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Increased use of ethanol-blended gasoline (gasohol) and its potential release into the subsurface have spurred interest in studying the biodegradation of and interactions between ethanol and gasoline components such as benzene, toluene, ethylbenzene and xylene isomers (BTEX) in groundwater plumes. The preferred substrate status and the high biological oxygen demand (BOD) posed by ethanol and its biodegradation products suggests that anaerobic electron acceptors (EAs) will be required to support in situ bioremediation of BTEX. To develop a strategy for aromatic hydrocarbon bioremediation and to understand the impacts of ethanol on BTEX biodegradation under strictly anaerobic conditions, a microcosm experiment was conducted using pristine aquifer sand and groundwater obtained from Canadian Forces Base Borden, Canada. The initial electron accepter pool included nitrate, sulfate and/or ferric iron. The microcosms typically contained 400 g of sediment, 600 approximately 800 ml of groundwater, and with differing EAs added, and were run under anaerobic conditions. Ethanol was added to some at concentrations of 500 and 5000 mg/L. Trends for biodegradation of aromatic hydrocarbons for the Borden aquifer material were first developed in the absence of ethanol, The results showed that indigenous microorganisms could degrade all aromatic hydrocarbons (BTEX and trimethylbenzene isomers-TMB) under nitrate- and ferric iron-combined conditions, but not under sulfate-reducing conditions. Toluene, ethylbenzene and m/p-xylene were biodegraded under denitrifying conditions. However, the persistence of benzene indicated that enhancing denitrification alone was insufficient. Both benzene and o-xylene biodegraded significantly under iron-reducing conditions, but only after denitrification had removed other aromatics. For the trimethylbenzene isomers, 1,3,5-TMB biodegradation was found under denitrifying and then iron-reducing conditions. Biodegradation of 1,2,3-TMB or 1,2,4-TMB was slower under iron-reducing conditions. This study suggests that addition of excess ferric iron combined with limited nitrate has promise for in situ bioremediation of BTEX and TMB in the Borden aquifer and possibly for other sites contaminated by hydrocarbons. This study is the first to report 1,2,3-TMB biodegradation under strictly anaerobic condition. With the addition of 500 mg/L ethanol but without EA addition, ethanol and its main intermediate, acetate, were quickly biodegraded within 41 d with methane as a major product. Ethanol initially present at 5000 mg/L without EA addition declined slowly with the persistence of unidentified volatile fatty acids, likely propionate and butyrate, but less methane. In contrast, all ethanol disappeared with repeated additions of either nitrate or ferric iron, but acetate and unidentified intermediates persisted under iron-enhanced conditions. With the addition of 500 mg/L ethanol and nitrate, only minor toluene biodegradation was observed under denitrifying conditions and only after ethanol and acetate were utilized. The higher ethanol concentration (5000 mg/L) essentially shut down BTEX biodegradation likely due to high EA demand provided by ethanol and its intermediates. The negative findings for anaerobic BTEX biodegradation in the presence of ethanol and/or its biodegradation products are in contrast to recent research reported by Da Silva et al. [Da Silva, M.L.B., Ruiz-Aguilar, G.M.L., Alvarez, P.J.J., 2005. Enhanced anaerobic biodegradation of BTEX-ethanol mixtures in aquifer columns amended with sulfate, chelated ferric iron or nitrate. Biodegradation. 16, 105-114]. Our results suggest that the apparent conservation of high residual labile carbon as biodegradation products such as acetate makes natural attenuation of aromatics less effective, and makes subsequent addition of EAs to promote in situ BTEX biodegradation problematic.

Abstract Variations in 13 C natural abundance and distribution of total C among five size and density fractions of soil organic matter, water soluble organic C (WSOC) and microbial biomass C (MBC) were investigated in the upper layer (0–20 cm) of a continuous grassland soil (CG, C 3 vegetation), a C 3 ‐humus soil converted to continuous maize cultivation (CM, C 4 vegetation) and a C 3 ‐humus soil converted to a rotation of maize cultivation and grassland (R). The amounts of WSOC and MBC were both significantly larger in the CG than in the CM and the R. In the three soils, WSOC was depleted while MBC was enriched in 13 C as compared with whole soil C. The relative contributions to the total C content of C stored in the macro‐organic matter and in the size fraction 50–150 µm decreased with decreasing total C contents in the order CG > R > CM, while the relative contribution of C associated with the clay‐ and silt‐sized fraction <50 µm increased. This reflects a greater stability and physical protection against microbial degradation associated with soil disruption (tillage) of the clay‐ and silt‐associated organic C, in relation to the organic C in larger size fractions. The size and density fractions from the CG soil showed significant differences in 13 C enrichment, indicating different degrees of microbial degradation and stability of soil organic C associated with physically different soil organic matter (SOM) fractions. δ 13 C analysis of the size and density fractions from CM and R soils reflected a decreasing turnover rate of soil organic C with increasing density among the macro‐organic matter fractions and with decreasing particle size. Copyright © 2002 John Wiley & Sons, Ltd.

In this study, a novel biomass pretreatment process using three kinds of deep eutectic solvents (DESs) was developed to improve saccharification efficiency and lignin valorization. The major components of xylose residue including cellulose and lignin fractions were released, recovered and utilized. Pretreatment with betaine/lactic acid system at 120 °C for 2 h was found to be the optimal conditions with prominently increased enzymatic digestibility (from 55.3% to 96.8%). The efficient conversion was mainly ascribed to the significant delignification efficiency of 81.6% after betaine/lactic acid pretreatment, which caused incompact structure and corrosive surface of treated xylose residue. The recoverable lignin had high purity, low molecular weight (630-2040 g/mol) and polydispersity (1.07-1.76). Based on the comprehensive analysis, the one-pot DESs system provides us a facile and effective approach for whole components valorization of lignocellulosic materials.

AbstractBACKGROUNDReducing spoilage and prolonging the shelf‐life of food materials are both critically important in the food industry. Among the many available preservatives, ethanol has been widely used for the storage of fruits and vegetables. Although a few ethanol emitters are available in the form of antimicrobial packaging, these ethanol emitters demonstrate high volatility, uncontrolled release and other disadvantages, and so the practical applications are limited.RESULTSA novel ethanol gel with a controlled release rate was prepared by a gelatification reaction between ethanol and sodium stearate to overcome the disadvantage of conventional ethanol emitters. The hardness, adhesiveness and cohesiveness of developed ethanol gels increased, whereas the springiness decreased along with an increase in the sodium stearate concentration. The release rate of ethanol in the gels was controlled by the concentration of sodium stearate, in which a first‐order release kinetic was observed. The release rate constant (k) of the gels with 12.5, 37.5, 62.5 g kg−1 of sodium stearate was 0.58 ± 0.029, 0.49 ± 0.035 and 0.41 ± 0.021 h−1, respectively, at 25 °C. The application of the controlled release ethanol emitter with respect to the storage of Chinese bayberry fruit demonstrated its ability to reduce the decay rate, maintain firmness and inhibit increased malondialdehyde content at 4 °C.CONCLUSIONIn terms of practical applications, an appropriate sodium stearate content can be selected in accordance with the storage period, aiming to achieve precise storage goals. Therefore, the ethanol emitter has potential application prospects as an active packaging for Chinese bayberry fruit, as well as for other perishable products. © 2017 Society of Chemical Industry

One of the greatest current challenges is to find cost-effective and eco-friendly solutions to the ever increasing needs of modern society. Some plant species are suitable for a multitude of biotechnological applications such as bioenergy production and phytoremediation. A sustainable practice is to use energy crops to clean up polluted lands or to treat wastewater in constructed wetlands without claiming further arable land for biofuel production. However, the disposal of combustion by-products may add significant costs to the whole process, especially when it deals with toxic waste. This study aimed to investigate the possibility of recycling ash from energy biomass as a fertilizer for agriculture and forestry. In particular, the concentrations of Cd, Cr, Cu, Mn, Pb and Zn were analyzed in the plant tissues and corresponding ash of the grasses Phragmites australis and Arundo donax, collected in an urban stream affected by domestic sewage. Results showed that the metal concentration in ash is 1.5-3 times as high as the values in plant tissues. However, metal enriched ash showed much lower element concentrations than the legal limits for ash reutilization in agriculture and forestry. This study found that biomass ash from constructed wetlands may be considered as a potential fertilizer rather than hazardous waste. Energy from biomass can be a really sustainable and clean option not only through the reduction of greenhouse gas emissions, but also through ash recycling for beneficial purposes, thus minimizing the negative impacts of disposal.

Abstract The greenhouse is a modern agriculture technology that is widely used to provide a favorable microclimate for vegetable growth when an open field is inappropriate for cultivation. Field tests were conducted to test diurnal variations of temperature, relative humidity, and solar radiation and to analyze the microclimate characteristics in naturally ventilated single-sloped greenhouses of different sizes. The results showed that indoor air temperature and humidity under natural ventilation varied from 28.9 °C to 25.8 °C and 96% to 84%, which illustrates that ventilated greenhouses are able to create a favorable self-maintained, energy-balanced environment for vegetable growth. Moreover, it was found that a greater height and shorter span facilitates heat preservation and energy saving in single-sloped greenhouses. In addition, the relationship between the incident solar radiation and indoor air temperature was determined. This study provides a reference for further research to reduce energy consumption and achieve a favorable greenhouse microclimate, leading to higher product quality, improved yield and shorter cultivation time in single-sloped greenhouses.

Abstract Temporal solar variability significantly affects the integration of solar power systems into the grid. It is thus essential to predict temporal solar variability, particularly given the increasing popularity of solar power generation globally. In this paper, the daily variability of solar irradiance at four sites across Australia is quantified using observed time series of global horizontal irradiance for 2003–2012. It is shown that the daily variability strongly depends on sky clearness with generally low values under a clear or overcast condition and high values under an intermittent cloudiness condition. Various statistical techniques are adopted to model the daily variability using meteorological variables selected from the ERA-Interim reanalysis as predictors. The nonlinear regression technique (i.e. random forest) is demonstrated to perform the best while the performance of the simple analog method is only slightly worse. Among the four sites, Alice Springs has the lowest daily variability index on average and Rockhampton has the highest daily variability index on average. The modelling results of the four sites produced by random forest have a correlation coefficient of above 0.7 and a median relative error around 40%. While the approach of statistical downscaling from a large spatial domain has been applied for other problems, it is shown in this study that it generally suffices to use only the predictors at a single near point for the problem of solar variability. The relative importance of the involved meteorological variables and the effects of clearness on the modelling of the daily variability are also explored.

We contribute to the literature on the effectiveness of aid and to energy poverty literature by providing the first study that examines the effect of aid on energy poverty. Using eight rounds of the Demographic and Health Surveys (DHS) and sub-national aid data for Senegal, we find that aid lowers the probability of energy poverty. Our main results show that living within a 25km radius of an aid project reduces the likelihood of being energy poor by 4.5 percentage points. This finding is robust to a suite of sensitivity checks. We also examine four channels through which aid could influence energy – income poverty, education, health and economic growth – and find that income poverty, education and economic growth are mechanisms through which aid transmits to energy poverty.

Ni3Mo3C was prepared by a modified organic colloid method and explored as anode catalyst for high-performance microbial fuel cell (MFC) based on Klebsiella pneumoniae (K. pneumoniae). The prepared sample was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and Brunauer-Emmett-Teller (BET). The activity of the sample as anode catalyst for MFC based on K. pneumoniae was investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and polarization curve measurement. The results show that the adding of nickel in Mo2C increases the BET surface area of Mo2C and improves the electrocatalytic activity of Mo2C towards the oxidation of microbial fermentation products. The power density of MFC with 3 mg cm(-2) Ni3Mo3C anode is far higher than that of the MFC with carbon felt as anode without any catalyst, which is 19 % higher than that of Mo2C anode and produced 62 % as much as that of Pt anode, indicating that Ni3Mo3C is comparative to noble metal platinum as anode electrocatalyst for MFCs by increasing the loading.