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891.
Understanding patterns, dynamics, and drivers of land use is crucial for improving our ability to cope with sustainability challenges. The human appropriation of net primary production (HANPP) framework provides a set of integrated socio-ecological indicators that quantify how land use alters energy flows in ecosystems via land conversions and biomass harvest. Thus, HANPP enables researchers to systematically and consistently assess the outcome of changes in land cover and land-use intensity across spatio-temporal scales. Yet, fine-scale HANPP assessments are so far missing, an information important to address site-specific ecological implications of land use. Here, we provide such an assessment for Europe at a 1-km scale for the years 1990, 2000, and 2006. The assessment was based on a consistent land-use/biomass flow dataset derived from statistical data, remote sensing maps, and a dynamic global vegetation model. We find that HANPP in Europe amounted to ~43 % of potential productivity, well above the global average of ~25 %, with little variation in the European average since 1990. HANPP was highest in Central Europe and lower in Northern and Southern Europe. At the regional level, distinct changes in land-use intensity were observed, most importantly the decline of cropland areas and yields following the breakdown of socialism in Eastern Europe and the subsequent recovery after 2000, or strong dynamics related to storm events that resulted in massive salvage loggings. In sum, however, these local dynamics cancelled each other out at the aggregate level. We conclude that this finding warrants further research into aspects of the scale-dependency of dynamics and stability of land use.  相似文献   
892.
893.
Coal ash from power stations has long been used successfully in the cement industry as binders in several Portland formulations. This is not the case for municipal solid waste (MSW) ash as chloride concentrations, ranging from 10 to 200 g kg(-1) dry weight in the bottom and fly ash, respectively, exceed the maximum allowable concentration in most cement mixtures. To reduce chloride content in MSW bottom ash, a laboratory investigation was carried out based on the exhaustive washing in tap water. The influence of operative parameters such as temperature, granulometric properties and solid/liquid ratio of extraction was evaluated. In addition to optimization of the mentioned operative parameters for full-scale application, the paper gives preliminary indications on mechanistic aspects of the washing operation.  相似文献   
894.
Laboratory and field filtration experiments were conducted to study the effectiveness of As(V) removal for five types of adsorbent media. The media included activated alumina (AA), modified activated alumina (MAA), granular ferric hydroxide (GFH), granular ferric oxide (GFO), and granular titanium dioxide (TiO?). In laboratory batch and column experiments, the synthetic challenge water was used to evaluate the effectiveness for five adsorbents. The results of the batch experiments showed that the As(V) adsorption decreased as follows at pH 6.5: TiO? > GFO > GFH > MAA > AA. At pH 8.5, however, As(V) removal decreased in the following order: GFO = TiO? > GFH > MAA > AA. In column experiments, at pH 6.5, the adsorbed As(V) for adsorbents followed the order: TiO? > GFO > GFH, whereas at pH 8.5 the order became: GFO = TiO? > GFH when the challenge water containing 50 μg/L of As(V) was used. Field filtration experiments were carried out in parallel at a wellhead in New Jersey. Before the effluent arsenic concentration increased to 10 μg/L, approximately 58,000 and 41,500 bed volumes of groundwater containing an average of 47 μg/L of As(V) were treated by the filter system packed with GFO and TiO?, respectively. The As(V) adsorption decreased in the following sequence: GFO > TiO? > GFH > MAA > AA. Filtration results demonstrated that GFO and TiO? adsorbents could be used as media in small community filtration systems for As(V) removal.  相似文献   
895.
The high hydrophobicity of polycyclic aromatic hydrocarbons (PAHs) greatly hamper their degradation in liquid media. The use of an organic solvent can assist the degradative action of ligninolytic enzymes from white rot fungi. The enzymatic action of the enzyme manganese peroxidase (MnP) in media containing a miscible organic solvent, acetone (36% v/v), was evaluated as a feasible system for the in vitro degradation of three PAHs: anthracene, dibenzothiophene and pyrene. These compounds were degraded to a large extent after a short period of time (7, 24 and 24h, respectively), at conditions maximizing the MnP-oxidative system. The initial amount of enzyme present in the reaction medium was determinant for the kinetics of the process. The order of degradability, in terms of degradation rates was as follows: anthracene>dibenzothiophene>pyrene. The intermediate compounds were determined using gas chromatography-mass spectrometry and the degradation mechanisms were proposed. Anthracene was degraded to phthalic acid. A ring cleavage product of the oxidation of dibenzothiophene, 4-methoxybenzoic acid, was also observed.  相似文献   
896.
Measurement of intertidal rock assemblages was investigated as a potential biological indicator to provide a quantitative estimate of the impact of urbanised catchment discharge on the estuaries of Sydney, Australia, from 1995 to 1999. Based on the presence and characteristics of adjacent human activities, sampling locations were categorised as: Bush; Urban; Urban with Sewer Overflows; and Industry with Sewer Overflows. In Sydney Harbour, variation in assemblage structure was measured between most impact categories, however differences between impact categories were not consistent for each year. Nevertheless, in years of above average rainfall (1998–1999), reference assemblages adjacent to national parks and distant from urbanisation were different to all other putatively impacted assemblages. Variability within assemblages was least at reference locations in each year and greatest at locations adjacent to stormwater canals and sewer overflows, particularly in 1998–1999. Variation in assemblage structure in Sydney estuaries was most strongly correlated with chlorophyll – a concentrations. Univariate analysis also identified highly significant differences for a number of factors, however, interactions between year, impact categories and location for numerous analyses, confounded the differentiation between impact categories. The results suggest that intertidal rock assemblages in Sydney Harbour and surrounding estuaries appear to be responding to the quality and quantity of discharge from urbanised catchments and, furthermore, that assemblages are more suitable than individual taxa to indicate the difference between Bush and anthropogenically disturbed estuarine locations.  相似文献   
897.
This research was undertaken during 2003-2004 growing season to evaluate the effects of type [forage sorghum "hybrid Cober Exp" (Sorghum bicolor x Sorghum sudanense), forage millet (Pennisetum americanum "var. BN2"), finger millet (Eleusine coracana), and St Lucia grass (Brachiaria brizantha)] and amount of straw cover (5.5 and 3.0 t ha(-1)) upon the emergence of Bidens pilosa, Chamaesyce spp., Amaranthus spp., and Commelina benghalensis, under field conditions of the Brazilian Cerrado, in the region of Uberlandia--MG. The control consisted additional treatment lacking the straw cover. Emergence of weed depended on the type and amount of straw cover, as well as the weed species. The lowest number of B. pilosa seedlings was found in the presence of forage sorghum straw; Chamaesyce spp. in the lack of straw; Amaranthus spp. in the presence of higher amount of forage sorghum and forage millet, and lower amounts of forage millet and Finger Millet. All the types and amounts of straw reduced the emergency of C. benghalensis, except at the lowest level of St Lucia grass and the lack of straw.  相似文献   
898.
There is currently a considerable emphasis on delivering major renewable energy infrastructure projects. Such projects will have impacts on local communities; some impacts may be perceived as positive but others will be viewed more negatively. Any just regulatory process for considering and permitting such infrastructure will need to heed the concerns that local communities voice. But what counts as a local voice? In this paper it is argued that the regulatory process plays a performative role, constructing what counts as a local voice. Furthermore, this has consequences for how regulatory deliberations proceed and the outcomes of regulatory processes. The empirical basis for this argument is a study of major offshore renewable energy infrastructure in England and Wales and the way that it is regulated through a specific regime – the Nationally Significant Infrastructure Projects (NSIPs) regime established by the Planning Act 2008. Through a detailed study of eight projects that have passed through the regime, the analysis unfolds the way that the voices of local residents, local businesses, local NGOs and local authorities are constructed in the key boundary object of the Examining Authority’s report; it then draws out the implications for the mitigation measures that are negotiated. The research suggests that what counts as a local voice is constrained by how the performative role of the NSIPs regulatory regime differentiates between interests and suggests that new ways of giving voice to local people are required.  相似文献   
899.
Artificial recharge improves several water quality parameters, but has only minor effects on recalcitrant pollutants. To improve the removal of these pollutants, we added a reactive barrier at the bottom of an infiltration basin. This barrier contained aquifer sand, vegetable compost, and clay and was covered with iron oxide dust. The goal of the compost was to sorb neutral compounds and release dissolved organic carbon. The release of dissolved organic carbon should generate a broad range of redox conditions to promote the transformation of emerging trace organic contaminants (EOCs). Iron oxides and clay increase the range of sorption site types. In the present study, we examined the effectiveness of this barrier by analyzing the fate of nine EOCs. Water quality was monitored before and after constructing the reactive barrier. Installation of the reactive barrier led to nitrate-, iron-, and manganese-reducing conditions in the unsaturated zone below the basin and within the first few meters of the saturated zone. Thus, the behavior of most EOCs changed after installing the reactive barrier. The reactive barrier enhanced the removal of some EOCs, either markedly (sulfamethoxazole, caffeine, benzoylecgonine) or slightly (trimethoprim) and decreased the removal rates of compounds that are easily degradable under aerobic conditions (ibuprofen, paracetamol). The barrier had no remarkable effect on 1H-benzotriazole and tolyltriazole.  相似文献   
900.
Olive mill wastewater contains some phenolic compounds that cause antibacterial activity of a kind that prevents biological treatment without previous dilution. Among these phenolic compounds, p-hydroxybenzoic acid (PHB) is considered to be one of the most representative. This work examines the biodegradation of PHB by aerobic microbial mixed cultures previously acclimatized to glucose, which was used as an easily biodegradable model compound. Microbial growth runs were carried out in a batch reactor in the PHB concentration range of 200-1000 mg/L. In all the runs the PHB proved to be completely degradable. The specific growth rates obtained were in the range of 0.16-0.35 l/h. Experimental runs showed that the functional relationship between the specific growth rate and PHB concentration was that proposed by Monod. The kinetic constants of the Monod equation (mu(max) and K(S)) and biomass yield coefficient (Y) were determined experimentally. With the parameter values thus obtained, a mathematical model that also takes account of the duration of the lag phase was employed to describe both the microbial growth and the consumption of PHB. The concentration values of the model fit well with the data obtained experimentally.  相似文献   
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