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151.
152.
以近期中国荷斯坦奶牛产污系数试验资料为基础,分析饲料摄入量及成分与排出粪污污染物之间的关系,建立了奶牛产污系数模型并进行了验证.结果表明:育成牛排粪量可用采食量、摄入氮、摄入磷和摄入铜4因子预测,其模型拟合度高于产奶牛;育成牛排氮量可用采食量、摄入氮两因子预测,产奶牛的排氮量可用摄入氮预测;产奶牛和育成牛的排磷量均可用摄入磷预测.该模型由于包括了不同季节、不同样本、不同奶牛养殖场等影响因素,使结果具有广泛的适用性,可用于分析中国荷斯坦奶牛养殖对环境的污染及粪污农田的消纳利用. 相似文献
153.
Using Demographic Invariants to Detect Overharvested Bird Populations from Incomplete Data 总被引:1,自引:0,他引:1
Abstract: Conservation biology must be able to provide guidelines even when available data are incomplete, because data on rare and endangered species are usually limited. For instance, data on the effect of additional—human-induced—sources of mortality on vertebrate populations, such as bycatch of seabirds by longline fisheries, are typically incomplete. The importance of an additional source of mortality can be evaluated by comparing it with the maximum annual growth rate of the species of concern, and various authors have attempted to determine the maximum growth rate from incomplete data. We developed a procedure we call the "demographic invariant method" (DIM). First we determined that the maximum growth rate per generation does not vary, by recalling that it is a dimensionless number primarily independent of body weight and also by empirically establishing its near constancy over a restricted set of bird species for which reliable demographic information was available. This first step provided an implicit function linking generation time and maximum annual growth rate, from which we obtained the maximum annual growth rate as a simple function of generation time. From several different ways of obtaining estimates of generation time, we derived in turn several ways to estimate the maximum annual growth rate of a bird species from incomplete demographic data set. We applied our approach to the Black-footed Albatross (Phoebastria nigripes) and determined from incomplete data that longline fishery bycatch has a biologically significant impact on the growth potential of Black-footed Albatross populations. Our method can be applied broadly to the conservation and management of harvested bird populations. 相似文献
154.
模拟生物反应器加速产甲烷过程研究 总被引:1,自引:0,他引:1
渗滤液原液回灌易导致填埋垃圾产甲烷过程的滞后,从而对甲烷收集利用产生不利影响。通过3根实验室模拟生物反应器,研究了原液回灌(C1)、渗滤液好氧预处理后回灌(C2)和原液回灌+垃圾层上部通风曝气(C3)3种填埋方式下的填埋气产气规律。结果表明,C1甲烷浓度经历短暂上升,达到19.5%后开始逐渐降低,产甲烷速率和产甲烷总量均很低;C2甲烷浓度逐渐上升,在第121天时甲烷浓度达到50%,产甲烷最高速率和产甲烷总量分别为0.31 L/(kg·d)和25.2 L/kg。在停止上部垃圾层通风曝气后,C3甲烷浓度迅速上升,在81 d时甲烷浓度便达到50%以上,最大产甲烷速率和产甲烷总量分别为0.22 L/(kg·d)和16.0 L/kg。对各模拟柱填埋气可回收性评价结果表明,C3填埋气可回收利用比例最高,C2略低,C1在实验期间内则无可回收利用气体产生。 相似文献
155.
156.
我国工业危险废物产生特性研究 总被引:1,自引:1,他引:1
工业生产是危险废物的主要来源,工业危险废物是世界各国固体废物管理的重要方面.以我国历年环境统计数据为基础,全面分析了我国工业危险废物产生现状和特点.研究了工业危险废物产生量、利用量和处置量、工业危险废物区域和行业分布特点、工业危险废物与工业固体废物的关系、工业危险废物产生量与工业产值的关系及工业危险废物产生的变化趋势等.提出今后我国既要重视对传统的石油化工、化学工业和冶金工业等行业产生的危险废物管理,又要重视对高新技术产业和西部资源省份产生工业危险废物的管理. 相似文献
157.
江苏省光伏电池行业的飞速发展带来了环境污染问题,特别是产排污泥等固体废物。目前缺乏关于光伏电池行业污泥的危险废物处理鉴定的管理标准、技术政策等,相关研究更是匮乏。经过调研考察,选取江苏省5家光伏电池企业作为代表进行分析计算,调查其产品类型及工艺流程,计算其产量和废水量、污泥产量,含氟污泥的氟化物浓度和重金属浸出浓度等。以一家企业为例,对产生氟化物的各生产环节进行定量计算。结果表明:光电伏电池企业污泥排污系数分布在1.2~6.4 t/MW,氟化物排污系数为1.28~2.05 mg/MW;污泥的产量不仅与废水量有关,还与废水的来源、处理工艺、污泥的含水率等有关;典型企业的氟化物产生量即产污系数为2.859 t/MW;污泥重金属浸出浓度较低。 相似文献
158.
Traditionally solid waste management has evolved as mainly the removal of municipal wastes by hauling them out of the city boundaries and dumping them ‘there’. This is in conformity with the ‘out of sight out of mind’ philosophy. However, with the ever increasing tonnage of refuse due to the expansion of urban centers, which implies increased collection, transportation and disposal costs, recycling is currently accepted as a sustainable approach to solid waste management. This paper reports on the findings of a study, conducted in the city of Dar es Salaam between the years 1993 and 1995, on the scavenging activities and recycling trends of some selected items in Dar es Salaam. Apart from the discussions on existing solid waste generation rates (2000 tonnes/day), composition (60% being organic/or vegetable matter) and their management in Dar es Salaam, the paper also presents data obtained through a survey of Vingunguti dump site and other waste collection centers. It was established that there are currently about 600 solid waste scavengers in Dar es Salaam, approximately 109 of whom operate at Vingunguti dump site and others at 14 different collection centers. Many of them opted for scavenging due to unemployment. The study findings indicate that their average monthly income exceeded the official minimum wage (at the time of study) enabling them to support their families. This demonstrates the potential of recycling to generate gainful employment with implied lower crime rates among the unemployed. Recycling activities in the city were observed to be not only a critical source of raw materials for small-scale industries, in the absence of which they would cease to operate, but also a widely accepted environmentally friendly technology for solid waste management. Out of 294 tonnes of studied waste materials (paper, metal, plastic, glass and textiles) only 4 tonnes are recovered and recycled. The remaining 290 tonnes/day of recyclable material are left to pollute the environment or are collected and transported for final disposal and, therefore, unnecessarily contribute to the shortening of the life span of the dump site. Finally, the paper gives some recommendations for improved recycling activity so as to make it an important means of reducing the overall volume of waste materials to be transported and deposited in the dump site and at the same time provide a potential opportunity for employment for unskilled workers. 相似文献
159.
160.
Arthur R. Giaquinta Thomas E. Croley II 《Journal of the American Water Resources Association》1981,17(3):423-429
Power plant water consumption (evaporative water loss) for various river temperature standards is presented for existing and proposed power plants located along the Missouri and Upper Mississippi Rivers in the MAPP geographical area. Thermodynamic and economic models are combined to evaluate the cooling related water consumption at various river thermal standards. The existing thermal standards and a number of other hypothetical thermal regulations including the extreme cases of no thermal standards and no allowable heated discharges are examined to show the dependence on thermal standards of power production related water consumption. A critical appraisal of the cost of thermal standards in terms of water consumption is thereby possible so that subjective assessments of the standards can proceed with full knowledge of the tradeoffs involved between the “water costs” of power production and environmental enhancement. 相似文献