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11.
Pollution of water bodies causes stress on organisms inhabiting them. Determination of biomarkers and bioindicators on fish populations reflects whether they are subject to stress. We assessed two populations of Ameca splendens and Goodea atripinnis in a reference site (spring "El Rincon") and De La Vega reservoir, which receives wastewater of a sugar industry, on Ameca River course. We analyzed level of lipid peroxidation and enzymatic activities of gamma-glutamyl-transpeptidase, acetylcholinesterase and ethoxyresorufin-O-deethylase as biomarkers; we also studied age classes and various body indexes. Environmental factors were recorded and a water quality index was assessed. Water quality was better in the spring than in the reservoir. Organisms inhabiting the reservoir presented higher oxidative stress by the lipid peroxidation levels, and neurotoxic impacts by the acetylcholinesterase and some detoxification mechanisms were evident by the gamma-glutamyl-transpeptidase and ethoxyresorufin-O-deethylase activities. Integrated Biomarker Response demonstrate that De La Vega reservoir is a more stressing place to organisms living there, particularly for A. splendens. In both species, males were more affected than females. Condition and reproductive parameters in reservoir showed evidences of physiological changes due to xenobiotics exposure and suggest a tactic of the organisms to survive in this site. Both biomarkers and body indexes revealed that A. splendens is a more sensitive species than G. atripinnis to environmental stress.  相似文献   
12.
Enteric viruses transmitted via the faecal-oral route occur in high concentrations in wastewater and may contaminate drinking water sources and cause disease. In order to quantify enteric adenovirus and norovirus genotypes I and II (GI and GII) impacting a drinking source in Norway, samples of surface water (52), wastewater inlet (64) and outlet (59) were collected between January 2011 and April 2012. Samples were concentrated in two steps, using an electropositive disc filter and polyethylene glycol precipitation, followed by nucleic acid extraction and analysis by quantitative polymerase chain reaction. Virus was detected in 47/52 (90.4 %) of surface water, 59/64 (92 %) of wastewater inlet and 55/59 (93 %) of wastewater outlet samples. Norovirus GI occurred in the highest concentrations in surface water (2.51e + 04) and adenovirus in wastewater (2.15e + 07). While adenovirus was the most frequently detected in all matrices, norovirus GI was more frequently detected in surface water and norovirus GII in wastewater. This study is the first in Norway to monitor both sewage and a drinking water source in parallel, and confirms the year-round presence of norovirus and adenovirus in a Norwegian drinking water source.  相似文献   
13.
The potential contamination of groundwater by herbicides is often controlled by processes in the vadose zone, through which herbicides travel before entering groundwater. In the vadose zone, both physical and chemical processes affect the fate and transport of herbicides, therefore it is important to represent these processes by mathematical models to predict contaminant movement. To simulate the movement of simazine, a herbicide commonly used in Chilean vineyards, batch and miscible displacement column experiments were performed on a disturbed sandy soil to quantify the primary parameters and processes of simazine transport. Chloride (Cl(-)) was used as a non-reactive tracer, and simazine as the reactive tracer. The Hydrus-1D model was used to estimate the parameters by inversion from the breakthrough curves of the columns and to evaluate the potential groundwater contamination in a sandy soil from the Casablanca Valley, Chile. The two-site, chemical non-equilibrium model was observed to best represent the experimental results of the miscible displacement experiments in laboratory soil columns. Predictions of transport under hypothetical field conditions using the same soil from the column experiments were made for 40 years by applying herbicide during the first 20 years, and then halting the application and considering different rates of groundwater recharge. For recharge rates smaller than 84 mm year(-1), the predicted concentration of simazine at a depth of 1 m is below the U.S. EPA's maximum contaminant levels (4 microg L(-1)). After eight years of application at a groundwater recharge rate of 180 mm year(-1) (approximately 50% of the annual rainfall), simazine was found to reach the groundwater (located at 1 m depth) at a higher concentration (more than 40 microg L(-1)) than the existing guidelines in the USA and Europe.  相似文献   
14.
Experiments were carried out to evaluate the use of some agroindustrial wastes as supports in solid state cultures for the biodegradation of crude oil Maya in static column reactors over 15-20 days periods. Spent compost and cane bagasse wastes showed superior qualities over peat moss waste as support candidates with the advantage that they contain appreciable densities of autochthonous microorganisms in the order of 10(2) cfu g(-1). Mercuric chloride (2%) was able to completely inhibit growth of these microfloras. Biodegradation was enhanced in the presence of the IMP consortium and highest when microflora from cane bagasse only was the bioaugmentation partner (180.7 mg kg(-1) day(-1)). Combination of these waste materials (3:1 ratio, respectively) was observed to significantly biodegrade the crude oil by approximately 40% in 15 days from an initial concentration of 10,000 mg kg(-1) with a four order of magnitude increase in microbial density during this period. Spent compost and cane bagasse wastes are veritable solid support candidates for use in the biodegradation of crude oil polluted systems.  相似文献   
15.
The use of petroleum-derived products should be avoided regarding the principles of green and sustainable chemistry. The work reported herein, is aimed at the liquefaction of pine shavings for the production of an environmentally-friendly polyol suitable to be used in the formulations of sprayable polyurethane foams. The biopolyols were obtained in high yield and were used to replace those derived from fossil sources, to produce more “greener” polyurethane foams and therefore, less dependent on petroleum sources, since the polyol component was substituted by products resulting from biomass liquefaction. The partial and fully exchange of the polyols was accomplished, and the results compared with a reference foam. The foams were afterward, chemical, physical, morphological, and mechanically characterized. The complete replacement of polyether polyol and polyol polyester has presented some similar characteristics as that used as a reference, validating that the path chosen for the development of more sustainable materials is on the right track for the contribution to a cleaner world.  相似文献   
16.
Generally, one expects evapotranspiration (ET) maps derived from optical/thermal Landsat and MODIS satellite imagery to improve decision support tools and lead to superior decisions regarding water resources management. However, there is lack of supportive evidence to accept or reject this expectation. We “benchmark” three existing hydrologic decision support tools with the following benchmarks: annual ET for the ET Toolbox developed by the United States Bureau of Reclamation, predicted rainfall‐runoff hydrographs for the Gridded Surface/Subsurface Hydrologic Analysis model developed by the U.S. Army Corps of Engineers, and the average annual groundwater recharge for the Distributed Parameter Watershed Model used by Daniel B. Stephens & Associates. The conclusion of this benchmark study is that the use of NASA/USGS optical/thermal satellite imagery can considerably improve hydrologic decision support tools compared to their traditional implementations. The benefits of improved decision making, resulting from more accurate results of hydrologic support systems using optical/thermal satellite imagery, should substantially exceed the costs for acquiring such imagery and implementing the remote sensing algorithms. In fact, the value of reduced error in estimating average annual groundwater recharge in the San Gabriel Mountains, California alone, in terms of value of water, may be as large as $1 billion, more than sufficient to pay for one new Landsat satellite.  相似文献   
17.
Zinc oxide nanoparticles (ZnO NPs) are used in an array of products and processes, ranging from personal care products to antifouling paints, textiles, food additives, antibacterial agents and environmental remediation processes. Soils are an environment likely to be exposed to manmade nanoparticles due to the practice of applying sewage sludge as a fertiliser or as an organic soil improver. However, understanding on the interactions between soil properties, nanoparticles and the organisms that live within soil is lacking, especially with regards to soil bacterial communities. We studied the effects of nanoparticulate, non-nanoparticulate and ionic zinc (in the form of zinc chloride) on the composition of bacterial communities in soil with a modified pH range (from pH 4.5 to pH 7.2). We observed strong pH-dependent effects on the interaction between bacterial communities and all forms of zinc, with the largest changes in bacterial community composition occurring in soils with low and medium pH levels (pH 4.8 and 5.9). The high pH soil (pH 7.2) was less susceptible to the effects of zinc exposure. At the highest doses of zinc (2500 mg/kg dw soil), both nano and non-nano particulate zinc applications elicited a similar response in the soil bacterial community, and this differed significantly to the ionic zinc salt treatment. The results highlight the importance of considering soil pH in nanotoxicology studies, although further work is needed to determine the exact mechanisms controlling the toxicity and fate and interactions of nanoparticles with soil microbial communities.  相似文献   
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19.
This paper investigates multi-stakeholder arrangements initiated by businesses and NGOs from the North that aim to enhance a more sustainable agricultural production at specific localities in Southern countries. We aim to better understand the search for concerted action in multi-actor arrangements. Therefore, this paper presents a diagnostic framework with three strategic challenges the partnership projects are facing: linking global economic objectives to local needs, values and interests; bridging public and private interests and responsibilities; and seeking trade-offs between social, environmental and economic values. Starting from the partnerships’ Theory of Change, this diagnostic framework is applied to comparative case studies of partnership projects in the cocoa sector in Indonesia, which are part of a Northern-based public–private partnership to improve farmers’ prospective. It is concluded that the economic reality faced by the farmers differs from that of the Northern actors; collaboration with governments is difficult because of different organizational cultures; and the partnership projects underestimate the strength of vested social relations the smallholders are part of. Overall, the initiators of the partnerships seem to work with a too restricted economic interpretation of the local reality.  相似文献   
20.
Power-line grids are increasingly expanding worldwide, as well as their negative impacts on avifauna, namely the direct mortality through collision and electrocution, the reduction of breeding performance, and the barrier effect. On the other hand, some bird species can apparently benefit from the presence of power lines, for example perching for hunting purposes or nesting on electricity towers. In this perspective essay, we reviewed the scientific literature on both costs and benefits for avifauna coexisting with power lines. Overall, we detected a generalized lack of studies focusing on these costs or benefits at a population level. We suggest that a switch in research approach to a larger spatio-temporal scale would greatly improve our knowledge about the actual effects of power lines on bird populations. This research approach would facilitate suitable landscape planning encompassing both mitigation of costs and promotion of benefits for bird populations coexisting with power lines. For example, the strategic route planning of electricity infrastructures would limit collision risk or barrier effects for threatened bird populations. Concurrently, this strategic route planning would promote the range expansion of threatened populations of other bird species, by providing nesting structures in treeless but potentially suitable landscapes. We suggest establishing a collaborative dialogue among the scientific community, governments, and electricity companies, with the aim to produce a win–win scenario in which both biodiversity conservation and infrastructure development are integrated in a common strategy.  相似文献   
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