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21.
Influences on dust emissions from livestock operations are number, weight, and kind of animals and characteristics of the housing system. Differences between facilities cannot be explained solely by mechanistic input variables. The objective of this study was to characterize the main input variables for modeling emissions of particulate matter with a mass median diameter < or = 10 microm (PM10) from swine facilities using a data-based model. Investigations were performed in mechanically ventilated facilities for weaning, growing-finishing, and sows in Italy and Germany. The measurements included inside and outside concentration of airborne PM10 particles (scatter light photometry), ventilation rate (calibrated measuring fans), indoor air climate at a measuring frequency of 60 s, feeding times, and animal-related data such as weight and animal activity. Dust concentration and emission were simulated using a dynamic transfer function. The results indicated that the average PM10 emission rate was influenced considerably by housing system. The simulation of the PM10 emission rate resulted in a mean percentage error per data set of 21 to 39%, whereas the average simulated and measured emission rate per data set differed by about 4 to 19%. High prediction errors occurred especially during situations in which the absolute level and spatial location of the measured activity peaks did not correspond with the measured dust peaks. Further recommendations of the study were to improve continuous and accurate measurements of input variables, such as the activity level in animal houses, and to optimize the amount of measuring days in relation to the model accuracy.  相似文献   
22.
In this work, we have analyzed the changes in the protein expression profile elicited by chromium (Cr) exposure in the freshwater green alga Pseudokirchneriella subcapitata, a well known bio-indicator of water pollution. We tested two experimental conditions, namely 0.2 and 1 ppm of potassium dichromate; this concentration range includes the environmentally-relevant concentrations. Results show that neither concentration of potassium dichromate tested inhibited algal growth. However, the proteomic approach allowed the identification of relevant modifications in protein expression. In fact, among 800 protein spots detected by two-dimensional electrophoresis, 16 Cr-regulated proteins, including predicted and novel ones, were identified using tandem mass spectromic protein analysis.The results demonstrate a Cr-specific action in altering several photosynthetic proteins, such as ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO), RuBisCO activase, Light Harvesting Chla/b protein complex, and stress related Chla/b binding protein1. Although Cr toxicity with respect to photosynthesis has been already documented, here we have identified, for the first time, the target proteins of this toxicity. Cr also induced a modulation of some proteins involved in the metabolism of the amino acids glutamine, arginine and methionine. These data are supported by changes in cellular polyamine (PA) accumulation. Present findings provide new insight into the molecular mechanisms underlying Cr toxicity in P. subcapitata.  相似文献   
23.
The object of this study was to develop an accurate estimation method to evaluate the contribution of the various compartments of swine husbandry to dust and GHG (greenhouse gases, CO2, CH4 and N2O) emission into the atmosphere during one year of observation.A weaning, a gestation, a farrowing and a fattening room in an intensive pig house were observed in three different periods (Autumn–Winter, Springtime and Summer, monitoring at least 60% of each period (20% at the beginning, in the middle and at the end) of each cycle).During monitoring, live weight, average live weight gain, number of animals and its variation, type of feed and feeding time were taken into account to evaluate their influence on PM10, or the fraction of suspended particulate matter with an aerodynamic diameter less than or equal to 10 μm [Emission Inventory Guidebook, 2007. B1100 Particle Emissions from Animal Husbandry Activities. Available from: <http://reports.eea.europa.eu/EMEPCORINAIR5/en/B1100vs1.pdf> (accessed October 2008)] and to define GHG emission.The selected piggery had a ventilation control system using a free running impeller to monitor continuously real-time environmental and management parameters with an accuracy of 5%.PM10 concentration was monitored by a sampler (Haz Dust EPAM 5000), either continuously or through traditional gravimetric technique, and the mean value of dust amount collected on the membranes was utilized as a correction factor to be applied to continuously collected data.PM10 concentration amount incoming from inlets was removed from PM10 emission calculation, to estimate the real contribution of pig house dust pollution into atmosphere.Mean yearly emission factor of PM10 was measured in 2 g d?1 LU?1 for the weaning room, 0.09 g d?1 LU?1 for the farrowing room, 2.59 g d?1 LU?1 for the fattening room and 1.23 g d?1 LU?1 for the gestation room. The highest PM10 concentration and emission per LU was recorded in the fattening compartment while the lowest value was recorded in the farrowing room.CO2, CH4 and N2O concentrations were continuously measured in the exhaust ducts using an infrared photoacoustic detector IPD (Brüel & Kjaer, Multi-gas Monitor Type 1302, Multipoint Sampler and Doser Type 1303) sampling data every 15 min, for the 60% of the cycles.Yearly emission factor for CO2 was measured in 5997 g d?1 LU?1 for the weaning room, 1278 g d?1 LU?1 for the farrowing room, 13,636 g d?1 LU?1 for the fattening room and 8851 g d?1 LU?1 for the gestation room.Yearly emission factor for CH4 was measured in 24.57 g d?1 LU?1 for the weaning room, 4.68 g d?1 LU?1 for the farrowing room, 189.82 g d?1 LU?1 for the fattening room and 132.12 g d?1 LU?1 for the gestation room.Yearly emission factor for N2O was measured in 3.62 g d?1 LU?1 for the weaning room, 0.66 g d?1 LU?1 for the farrowing room, 3.26 g d?1 LU?1 for the fattening room and 2.72 g d?1 LU?1 for the gestation room.  相似文献   
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25.
Against the background of the current state of provision of drinking water and sanitation in the world — with one billion lacking safe water, and 2.2 billion not having adequate sanitation — this article argues that private participation is necessary. The most important issues for the management of water utilities in the 21st century are identified as mobilizing investment for the highly capital intensive operation of water supply and sanitation infrastructure, and achieving efficiency in the delivery of services. The article highlights the issues that need to be raised if private investment is to be seriously considered as an alternative. Case studies, especially from Latin America (Argentina, Chile, Peru, Bolivia), illustrate different modes of private participation, and possible reasons for successes and failures are discussed. The article stresses that regardless of the modality of private sector involvement, on‐going government regulatory responsibility in the water sector is crucial. It suggests that regulatory policy must go beyond just setting tariffs, to develop standards for drinking water quality and waste treatment, as well as other standards. In conclusion, the article recognizes that numerous and increasingly difficult challenges face utilities in fulfilling their responsibility to deliver drinking water of adequate quality, in sufficient quantity, and at affordable prices, as well as safe and sustainable disposal of wastewaters for members of urban and rural communities.  相似文献   
26.
Five arsenic-resistant bacterial strains designated MT1, MT2, MT3, V1 and V2 were isolated from sediments of the Oliveri-Tindari Lagoon (Italy), which comprises six small lakes whose sediments contain low arsenic concentrations. Phylogenetic analysis of the 16S rRNA gene sequences assigned them to the genus Bacillus. Bacillus sp. strain MT3 showed higher tolerance to As(III) and As(V), as indicated by minimum inhibitory concentrations of 14 and 135 mmol?1, respectively. Bacillus sp. strain V1 showed growth inhibition at 14 mmol?1 in the presence of As(III) and at 68 mmol?1 in the presence of As(V), whereas the arsenic resistance of Bacillus sp. strain MT1 was 10 and 27 mmol?1 for As(III) and As(V), respectively. The strains Bacillus spp. MT2 and V2 showed low levels of As(III) and As(V) resistance, as it was unable to grow at concentrations>7 and 14 mmol?1, respectively. The isolated arsenic-resistant Bacillus spp. strains were able to reduce As(V) to As(III), especially Bacillus spp. strain MT3. This study suggests that the isolated bacterial strains play a role in the arsenic biogeochemical cycle of arsenic-poor sediments in the Oliveri-Tindari Lagoon.  相似文献   
27.
Environment, Development and Sustainability - An integrative negotiation model is proposed so that watershed committees (WSC) can deal better with conflicts over alternatives for protecting water...  相似文献   
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