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21.
随着国家对流域水质改善要求的逐渐提高,流域污染源管理变得日益重要。提出了一种基于CPNTOOLS的辽河流域畜禽养殖行业污染源仿真技术,并采用CPNTOOLS软件对辽河流域内一家典型畜禽养殖基地进行了仿真研究,经过多次仿真与数据统计分析,分别得出了该畜禽养殖基地的CODCr,BOD5,NH3-N,TP,TN日排放量的正态分布均值在90%,95%,99%置信水平下的置信区间,并结合排水量分别计算出各污染物指标排放浓度的区间。结合BAT处理技术对污染物浓度削减进行了计算仿真,并得出了处理后CODCr,BOD5,NH3-N,TP,TN排放浓度的正态分布均值在90%,95%,99%置信水平下的置信区间以及排放浓度的极大值和极小值。 相似文献
22.
采用道化学公司火灾、爆炸危险指数法对中国石化某厂综合储罐区进行安全评价,得出了其安全措施补偿前后的火灾、爆炸指数(F&EI)、危险等级、暴露半径、暴露面积以及暴露体积等。结果表明,该企业综合储罐区采取的安全措施较为适用,能降低火灾、爆炸事故发生的概率和事故损害. 相似文献
23.
珠江三角洲人为氨源排放清单及特征 总被引:35,自引:10,他引:25
根据收集的珠江三角洲(珠三角)人为氨源的活动水平数据,采用合理的估算方法和排放因子,建立了该地区2006年人为氨源分类别和分城市的排放清单.结果表明:①2006年珠三角地区人为氨源NH3排放总量约为194.8kt;②农业源是珠江三角洲地区人为氨源的主要排放贡献源,其中畜禽源排放的NH3占总排放量的62.1%,其次是氮肥施用源,其贡献率为21.7%;③畜禽源中肉鸡是NH3排放最大贡献源,占畜禽源NH3排放总量的43.4%,其次是肉猪,其贡献率为32.1%;④广州是珠三角地区2006年人为氨源排放量最大的城市,其次是江门,分别占NH3总排放量的23.4%和19.1%,主要的排放源均为畜禽和氮肥施用源. 相似文献
24.
Helen Sheridan Barry J. McMahonTim Carnus John A. FinnAnnette Anderson Alvin J. HeldenAnne Kinsella Gordon Purvis 《Agriculture, ecosystems & environment》2011,144(1):130-135
In this study, habitat surveys were undertaken on 50 grass-based farms in SE Ireland and data digitised onto aerial photography. Additional data i.e. stocking rates, and participation (or otherwise) in the Irish Rural Environment Protection Scheme (REPS) were collected and analysed as possible explanatory variables for farm habitat composition.Results indicated that approximately 14.3% of the land area of sampled farms comprised of semi-natural habitat types, a proportion substantially greater than has been reported for many other European countries. The most frequently recorded semi-natural habitats included, field boundaries, scrub, and deciduous and riparian woodlands.Multivariate analysis of farm habitat configuration showed a strong dichotomy between dairy and non-dairy farming systems. Habitats such as intensively managed grassland and built ground were closely associated with dairy-based enterprises. In contrast, the incidence of other habitat types was associated with non-dairy and/or REPS participating enterprises. The ecological quality of field boundaries as assessed by the Field Boundary Evaluation and Grading System (FBEGS) Index was significantly greater on dairy, compared with dry-stock farms.This dichotomy in farm habitat composition is not reflected within current Agri-Environment (AE) policy. Integration of locally important drivers of habitat diversity into the design and implementation of AE policy, is integral to the successful performance of AE schemes. 相似文献
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The nitrogen changes and the nitrogen mass balance in a free water surface flow constructed wetland (CW) using the four-year monitoring data from 2008 to 2012 were estimated. The CW was composed of six cells in series that include the first settling basin (Cell 1), aeration pond (Cell 2), deep marsh (Cell 3), shallow marsh (Cell 4), deep marsh (Cell 5) and final settling basin (Cell 6). Analysis revealed that the NH4+-N concentration decreased because of ammonification which was then followed by nitrification. The NO4+-N and NO4+-N were also further reduced by means of microbial activities and plant uptake during photosynthesis. The average nitrogen concentration at the influent was 37,819 kg/year and approximately 45% of that amount exited the CW in the effluent. The denitrification amounted to 34% of the net nitrogen input, whereas the accretion of sediment was only 7%. The biomass uptake of plants was able to retain only 1% of total nitrogen load. In order to improve the nutrient removal by plant uptake, plant coverage in four cells (i.e., Cells 1, 3, 4 and 5) could be increased. 相似文献
28.
畜禽养殖业是"十二五"期间氨氮总量减排的重点,其清洁生产与末端治理技术种类繁多,不同技术在不同应用条件下减排效果差别显著。深入分析了国内外畜禽养殖业发展与污染现状,系统归纳了国内畜禽养殖业氨氮总量减排技术区域特征,综合使用层次-灰色综合评判法、费用-效益法、表单法等对氨氮总量减排技术进行了综合性的评价研究,构建了基于面向服务架构(SOA)的氨氮减排技术评估咨询平台。结果表明,氨氮总量减排技术评估方法与平台可大幅度提高技术评价的效率和精确度,可广泛应用于企业和管理部门氨氮减排的工程技术与环境管理工作。 相似文献
29.
Characterizing sources of nitrate leaching from an irrigated dairy farm in Merced County, California
Martin L. van der Schans Thomas Harter Anton Leijnse Marsha C. Mathews Roland D. Meyer 《Journal of contaminant hydrology》2009,110(1-2):9-21
Dairy farms comprise a complex landscape of groundwater pollution sources. The objective of our work is to develop a method to quantify nitrate leaching to shallow groundwater from different management units at dairy farms. Total nitrate loads are determined by the sequential calibration of a sub-regional scale and a farm-scale three-dimensional groundwater flow and transport model using observations at different spatial scales. These observations include local measurements of groundwater heads and nitrate concentrations in an extensive monitoring well network, providing data at a scale of a few meters and measurements of discharge rates and nitrate concentrations in a tile-drain network, providing data integrated across multiple farms. The various measurement scales are different from the spatial scales of the calibration parameters, which are the recharge and nitrogen leaching rates from individual management units. The calibration procedure offers a conceptual framework for using field measurements at different spatial scales to estimate recharge N concentrations at the management unit scale. It provides a map of spatially varying dairy farming impact on groundwater nitrogen. The method is applied to a dairy farm located in a relatively vulnerable hydrogeologic region in California. Potential sources within the dairy farm are divided into three categories, representing different manure management units: animal exercise yards and feeding areas (corrals), liquid manure holding ponds, and manure irrigated forage fields. Estimated average nitrogen leaching is 872 kg/ha/year, 807 kg/ha/year and 486 kg/ha/year for corrals, ponds and fields respectively. Results are applied to evaluate the accuracy of nitrogen mass balances often used by regulatory agencies to assess groundwater impacts. Calibrated leaching rates compare favorably to field and farm scale nitrogen mass balances. These data and interpretations provide a basis for developing improved management strategies. 相似文献
30.
Adesoji O. Adelaja Robin G. Brumfield 《Journal of Agricultural and Environmental Ethics》1991,4(1):82-88
Many state governments in the United States promote locally-produced farm products. This paper discusses issues related to the ethics and equity of such promotional programs. The paper argues that generic promotion is generally easier to justify in terms of ethics and equity than brand promotion. It also argues that informative and factual brand promotions are easier to justify than deceptive and persuasive brand promotions. Additional equity issues arising when taxpayers finance state-promotional programs are also discussed. 相似文献