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141.
Botta C Labille J Auffan M Borschneck D Miche H Cabié M Masion A Rose J Bottero JY 《Environmental pollution (Barking, Essex : 1987)》2011,159(6):1543-1550
This work investigates the physical-chemical evolution during artificial aging in water of four commercialized sunscreens containing TiO2-based nanocomposites. Sunscreens were analyzed in terms of mineralogy and TiO2 concentration. The residues formed after aging were characterized in size, shape, chemistry and surface properties. The results showed that a significant fraction of nano-TiO2 residues was released from all sunscreens, despite their heterogeneous behaviors. A stable dispersion of submicronic aggregates of nanoparticles was generated, representing up to 38 w/w% of the amount of sunscreen, and containing up to 30% of the total nano-TiO2 initially present in the creams. The stability of the dispersion was tested as a function of salt concentration, revealing that in seawater conditions, a major part of these nano-TiO2 residues will aggregate and sediment. These results were put in perspective with consumption and life cycle of sunscreens to estimate the amount of nano-TiO2 potentially released into AQUATIC environment. 相似文献
142.
Onandia G Olsson AK Barth S King JS Uddling J 《Environmental pollution (Barking, Essex : 1987)》2011,159(10):2350-2354
With rising concentrations of both atmospheric carbon dioxide (CO2) and tropospheric ozone (O3), it is important to better understand the interacting effects of these two trace gases on plant physiology affecting land-atmosphere gas exchange. We investigated the effect of growth under elevated CO2 and O3, singly and in combination, on the primary short-term stomatal response to CO2 concentration in paper birch at the Aspen FACE experiment. Leaves from trees grown in elevated CO2 and/or O3 exhibited weaker short-term responses of stomatal conductance to both an increase and a decrease in CO2 concentration from current ambient level. The impairement of the stomatal CO2 response by O3 most likely developed progressively over the growing season as assessed by sap flux measurements. Our results suggest that expectations of plant water-savings and reduced stomatal air pollution uptake under rising atmospheric CO2 may not hold for northern hardwood forests under concurrently rising tropospheric O3. 相似文献
143.
对净化废气中SO2的生物膜填料塔内的微生物进行了分离纯化并做鉴定,得到一株嗜酸性氧化硫硫杆菌(Acidithiobacillus thiooxidans IEL001)和一株分类地位非常接近链二孢属(Bispora sp.)的极端嗜酸真菌IEL002,生物膜填料塔内的极端酸性环境和有机营养的缺乏导致生物膜上的微生物种类较为单一,多样性程度不高。本研究还发现IEL002自身并不能氧化单质硫,但它能促进Acidithiobacillus thiooxidans IEL001对单质硫的氧化。 相似文献
144.
145.
本文利用DEA的方法从全要素生产率中分解出规模效率、技术进步和纯技术效率三个指标,然后基于1998-2008年的省际面板数据分析了不同地区的工业规模效率及技术进步对CO2排放影响的程度及差异化的原因.研究结果显示:从总体来看,技术进步对单位GDP的CO2排放有抑制作用,而规模效率则与CO2排放呈正向关系,但各个地区的情况不同,东中部地区的技术进步对单位GDP的CO2排放起到了抑制作用,东北地区和西部地区的技术进步则对单位GDP的CO2排放起到了促进作用;东中部地区的规模效率对单位GDP CO2排放的影响程度要远小于东部地区和西部地区;产生这些差异的原因可能是与我国区域间技术进步与规模效率所属的种类不同有关,东部地区的技术进步可能属于节能型技术进步,而西部地区则属于耗能型的技术进步;东北地区和西部地区规模效率的提升可能更多地依靠能源消耗,中东部地区则有所改善. 相似文献
146.
147.
Justin M. Langridge R. Joel Gustafsson Paul T. Griffiths R. Anthony Cox Richard M. Lambert Roderic L. Jones 《Atmospheric environment (Oxford, England : 1994)》2009,43(32):5128-5131
The photoenhanced uptake of nitrogen dioxide (NO2) to the surface of commercially available self-cleaning window glass has been studied under controlled laboratory conditions. This material is one of an array of modern building products which incorporate titanium dioxide (TiO2) nanoparticles and are finding increasing use in populated urban areas. Amongst the principal drivers for the use of these materials is that they are thought to facilitate the irreversible removal of pollutants such as NO2 and organic molecules from the atmosphere and thus act to remediate air quality. While it appears that TiO2 materials do indeed remove organic molecules from built environments, in this study we show that the photoenhanced uptake of NO2 to one example material, self-cleaning window glass, is in fact accompanied by the substantial formation (50–70%) of gaseous nitrous acid (HONO). This finding has direct and serious implications for the use of these materials in urban areas. Not only is HONO a harmful respiratory irritant, it is also readily photolysed by solar radiation leading to the formation of hydroxyl radicals (OH) together with the re-release of NOx as NO. The net effect of subsequent OH initiated chemistry can then be the further degradation of air quality through the formation of secondary pollutants such as ozone and VOC oxidation products. In summary, we suggest that a scientifically conceived technical strategy for air quality remediation based on this technology, while widely perceived as universally beneficial, could in fact have effects precisely opposite to those intended. 相似文献
148.
In 1988 the Toronto World Conference on the Changing Atmosphere called for a reduction of CO2 emissions of the industrialized countries by approximately 20% by the year 2005 as compared with 1988. A stabilization of
CO2 concentrations would require an eventual emissions reduction of more than 50% of present levels. Model runs were performed
with the Dutch Integrated Model for the Assessment of the Greenhouse Effect (IMAGE) to put these figures into perspective.
It was found that the suggested emissions reduction levels could indeed be adequate to prevent global temperature change from
moving beyond past climate experience. However, this would only be the case when these reduced levels of emissions were achieved
at a global scale and maximum emission control for the other greenhouse gases was implemented. A delayed response analysis
shows that the policies of the coming decades are crucial for the eventual control of the greenhouse effect. 相似文献
149.
Effects of landfill gas on subtropical woody plants 总被引:2,自引:0,他引:2
An account is given of the influence of landfill gas on tree growth in the field at Gin Drinkers' Bay (GDB) landfill, Hong
Kong, and in the laboratory. Ten species (Acacia confusa, Albizzia lebbek, Aporusa chinensis, Bombax malabaricum, Castanopsis fissa, Liquidambar formosana, Litsea glutinosa,
Machilus breviflora, Pinus elliottii, andTristania conferta), belonging to eight families, were transplanted to two sites, one with a high concentration of landfill gas in the cover
soil (high-gas site, HGS) and the other with a relatively low concentration of gas (low-gas site, LGS). Apart from the gaseous
composition, the general soil properties were similar. A strong negative correlation between tree growth and landfill gas
concentration was observed. A laboratory study using the simulated landfill gas to fumigate seedlings of the above species
showed that the adventitious root growth ofAporusa chinensis, Bombax malabaricum, Machilus breviflora, andTristania confera was stimulated by the gas, with shallow root systems being induced.Acacia confusa, Albizzia lebbek, andLitsea glutinosa were gas-tolerant, while root growth ofCastanopsis fissa, Liquidambar formosana, andPinus elliottii was inhibited. In most cases, shoot growth was not affected, exceptions beingBombax malabaricum, Liquidambar formosana, andTristania conferta, where stunted growth and/or reduced foliation was observed.
A very high CO2 concentration in cover soil limits the depth of the root system. Trees with a shallow root system become very susceptible
to water stress. The effects of low O2 concentration in soil are less important than the effects of high CO2 concentration.Acacia confusa, Albizzia lebbek, andTristania conferta are suited for growth on subtropical completed landfills mainly due to their gas tolerance and/or drought tolerance. 相似文献
150.
Energy and carbon balances of wood cascade chains 总被引:1,自引:0,他引:1
In this study we analyze the energy and carbon balances of various cascade chains for recovered wood lumber. Post-recovery options include reuse as lumber, reprocessing as particleboard, pulping to form paper products, and burning for energy recovery. We compare energy and carbon balances of chains of cascaded products to the balances of products obtained from virgin wood fiber or from non-wood material. We describe and quantify several mechanisms through which cascading can affect the energy and carbon balances: direct cascade effects due to different properties and logistics of virgin and recovered materials, substitution effects due to the reduced demand for non-wood materials when wood is cascaded, and land use effects due to alternative possible land uses when less timber harvest is needed because of wood cascading. In some analyses we assume the forest is a limiting resource, and in others we include a fixed amount of forest land from which biomass can be harvested for use as material or biofuel. Energy and carbon balances take into account manufacturing processes, recovery and transportation energy, material recovery losses, and forest processes. We find that land use effects have the greatest impact on energy and carbon balances, followed by substitution effects, while direct cascade effects are relatively minor. 相似文献