Graphical strategies for design of evaporation crystallization networks for environmental wastewater applications

This paper introduces graphical strategies for the design of an evaporation/crystallization network for ternary wastewater environmental applications. Sources, sinks and other streams are located on a ternary composition diagram. While a source is any wastewater stream that has the potential to be recycled, a sink is any unit in the process that can accept sources. The proposed methodology is extremely simple to understand and implement, as it only requires basic solid-liquid phase equilibria data and uses lever arm principles to generate alternative process designs. Geometric constructions are carried out on the ternary composition diagram and the respective lever arms are used to determine intermediate flow rates in the evaporation/crystallization network. The relative locations and flow rates of the sources and sinks under consideration, as well as the unique shape of the solid-liquid equilibrium, drive the design of the separation (via evaporation/crystallization) network. Some generic structures are proposed for a typical evaporation and crystallization network. Once the general problem statement has been defined, special cases consisting of a single source-single sink, single source-two sinks and two sources-single sink are described. These special cases are representative of commonly occurring industrial wastewater design problems. Several graphical insights are listed that allow one to represent evaporation and crystallization operations on a ternary triangular composition diagram and avoid mathematical complexity. The possibility of bypassing a part of the initial feed streams is also considered. Certain feasible composition regions are identified on the ternary composition diagram for cases dealing with multiple sources and sinks. The methodology is useful in pre-screening and eliminating certain sources/sinks and is readily applicable to cases with lower number of sources and sinks. A case study involving the ammonium nitrate manufacturing process is included to demonstrate the broad applicability and value of the proposed approach.     

广东省海堤规划工程环境影响分析及对策

对海堤工程所产生的环境影响进行分析 ,并提出减轻不利影响的对策措施 ,以保证工程充分发挥其效益。     

Service transformation—managing a shift from business travel to virtual meetings

It has been shown that the potential for environmental, and financial improvements through the increased substitution of in-person meetings by virtual communication is considerable. However, it has also been shown that this potential is not automatically realized by investing in the technology that can enable virtual meetings. This paper describes two case studies that explored the factors that influenced communication and meeting behavior. A number of drivers and barriers for virtual meetings are identified, and, in addition, measures are proposed to improve the utilization of virtual tools for business communication.     

中国公路建设项目环境保护管理综述

综述了中国公路建没项目环境保护管理的有关规定，包括环境保护管理的内容与程序、分类管理、环境影响评价市批与环境影响咨洵收费管理等。     

可持续发展与战略环境评价

可持续发展的实施需要具体的手段和方法。在对可持续发展和战略环境评价（SEA）的概念、内涵和特征进行概略分析的基础上,通过分析两者之间的内在联系,着重考察以SEA实施可持续发展的理论依据和方法。结果表明：SEA能为实施可持续发展提供整体性方法,全面考虑战略替代方案,系统分析累积环境影响,建立环境监控计划及运用适应性环境管理方法,扩展决策过程中的公众参与。认为SEA是实施可持续发展的一种重要工具。为了贯彻实施我国的可持续发展战略,应在我国进一步开展SEA的理论和实践研究。     

购买审计与生态导向型消费探析

生态导向型消费需要政府采取一些措施来鼓励或强迫消费者在产品消费中符合环保要求。购买审计便是对消费者市场施加影响的手段之一，是内部审计的重要组成部分，它包括评估所有与购买商品和服务相关的组织政策和行为对环境的影响。探讨了地方政府购买行为对环境的影响和如何减少这些影响的方法，以及购买审计对生态导向型消费的影响。包括：购买审计的方法、生态型购买政策的成功实施、购买审计对生态型消费的影响。     

环境意识深化与环境责任原则

环境责任原则的变化反映环境意识的发展。环境责任原则是环境意识深化的外在表现，而环境意识的深化使环境责任原则的含义不断扩展与延伸。分析我国环境责任原则的发展历程，比较我国环境责任原则与国际通行环境责任原则的异同。阐述环境意识发展的一般历程。     

环境思想史和环境科学历史发展

人类主体与环境客体的相分导致明确环境概念的产生。人类产生过“环境决定论”、“环境可能论”和“人类中心论”等环境思想。对日趋严重的环境问题的认识中产生“环境报复论”和“环境和谐论”等思想,推动了环境科学的诞生和发展。环境科学发展了“环境质量学说”,正将注意力转向社会与环境协调发展上。环境科学仍处于发展与完善之中。     

高频电磁辐射防护材料的研究

电磁污染已经成为一种不容忽视的全球性社会公害。因此，本文通过测量多种材料在不同高频电磁场源（即高频设备）和不同距离时对高频电磁场的屏蔽效率，获得了大量数据，并对所测数据用最小二乘法进行拟合处理，绘出了这些材料在不同高频场源下的屏蔽效果曲线。经分析，筛选出经济实用的高频近区场个人防护材料，具有推广应用的价值。     

未确知测度模型及在环境质量评价中的应用

对未确知测度综合评价模型作一简要介绍，并将该模型应用于环境质量评价，提出了确定污染指标权重的新方法。通过6个湖库水体高营养化程度综合评价实例比较，结果表明，其评价结果与调查实况相符，可应用于其他环境质量评价领域。