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Light absorption enhancement of black carbon from urban haze in Northern China winter
2016
Chen, Bing | Bai, Zhe | Cui, Xinjuan | Chen, Jianmin | Andersson, August | Gustafsson, Örjan
Atmospheric black carbon (BC) is an important pollutant for both air quality and Earth's energy balance. Estimates of BC climate forcing remain highly uncertain, e.g., due to the mixing with non-absorbing components. Non-absorbing aerosols create a coating on BC and may thereby act as a lens which may enhance the light absorption. However, this absorption enhancement is poorly constrained. To this end a two-step solvent dissolution protocol was employed to remove both organic and inorganic coatings, and then investigate their effects on BC light absorption. Samples were collected at a severely polluted urban area, Jinan, in the North China Plain (NCP) during February 2014. The BC mass absorption cross-section (MAC) was measured for the aerosol samples before and after the solvent-decoating treatment, and the enhancement of MAC (EMAC) from the coating effect was defined as the ratio. A distinct diurnal pattern for the enhancement was observed, with EMAC 1.3 ± 0.3 (1 S.D.) in the morning, increasing to 2.2 ± 1.0 in the afternoon, after that dropping to 1.5 ± 0.8 in the evening-night. The BC absorption enhancement primarily was associated with urban-scale photochemical production of nitrate and sulfate aerosols. In addition to that, regional-scale haze plume with increasing sulfate levels strengthened the absorption enhancement. These observations offer direct evidence for an increased absorption enhancement of BC due to severe air pollution in China.
显示更多 [+] 显示较少 [-]Developments in greenhouse gas emissions and net energy use in Danish agriculture – How to achieve substantial CO₂ reductions?
2011
Dalgaard, T. | Olesen, J.E. | Petersen, S.O. | Petersen, B.M. | Jørgensen, U. | Kristensen, T. | Hutchings, N.J. | Gyldenkærne, S. | Hermansen, J.E.
Greenhouse gas (GHG) emissions from agriculture are a significant contributor to total Danish emissions. Consequently, much effort is currently given to the exploration of potential strategies to reduce agricultural emissions. This paper presents results from a study estimating agricultural GHG emissions in the form of methane, nitrous oxide and carbon dioxide (including carbon sources and sinks, and the impact of energy consumption/bioenergy production) from Danish agriculture in the years 1990–2010. An analysis of possible measures to reduce the GHG emissions indicated that a 50–70% reduction of agricultural emissions by 2050 relative to 1990 is achievable, including mitigation measures in relation to the handling of manure and fertilisers, optimization of animal feeding, cropping practices, and land use changes with more organic farming, afforestation and energy crops. In addition, the bioenergy production may be increased significantly without reducing the food production, whereby Danish agriculture could achieve a positive energy balance.
显示更多 [+] 显示较少 [-]C-offset and crop energy efficiency increase due industrial poultry waste use in long-term no-till soil minimizing environmental pollution
2021
Romaniw, Jucimare | de Moraes Sá, João Carlos | Lal, R. | de Oliveira Ferreira, Ademir | Inagaki, Thiago Massao | Briedis, Clever | Gonçalves, Daniel Ruiz Potma | Canalli, Lutécia Beatriz | Padilha, Alessandra | Bressan, Pamela Thaísa
Brazil is one of the major global poultry producers, and the organic waste generated by the chicken slaughterhouses can potentially be used as a biofertilizer in agriculture. This study was designed to test the hypothesis that continuous use of biofertilizer to the crops, substituting the use of mineral fertilizer promote C-offset for the soil and generate crop energy efficiency for the production system. Thus, the objectives of this study were to evaluate the effects of biofertilizer use alone or in combination with mineral fertilizer on soil organic carbon (SOC) stock, carbon dioxide (CO₂) mitigation, C-offset, crop energy efficiency and productivity, and alleviation of environmental pollution. The experiment was established in southern Brazil on a soil under 15 years of continuous no-till (NT). Experimental treatments were as follows: i) Control with no fertilizer application, ii) 100% use of industrial mineral fertilizer (Min-F); iii) 100% use of organic waste originated from poultry slaughterhouses and hereinafter designated biofertilizer (Bio-F), and iv) Mixed fertilizer equivalent to the use of 50% mineral fertilizer + 50% of biofertilizer (Mix-F). Effects of experimental treatments were assessed for the crop sequence based on bean (Phaseolus vulgaris), soybean (Glycine max) and corn (Zea mays) in the summer and wheat (Triticum aestivum) and black oat (Avena strigosaSchreb) in the winter composing two crops per year, as follow: bean/wheat-soybean/black oat-corn/wheat-soybean/black oat-corn/wheat-bean. The continuous use of Bio-F treatment significantly increased the index of crop energy efficiency. It was higher than that of control, and increased it by 25.4 Mg CO₂eq ha⁻¹ over that of Min-F treatment because of higher inputs of crop biomass-C into the system. Further, continuous use of Bio-F resulted in a significantly higher CO₂eq stock and offset than those for Min-F treatment. A positive relationship between the C-offset and the crop energy efficiency (R² = 0.71, p < 0.001) indicated that the increase of C-offset was associated with the increase of energy balance and the amount of SOC sequestered. The higher energy efficiency and C-offset by application of Bio-F indicated that the practice of crop bio fertilization with poultry slaughterhouse waste is a viable alternative for recycling and minimizing the environmental impacts.
显示更多 [+] 显示较少 [-]Microplastics induce dose-specific transcriptomic disruptions in energy metabolism and immunity of the pearl oyster Pinctada margaritifera
2020
Gardon, Tony | Morvan, Lucie | Huvet, Arnaud | Quillien, Virgile | Soyez, Claude | Le Moullac, Gilles | Le Luyer, Jérémy
A combined approach integrating bioenergetics and major biological activities is essential to properly understand the impact of microplastics (MP) on marine organisms. Following experimental exposure of polystyrene microbeads (micro-PS of 6 and 10 μm) at 0.25, 2.5, and 25 μg L⁻¹, which demonstrated a dose-dependent decrease of energy balance in the pearl oyster Pinctada margaritifera, a transcriptomic study was conducted on mantle tissue. Transcriptomic data helped us to decipher the molecular mechanisms involved in P. margaritifera responses to micro-PS and search more broadly for effects on energetically expensive maintenance functions. Genes related to the detoxification process were impacted by long-term micro-PS exposure through a decrease in antioxidant response functioning, most likely leading to oxidative stress and damage, especially at higher micro-PS doses. The immune response was also found to be dose-specific, with a stress-related activity stimulated by the lowest dose present after a 2-month exposure period. This stress response was not observed following exposure to higher doses, reflecting an energy-limited capacity of pearl oysters to cope with prolonged stress and a dramatic shift to adjust to pessimum conditions, mostly limited and hampered by a lowered energetic budget. This preliminary experiment lays the foundation for exploring pathways and gene expression in P. margaritifera, and marine mollusks in general, under MP exposure. We also propose a conceptual framework to properly assess realistic MP effects on organisms and population resilience in future investigations.
显示更多 [+] 显示较少 [-]Estimation of the isoprene emission from the Inner Mongolia grassland
2015
Bai, Jianhui
Measurements of isoprene emissions, solar spectral radiation, temperature and relative humidity were carried out at a grassland site in the Inner Mongolia, China during the growing seasons in 2002 and 2003. Isoprene emissions are dependent on PAR (Photosynthetically Active Radiation) and temperature nonlinearly. PAR controls the main processes related to isoprene emission, thus, PAR energy balance is used to establish quantitative relationship between isoprene emission and its affecting factors. An empirical Equation of isoprene emission was built on the basis of PAR energy balance. The calculated values were in good agreement with those measured for 2002 and 2003 summer seasons, the relative biases of 70% estimated emissions were within 50% compared to measured fluxes. The chamber changes the inside environment and emission fluxes, the emission differences were estimated by using the empirical Equation. The results show that isoprene emission flux around the noon decreases by 37% when the chamber is used, i.e., the biggest effect was resulted from PAR difference caused by the chamber. Isoprene emission measured by chamber should be corrected. The empirical model of isoprene emission showed that isoprene emission fluxes were close to zero, when PAR was low in early morning and in late evening. Total isoprene emissions emitted from the grassland in the Inner Mongolia were 1.10 and 1.00gC m−2 during the growing seasons of 2002 and 2003, respectively, which contributed to about 3.1–4.3% and 2.8−3.9% to grass respiration. The averaged isoprene emission normalized to a standard light (1 500μmolm−2 s−1) and temperature (30 °C) condition was 482.8μg m−2 h−1.
显示更多 [+] 显示较少 [-]A marine secondary producer respires and feeds more in a high CO₂ ocean
2012
Li, Wei | Gao, Kunshan
Climate change mediates marine chemical and physical environments and therefore influences marine organisms. While increasing atmospheric CO₂ level and associated ocean acidification has been predicted to stimulate marine primary productivity and may affect community structure, the processes that impact food chain and biological CO₂ pump are less documented. We hypothesized that copepods, as the secondary marine producer, may respond to future changes in seawater carbonate chemistry associated with ocean acidification due to increasing atmospheric CO₂ concentration. Here, we show that the copepod, Centropages tenuiremis, was able to perceive the chemical changes in seawater induced under elevated CO₂ concentration (>1700μatm, pH<7.60) with avoidance strategy. The copepod’s respiration increased at the elevated CO₂ (1000μatm), associated acidity (pH 7.83) and its feeding rates also increased correspondingly, except for the initial acclimating period, when it fed less. Our results imply that marine secondary producers increase their respiration and feeding rate in response to ocean acidification to balance the energy cost against increased acidity and CO₂ concentration.
显示更多 [+] 显示较少 [-]Tire rubber chemicals reduce juvenile oyster (Crassostrea gigas) filtration and respiration under experimental conditions
2022
Tallec, Kevin | Gabriele, Marta | Paul Pont, Ika | Alunno-Bruscia, Marianne | Huvet, Arnaud
Tires can release a large number of chemical compounds that are potentially hazardous for aquatic organisms. An ecophysiological system was used to do high-frequency monitoring of individual clearance, respiration rates, and absorption efficiency of juvenile oysters (8 months old) gradually exposed to four concentrations of tire leachates (equivalent masses: 0, 1, 10, and 100 μg tire mL⁻¹). Leachates significantly reduced clearance (52 %) and respiration (16 %) rates from 1 μg mL⁻¹, while no effect was observed on the absorption efficiency. These results suggest that tire leachates affect oyster gills, which are the organ of respiration and food retention as well as the first barrier against contaminants. Calculations of scope for growth suggested a disruption of the energy balance with a significant reduction of 57 %. Because energy balance directs whole-organism functions (e.g., growth, reproductive outputs), the present study calls for an investigation of the long-term consequences of chemicals released by tires.
显示更多 [+] 显示较少 [-]PLATIN (plant-atmosphere interaction) I: a model of plant-atmosphere interaction for estimating absorbed doses of gaseous air pollutants
1997
Grunhage, L. | Haenel, H.D. (Institute for Plant Ecology, University of Giessen, Heinrich-Buff-Ring 38, D-35392 Giessen, Germany)
Assessment of the Effectiveness of a Solar System Heating an Anaerobic Bioreactor
2012
Ch. Yiannopoulos, Andrew | Manariotis, Ioannis D. | Chrysikopoulos, Constantinos V.
The performance of a solar system designed to heat a packed bed reactor for anaerobic treatment of municipal wastewater was evaluated, and the feasibility of employing low-scale solar reactors in small settlements or enterprises was investigated. An energy balance was performed using a simple reactor model previously proposed by Yiannopoulos et al. (Bioresource Technology 99:7742–7749, 2008) to estimate the size of a solar system in Patras, Greece. The main objective is to feed the reactor with warm water produced by solar energy and achieve an increase of temperature close to 35°C for the majority of the year. Model simulations indicated that the heat demand of the reactor could be balanced practically by a number of flat plate solar collectors supplying warm water at above 20°C for over 95% of the year. Therefore, the proposed system can offer a viable alternative to enhancing anaerobic treatment in wastewater facilities.
显示更多 [+] 显示较少 [-]An investigation on dissimilarity of mass flow rate and N on exergo-enviro-economic parameters for solar still of single slope type integrated with N similar PVT flat plate collectors having series connection
2022
Sharma, Gaurav Kumar | Mallick, Ashis | Sharma, Ram K | Dobriyal, Ritvik | Kumar, Navneet | Singh, Desh Bandhu
This paper investigates analytically the effect of dissimilarity of mass flow rate [Formula: see text] and number of collectors (N) on exergo-enviro-economic parameters for solar still of single slope type integrated with N similar photovoltaic thermal flat plate collectors having series connection (NPVTFPC-SS) keeping water depth as 0.14 m. All four kinds of weather conditions for New Delhi have been taken for the computation of different parameters. All relevant equations obtained using energy balance equations for all components of the system have been fed to a computer code inscribed in MATLAB-2015a for computing different parameters. The computation of different relevant parameters has been performed for various values of [Formula: see text] and N while keeping water depth as constant to know the effect of variation of [Formula: see text] and N on exergo-enviro-economic parameters for NPVTFPC-SS. It has been concluded that the value of carbon credit earned, enviroeconomic and exegoeconomic parameters, and productivity diminishes with the enhancement in [Formula: see text] at given N. The optimum value of N for given value of [Formula: see text] has been found to be 10 from exergoeconomic parameter viewpoint and 6 from productivity viewpoint.
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