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62.
城市污水除磷技术发展   总被引:8,自引:4,他引:8  
侯红娟  周琪 《四川环境》2004,23(6):41-44,49
磷是水体富营养化的一个主要限制因素,控制出水中磷的浓度尤其重要。污水除磷方法有生物除磷、化学除磷及生态除磷,也可将各种方法组合使用,如生物一化学除磷、生物一生态除磷等,实际应用中应根据具体情况选择适宜的除磷方法。  相似文献   
63.
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   
64.
基于速度的交通事故分析   总被引:10,自引:8,他引:10  
速度对交通事故的发生以及严重程度有着直接影响,是道路交通事故的重要诱因之一。为了准确地反映速度与事故之间的关系,减轻由于速度因素所造成的交通事故的损失,笔者对国内外速度与交通安全的情况进行分析;研究了平均速度与事故危险性、速度离散度与事故率以及速度与事故严重性的关系;提出了加强速度管理,控制交通流平均速度和减小相邻路段的速度差值的对策。基于速度的交通事故分析,建议采用85%位车速作为控制速度的上限值;提出限速措施,以达到减少交通事故及其损失的目的。  相似文献   
65.
工业兴市是一个区域经济发展的必然选择,而建设一个绿色生态化工城又是葫芦岛市发展的必由之路.以人为本、科技领先、加强环境保护、推进循环经济发展,以提高城市品位,力争全面达到创建"国家环保模范城"标准,营造一个最适宜人类居住的绿色生态城市.  相似文献   
66.
采用化学法自动控制处理含铬和含镍电镀废水,选择合适的化学药剂和pH、ORP控制参数,连续式处理电镀废水.运行结果表明:该工艺简单、处理效果良好、运行稳定、可操作性好、运行成本适中、能很好的适应水质的波动,处理后的水质完全符合排放标准.  相似文献   
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为分析“十三五”期间(2016—2020年)我国化工和危险化学品事故发生情况,统计“十三五”期间化工和危险化学品事故数量及死亡人数,从发生月份、发生区域、行业分布等方面分析事故特征,从事故类别、事故环节、关键作业等方面分析事故原因,总结2011—2020年我国化工和危险化学品事故发展趋势,按照全国4大经济区域研究2013—2020年事故特征。结果表明:“十三五”期间我国化工和危险化学品事故数量呈下降趋势,死亡人数出现波动,总体形势较为平稳。2011—2020年化工和危险化学品事故风险向中西部转移趋势明显,东北、西部地区事故死亡率普遍高于东部地区。研究结果可为相关行业从业者及监管部门提供决策参考。  相似文献   
69.
Petroleum lubricating oils, used throughout the economy, are distinct among petroleum products in their capacity to be recovered and recycled at the end of their useful life. Used lubricating oil is regulated at the state and federal level because of concerns about environmental impacts arising from improper disposal, although rates of recovery are not known. We present a material flow analysis of lubricants through California's economy in the years 2007–2012. We introduce a novel technique for computing aggregate waste generation from a collection of hazardous waste manifest records, and apply it in order to determine a recovery rate for used oil and to estimate the quantity of oil managed informally in the state. The records also offer a detailed view of the fate of used oils after they are recovered. We find that around 62% of lubricants are recoverable at end of life, of which 70–80% is being recovered. This rate shows a slight downward trend. If the trend is accurate, measures should be taken to improve the performance of the used oil management system. Policy opportunities exist to reduce the quantity of oil managed informally through improving access to responsible used oil management methods. These include increasing the collection of used oil from industrial sources as well as “do it yourself” oil changes, expanding in-state reprocessing capacity, and promoting increased out-of-state reprocessing of used oil. Our methods introduce new possibilities to make use of direct observation in material flow analysis, potentially improving data availability and quality and increasing the relevance of material flow methods in policy applications.  相似文献   
70.
The inherent risks associated with accidental releases of hazardous materials during transport have drawn attention and concerns in the recent decades. The aim of this study is to propose a tool for evaluation and comparison of the transportation networks which can be used to assess the routing options between origins and destinations of the cargos for their suitability for transporting hazardous material cargos by tanker trucks and to identify routes which provide lower accidental release risks, lower public exposure risks, and offer economical benefits. Each route segment of transportation networks were evaluated using specific criteria which included health risk and cost of delay in case of an accidental release of materials, trucking cost and proximity to vulnerable areas. Since, the health impact of hazardous materials differ depending on the characteristics of the material being transported as well as release quantities and atmospheric conditions; this paper aimed in providing a tool that can be used to estimate the impact radius (for health risks) after accidental release of hazardous materials by taking into account different atmospheric conditions based on the meteorological data and solar elevation angle. The Gaussian air dispersion model paired with ArcGIS using Python programming were employed to estimate the health risk impact zones by considering the meteorological data, and accordingly to analyze road segments for cost impacts (delay and trucking costs), and the proximity to vulnerable areas. The route assessment tool was demonstrated with a case study. The results of this study can efficiently aid decision makers for transportation of hazardous materials.  相似文献   
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