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181.
将石灰混凝处理后的沉淀泥渣进行回流,对石灰混凝法进行改进,研究改进后的石灰混凝法对城市污水二级出水中有机物的去除效果。结果表明,活性泥渣回流有利于提高石灰混凝法对城市污水二级出水中有机物的去除。回流位置在石灰投加前、复合絮凝剂投加后,最佳回流量为新泥渣产生量的100%~200%,活性泥渣回流的最佳pH为11.0~11.5;活性泥渣中CaCO3、Mg(OH)2、Fe(OH)3等沉淀物以及有机高分子絮体均有助于提高其对有机物的去除效果,其中Mg(OH)2沉淀物起主导作用;含循环泥渣的活性污泥回流,对有机物的去除效果无明显影响。 相似文献
182.
The Ethical Contract as a Tool in Organic Animal Husbandry 总被引:1,自引:3,他引:1
Vonne Lund Raymond Anthony Helena Röcklinsberg 《Journal of Agricultural and Environmental Ethics》2004,17(1):23-49
This article explores what an ethicfor organic animal husbandry might look like,departing from the assumption that organicfarming is substantially based in ecocentricethics. We argue that farm animals arenecessary functional partners in sustainableagroecosystems. This opens up additional waysto argue for their moral standing. We suggestan ethical contract to be used as acomplementary to the ecocentric framework. Weexpound the content of the contract and end bysuggesting how to apply this contract inpractice. The contract enjoins us to share thewealth created in the agroecosystem (by ourjoint contributions) by enjoining us to carefor the welfare and needs of the individualanimal, and to protect them from exploitation(just as human co-workers should not beexploited). The contract makes promoting goodanimal welfare a necessary condition forbenefiting farm animals. Animals for their partare guaranteed coverage under the contract solong as they continue to contribute to thesystem with products and services. 相似文献
183.
Hao-Jan Hsing Fang-Kuo Wang Pen-Chi Chiang Wan-Fa Yang 《Resources, Conservation and Recycling》2004,40(4):42
More than 50,000 tons of hazardous waste are imported and exported worldwide each year. Over 50% of hazardous waste is exported to Southeast Asia, of which leather waste is the major component. The exportation quantities of hazardous waste to Organization of Economic Cooperation and Development (OECD) countries are decreasing while they are on the increase to non-OECD countries. Some of these wastes are intended for recycling purposes but the usage of some others is not stipulated. The hazardous waste importation quantity kept fairly steady from 1997 to 2000, of which ash or residues containing copper or copper compounds were the major component. Under existing regulations and measures, the transboundary movement of hazardous waste cannot be effectively controlled and monitored. In order to ensure environmentally sound hazardous waste management, EPA-Taiwan revised the Waste Disposal Act in 2001 and cooperated with the Industrial Development Bureau (IDB) to promote industrial waste reduction and recycling projects. Strategies were proposed based on evaluation according to the 3Es Principles and the site investigation in this study. 相似文献
184.
Mario Tiscareo‐Lpez Miguel Velsquez‐Valle Jaime Salinas‐Garcia Alma Delia Bez‐Gonzlez 《Journal of the American Water Resources Association》2004,40(2):401-408
ABSTRACT: Intensive cropping systems based on mechanical movement of soil have induced land degradation in most agricultural areas due to soil erosion and soil fertility losses. Thus, farmers have been increasing fertilization rates to maintain an economically competitive crop yield. This practice has resulted in water quality degradation and lake eutrophication in many agricultural watersheds. Research was conducted in the Patzcuaro watershed in central Mexico to develop appropriate technology that prevents nonpoint source pollution from fertilizers. Organic matter (OM) and nitrogen (N) losses in runoff and nitrate (NO3‐N) percolation in Andisols with corn under conventional till (CT) and no‐till (NT) treatments using variable percentages of crop residue as soil cover were investigated for steep‐slope agriculture. USLE type runoff plots were used to collect water runoff, while suction tubes with porous caps at 30, 60, and 90 cm depth were used to sample soil water solutes for NO3‐N analyses. Results indicated a significant reduction of N and OM losses in runoff as residue cover increased in the NT treatments. Inorganic N in runoff was 25 kg/ha for NT without residue cover (NT‐0) and 6 kg/ha for the NT with 100 percent residue cover (NT‐100). Organic matter losses in runoff were 157 and 24 kg/ha for the NT‐0 and NT‐100 treatments, respectively. Nitrate‐N percolation was evident in CT and NT with 100 percent residue cover (NT‐100). However, NT‐100 had higher NO3‐N concentration at the root zone, suggesting the possibility of reducing fertilization rates with the use of NT treatments. 相似文献
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187.
气浮+生物接触氧化工艺处理食品加工废水 总被引:2,自引:0,他引:2
通过气浮 生物接触氧化工艺处理速冻食品加工废水的实验、设计和工程运行,结果表明:废水COD去除率能达到97%以上,使得最终出水的COD<100mg/l.该工艺对冲击负荷有较强的适应性. 相似文献
188.
论述了生物有机肥在发展农业生产中的重要地位,以及生产中存在着的大量使用集约化畜禽养殖场的畜禽粪对土壤、水体等环境质量和农产品质量安全产生严重影响的问题,提出以茶粕作为原料生产有机肥具有生产过程相对安全、克服有机肥二次污染的优点.此外,茶叶次生代谢物茶多酚、茶色素、茶皂素和茶皂甙等具有抗氧化、清除自由基、络合金属离子、调节植物生长和生物防虫、灭虫等独特生理功效,将极大地提高茶粕有机肥的生物有效性,显示出其广阔的应用前景. 相似文献
189.
厌氧-好氧一体化反应器处理高浓度有机废水的运行特性研究 总被引:4,自引:0,他引:4
本实验采用新型厌氧—好氧一体化反应器处理高浓度有机废水,主要研究了系统的启动与运行性能,并对系统的NH3 N去除效果作了初步考察。实验结果表明:在16℃~24℃的自然温度下,采用递增负荷、厌氧和好氧分期启动的方式,系统可在38天内达到较好的启动效果;在系统负荷运行期内,当系统总进水COD浓度平均值为3601 8mg/L,总出水COD浓度平均值为384 0mg/L,系统容积负荷平均值为2 54kgCOD/(m3·d),系统总HRT平均值为35 1h时,系统总COD去除率平均值达90 6%。实验还发现:当进水NH3 N浓度为280 3~350 7mg/L,整个系统的NH3 N去除率在68 5%~91 7%,平均为81 0%。由此说明,本反应器具有很好的COD去除性能和NH3 N去除效果,适合于处理COD浓度高且含有中等NH3 N浓度的有机废水。 相似文献
190.
从地域优势、农产品特征、生态条件等方面,论述了新疆发展有机食品生产的适宜性和重要意义.认为新疆发展有机食品生产可以利用得天独厚的气候、水土等自然资源,以及工业污染环境影响较小的有利条件,保护和改善农村生态环境,充分发挥独特的农产品资源优势,提高农产品附加值,变资源优势为经济优势,并结合新疆区情,从多方面提出了新疆发展有机食品的思路和措施. 相似文献