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Key message: Strigolactone has the potential to influence hormone metabolism, in addition to having a role in inhibiting axillary bud elongation, which could be regulated by the expression of phytohormones-related genes. The elongation of axillary buds affects the economic benefits of tobacco. In this study, it was investigated the effect of strigolactone (SL) on the elongation of tobacco axillary buds and its endogenous hormone metabolism and related gene expression by applying the artificial analog of SL, GR24, and an inhibitor of SL synthesis, TIS-108, to the axillary buds. The results showed that the elongation of axillary buds was significantly inhibited by GR24 on day 2 and day 9. Ultra-high-performance liquid-chromatography-mass spectrometry results further showed that SL significantly affected the metabolism of endogenous plant hormones, altering both their levels and the ratios between each endogenous hormone. Particularly, the levels of auxin (IAA), trans-zeatin-riboside (tZR), N6-(∆2-isopentenyl) adenine (iP), gibberellin A4 (GA4), jasmonic acid (JA), and jasmonoyl isoleucine (JA-Ile) were decreased after GR24 treatment on day 9, but the levels of 1-aminocyclopropane-1-carboxylic acid (ACC) and gibberellin A1 (GA1) were significantly increased. Further analysis of endogenous hormonal balance revealed that after the treatment with GR24 on day 9, the ratio of IAA to cytokinin (CTK) was markedly increased, but the ratios of IAA to abscisic acid (ABA), salicylic acid (SA), ACC, JAs, and, GAs were notably decreased. In addition, according to RNA-seq analysis, multiple differentially expressed genes were found, such as GH3.1, AUX/IAA, SUAR20, IPT, CKX1, GA2ox1, ACO3, ERF1, PR1, and HCT, which may play critical roles in the biosynthesis, deactivation, signaling pathway of phytohormones, and the biosynthesis of flavonoids to regulate the elongation of axillary buds in tobacco. This work lays the certain theoretical foundation for the application of SL in regulating the elongation of axillary buds of tobacco. [ABSTRACT FROM AUTHOR]

CO2 catalytic conversion to CO would likely be an important part of CO2 mitigation and utilization. In this work, CuAl2O4 was developed with a spinel structure that acts as an active and stable catalyst for this reaction. Here, the fundamental characteristics of CuAl2O4 catalyst were studied to understand the catalytic mechanism for the Reverse Water Gas Shift reaction. Based on the catalytic mechanism, the CuAl2O4 catalyst was found to have exceptional catalytic activity due to the high dispersion of copper on its surface, and it could have higher catalytic activity by increasing the oxygen vacancies on the surface of the catalyst via alkalinization treatment. By combining with XPS spectra, the relationship between the Raman mode and the oxygen vacancy structure on the CuAl2O4 surface was proved. Through these studies, it was proved that alkalinization treatment can regulate the oxygen vacancies on the surface of the catalyst and thus enhance the catalytic activity. [ABSTRACT FROM AUTHOR]

Nitrogen oxides released from the combustion of fossil fuels are one of the main air pollutants. Selective catalytic reduction technology is the most widely used nitrogen oxide removal technology in the industry. With the development of nanomaterials science, more and more novel nanomaterials are being used as catalysts for the selective reduction of nitrogen oxides. In recent years, metal-organic frameworks (MOFs), with large specific surface areas and abundant acid and metal sites, have been extensively studied in the selective catalytic reduction of nitrogen oxides. This review summarizes recent progress in monometallic MOFs, bimetallic MOFs, and MOF-derived catalysts for the selective catalytic reduction of nitrogen oxides and compares the reaction mechanisms of different catalysts. This article also suggests the advantages and disadvantages of MOF-based catalysts compared with traditional catalysts and points out promising research directions in this field. [ABSTRACT FROM AUTHOR]

Thermochemical processes are considered as a promising technology for sewage sludge management, which could achieve volume reduction, energy and resource recovery, and effective destruction of pathogens. However, there are still many technology limitations and challenges of the thermochemical processes toward industrialization and commercialization. This review first briefly discusses the impact of sewage sludge on environmental sustainability and its current treatment and disposal methods. Typical thermochemical conversion technologies i.e., incineration/combustion, pyrolysis, gasification, and hydrothermal liquefaction for energy and resource recovery from sewage sludge are then comprehensively summarized. Subsequently, the technical challenges of thermochemical conversion of sewage sludge and the solutions that have been and/or are being developed to address the challenges are in-depth analyzed. Meanwhile, the prospects and future directions of the thermochemical technologies are outlined. In addition, the economic analysis and life cycle assessment of thermochemical conversion technologies are evaluated. Finally, the conclusions are put forward. [ABSTRACT FROM AUTHOR]

Environmental contamination by 4-chlorophenol (4-CP) is a major concern. Photosynthetic bacteria have the ability to biodegrade 4-CP under dark aerobic conditions. In this study, we found that using different carbon sources (i.e. glucose, sodium acetate, sodium propionate sucrose, and malic acid) as co-metabolic substrates accelerated the biodegradation of 4-CP, and this acceleration was especially pronounced in the glucose treatment. A maximum degradation rate of 96.99% was reached under a concentration of 3.0 g·L−1 after 6 days of culture. The optimum conditions were pH 7.5, a temperature of 30°C, and a rotation speed of 135 rpm. The biodegradation of 4-CP was achieved at a range of salinities (0–3.0% NaCl, w/v). The biodegradation kinetics agreed with the Haldane model, and the kinetic constants were rmax = 0.14 d−1, Km = 33.9 mg·L−1, and Ki = 159.6 mg·L−1. Additionally, the coexistence of phenol or 2,4-dichlorophenol (2, 4-DCP) had a certain impact on the degradation of 4-CP under dark aerobic conditions. When the coexisting phenol concentration reached 100 mg·L−1, the maximum degradation rate of 4-CP reached 90.20%. The degradation rate of 4-CP decreased as the concentration of coexisting 2, 4-DCP increased. [ABSTRACT FROM AUTHOR]

Whether the reaction pathway is steady or dynamic over the whole life cycle of a catalyst process can facilitate our understanding of its catalytic behavior. Herein, the dynamic reaction pathways of nitrogen-doped carbon catalysts are investigated in acetylene hydrochlorination. When triggered, the reaction follows the Langmuir – Hinshelwood mechanism with pyrrolic N and pyridinic N as dual active sites. However, pyridinic N is deactivated first, due to the strong adsorption of hydrogen chloride, causing the reaction to further run with pyrrolic N as the single active site and follow the Eley – Rideal mechanism. This work provides a new promising way to study the catalytic behavior of nitrogen-doped carbon catalysts. [ABSTRACT FROM AUTHOR]

Ru-Based catalysts with distinct active phases from Ru0, to RuO2, RuCl3 and RuCl2N were synthesized and evaluated in acetylene hydrochlorination. RuCl2N is identified as the efficient active phase due to its co-activation of acetylene and hydrogen chloride. This discovery holds great potential to accelerate the large-scale application of Ru-based catalysts in industry. [ABSTRACT FROM AUTHOR]

With the on‐going development of nanotechnology, iron‐containing nanomaterials have received much attention in wastewater treatment and site remediation. Here, we synthesized a biochar‐supported iron oxide nanocomposite (FemOn/BC) by simply pyrolysing rice root, which is a natural source both of iron and carbon. The FemOn/BC nanocomposite nicely preserved the vascular bundle structure of rice root. With iron oxide doped on the mesoporous biocarbon, the composite has the usability as a Fenton‐like catalyst in the Fenton system. FemOn/BC‐700 (pyrolysis at 700 °C) was selected to catalysis the reactive brilliant red X‐3B degradation. Under the same catalytic effect, the service life of FemOn/BC‐700 almost doubles that of iron microparticles. We believe this green and energy‐efficient method might have value in biomass usage and helps sustainable development. [ABSTRACT FROM AUTHOR]

Recycling of chemicals from waste plastics is important for the reutilization of resources and the reduction of environmental pollution. The phase behaviors of poly (1,4-cyclohexylene dimethylene terephthalate) (PCT) in water at different temperature and time were observed in a fused silica capillary reactor (FSCR) with a microscope. The effects of the reaction temperature (260−340 °C), the reaction time (30−90 min), and the mass ratio of water/PCT (6:1−14:1) on the degradation of PCT were studied in an autoclave reactor on the basis of the results obtained from the FSCR. Under our research conditions, depolymerization of both 1,4-cyclohexanedimethanol and terephthalic acid (TPA) generated mainly phenol, and the maximum yield of phenol was obtained at 340 °C after its reaction with a water/PCT mass ratio of 10:1 for 90 min. Moreover, a reaction mechanism of PCT degradation in subcritical water was proposed. Our results suggest that PCT can be depolymerized rapidly and completely in subcritical water to produce phenol, and this method is conducive to the recycling of waste PCT. [ABSTRACT FROM AUTHOR]

Raman spectroscopy is a nondestructive and in situ analytical technique that could provide information on the chemical structure and structural ordering of carbonaceous materials. Based on the E2g symmetric stretching vibration mode in the aromatic layers (G band, ~1,580 cm−1) and the defect structure in graphite (D band, ~1,350 cm−1), Raman spectroscopy has been used extensively to characterize the structural features of carbonaceous matters since 1970. Coal is a complex organic compound made up mainly by carbon showing characteristic Raman bands. This article reviews the application of Raman spectroscopy for coal structure characterization under room temperature, to determine its chemical structure, crystallite size, coal rank, and combustion reactivity. Future research for collecting Raman spectra during coal pyrolysis at high temperatures is also discussed. The combination of high‐temperature hot stage with Raman spectroscopy technology allows direct collection of Raman spectra at high temperature. [ABSTRACT FROM AUTHOR]

Boron-doped carbon nanodot materials, comprising evenly distributed BC3-nanodots in a layered carbon matrix, are prepared through a pre-assembly assisted carbonization synthetic strategy. The prepared materials are endowed with high electron affinity and distortion resistance, which provides a stable framework while generating affinity to substrates. [ABSTRACT FROM AUTHOR]

Developing highly efficient non-noble metal electrocatalysts for the oxygen evolution reaction (OER) at large current densities remains a challenge for water electrolysis. Herein, we developed a novel 3D ternary hybrid electrocatalyst consisting of Fe2O3 strongly coupled with Ni2P/Ni(PO3)2 grown on commercial Ni foam (denoted as Fe2O3@Ni2P/Ni(PO3)2/NF) through a thermal phosphorization reaction. In this 3D hybrid structure, the Fe2O3@Ni2P/Ni(PO3)2 nanoparticles with a length of ∼300 nm and width of ∼200 nm are homogeneously grown on the surface of 3D Ni foam. Owing to the synergistic effect between Fe2O3@Ni2P/Ni(PO3)2/NF and their strong coupling effect, the 3D Fe2O3@Ni2P/Ni(PO3)2/NF hybrid achieves a superior electrocatalytic OER performance at ultra-high current densities in alkaline electrolyte. High catalytic current densities of 500 and 1000 mA cm−2 are reached by applying only potentials of 1.57 and 1.60 V, respectively, which are almost the lowest potentials among all previously reported transition metal (Ni and Fe) based phosphide and phosphate electrocatalysts, and even better than that of the benchmark Ir/C catalyst (1.64 and ＞1.8 V at 100 and 500 mA cm−2). In situ Raman spectroscopy revealed that the NiOOH and FeOOH species were the real active phases in Fe2O3@Ni2P/Ni(PO3)2/NF during the OER process. A two-electrode electrolyzer with Fe2O3@Ni2P/Ni(PO3)2/NF delivers a cell voltage of 1.93, 2.48, and 3.02 V at 100, 500, and 1000 mA cm−2 for overall-water-splitting. [ABSTRACT FROM AUTHOR]

Depolymerization of poly(ethylene naphthalate) (PEN) in subcritical water was performed in a fused silica capillary reactor (FSCR) and an autoclave reactor. The phase behaviors of PEN in water during the heating-cooling process in the FSCR were observed under microscope and images were captured by digital camera. Reaction conditions for PEN hydrolysis in the autoclave reactor were chosen based on the experimental results obtained from the FSCR. Under autogenous pressures in the autoclave reactor, the effects of the water/PEN mass ratio (8.0 g/1.0 g to 16.0 g/1.0 g), reaction temperature (240-280°C) and reaction time (5-60 min) on the depolymerization yield and products yields were investigated. The main products of depolymerization were identified and quantified as 2,6-naphthalene dicarboxylic acid (2,6-NDA) and ethylene glycol (EG). PEN was completely depolymerized at 260°C in 60 min with an optimal water/PEN mass ratio of 12.0 g/1.0 g (12:1). The yields of 2,6-NDA and EG were optimized to 83.1% and 79.7%, respectively. Reaction kinetics analysis showed that the PEN depolymerization in subcritical water was first-order and the activation energy was 95 kJ mol−1. Additionally, a reaction pathway was proposed based on the experimental results. POLYM. ENG. SCI., 57:1382-1388, 2017. © 2017 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

A fused silica capillary reactor combined with a heating/cooling stage, a microscope and a digital camera were used to investigate phase behavior during the hydrothermal liquefaction of microalgae (Dunaliella tertiolecta) and model compounds, including soya protein and glycine, starch, glucose and xylose, stearic acid and palmitic acid. Bubbles were generated at 246°C and disappeared at 360°C upon heating whenDunaliella tertiolectaused as feedstocks. Moreover, liquid products were generated at 300°C upon heating and oily liquid products began to separate out at 250°C upon cooling. The phase behavior of soya protein was similar to that of theDunaliella tertiolecta. Meanwhile, there only observed the bubbles generation during hydrothermal liquefaction of glycine. Heating the starch, glucose and xylose above 350°C generated black solids from carbonization. Stearic acid and palmitic acid only had the process of melting, dissolution, dispersion and precipitation. [ABSTRACT FROM AUTHOR]

Hot compressed water (HCW), with its unique properties, is regarded as a promising solvent for industrial applications. A number of methods to measure the solubility of hydrophobic organic compounds (HOCs) in HCW have been reported. However, these methods were conducted in large-scale stainless-steel reactors, and few included an in situ study regarding the dissolution mechanism of HOCs in HCW during the solubility determination process. In this study, a fused silica capillary reactor in combination with Raman spectroscopy was applied to investigate phase changes, determine the solubility, and study the dissolution mechanism of 1,2-dichlorobenzene in HCW. The total dissolution process of 1,2-dichlorobenzene in HCW was observed under a microscope, and the images were recorded continuously using a digital camera. Raman spectroscopy was used to confirm the homogeneity of the 1,2-dichlorobenzene solution during dissolution. The solubility of 1,2-dichlorobenzene increased from 35.9 to 85.7 mg g−1 in water with increasing temperature from 256.7 to 294.1 °C. Furthermore, the dissolution mechanism of 1,2-dichlorobenzene in HCW is proposed based on the Raman spectra of 1,2-dichlorobenzene and water during the dissolution process in the fused silica capillary reactor. The breakage of the fully hydrogen-bonded (tetrahedral) configuration and the consequent change in the static dielectric constant of water are deemed to be compelling reasons for the high solubility of 1,2-dichlorobenzene in HCW. Our experimental method exhibits great potential for determining the solubility of HOCs in HCW and for investigating their dissolution behavior and dissolution mechanism at elevated pressure and temperature conditions. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: A novel and practical strategy of preparing mixed oxides/monolithic catalysts for exhaust gas purification is presented in this work. Highly active nano‐CuCe catalyst dispersion liquid is synthesized through solvothermal method, and then various CuCe monolithic catalysts are prepared just by a simple spraying method. The as‐prepared catalysts showed excellent activity and stability for volatile organic compounds (VOCs) destruction, which can be attributed to the good structural and chemical properties of the well‐dispersed CuCe active species on the carrier surface. This strategy provides a very facile and flexible way for preparation of monolithic catalysts with versatile shapes to accommodate VOCs combustion facilities. It shows great potential in practical applications. [ABSTRACT FROM AUTHOR]

Depolymerization is a potentially viable means of recycling waste polymers, converting them back into monomers or other useful compounds. Terephthalic acid (TPA) and 1,4-butanediol (1,4-BD) are the depolymerization monomer products of polybutylene terephthalate. Their yields from depolymerization in hot compressed water (HCW) were previously found to be lower than reported theoretical values. Thus, the phase behavior, stability, and mechanism of monomers in HCW were investigated in a fused silica capillary reactor (FSCR) and a stainless steel autoclave reactor. Phase change observations showed that TPA was completely dissolved in water at 300°C, was relatively stable at 320 to 350°C, and that its recovery significantly decreased at temperatures above 350°C. The decomposition of TPA increased with increasing heating time. However, the recovery of 1,4-BD decreased rapidly with increasing temperature or heating time. A mechanism for the stability of TPA and 1,4-BD is proposed based on their depolymerization products. The products were quantified by Fourier transform-infrared spectroscopy, high-performance liquid chromatography, and gas chromatography coupled with mass spectrometry. The wall effect of the stainless steel autoclave promoted the decomposition of TPA and 1,4-BD in HCW. POLYM. ENG. SCI., 57:544-549, 2017. © 2016 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

The coliquefaction of coal and polystyrene (PS) in supercritical water (SCW) was carried out in a 50-mL batch stainless steel autoclave reactor, and the effects of the polymer ratio by weight (10–40%), reaction temperature (633.5–703.5 K), and reaction time (30–120 min) were investigated. The main products were analyzed qualitatively by Fourier transform infrared spectroscopy and high-performance liquid chromatography. The results show that polystyrene stimulates coal liquefaction as a hydrogen donor, and the synergistic effects during coliquefaction in SCW were confirmed. The conversion reached a maximum of 62.26% after 60 min at 673.5 K. The phase behavior during coliquefaction was observed in a fused silica capillary reactor using a combined microscope and video recorder system. [ABSTRACT FROM PUBLISHER]

Water transfer from the Qiantang River to the West Lake, Hangzhou City, China, has been performed since 1985 to improve the lake water quality. This study was conducted to assess the water quality and estimate the pollutant fluxes from different sources into the lake to enable better water quality management. Monthly variations in water quality variables, namely chemical oxygen demand (COD), 5-day biochemical oxygen demand (BOD), total phosphorus (TP), total nitrogen (TN), ammonium nitrogen (NH-N), and nitrate nitrogen (NO-N), and flow were analyzed for 1-year period from April 2012 to March 2013. The pollutant fluxes into the lake were mainly contributed by the water transferred from the Qiantang River, followed by runoff and rainfall. The results showed that the annual influxes of COD, BOD, TP, TN, NO-N, and NH-N into the lake were 1,595.3, 255.8, 8.2, 576.0, 360.3, and 84.2 t, respectively, while the annual fluxes out of the lake were 2,204.6, 301.8, 7.1, 336.5, 191.6, and 36.1 t, respectively. The annual net flux of pollutants in decreasing order was TN > NO-N > NH-N > TP > BOD > COD, and nitrogen was found to be the major pollutant in the West Lake. It is recommended that the water transferred from the Qiantang River should be treated by chemical precipitation as well as denitrification technology to reduce the nitrogen concentration. [ABSTRACT FROM AUTHOR]

This study investigated the biodegradation of synthetic wastewater containing 2,4,6-trichlorophenol (TCP) in a sequencing batch-fluidized bed bioreactor (SBFBBR) with waste coke particles (WCPs) as the biofilm carrier. The irregular surfaces of WCPs (diameter range from 0.6 to 2.3 mm) rendered them ideal biomass carriers. The attached biomass was 4.0-4.5 mg volatile suspended solids WCPs 3 weeks after reactor start-up, and the biofilm thicknesses were 35-110 μm. Biodegradation, not adsorption-degradation or volatilization-degradation, was found to be the main TCP removal mechanism. At the initial chemical oxygen demand (COD) concentration of , removal of COD was more efficient and faster than that of TCP. The air-water ratio (ranging from 0.280 to ) exerted negligible effects at dissolved oxygen (DO) concentrations above . Maximum TCP degradation (62.1% after 3 h retention time and 75.8% after 6 h) occurred at initial COD concentration of . TCP can be removed by biofilm as a sole source of carbon and energy. Furthermore, the TCP biodegradation follows zero-order reaction kinetics, with the zero-order specific biodegradation rate dependent on initial COD concentration. [ABSTRACT FROM AUTHOR]

Significance The solubilities of hydrophobic organic compounds (HOCs) in hot compressed water (HCW) were measured using an optically transparent fused silica capillary reactor (FSCR). The total dissolution temperatures of HOCs in HCW were determined visually; the solution homogeneity in the FSCR during HOCs dissolution was checked using Raman spectroscopy. The solubility of 2,4-dichlorotoluene increased linearly with increasing temperature in the range of 266.3-302.4°C. © 2013 American Institute of Chemical Engineers AIChE J, 59: 2721-2725, 2013 [ABSTRACT FROM AUTHOR]

Considering the reverse logistics system composed of two manufacturers and two recyclers under the cross-competitive take-back mode, which is influenced by multiple factors (industry competition, economies of scale, government subsidies, remanufacturing rate, etc.), a model for remanufacturing reverse logistics system based on Stackelberg game is established. Then, the Nash equilibrium solution of decision variables is solved to obtain the best profit of all participants under the cross-competitive take-back mode. Furthermore, the parameter constraint analysis is carried out, and the monopolistic take-back mode is introduced for comparative analysis. Then, the sensitivity analysis of the model is carried out. At last, a case analysis is carried out based on the current situation of waste electrical and electronic equipment (WEEE) recycling in China. The results show that the cross-competitive take-back mode is more advantageous to all participants in the reverse logistics system than the monopolistic take-back mode. Recyclers should actively sign contracts with multiple manufacturers to recycle waste products, making full use of the advantages of cross-competitive take-back mode to maximize the profits of all participants, so as to encourage them to recycle waste products and achieve sustainable development. [ABSTRACT FROM AUTHOR]