首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   35篇
  免费   0篇
  国内免费   4篇
废物处理   5篇
环保管理   2篇
综合类   14篇
基础理论   2篇
污染及防治   10篇
评价与监测   2篇
社会与环境   4篇
  2020年   1篇
  2019年   1篇
  2018年   1篇
  2016年   1篇
  2015年   3篇
  2014年   3篇
  2013年   9篇
  2012年   4篇
  2011年   1篇
  2010年   1篇
  2009年   4篇
  2008年   1篇
  2007年   3篇
  2006年   1篇
  2005年   1篇
  2002年   2篇
  1993年   1篇
  1992年   1篇
排序方式: 共有39条查询结果,搜索用时 15 毫秒
21.
Organic poultry is an alternative to conventional poultry which is rapidly developing as a response to customers' demand for better food and a cleaner environment. Although organic poultry manure can partially be utilized by organic horticultural producers, litter accumulation as well as excessive nitrogen still remains a challenge to maintain environment pureness, animal, and human health. Compared to conventional poultry, diet formulation without nitrogen overloading in organic poultry is even more complicated due to specific standards and regulations which limit the application of some supplements and imposes specific criteria to the ingredients in use. This is especially valid for methionine provision which supplementation as a crystalline form is only temporarily allowed. This review is focused on the utilization of various protein sources in the preparation of a diet composed of 100% organic ingredients which meet the avian physiology need for methionine, while avoiding protein overload. The potential to use unconventional protein sources such as invertebrates and microbial proteins to achieve optimal amino acid provision is also discussed.  相似文献   
22.
畜禽养殖污水生态处理及资源化利用方式的探讨   总被引:7,自引:2,他引:5  
论述了畜禽养殖场污水的排放特征,并提出污水治理对策。同时阐述了不同类型人工湿地系统用于污水生态处理的优势,并对人工湿地应用畜禽养殖污水资源化的可行性进行分析介绍。  相似文献   
23.
人工湿地系统处理鸡粪污水的技术经济可行性   总被引:5,自引:0,他引:5  
介绍了人工湿地系统的组合方式和工艺流程,污染物去除率的测定,生化反应动力学参数,投资和运行费用的分析等内容。经该系统处理后,污染物总的去除率,COD_(cr)为93.0%—98.2%,BOD_5为93.5%—99.6%,NH_3—N约为94%。其中,厌氧沟的设置,是系统的独创之处,经运行结果证明,它在整个系统中对有机污染物的去除起很大作用。  相似文献   
24.
This study was carried out to assess the material and energy recovery by organic solid wastes generated from a poultry slaughterhouse. In a poultry slaughterhouse involving the slaughtering of 100,000 heads per day, poultry manure & feather from the mooring stage, blood from the bleeding stage, intestine residue from the evisceration stage, and sludge cake from the wastewater treatment plant were discharged at a unit of 0.24, 4.6, 22.8, and 2.2 Mg day?1, consecutively. The amount of nitrogen obtained from the poultry slaughterhouse was 22.36 kg 1000 head?1, phosphate and potash were 0.194 kg 1000 head?1 and 0.459 kg 1000 head?1, respectively. As regards nitrogen recovery, the bleeding and evisceration stages accounted for 28.0% and 65.8% of the total amount of recovered nitrogen. Energy recovered from the poultry slaughterhouse was 35.4 N m3 1000 head?1 as CH4. Moreover, evisceration and wastewater treatment stage occupied 88.1% and 7.2% of the total recovered CH4 amount, respectively.  相似文献   
25.
Poultry litter is known to be an excellent organic fertilizer, but the common practice of spreading litter on the surface of pastures has raised serious water-quality concerns and may limit potential benefits of litter applications. Because surface-applied litter is completely exposed to the atmosphere, runoff can transport nutrients into nearby streams and lakes, and much of the ammonium nitrogen volatilizes before it can enter the soil. Our previous research showed that a manual knifing technique to apply dry litter under a perennial pasture surface effectively prevented about 90% of nutrient loss with runoff from surface-applied litter, and tended to increase forage yield. However, this technique (known as subsurface banding) cannot become a practical management option for producers until it is mechanized. To begin that process, we tested an experimental single-shank, tractor-drawn implement designed to apply poultry litter in subsurface bands. Our objective was to compare this mechanized subsurface-banding method against conventional surface application to determine effects on nutrient loss with runoff from a perennial grassland treated with dry poultry litter. Early in the growing season, broiler litter was applied (6.7 dry-weight Mg ha−1) to each plot (except three control plots) using one of two application methods: surface broadcast manually or subsurface banded using the tractor-drawn implement. Simulated rainfall (5 cm h−1) generated 20 min of runoff from each plot for volume and analytical measurements. Results showed that subsurface-banded litter increased forage yield while decreasing nutrient (e.g. N and P) loss in runoff by at least 90% compared to surface-broadcast litter.  相似文献   
26.
赵薇 《环境保护科学》2007,33(6):89-90,93
目前沈阳市畜禽养殖污染严重,COD年排放量已达88万t,畜牧业发展过程中的排放物已成为不可忽视的污染源。因此,解决畜牧业环境污染问题已成为沈阳市现阶段环境保护和可持续发展的紧迫任务和重要内容。  相似文献   
27.
Databases have been compiled to derive parameter values relevant to the transfer of radionuclides from feedstuffs to domestic animal products to provide a revision to the IAEA Handbook on transfer parameters TRS 364. Significant new data inputs have been incorporated into the databases from an extensive review of Russian language information and inclusion of data published since the early 1990s. Fractional gastrointestinal absorption in adult ruminants presented in the revised handbook are generally similar to those recommended for adult humans by the ICRP. Transfer coefficient values are presented in the handbook for a range of radionuclides to farm animal products. For most animal products, transfer coefficient values for elements additional to those in TRS 364 are provided although many data gaps remain. Transfer coefficients generally vary between species with larger species having lower values than smaller species. It has been suggested that the difference is partly due to the inclusion of dietary dry matter intake in the estimation of transfer coefficient and that whilst dietary intake increases with size nutrient concentrations do not. An alternative approach to quantifying transfer by using concentration ratios (CR), which do not consider dietary intake, has been evaluated. CR values compiled for the handbook vary considerably less between species than transfer coefficient values. The advantage of the CR approach is that values derived for one species could be applied to species for which there are no data. However, transfer coefficients will continue to be used as few studies currently report CR values or give data from which they can be estimated.  相似文献   
28.
Recent reviews have established benchmark values for transfer factors that describe radionuclide transfer from plants to animal food product such as milk, eggs and meat. They also illustrate the paucity of data for some elements and some food products. The present study quantified transfer data using indigenous elements measured in dairy, poultry and other livestock farms in Canada. Up to 62 elements are reported, with particular emphasis on iodine (I) because of the need to accurately assess the behaviour of 129I from disposal of nuclear fuel waste. There was remarkable agreement with the literature values, and for many elements the present study involved many more observations than were previously available. Perhaps the most important observation was that product/substrate concentration ratios (CR) were quite consistent across species, whereas the traditional fractional transfer factors (TF, units of d kg−1 or d L−1) necessarily vary with body mass (feed intake). This suggests that for long-term assessments, it may be advisable to change the models to use CR rather than TF.  相似文献   
29.
Abstract

The objective of the present study was to examine the combined effects of zinc compounds with different acidic pH levels on the aerobic growth of a S. typhimurium poultry isolate in either rich or minimal media. When overall main effects of pH levels of medium or concentrations of Zn compounds were compared, growth rates of the S. typhimurium poultry isolate were significantly ( p < 0.05) decreased by stepwise increase of pH levels of medium (pH 4, 5, 6, and 7) or concentrations (0.67, 3.35, and 6.03%) of Zn compounds (Zn acetate and Zn sulfate). In general growth rates of S. typhimurium poultry isolate appeared to be more reduced by Zn acetate than by Zn sulfate and more reduced in minimal media compared to rich media.  相似文献   
30.
Abstract

Salmonella and Campylobacter are significant issues for poultry processors because of increasing regulatory standards as well as public health concerns. The goal of this study is to report the effects of two different pre-chiller systems that utilize different temperatures and water recirculation systems on whole bird carcass rinsates. Both pre-chiller tanks were contained within a single poultry processing facility and operated at different temperatures and water systems. The incidence of Campylobacter spp. and Salmonella spp., as well as the aerobic plate counts on whole bird carcass rinses are reported in this study from each pre-chiller system. The results from this study reveal that there are significant differences in how microbial populations and pathogens change over time in each pre-chiller system. Furthermore, we identify that these patterns are different per system. Such data are impactful as it indicates that measuring carcasses within a plant must consider both temperature and water recirculation as it may prevent comparability of different lines within a single processing facility.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号