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Graphene-titanium nanotube composites with different ratios of graphite oxide were prepared via the hydrothermal method using ascorbic acid as a reducing agent. Properties of materials were characterized by X-ray diffraction, Fourier Transform Infrared Spectroscopy, high resolution transmission electron microscopy and UV–vis diffuse reflectance spectroscopy. The average diameter of the titanium dioxide nanotubes was about 8 nm. The photoresponse of nanocomposites have been extended to visible-light regions. In addition, graphene-titanium nanotube composites showed higher photocatalytic degradation efficiency for reactive black 5 (RBK5) than pure titanium dioxide and the 15%graphene-titanium nanotube composites catalysts possessed the best photocatalytic activity. The degradation efficiency for RBK5 dyes increased with increased dosage of graphite oxide from 3%-15% and decreased with increasing initial RBK5 concentration. This paper not only reports the fabrication of highly active photocatalysts but also provides insight into the photocatalytic mechanism of graphene-titanium nanotube composites. [ABSTRACT FROM PUBLISHER]

In this study, polyvinyl alcohol (PVA) and titania (TiO2) Degussa P-25 were mixed to generate TiO2nonwoven filters using electrospinning. The wires of titanium dioxide and the nonwoven binding titania nanofibers were formed using 14 kV voltage and a distance of 15 cm. A single-factor experimental method was used to investigate the effects of parameters such as initial concentration, retention time, and light source on acetone removal by nonwoven binding titania nanofibers. Furthermore, the effects of parameters such as gas pressure, particle size, initial concentration, and retention time on the removal of particulates were also assessed. The results showed that the degradation efficiency increased with decreasing initial concentrations and increasing retention time. The best operational conditions during this study for the removal of acetone using the TiO2nonwoven filters were a retention time of 100 sec, initial acetone concentration of 250 ppm, and ultraviolet (UV) light source of 254 nm. Under those conditions, 99% acetone removal efficiency was obtained. In addition, 90% particulate matter removal efficiency was reached when the particulate size was greater than 200 nm and the reaction time was longer than 5 minutes. The prepared TiO2/nanofiber has good performance for volatile organic compounds (VOCs) and particulate removal at the same time. Implications:In this study, polyvinyl alcohol (PVA) and titania (TiO2) Degussa P-25 were mixed to generate TiO2 nonwoven filters using electrospinning. The results showed that the optimum operating conditions for the removal of acetone using the TiO2 nonwoven filters were a retention time of 100 sec, initial acetone concentration of 250 ppm, and UV light source of 254 nm. Under those conditions, 99% acetone removal efficiency was obtained. [ABSTRACT FROM AUTHOR]

Graphene-TiO2was obtained by reduction of graphite oxide by the hydrothermal method. Using photocatalytic activity to reduce carbon dioxide to methanol and formic acid was investigated in this study. The results show that the graphene loading affects the absorption of light in the visible light region. A larger surface area can also improve the catalytic activity. The largest yield of methanol and formic acid, under light of 365 nm, can reach 160 and 150 μmol g−1, respectively, with 8.5% graphene loading. An increase in graphene loading can enhance photocatalytic performance, but too much will also decrease the reduction efficiency by shielding the light from reaching the catalytic surface. The effect of pH was also investigated. The mechanism of the reaction was also discussed in this study.Implications: Graphene-TiO2 hybrids were prepared by the hydrothermal method. Surface area and visible light adsorption increased with the graphene loading. Increased graphene loading improved the methanol and formic acid production. Too much graphene loading will decrease the reduction efficiency. The effect of pH shows that the HCO3− species prefers the formation of formic acid. The mechanism of the reaction was also discussed in this study. [ABSTRACT FROM PUBLISHER]

Photocatalytic degradation of malathion, is investigated using Titanium Nanotubes (TNT) and Pt modified TNT (Pt-TNT) photocatalyst in an aqueous solution under 365 nm UV lamp irradiation. The TNT photocatalyst is prepared on pretreated strong alkaline solution via the hydrothermal method. The Pt-TNT was prepared by light deposition. The variations in morphology, formation mechanism, phase structure, and pore structure of TNT and Pt-TNT are characterized using UV-Vis, transmission electron microscopy (TEM), and N2adsorption/desorption isotherm analyzer, respectively. The effect of the initial malathion concentration, reaction temperature, catalyst loading, solution pH value, irradiation time and Pt loading are studied and the optimized values are obtained. Moreover, the photodegradation performance and kinetics of malathion onto TNT and Pt-TNT are also examined with the aid of model analysis by kinetic data. The results show that under acid conditions, the performance of photocatalysts for treating malathion is high. The time of complete degradation increases with an increase in the initial malathion concentration. The degradation rate decreases with increasing initial malathion concentration. The degradation efficiency can reach 100% under acid conditions for any initial malathion concentration when the reaction time is 70 min. In addition, experimental decoloration kinetics data follow the pseudo-first-order reaction model. [ABSTRACT FROM AUTHOR]

Woven straw has been demonstrated to be a cheap and effective method to prevent fugitive particular matter (PM), which is a typical air pollution source emitted from the exposed area, like farmland or a construction site. From the engineering application point of view, an approach using dimensionless analysis with a multivariable regression method based on experimental data would be worth exploring to predict the prevention efficiencies of woven straw to reduce the fugitive PM10 (PM sized less than 10 μm). A series of field-analogous experiments were carried out to continuously measure PM10 using β-attenuation particle monitors in an artificial wind tunnel system. It was found that the prevention efficiencies of woven straw to reduce PM10 is significantly dependent on the coverage ratio of woven straw, and the maximum prevention efficiency of PM10 is about 42%. It is emphasized that the prevention efficiency approaches zero as the coverage ratio is less than about 40%. This implies that PM10 reduction was inefficient if the exposed area was not covered enough with woven straw. Another point of interest is that total elimination of PM10 emission is not possible using full coverage woven straw. The effects of wind velocity, silt content, and moisture on prevention efficiency are also discussed in this paper. Correlated with major parameters, a useful equation is proposed to estimate the prevention efficiencies that would be valid under the appropriate conditions suggested by this work. [ABSTRACT FROM AUTHOR]

Abstract: This study provides a novel attempt to assess the effectiveness of control strategies for reducing volatile organic compounds (VOCs) emission from polyurea-formaldehyde resin synthetic fiber leather (PU) industry. Dimethyl formamide (DMF), major content of solvents, accounts for roughly 2500tonnes/year to avoid excessive viscosity of polyurea-formaldehyde and to increase facility in working. The other solvent contents, methyl ethyl ketone (MEK) and toluene, are used as carrier of DMF. Emission of these VOCs from solvent causes serious odor problems. It is important to know the VOCs pollution sources and emission characteristics before treating the VOCs in PU industry. In this study, 80 stacks in five factories were tested to evaluate emission characteristics at each VOCs source. After examining the VOCs concentrations in the flue gases and contents in the PU, the DMF emission rate before treatment and from fugitive source is 2300 and 80tonnes/year, respectively. To reduce VOCs emission rate, it is important to assess reducing solvent content in painting and increasing control efficiency of treatment equipment. In this study, the zeolite rotator is recommended to be used as effective control equipment. [Copyright &y& Elsevier]

This study presents the first attempt at employing catalytic biochar to remove ground-level ozone at ambient temperature. With the increase in human activity, ozone has become a critical inorganic pollutant that needs to be addressed, using more sustainable methods. Fe- and Mn-impregnated catalytic biochars were prepared from a sugarcane feedstock via the wet impregnation method and pyrolysis at various temperatures, where the optimum value was determined to be 550 °C. The metal-impregnated biochar samples demonstrated enhanced surface areas and pore volumes compared with the pristine biochar (SCB550), resulting in improved ozone-adsorption capacity. SCB550-Fe exhibited an ozone-adsorption capacity of 52.1 mg/g at 20 ppm, which was approximately four times higher than that of SCB550. SCB550-Fe demonstrated superior ozone-removal performance compared to SCB550-Mn; 122 mg/g capacity as opposed to 116.2 mg/g at 80 ppm, respectively. Isothermal and kinetic modeling are also presented to suggest a plausible mechanism of ozone removal by catalytic biochar. This includes physical adsorption, complexation, electrostatic interaction, and electron transfer during the redox reaction between ozone and metals. Overall, this study should provide preliminary insights into ozone removal using biochar and promote further research regarding material optimization and kinetic studies. [ABSTRACT FROM AUTHOR]

This study prepares a novel phosphorene (PN) and loads it onto TiO2 to fabricate PN-TiO2 and effectively photodegrade the hydrophobic environmental hormone 17β-estradiol in aqueous solutions. The effect of the PN on degradation efficiency is systematically investigated. It is observed that the doping of TiO2 with PN significantly enhances its photocatalytic and adsorption properties compared with that in the absence of PN; that is, the addition improves the adsorption capability of the composite. The optimal PN weight content is found to be 0.5%. The performance of the PN-TiO2 photocatalyst in degrading E2 is around 67.5%. However, its photodegradation efficiency gradually decreases when the PN content is further increased. This optimal PN content directly suggests synergistic interactions affecting the photodegrading efficiency. Compared with other PN-based photocatalysts mentioned in the literature, this PN-based material possesses striking advantages, such as higher energy efficiency, greater removal capacity, and superior cost-effectiveness. Further, the decrease in the biotoxicity of the water after treatment is evident in observing the development of zebrafish embryos. The studies of the catalyst performed on the zebrafish show that it results in a higher mortality rate at 96 h with a superior hatching rate and healthy fish development. In summary, the prepared PN-based materials exhibited promising photocatalytic capabilities for the removal and biotoxicity reduction of 17β-estradiol in aqueous solutions. [ABSTRACT FROM AUTHOR]

A well‐established electrode modifier, i. e. carboxylic acid (CA) functionalized‐multiwalled carbon nanotubes (f‐MWCNT), and a less explored safranin O (SFO) were fabricated on cuboidal graphite electrodes to develop two different voltammetric sensors for norfloxacin's electrochemical detection. The developed CA f‐MWCNT/graphite electrode and SFO/graphite showed a linear range of 3.10×10−7 to 3.13×10−5 M and 2.50×10−8 to 4.06×10−7 M with a limit of detection of 1.60×10−8 and 4.80×10−9 M, respectively. The practical applicability was tested in the spiked hospital wastewater, milk, and orange juice. It showed that the SFO could be a potential modifier for rapid, simple, and sensitive voltammetric detection of norfloxacin. [ABSTRACT FROM AUTHOR]

The global warming and the dangerous climate change arising from the massive emission of CO2 from the burning of fossil fuels have motivated the search for alternative clean and sustainable energy sources. However, the industrial development and population necessities make the decoupling of economic growth from fossil fuels unimaginable and, consequently, the capture and conversion of CO2 to fuels seems to be, nowadays, one of the most promising and attractive solutions in a world with high energy demand. In this respect, the electrochemical CO2 conversion using renewable electricity provides a promising solution. However, faradaic efficiency of common electro-catalysts is low, and therefore, the design of highly selective, energy-efficient, and cost-effective electrocatalysts is critical. Carbon-based materials present some advantages such as relatively low cost and renewability, excellent electrical conductivity, and tunable textural and chemical surface, which show them as competitive materials for the electro-reduction of CO2. In this review, an overview of the recent progress of carbon-based electro-catalysts in the conversion of CO2 to valuable products is presented, focusing on the role of the different carbon properties, which provides a useful understanding for the materials design progress in this field. Development opportunities and challenges in the field are also summarized. [ABSTRACT FROM AUTHOR]

In this study, zeolite synthesized based on bentonite via the alkali fusion-hydrothermal method, and the effects of different synthesis parameters on the crystallinity and silicon-aluminum ratio of zeolite were investigated. The zeolite particles were modified by cationic surfactant and magnetized to prepare a MCTAB-BZ composite, which was then applied to the adsorption of diethyl phthalate (DEP) from aqueous solution. The effects of operating factors, including pH value, adsorption dosage, temperature, and adsorption time on the kinetic and isotherm adsorption behavior were studied. Highly crystalline ANA-zeolite can be prepared with the alkali content of 1:1, the aging time of 20 h, the aging water content of 1:15, and the crystallization time of 24 h. The results of the adsorption experiment show that the novel adsorbent-MCTAB-BZ composite shows the best adsorption capacity when the adsorption dosage is 6.25 g/L, temperature is 30 °C and adsorption time is 180 min at the original pH value of the aqueous solution. The adsorption results are presented well by the pseudo-second-order kinetic model and the Freundlich isotherm model. [Display omitted] • Highly crystalline ANA-zeolite can be prepared under the best conditions. • The feasibility of using bentonite-synthesized zeolites as structural backbone synthetic adsorbents was demonstrated. • MCTAB-BZ was successfully applied on the DEP adsorption. • The best DEP adsorption onto MCTAB-BZ conditions were determined in this study. [ABSTRACT FROM AUTHOR]

A facile method was applied to achieve complete degradation of oxytetracycline to carbon dioxide and water. In most abiotic degradation, it fails to degrade oxytetracycline to non-toxic products and leaves some intermediates. In this study, sonocatalytic degradation was performed to degrade the more toxic oxytetracycline to less toxic intermediates. In addition, the above intermediates was degraded by biological method, by providing these intermediates as carbon source for bacteria. In the sono degradation process, ZnO was used as sonocatalyst material, which was prepared by simple chemical precipitation method. At first 30 min removal of oxytetracycline was achieved by adsorption and following 30 min will be degraded under ultra-sonication. In addition, sodium peroxydisulfate was used to achieve complete degradation of oxytetracycline. For the best degradation, various parameters such as pH, temperature, dosage of ZnO and concentration of peroxydisulfate, were optimized. At a pH 7, temperature of 55 oC, ZnO dosage of 3 g L-1 and peroxydisulfate concentration of 1 g L-1, the removal efficiency is nearly 99% at the end of 60 min for initial oxytetracycline concentration of 2 ppm. After sonocatalytic degradation, the intermediate formed was naphthalene and was confirmed in this study. Pseudomonas aeruginosa was used for biodegradation of intermediates. This strain is best for using various aromatic compounds as carbon source as it can easily break naphthal rings using naphthalene dehydrogenase enzymes. The removal performance of oxytetracycline and intermediates by sono-bio catalytic degradation was also confirmed by analyzing the total organic carbon (TOC) concentration in the test sample. [ABSTRACT FROM AUTHOR]

Gac fruit (Momordica cochinchinensis Spreng.) is a prominent source of carotenoids, renowned for its exceptional concentration of these compounds. This study focuses on optimizing the extraction of active components from the aril of gac fruit by evaluating the effects of extraction temperature, solid–liquid ratio, and extraction time. The primary objective is to maximize the yield of gac oil while assessing its antioxidant capacity. To analyze the kinetics of the solid–liquid extraction process, both first-order and second-order kinetic models were employed, with the second-order model providing the best fit for the experimental data. In addition, the potential of gac fruit peel as a precursor for biochar production was investigated through carbonization. The resultant biochars were evaluated for their efficacy in adsorbing crystal violet (CV) dye from aqueous solutions. The adsorption efficiency of the biochars was found to be dependent on the carbonization temperature, with the highest efficiency observed for BCMC550 (91.72%), followed by BCM450 (81.35%), BCMC350 (78.35%), and BCMC250 (54.43%). The adsorption isotherm data conformed well to the Langmuir isotherm model, indicating monolayer adsorption behavior. Moreover, the adsorption kinetics were best described by the pseudo-second-order model. These findings underscore the potential of gac fruit and its byproducts for diverse industrial and environmental applications, highlighting the dual benefits of optimizing gac oil extraction and utilizing the peel for effective dye removal. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) are common organic pollutants that can cause adverse effects on human health. Treatment techniques, including photocatalytic oxidation, have been studied to remediate VOCs. Acetone was used as a model pollutant to investigate the photocatalytic degradation performance of electrospun photocatalytic nanofibers with synthesized flower-like titanium dioxide (F-TiO2) and cellulose acetate (CA). The synthesized F-TiO2 and photocatalytic nanofibers were characterized using FE-SEM, XRD, FTIR, UVVis, XPS, and a pore size and porosity analyzer. The addition of F-TiO2 decreases the diameter of the nanofibers. The photocatalytic degradation performance test showed an enhanced acetone degradation efficiency on F-TiO2/CA photocatalytic nanofibers (FT-CFs), with an up to 95.0% acetone degradation efficiency under optimum conditions, over P25 TiO2/CA photocatalytic nanofibers (T-CFs). The filtration efficiency of 3.0%FT-CF reached 99.9% with a filter basis weight of 0.660 g m−2 and face velocity of 5.0 cm−1 s. The filtration and photocatalytic degradation cycle tests revealed excellent reusability, with 97% particle filtration and no sign of material deterioration. Moreover, the biodegradability tests showed that the material can biodegrade in water and in soil for 30 and 40 days, respectively. This study demonstrates that electrospun FT-CFs exhibit exceptional photocatalytic degradation of acetone, a high filtration efficiency, excellent reusability, and biodegradability, making them a promising solution for VOC remediation. [ABSTRACT FROM AUTHOR]

Acetone is solvent widely used in laboratories and factories. Serious problems will occur when it is exposed to the environment. Therefore, a new design for a bimetallic metal functional group catalyst that can convert acetone into carbon dioxide and water within 250 °C was prepared, in order to effectively treat acetone and reduce the required energy. Hydrophobic Y type zeolite adsorption and low-temperature catalytic combustion were used to continuously treat acetone, and the effect of different operating parameters (including different metal loads, metal content, transformation temperature, pollutant concentration, and space velocity) on the efficiency of acetone treatment was discussed in this study. The isothermal adsorption model, kinetics, and thermodynamic model analysis were also used to establish the reaction mechanism, and to explore the factors affecting the catalyst reaction rate. The results show that the acetone conversion rate of 10-Fe1Mn1-USY reaches 90% at 400 ppm, 20,000 h−1 space velocity, and 227 °C. The kinetic behavior of the reaction between 10-Fe1Mn1-USY and acetone is more suited to the Power-rate Law model. Arrhenius equation analysis results show that the required activation energy for the reaction between 10-Fe1Mn1-USY and acetone is 70.2 kJ mol−1, and the collision frequency factor is 2.81 × 105 s−1. This reaction is an endothermic reaction, and the main reaction mechanism is surface metal oxidation. A new design for a bimetallic metal functional group catalyst that can convert acetone into carbon dioxide and water within 250 ℃ was prepared, in order to effectively treat acetone and reduce the required energy. Hydrophobic Y type zeolite adsorption and low-temperature catalytic combustion were used to continuously treat acetone, and the effect of different operating parameters on the efficiency of acetone treatment was discussed in this study. Result shown that the redox reaction between the adsorbed acetone and the active oxygen on the surface of the catalyst to generate CO2 and H2O. [ABSTRACT FROM AUTHOR]

Ti-doped MCM-41 with different Si/Ti molar ratios was prepared at room temperature to degrade tetracycline antibiotics in aqueous solution. The Ti was doped into the skeleton structure of MCM-41. The photocatalytic activity of Ti-doped MCM-41 was investigated. The optimal catalyst had Si/Ti molar ratio of 25 and over 99% removal of oxytetracycline in 150 min, and the removal could maintain 98% after 5 reuses. Ions and soluble organic matters in natural water affected the degradation reaction when Ti-doped MCM-41 was used to treat simulated wastewater of chicken farms. The degradation products of oxytetracycline, tetracycline and chlortetracycline were detected by Escherichia coli DH5α and HPLC–MS/MS. No intermediate product with higher toxicity was detected. [ABSTRACT FROM AUTHOR]

S–modified MXene (Ti3C2Tx@S–5) was prepared to improve the catalytic activity of MXene in the electrocatalytic degradation of tetracycline hydrochloride (TC). Here, S groups in the form of Ti–S and S–O species were anchored onto MXene, resulting in superior conductivity and surface activity. Ti3C2Tx@S–5 exhibited an excellent performance of 100% TC degradation under the conditions of 25 °C, a pH of 6, a TC concentration of 10 mg L−1, and an applied current of 20 mA. Radical quenching and EPR analyses revealed that ·O2− and 1O2 played dominant roles in Ti3C2Tx@S–5 and Ti3C2Tx systems. Furthermore, S modification promoted the triggering of ·OH and active chlorine, which contributed to the acceleration of TC degradation. The involvement of these active substances in degradation pathways was further proven. This research advances the S modification of MXene and improves TC degradation by promoting the triggering of ·OH and active chlorine, broadening the applicability of MXene material. [ABSTRACT FROM AUTHOR]

The skeletal muscle progenitors' proliferation and migration are crucial stages of myogenesis. Identifying drug candidates that contribute to myogenesis can have a positive impact on atrophying muscle. The purpose of the study is to synthesize the Antrodia cinnamomea (AC)-β-cyclodextrin (BCD) inclusion complex (IC) and understand its in vitro pro-regenerative influence in murine skeletal C2C12 myoblasts. The IC was subjected to various nano-characterization studies. Fluorescent IC was synthesized to understand the cellular uptake of IC. Furthermore, 25 µg/mL, 12.5 µg/mL, and 6.25 µg/mL of IC were tested on murine C2C12 skeletal muscle cells for their anti-inflammatory, pro-migratory, and pro-proliferative action. The cellular internalization of IC occurred rapidly via pinocytosis. IC (252.6 ± 3.2 nm size and −37.24 ± 1.55 surface charge) exhibited anti-inflammatory action by suppressing the secretion of interleukin-6 and enhanced cell proliferation with promising cytocompatibility. A 12.5 μg/mL dose of IC promoted cell migration in 24 h, but the same dose of AC significantly reduced cell migration, suggesting modification by BCD. Molecular studies revealed that IC promoted C2C12 myoblasts migration by upregulating long non-coding RNA (lncRNA) NEAT-1, SYISL, and activating the pPKC/β-catenin pathway. Our study is the first report on the pro-proliferative and pro-migratory effects of BCD-modified extracts of AC. [ABSTRACT FROM AUTHOR]

Abstract: This study used various biocarriers (e.g., porites corals, Biolite™, porous ceramic filter media (PCFM)) to immobilize cells in fixed bed bioreactor (FBB) for wastewater decolorization. As prior studies proposed, an innovative graphical method of constant-slope isoclines to determine maximal allowable treatment capacity (MATC) was used as screening criteria for feasibility of packing matrices of immobilized cell systems (ICSs). Moreover, detailed inspection upon physical and chemical characteristics of packing matrices was also carried out to confirm the consistency of MTAC. The result of isocline analysis was in parallel with physical characteristics of biocarriers (i.e., porites coral>Biolite™>PCFM). This first-attempt study successfully provided perspective in general terms to assess how the selected supporting materials were suitable to be packing matrices of ICSs for industrial applications (e.g., wastewater treatment). [Copyright &y& Elsevier]

Abstract: Mesoporous MCM-41 was synthesized using cetyltrimethyl ammonium bromide (CTAB) as a cationic surfactant and spent glass as the silica source. The prepared samples were characterized by X-ray powder diffraction (XRD), nitrogen adsorption–desorption analysis, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscope–energy dispersive spectroscopy (SEM–EDS). The results showed that the surface area, pore volume and pore diameter could be up to 1328m2 g−1, 0.82cm3 g−1 and 2.62nm, respectively. The toluene adsorption capacity of MCM-41 (from pure chemical sources) at different concentrations could be calculated to be about 60, 104, 195 and 262mgg−1, respectively. In terms of breakthrough curve shape, the experimental results for G-MCM (from spent glass) were similar to those for MCM-41. Furthermore, the adsorption capacities of MCM-41 and G-MCM (mesoporous silica materials synthesized from spent glass) were almost the same. In this study, the effects of operation parameters, such as contact time and mixture concentration, on adsorption performance were also assessed. [Copyright &y& Elsevier]

Abstract: The goal of this study is to find out the exhaust emissions differences produced by different kinds of fatty acid methyl esters (FAME) derived from used cooking oils and animal fats, as well as the importance of the purification step in exhaust emissions production. A total of 120L of waste vegetable oil and 30L of waste frying oil were collected and converted into three batches of FAME. There were two batches of FAME produced from waste vegetable oil (B01 and B02), and one batch of FAME produced by mixing 2% of waste frying oil with waste vegetable oil (B03). The FAMEs used in this study had higher density, kinematic viscosity, and flash point, but a lower gross heating value, when compared to the premium diesel. The B01 engine produced higher CO formation and the diesel-fuelled engine produced higher CO than the B02 and B03 did for engine speeds higher than 1400rpm. Most of the FAME fuels produced higher CO2 than the diesel fuel did. The FAME fuels emitted higher NO x and PM, but lower SO2, than the diesel fuel. C n H2n+2, diphenyl sulfone (C12H10O2S), and diethyl phthalate (C12H14O4) can be selected as the character index for the combustion of FAME. [Copyright &y& Elsevier]

Abstract: In this study, wasted cooking oil from restaurants was used to produce neat (pure) biodiesel through transesterification, and this converted biodiesel was then used to prepare biodiesel/diesel blends. The goal of this study was to compare the trace formation from the exhaust tail gas of a diesel engine when operated using the different fuel type: neat biodiesel, biodiesel/diesel blends, and normal diesel fuels. B20 produced the lowest CO concentration for all engine speeds. B50 produced higher CO2 than other fuels for all engine speeds, except at 2000rpm where B20 gave the highest. The biodiesel and biodiesel/diesel blend fuels produced higher NO x for various engine speeds as expected. SO2 formation not only showed an increasing trend with increased engine speed but also showed an increasing trend as the percentage of diesel increased in the fuels. Among the collected data, the PM concentrations from B100 engines were higher than from other fuelled engines for the tested engine speed and most biodiesel-contained fuels produced higher PM than the pure diesel fuel did. Overall, we may conclude that B20 and B50 are the optimum fuel blends. The species of trace formation in the biodiesel-contained fuelled engine exhaust were mainly C n H2n+2, DEP, and DPS. For the B100, B80, B50, and D fuelled engines, C15H32 was the dominant species for all engine speeds, while squalene (C30H50) was the dominant for B20. DEP was only observed in the B100, B80, and B50 fuelled engines in this study. The D fuelled engine showed a higher DPS production for engine speeds higher than 1200rpm. [Copyright &y& Elsevier]

Abstract: This study evaluated the performance of photo-Fenton reaction initiated by the UV irradiation with H2O2/Fe3+, denoted as UV/H2O2/Fe3+, to decompose di-n-butyl phthalate (DBP) in the aqueous solution. The concentration of total organic carbon (TOC) was chosen as a mineralization index of the decomposition of DBP by the UV/H2O2/Fe3+ process. A second-order kinetic model with respect to TOC was adequately adopted to represent the mineralization of DBP by the UV/H2O2/Fe3+ process. The experimental results of this study suggested that the dosages with 4.74×10−5 molmin−1 L−1 H2O2 and initial Fe3+ loading concentration of 4.50×10−4 molL−1 in the solution at pH 3.0 with 120μWcm−2 UV (312nm) provided the optimal operation conditions for the mineralization of DBP (5mgL−1) yielding a 92.4% mineralization efficiency at 90min reaction time. [Copyright &y& Elsevier]

Abstract: Basic oxygen furnace slag (BOF slag) is a solid waste arisen from the steel making process. FeO is one of the major components of BOF slag. The FeO-containing property of BOF slag makes it possible to catalyze the Fenton reaction. Reactive Black 5 (RB5) dye is chosen as the target compound in this study. This study has investigated the catalytic performance of BOF slag on the Fenton reaction to decompose RB5 in aqueous solution. A first-order kinetic model with respect to TOC was adopted to explain the mineralization of RB5 by the H2O2/BOF slag process. The experimental results in this study suggested that dosage with 1.49×10−4 Mmin−1 H2O2 and 12.5g l−1 BOF slag in the solution at pH 2 provided the optimal operation conditions for the mineralization of RB5 yielding a 51.2% treatment efficiency at 100min reaction time, and complete decoloration can be achieved within 30min reaction time. The H2O2/Fe2+ ratio was then determined to be 6.06:1. [Copyright &y& Elsevier]

• Electro sorption of copper phthalocyanine over activated carbon fibers. • Electro-oxidative degradation of glyphosate using a carbon and copper electrode. • Central composite design for electro-oxidation of glyphosate. • Response surface methodology for reaction parameter optimization. • Kinetic assessment of glyphosate degradation during electro-oxidation. A novel approach is proposed in this study for degrading aqueous glyphosate (GLYP) efficiently via electro-oxidation (EO) using a novel copper phthalocyanine (CuPc)-dispersed activated carbon fiber (ACF) electrode. Green synthesis of the CuPc-ACF electrode was achieved by electro-sorption process through oxidation-reduction of the Cu species, using cyclic voltammetry, also for the first time. The prepared electrode was directly applied to degrade the aqueous recalcitrant pollutant without supplementation of an electrolyte and external source of oxidant. Operating parameters of the EO system were optimized via response surface methodology (RSM) based on central composite design using performance index of the area under the curve (AUC). A complete degradation of a synthetic GLYP solution at high concentration (1000 mg L−1) was indicated at the optimized pH and biased potential of 11 and 2.5 V (vs Ag/AgCl), respectively. Kinetic assessment of the experimental data revealed a threshold voltage between 1.5 and 2.0 V required to trigger an effective and irreversible degradation of the aminomethyl phosphonic acid (AMPA) intermediate. The kinetics for degradation of GLYP was proposed via two pathways: a consecutive first-order reversible or an irreversible reaction forming the AMPA intermediate and a parallel reaction forming final transformed products. The study indicated a green route for the synthesis of the CuPc-ACF electrode for complete degradation of GLYP using EO as a green technology. [ABSTRACT FROM AUTHOR]

Multilayer ZnO nanoflowers were synthesized through a simple precipitation method and characterized by field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), X-ray photoelectron spectra (XPS) and nitrogen absorption-desorption techniques. The FE-SEM images show the integrated morphology of an individual flower-like ZnO nanostructure, which is made of nano-platelets with uniform thickness (20–30 nm). The average pore size and Brunauer-Emmet-Teller (BET) surface area of the as-synthesized ZnO were 27.25 nm and 13.53 m 2 /g. The sonocatalytic ability of the prepared samples was evaluated through norfloxacin (NF) degradation in an aqueous system using ultrasound (US) irradiation. To improve degradation efficiency, peroxydisulfate (Na 2 S 2 O 8 ) was introduced to develop a US/ZnO/peroxydisulfate system, which exhibited an excellent synergistic effect. The effects of ZnO dosage, Na 2 S 2 O 8 concentration, pH, and initial NF concentration were studied to determine the performances of the US/ZnO/peroxydisulfate process. Corresponding results showed that NF degradation rate increased with the increase of ZnO dosage but decreased with the increase of initial NF concentration. Under the optimal Na 2 S 2 O 8 concentration of 0.1 g L −1 at pH 9, the best degradation efficiency can be achieved. Moreover, based on the scavenging experiment results and literatures, NF degradation through US/ZnO/peroxydisulfate system is majorly induced by OH and SO 4 − radicals. [ABSTRACT FROM AUTHOR]

A novel category of improved performance membrane consisting of a hydrophobic mat and a hydrophilic electrospun layer for membrane distillation (MD) application has been presented. The nanofibrous non-woven layer was fabricated by electrospinning of polyvinylalcohol (PVA) incorporated with Triton X-100 directly onto the polypropylene (PP) mat. To render the membrane distillation process effective in terms of high permeate flux and salt rejection %, the concept of dual layer membrane is utilized with hydrophobic PP mat on top and hydrophilic PVA layer on bottom. In this study, PVA nanofibrous layer has been fabricated by incorporating non-ionic surfactant Triton X-100 for uniformity and homogeneity in fiber diameter. Additionally, the PP mat acts as a top support layer and PVA-TX nanofiber acts as base layer which absorb the water molecules (condensed vapour), that enhances the vapour flux across the membrane. The modified bilayer PP/PVA-TX membranes were characterized by the pore size distribution, permeate flux, and rejection %, then compared with original PP mat. The salt rejection of the dual layered PP/PVA-TX membrane showed > 99% and still maintained 2 times higher permeate flux compared to PP membrane for long term operation of 15 h. [ABSTRACT FROM AUTHOR]

In this study, a one-step solid dispersion method was used to synthesize titanium dioxide (TiO 2 )/Zeolite Socony Mobil-5 (ZSM-5) composites with substantially reduced time and energy consumption. A degradation efficiency of more than 95% was achieved within 10 min using 50% PTZ (synthesized TiO 2 /ZSM-5 composites with TiO 2 contents of 50 wt% loaded on ZSM-5) at pH 7 and 25 °C. The possible degradation pathway of azo-dye Reactive Black 5 (RB5) was investigated using gas chromatography–mass spectrometry and ion chromatography (IC). The bonds between the N atoms and naphthalene groups are likely attacked first and cleaved by hydroxyl radicals, ultimately resulting in the decolorization and mineralization of the azo dye. A comparative assessment of the characteristics of abiotic and biotic dye decolorization was completed. In addition, the toxicity effects of the degradation intermediates of azo-dye RB5 on cellular respiratory activity were analyzed. The bio-toxicity results showed that the decay rate constants of CO 2 production from the azo-dye RB5 samples at different degradation times increased initially and subsequently decreased, indicating that intermediates of higher toxicity could adhere to the catalyst surface and gradually destroyed by further photocatalytic oxidation. Additionally, EDTA (hole scavengers) and t -BuOH (radical scavengers) were used to detect the main active oxidative species in the system. The results showed that the hydroxyl radicals are the main oxidation species in the photocatalytic process. [ABSTRACT FROM AUTHOR]