Leaf and fruit necroses associated with vanadium-rich ash emitted from a power plant burning fossil fuel

Necrotic brown lesions developing on leaves and fruits of lemon, and other plants, near fossil-fuel-burning power plants emitting vanadium-rich ash, were reproduced experimentally by inoculating leaves with this type of ash, which is strongly acidic. Comparable lesions were formed when drops of vanadium oxide, dissolved in NaOH, were put on leaves and fruits. Neutralizing, or adding excess H₂SO₄ (to pH 3), did not alter lesion formation. The histology of these lesions was similar to that of lesions attributed to vanadium-rich ash.     

工程菌处理高纯二甲醚生产废水的研究

工程菌LEY7是以假单胞菌D3 菌株 (Pseudomonassp.D3 )为受体 ,以缓慢牙孢杆菌 3RM2 菌株 (Bacilluslentus 3RM2 ) ,假单胞菌W1 (Pseudomonassp .W1 )和W2 (Pseudomonassp .W2 )为供体 ,用多基因转化原生质球构建而成。工程菌LEY7能同时降解 4种化合物。用工程菌LEY7处理化工废水 ,工艺采用二级氧化。处理效果 :进水COD =10 0 0mg/L ,处理后出水COD在 10 0mg/L以下。COD去除率达到 90 %以上。     

Molten carbonate fuel cells fed with biogas: Combating H2S

The use of biomass and waste to produce alternative fuels, due to environmental and energy security reasons, is a high-quality solution especially when integrated with high efficiency fuel cell applications. In this article we look into the coupling of an anaerobic digestion process of organic residues to electrochemical conversion to electricity and heat through a molten carbonate fuel cell (MCFC). In particular the pathway of the exceedingly harmful compound hydrogen sulphide (H₂S) in these phases is analysed. Hydrogen sulphide production in the biogas is strongly interrelated with methane and/or hydrogen yield, as well as with operating conditions like temperature and pH. When present in the produced biogas, this compound has multiple negative effects on the performance and durability of an MCFC. Therefore, there are important issues of integration to be solved.Three general approaches to solve the sulphur problem in the MCFC are possible. The first is to prevent the formation of hydrogen sulphide at the source: favouring conditions that inhibit its production during fermentation. Secondly, to identify the sulphur tolerance levels of the fuel cell components currently in use and develop sulphur-tolerant components that show long-term electrochemical performance and corrosion stability. The third approach is to remove the generated sulphur species to very low levels before the gas enters the fuel cell.     

Delayed association of acute particulate matter 2.5 air pollution exposure with loss of complexity in cardiac rhythm dynamics: insight from detrended fluctuation analysis

Environmental Science and Pollution Research - There is a delayed (lag 1 to 2 days) correlation between acute PM 2.5 (particulate matter <?2.5 μm in aerodynamic...     

A full-scale sequencing batch reactor system for swine wastewater treatment

A full-scale sequencing batch reactor (SBR) system was evaluated for its ability to remove carbon and nitrogen from swine wastewater. The SBR was operated on four, six-hour cycles each day, with each cycle consisting of 4.5 hours of "React," 0.75 hours of "Settling", 0.75 hours for "Draw" and "Fill." Within each cycle, an amount of wastewater equivalent to about 5% of the reactor volume (5,500 litres) was removed and added. The SBR system was able to remove 82% of biochemical oxygen demand (BOD) and more than 75% of nitrogen. Even though the SBR effluent, with an average effluent BOD5 of about 588 mg L(-1), did not meet the discharge criteria, it enabled a reduction of the land base required for land application of swine wastewater by about 75%. Results indicated that the SBR system was a viable method for the treatment of swine wastewater.     

Food waste collection and recycling for value-added products: potential applications and challenges in Hong Kong

About 3600 tonnes food waste are discarded in the landfills in Hong Kong daily. It is expected that the three strategic landfills in Hong Kong will be exhausted by 2020. In consideration of the food waste management environment and community needs in Hong Kong, as well as with reference to the food waste management systems in cities such as Linköping in Sweden and Oslo in Norway, a framework of food waste separation, collection, and recycling for food waste valorization is proposed in this paper. Food waste can be packed in an optic bag (i.e., a bag in green color), while the residual municipal solid waste (MSW) can be packed in a common plastic bag. All the wastes are then sent to the refuse transfer stations, in which food waste is separated from the residual MSW using an optic sensor. On the one hand, the sorted food waste can be converted into valuable materials (e.g., compost, swine feed, fish feed). On the other hand, the sorted food waste can be sent to the proposed Organic Waste Treatment Facilities and sewage treatment works for producing biogas. The biogas can be recovered to produce electricity and city gas (i.e., heating fuel for cooking purpose). Due to the challenges faced by the value-added products in Hong Kong, the biogas is recommended to be upgraded as a biogas fuel for vehicle use. Hopefully, the proposed framework will provide a simple and effective approach to food waste separation at source and promote sustainable use of waste to resource in Hong Kong.     

Potential sources and meteorological factors affecting PM<Subscript>2.5</Subscript>-bound polycyclic aromatic hydrocarbon levels in six main cities of northeastern Italy: an assessment of the related carcinogenic and mutagenic risks

A yearlong sampling campaign (2012–2013) was conducted in six major cities of the Veneto region to investigate the spatial-temporal trends and the factors affecting the polycyclic aromatic hydrocarbon (PAHs) variations and identify the local sources. Sixty samples per city were collected for analyses in every alternate month (April, June, August, October, December, and February): 10 samples per sampling site in 10 consecutive days of the months selected. Samples were ultrasonically extracted with acetonitrile and processed through high-performance liquid chromatography. Total Σ-PAH concentrations ranged from 0.19 to 70.4 ng m^?3 with a mean concentration of 11.5 ng m^?3. The mean benzo[a]pyrene (BaP) concentration reached 2.0 ng m^?3, which is two-times higher than the limit set by the European Union. BaP contributed for 17.4% to the total concentration of PAHs, which showed the same pattern across the region with maxima during cold months and minima in the warm period. In this study, PAHs showed an inverse relationship with temperature, solar radiation, wind speed, and ozone. According to this study, biomass burning for household heating and cooking, followed by gaseous PAHs absorption on particles due to low atmospheric temperature, were the main reasons for increasing PAHs concentration in winter. Health risk, evaluated as lifetime lung cancer risk (LCR), showed a potential carcinogenic risk from the airborne BaP_TEQ six-fold higher in the cold season than in the warm one. Diagnostic ratios and conditional probability functions were used to locate the sources, and results confirmed that local emission, overall domestic heating, and road transport exhausts were responsible for higher concentration rates of PAHs as well as of PM_2.5.     

Effects of site-specific climatic conditions on the radial growth of the lichen biomonitor <Emphasis Type="Italic">Xanthoria parietina</Emphasis>

The protocols commonly applied in surveys with lichens as biomonitors of airborne trace elements require analyses of samples derived from thalli or parts of thalli grown in the last year before sampling, under the postulation that samples of the same size are of the same age. Unfortunately, the influence of ecological site-specific factors on lichen growth is still largely ignored, so that samples of the same size collected in environmentally and climatically diverse sites might actually differ in age. This work aims at quantifying the influence of climatic conditions on the radial growth rates (RaGRs) of Xanthoria parietina, one of the most popular lichen biomonitors. RaGR was monitored in seven populations distributed along an altitudinal transect of 30 km in the Classical Karst (NE Italy), from 20 to 500 m above sea level. For c. 17 months, lobe growth was measured seasonally with a digital calliper, and site-specific climatic variables were monitored by means of thermo-hygrometric sensors and implemented by meteorological data. Finally, the lobe growth of X. parietina was modelled as a function of 18 environmental variables. Results revealed that thalli of relatively dry sites had significantly lower seasonal RaGR with respect to moister ones. Considering that cumulative precipitations were equally distributed along the transect, it was concluded that RaGR of X. parietina is affected negatively by high air temperatures and positively by high relative humidity. The importance of RaGR variation in lichen bioaccumulation studies is critically discussed.     

Occurrence of PAH in the seasonal snowpack of the Eastern Italian Alps

PAH concentrations have been determined in 47 seasonal snowpack samples collected in the Valbelluna valley and in the Bellunesi Dolomites National Park, in the Italian North-Eastern Alps, during the winter of 2005. The ΣPAH concentration in high-altitude alpine sites (above 1700 m) was 32 ± 20 ng/kg while in valley bottom urban areas it was 165 ± 54 ng/kg with maximum values of 290 ng/kg. The GIS mapping technique was employed to produce a PAH spatial distribution. The urbanized Valbelluna valley, and in particular the SW part, had the highest accumulation of all PAH, with values an order of magnitude more than those in rural and alpine areas. This behaviour is consistent with urban air quality data, and is due to geo-morphological and meteorological factors such as the deeper shape of the valley at the position of the town of Feltre and the low altitude of the boundary layer during the winter season.