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671.
Representative samples of the following biowastes typically generated in Castilla La Mancha (Spain) were composted using a pilot-scale closed rotary drum composting reactor provided with adequate control systems: waste from the olive oil industry (olive mill waste; OMW), winery–distillery waste containing basically grape stalk and exhausted grape marc (WDW), and domestic sewage sludge. Composting these biowastes was only successful when using a bulking agent or if sufficient porosity was supported. OMW waste composting was not possible, probably because of its negligible porosity, which likely caused anaerobic conditions. WDW was successfully composted using a mixture of solid wastes generated from the same winery. SS was also successfully composted, although its higher heavy metal content was a limitation. Co-composting was an adequate strategy because the improved mixture characteristics helped to maintain optimal operating conditions. By co-composting, the duration of the thermophilic period increased, the final maturity level improved and OMW was successfully composted. Using the proposed reactor, composting could be accelerated compared to classical outdoor techniques, enabling easy control of the process. Moisture could be easily controlled by wet air feeding and leachate recirculation. Inline outlet gas analysis helped to control aerobic conditions without excessive aeration. The temperature reached high values in a few days, and sufficient thermal requirements for pathogen removal were met. The correct combination of biowastes along with appropriate reactor design would allow composting as a management option for such abundant biowastes in this part of Spain.  相似文献   
672.
无锡市工业SO2污染变化的空间特征及影响因素的分解分析   总被引:3,自引:0,他引:3  
运用分解分析方法对工业污染变化进行地区分解、影响因素分解和综合分解,建立包含地区和影响因素的工业污染分解模型,并且应用该模型对2001-2005年无锡市工业SO2排放量的变化进行实证分析.分析结果表明,无锡市工业So2排放量的变化主要是江阴的经济规模、能耗技术和排污技术,市区的经济规模和能耗技术,以及宜兴的经济规模共同作用的结果.从地区来看,无锡市工业SO2排放量的变化主要源于江阴,而宜兴的影响逐渐增强.市区的影响趋于减弱.从影响因素来看,三个地区的经济规模效应都为正,而且显著大于其他三种效应;经济结构是影响力最弱的因素:技术变迁有显著影响,但在三个地区闻存在差异性.为了同时实现经济发展和工业SO2减排,无锡需要采取节能减排措施以降低{特别是江阴的)工业SO2排放强度.  相似文献   
673.
Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) is a serious pest of corn in several American countries. It is mainly controlled with synthetic insecticides. The objectives of this study were to evaluate the effects of the natural products, neem oil and pyroligneous extract, and the synthetic insecticide, lufenuron, at 2.50mL water (0.25 %) on the mortality of 2-, 4- and 6-day-old caterpillars of S. frugiperda, and their selectivities against fourth instar larvae of Eriopis connnexa Germar (Coleoptera: Coccinellidae). Four- and 6-day-old S. frugiperda caterpillars showed higher mortality after exposure to neem oil (83.33 ± 0.83 and 89.58 ± 0.90 %, respectively) and lufenuron (95.83 ± 0.96 and 85.41 ± 0.83 %), compared to pyroligneous extract (68.75 ± 0.69 and 31.25 ± 0.31 %). The deleterious effect of pyroligneous extract was higher in 2- (83.33 ± 0.83 % mortality) and 4-day-old (68.75 ± 0.69 %) S. frugiperda caterpillars than in 6-day-old caterpillars (31.25 ± 0.31 %). Larval mortality of the predator E. connexa was lower with neem oil and pyroligneous extract (25.00 ± 0.33 %) than with lufenuron (91.66 ± 1.22 %). Neem oil is thus recommended for control of S. frugiperda because of its high toxicity, combined with its relatively low toxicity to larvae of the natural enemy E. connexa.  相似文献   
674.
In this study, we examined the effect of four different organic wastes (OW)—composted sheep manure (CSM), spent coffee grounds (SCG), composted pine bark (CPB) and coir (CR)—on the potential groundwater pollution of propanil and isoxaben (herbicides), cadusafos (insecticide) and pencycuron (fungicide) under laboratory conditions. For this purpose, leaching studies were conducted using disturbed soil columns filled with a clay loam soil (Hipercalcic calcisol). The addition of organic matter (OM) drastically reduced the movement of the studied pesticides. The results obtained point to the interest in the use of agro-industrial and composted OW in reducing the groundwater pollution by pesticide drainage.  相似文献   
675.
Selection of reservoir location, the floodable basin forest handling, and the design of dam structures devoted to water supply (e.g. water outlets) constitute relevant features which strongly determine water quality and frequently demand management strategies to be adopted. Although these crucial aspects should be carefully examined during dam design before construction, currently the development of ad hoc limnological studies tailoring dam location and dam structures to the water quality characteristics expected in the future reservoir is not typical practice. In this study, we use numerical simulation to assist on the design of a new dam project in Spain with the aim of maximizing the quality of the water supplied by the future reservoir. First, we ran a well-known coupled hydrodynamic and biogeochemical dynamic numerical model (DYRESM–CAEDYM) to simulate the potential development of anoxic layers in the future reservoir. Then, we generated several scenarios corresponding to different potential hydraulic conditions and outlet configurations. Second, we built a simplified numerical model to simulate the development of the hypolimnetic oxygen content during the maturation stage after the first reservoir filling, taking into consideration the degradation of the terrestrial organic matter flooded and the adoption of different forest handling scenarios. Results are discussed in terms of reservoir design and water quality management. The combination of hypolimnetic withdrawal from two deep outlets and the removal of all the valuable terrestrial vegetal biomass before flooding resulted in the best water quality scenario.  相似文献   
676.
The objective of this study was to identify the organic compounds removed from the leachate when treated with Fenton–Adsorption by gas chromatography coupled to mass spectrometry (GC–MS) in order to identify toxic compounds that could be harmful for the environment or human health.The physicochemical characterization of the raw leachate was carried out before and after the Fenton–Adsorption process. The effluent from each stage of this process was characterized: pH, Biological Oxygen Demand (BOD5), Chemical Oxygen Demand (COD), Total Organic Carbon (TOC), Total Carbon (TC), Inorganic Carbon (IC), Total Solids (TS), Total Suspended Solids (TSS) and Color. The organic compounds were determined by GC–MS.The removal of COD and color reached over 99% in compliance with the Mexican Standard NOM-001-SEMARNAT-1996, which establishes the maximum permissible limits for contaminants present in wastewater discharges to water and national goods. The chromatographic analysis from the Fenton–Adsorption effluent proved that this treatment removed more than 98% of the organic compounds present in the initial sample. The mono (2-ethylhexyl) ester 1,2-benzenedicarboxylic acid persisted, although it is not considered as toxic compound by the NOM-052-SEMARNAT-2005. Therefore, the treated effluent can be safely disposed of into the environment.  相似文献   
677.
The metropolitan area of Rio de Janeiro is one of the twenty biggest urban agglomerations in the world, with 11 million inhabitants in the metropolitan area, and has a high population density, with 1700 hab. km?2. For this aerosol source apportionment study, the atmospheric aerosol sampling was performed at ten sites distributed in different locations of the metropolitan area from September/2003 to December/2005, with sampling during 24 h on a weekly basis. Stacked filter units (SFU) were used to collect fine and coarse aerosol particles with a flow rate of 17 L min?1. In both size fractions trace elements were analyzed by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) as well as water-soluble species by Ion-Chromatography (IC). Also gravimetric analysis and reflectance measurements provided aerosol mass and black carbon concentrations. Very good detection limits for up to 42 species were obtained. Mean annual PM10 mass concentration ranged from 20 to 37 μg m?3, values that are within the Brazilian air quality standards. Receptor models such as principal factor analysis, cluster analysis and absolute principal factor analysis were applied in order to identify and quantify the aerosol sources. For fine and coarse modes, circa of 100% of the measured mass was quantitatively apportioned to relatively few identified aerosol sources. A very similar and consistent source apportionment was obtained for both fine and coarse modes for all 10 sampling sites. Soil dust is an important component, accounting for 22–72% and for 25–48% of the coarse and fine mass respectively. On the other hand, anthropogenic sources as vehicle traffic and oil combustion represent a relatively high contribution (52–75%) of the fine aerosol mass. The joint use of ICP-MS and IC analysis of species in aerosols has proven to be reliable and feasible for the analysis of large amount of samples, and the coupling with receptor models provided an excellent method for quantitative aerosol source apportionment in large urban areas.  相似文献   
678.
679.
Relative species abundances are the most frequently applied data type used for modern or paleolimnological diatom studies. In contrast, plant ecologists save time by commonly using ordinal scale data (class data), where the abundance of a species is estimated using dominance classes, instead of relative abundance data. This study compares the performance of models based on ordinal diatom species class data (class 1: sporadic (<0–1%) up to class 6: dominant (>60%)) with similar model types based on relative abundance data for different regional training sets and sediment cores. First, relative diatom abundances were converted into ordinal classes. Species response to total phosphorous (TP) was modelled using both types of data - relative abundance and ordinal class data. Secondly, TP was reconstructed for six sediment cores from North-East Germany, Switzerland, and Denmark using WA and WA-PLS based on both types of data. Thirdly, 20 lake sediment surface samples with known relative diatom abundances and known water TP concentrations were recounted using an ordinal data scale to create an independent test set. No significant differences were found between relative abundance and class data for (1) explained species variance, (2) reconstructed TP values, and (3) inferred TP values of the 20 recounted samples. This approach demonstrates that past TP concentrations may also be reliably reconstructed using class data instead of relative diatom abundances. Thus, by using class data lake managers may not only obtain more long-term records past water quality, but this approach is also quicker and therefore more cost effective. Moreover, the findings of this study may also advance the use of automatic diatom identification with digital image recognition, as we demonstrate that not every damaged diatom valve needs to be identified.  相似文献   
680.
Greenhouse gases (GHG) emissions from agricultural farming practice contribute significantly to European GHG inventories. For example, CO2 is emitted when grassland is converted to cropland or when peatlands are drained and cultivated. N2O emissions result from fertilization. Enabling farmers to reduce their GHG emissions requires sufficient information about its pressure–impact relations as well as incentives, such as regulations and funding, that support climate-friendly agricultural management. This paper discusses potentials to improve the supply of information on: farm-specific climate services or impacts, present policy incentives in Germany and England that support climate-friendly farm management and related adaptation requirements. Tools which have been developed for a farm environmental management software (to be added after review because of potential identification) are presented. These tools assess CO2 emissions from grassland conversion to cropland and peatland cultivation, as well as N2O emissions from nitrogen fertilization. As input data, the CO2 tool requires a classification of soil types according to soil organic carbon storage. The input data based on soil profile samples was compared with reference data from the literature. The N2O tool relies on farm data concerning fertilization. These tools were tested on three farms in order to determine their viability with respect to the availability of required data and the differentiation of results, which determines how well site-specific conservation measures can be identified. Assessing CO2 retention function of grassland conservation to cropland on the test farms leads to spatially differentiated results (~100 to ~900 potentially mitigated t CO2 ha?1). Assessed N2O emissions varied from 0.41 to 1.1 t CO2eq. ha?1 a?1. The proposed methods support policies that promote a more differentiated funding of climate conservation measures. Conservation measures and areas can be selected so that they will have the greatest mitigation effects. However, even though present policy instruments in Germany and England, such as Cross Compliance and agri-environmental measures, have the potential to reduce agricultural GHG, they do not appear to guide measures effectively or site-specifically. In order to close this gap, agri-environmental measures with the potential to support climate protection should be spatially optimized. Additionally, the wetland restoration measures which are most effective in reducing GHG emissions should be included in funding schemes.  相似文献   
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