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71.
白洋淀分散鸭养殖产生的污染物是导致其水体污染的主要来源之一。依据“减量化、就地处置资源化、养分循环”思路,提出湖心岛分散鸭养殖污染控制模式,主要包括:鸭粪收集系统(收集网、径流和冲洗水收集沟)、鸭粪沼气发酵与利用系统、沼液湿地净化和沼渣利用系统。选择安新县安新镇王家寨村占地5 000 m2养殖1 500只鸭的湖心岛建立综合控制示范工程。2010年4~11月,示范工程在典型降雨日和非降雨日排水的COD、总氮、总磷分别为351 mg/L、74.2 mg/L、7.1 mg/L和214 mg/L、42.1 mg/L、5.3 mg/L,水质符合《畜禽养殖业污染物排放标准》(GB 18596-2001);这是由于源头收集系统收集了陆上活动区40%的鸭粪,同时末端处理系统(沉淀池+人工湿地)对养鸭废水污染物的高效削减。沼气池产生的沼气和剩余的沼液沼渣可以作为能源和肥料加以利用。本文集成湖心岛分散鸭养殖污染控制模式简便、适用,具有推广价值。 相似文献
72.
《Communications in Soil Science and Plant Analysis》2012,43(6):415-420
Abstract The usefulness of the nitrate‐specific ion electrode (NE) for the determination of nitrate nitrogen (NO3‐N) in surface and ground water was determined. The NE method had several advantages that made it superior to the phenoldisulfonic acid (PDS) method in our environmental quality studies. Samples could be analyzed quickly and with a minimum of sample preparation. Sample coloration and soluble salts did not interfere with the performance of the electrode. Range of detection without dilution was much wider than by the PDS method. Also, the values obtained by the NE method, although slightly greater than those obtained by the PDS method, were satisfactory. 相似文献
73.
《Journal of Sustainable Forestry》2013,32(2-3):165-187
Summary It is some years now since forest decline was a major public concern in Europe and was one of the principal environmental issues around which international research programs were focused. A number of internationally coordinated activities were initiated in the 1980s and 1990s and have continued until now; these contributed significantly to our current understanding of forestry and to the way in which forestry policies have developed. In short, the concept of sustainable development has had an increasing influence and is now of immeasurable value in forest policy, with sustainable forest management well established as its guiding principle. This sequence of events is examined here. The extent to which understanding has advanced is remarkable; much has changed. Arguably this period gave the first indication of the extent to which forests and ecosystems globally are threatened by environmental change. On the basis of the last 20 years, it is tempting to conclude that we now have an effective institutional framework and have made excellent progress. However, some of the recorded ecosystem responses seem anomalous; there are surprises in system responses, e.g., the linkage between sulphur and nitrogen depositions and forest growth. Even more importantly some specific pollutant problems remain and will intensify, and climate change has become an environmental issue of overwhelming importance. 相似文献
74.
在我国养猪业面临产品安全和环境污染两大瓶颈的情势下,如何使所生产的猪肉食用卫生,所排粪污环境安全,纯天然、无污染、广效低毒、绿色环保的中兽医药学为破解这两大瓶颈提供了技术支撑。充分发挥我国传统的中兽医药技术的特色和优势,构建以中兽医药为主体的猪只康养技术供给体系,旨在集生产管理"适其天性"、所喂药料"无污染"、治疗药物"纯天然"、预防措施治"未病"、治疗方法"和谐调节"和四季保健"药饲同源"于一体的技术供给体系,从源头上破解这两大难题,从而实现猪只康养,环境安全,猪肉安康,凸显出中兽医药是猪只康养的最佳供给体系。 相似文献
75.
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77.
为从“源头控制”畜禽粪便减排,提高生猪养殖效益,本试验将同日龄、初始体重相近的(P>0.05)育肥猪40头分成4个组,1个对照组(正常饲喂)和3个试验组,每组10头,试验组分限饲10%组、限饲20%组、限饲30%组。试验组限饲50 d后,解除限制饲喂30 d,在管理条件基本相同情况下发现限饲期间,试验各组猪的粪便产生量、末重和平均日增重均显著低于对照组(P<0.05);解除限饲后,与对照组相比,限饲20%组和限饲30%组猪的粪便排放量显著降低,平均日增重显著增高(P<0.05),而限饲20%组猪的试验末重略高于对照组且差异不显著,限饲30%组则显著低于对照组。结果表明限饲20%组的猪粪便排泄量减少,补偿生长方式相对效果较好。 相似文献
78.
79.
Corfield GS Read RA Eastley KA Richardson JL Robertson ID Day R 《Australian veterinary journal》2007,85(6):212-216
Hip palpation has been used to provide semiquantitative information regarding passive joint laxity and susceptibility to hip dysplasia. The purpose of this study was to: (1) evaluate the intra- and inter-examiner repeatability of the hip reduction angle measured at 4 months of age by three examiners using manual goniometry and an electromagnetic tracking system; (2) compare the hip reduction angle measured with manual goniometry to the hip reduction angle measured with the electromagnetic tracking system; and (3) evaluate the hip reduction angle, distraction index and Ortolani manoeuvre at 4 months of age as predictors of the development of hip osteoarthritis at 12 months of age in 11 Labrador Retriever dogs. Intra- and inter-examiner repeatability was demonstrated for both the manual and electromagnetic goniometric measurement of the hip reduction angle (coefficient of variation < 4.3% and < 6.1%; and P = 0.163 and P = 0.836 respectively). The hip reduction angle measured by manual goniometry was moderately correlated to the hip reduction angle measured by the electromagnetic tracking system (r = 0.603, P < 0.0000). The hip reduction angle measured by manual and electromagnetic goniometry was a poor predictor of osteoarthritis at 12 months of age (r = 0.231, P < 0.062, and r = 0.321, P < 0.01). The distraction index was moderately correlated with the development of osteoarthritis by 12 months of age (r = 0.493, P < 0.0000). The Ortolani sign was sensitive (100%) but not specific (41%) for the development of osteoarthritis at 12 months of age. The hip reduction angle did not further quantify the Ortolani manoeuvre as a predictor of osteoarthritis in Labrador Retrievers. 相似文献
80.
随着经济的快速发展,温室气体的排放量不断增加,加之人类对自然资源的利用强度逐渐增加,导致全球生态系统的固碳能力减弱,大气中的温室气体浓度达到新高,所造成的温室效应已经成为国际社会普遍关注的重大全球性问题。中国草地碳汇资源得天独厚,发展草原碳汇经济成为履行国际承诺、打造碳汇新经济、建设美丽中国的重要载体。综述中国草地固碳减排现状及其影响因素,包括草地碳汇和家畜生产减排研究、气候变化背景下的草地碳汇、人工草地建设等方面,并提出中国草地固碳减排发展建议,以期为中国实现碳达峰、碳中和及草地固碳减排的贡献提供理论基础,为推动我国社会高质量发展、创造高品质生活提供坚实的技术支撑。 相似文献