaped gasifier. All catalysts prepared by the precipitation method were analyzed by X-ray diffraction, H2-temperature-programmed reduction, NH3-temperature-programmed desorption, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The Ni/Al2O3 catalyst was reduced incompletely, and low nickel concentrations were detected on the surface of the alumina. The basic oxides minimized the number of acid sites and suppressed the formation of nickel-aluminate (NiAlxOy) phase in catalyst. In addition, the basic oxides shifted nickel-aluminate reduction reaction to lower temperatures. It resulted in enhancing nickel concentration on the catalyst surface and increasing gas yield and hydrogen selectivity. The low gas yield of the Ni/Al2O3 catalyst was attributed to the low nickel concentration on the surface. The maximum gas yield (66.0 wt%) and hydrogen selectivity (63.8 vol%) of the 10 wt% SrO- 10 wt% Ni/Al2O3 catalyst correlated with the highly dispersed nickel on the surface and low acidity. Furthermore, coke deposition during steam gasification varied with the surface acidity of the catalysts and less coke was formed on 10 wt% SrO- 10 wt% Ni/Al2O3 due to efficient tar cracking. This study showed that the steam gasification efficiency of the Ni/Al2O3 catalyst could be improved significantly by the addition of SrO.