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.     

水土保持工作中存在的问题及对策

我国一直以来就是一个水土流失大国,治水保土工作一直备受重视。当前在我国经济快速发展,环境问题日益突出的情况下,合理开发和保护水资源,充分做好水土保持工作已经是各级政府部门和社会各界面临的一个重要课题。     

水土流失的危害及水土保持的作用研究

土石山区是我国西南地区常见的地理形态,但是由于其独特的地理构造特点等多种因素的影响经常会出现水土流失,给本地区的生态环境造成严重危害,也严重的影响到本地区的经济发展和社会进步。本文着重阐述了我国西南地区土石山区的水土流失造成的危害,产生危害的原因以及水土保持的重要作用和意义。     

金陵石化炼油厂第二污水处理场改造工程介绍

金陵石化炼油厂第二污水处理场改造工程中对原有处理设施进行了工艺调整和优化，采用了均质，二级好氧生物处理及后浮选工艺，工程运行结果表明所采用的技术、设备是合理有效的。     

Optimal design for water conservation and energy savings using green roofs in a green building under mixed uncertainties

Most water conservation and energy saving strategies for residential homes and commercial buildings have higher initial capital investment than traditional ones. Yet, the added benefits of these “green” building strategies should outweigh the increase of initial capital cost at the end of the house lifetime. Using green roof systems to cool houses gives rise to uncertainties from local precipitation patterns and the unstable market related costs and benefits. The optimal area of green roof to balance cost, benefit, and risk remains unknown. To achieve such a complex systems analysis, a grey stochastic programming model was prepared to address the optimal design strategies under mixed uncertainties. Such a cost-benefit-risk trade-off model was formulated for this study through an optimization framework to retrieve the optimal design strategies with respect to a typical Florida residential home (shingle and metal roofs). It is particularly designed to synergistically integrate a green roof with beneficial reuse of gray water and stormwater while achieving some degree of energy savings. The study identifies the optimal green roof area that keeps within the cost of a conventional home over a specific life time, such as 50 years. Research findings show that as the reliability level associated with the chance constraint was decreased, the upper bound of the green roof area did not vary much for either shingle or metal roofs. The lower bound was found to decrease in the same situation, however, due to the higher minimum cost of the cistern in relation to the greater volume of expected rainfall, forcing the required green roof area to decrease.     

大青山中高山地带阴坡水土保持效益的研究

本文对大青山高土地带阴坡三种不同水土保持林与农地，撩荒地比较，将枯落物持水性、土壤含水量及土壤性质、分散度、导水率进行了分析，阐明了大青山中高山地带阴坡三种不同林分有极强的哟水性、可拦蓄大量的径流；林地土壤含水量高、结构良好、渗透降水能力强，土本难以破坏。可有交地防治山地水土流失的发生。     

浅谈我国及内蒙古自治区城市水环境污染对策现状和水资源保护利用

本文在阐述我国及内蒙古自治区的城市水环境污染现状的基础上， 分析了存在的原因， 并提出了相关的水环境污染防治、水资源保护利用对策。     

Pre-listing conservation of candidate species under the endangered species act: An evaluation of prevalence,accessibility, and market-based conservation efforts

In 2011, a legal settlement required the U.S. Fish and Wildlife Service (USFWS) to develop a series of work plans to assess a backlog of candidate species for protection under the U.S. Endangered Species Act. Using the resulting USFWS Fiscal Year 2013–2018 work plan, which included 261 candidate species, we identified and analyzed pre-listing candidate conservation plans (PLCP) to determine their characteristics and evaluate the use of market-based mechanisms. Among the 34 PLCPs identified, we found that species-based conservation plans were more common than habitat-based plans, and market-based conservation approaches were infrequently implemented. Inconsistencies in plan documentation were present throughout the USFWS’s online portal, and not all documentation was publicly accessible. Lastly, we found that many states had implemented their own endangered species programs or initiated conservation plans through a state agency. Our work informs the recently-adopted USFWS pre-listing conservation policy and highlights needed improvements in tracking large numbers of at-risk species as they become the subject of regulations. Increased transparency and consistency in conservation plan databases, coupled with increased accessibility, will improve future at-risk species planning.     

华阳锅炉节能减排机理及效益分析

扎兰屯市华阳锅炉研究所发明研创的“环保型节能常压水锅炉”主要涉及热交换装置,其特征在于该锅炉为二次加氧燃烧消烟器,三次加氧燃烧消烟器,这种锅炉通过多次燃烧消烟,二次受热,提高热效率,比常规锅炉节能40％,二氧化硫的排放量减少30％,生态效益,社会效益显著,目前该产品获得中华人民共和国知识产权局发明专利。     

中国节能减排的压力与对策

本文分析了我国节能减排的困境与压力,研究提出了推动中国制造到中国设计的转变,实施名牌战略,开征碳转移税,完善指标体系,端正政绩观,全民总动员等节能减排措施。     

A process integration approach to industrial water conservation: a case study for an Indian starch industry

A case study for water using network of a Starch industry in the state of Gujarat, India, is undertaken with an aim to reduce demineralised water and freshwater flow rates and consequently the wastewater flow rate. The problem was identified as a multi contaminant, reuse and recycle problem. The freshwater consumption and demineralised water consumption were 100 t/h and 51 t/h respectively before modification and the network was dealing with three major contaminants such as total organic content, total dissolved solids and total suspended solids. A program was developed in MATLAB for analysis using Water Pinch. The improved water using network designed for the present work consumed less demineralised and freshwater. The reductions are of the tune of 28% and 64.38% for demineralised and fresh water respectively. Due to alteration in piping, there will be a saving of 406 026 INR per year, which will be utilized for development of efficient environment policy for the company. The entire concept had been implemented on plant level on 1st February-2009 and the reductions are of the tune of 25% and 60% for demineralised and fresh water respectively.     

中国海岛生态系统保护与开发综合权衡方法初探

应用生态学、生态经济学、环境地学等相关理论与方法初步探讨了海岛生态系统保护与开发宏观及局部区域层面的博弈权衡评估方法:从宏观战略层面提出了综合考虑海岛生态服务价值、开发适宜性、现有开发强度三个方面重要因素的区域准则,以判断哪些无人岛可以上岛开发哪些则需禁止开发,同时还能判断哪些有人岛开发不足可作为重点开发对象,哪些则开发过度需要限制开发和优化开发;从局部区域层面提出了海岛开发之前需要重点评估的供给功能、生命支持功能、生态调节功能、信息功能、干扰调节功能等的生态系统服务功能价值以及评估方法。这些博弈权衡评估方法对指导海岛有序开发以及实现海岛生态与经济共赢具有重要意义。     

污水资源化利用技术及其应用

污水经深度处理后进行资源化利用已逐渐成为我国今后缓解城市水资源紧缺的现实选择,污水资源化利用的关键是按需求确定回用对象及其水质目标,重点是选择合适的污水深度处理技术。本文在概述目前污水深度处理技术的基础上,介绍了国内外大量污水资源化利用的工程实例,并分析了其采用的深度处理技术,对进一步推动我国污水资源化利用工程实践的应用以及探讨污水新型深度处理组合工艺技术具有的重要意义。     

山西壶关峡谷国家地质公园地质遗迹保护方法初探

随着旅游地学研究的深入和地质公园建设的不断完善,作为地质公园建设核心的地质遗迹保护工作越来越显得重要和迫切。本文是作者几年来从事壶关峡谷国家地质公园地质遗迹保护的总结,主要目的是在对地质遗迹保护进行系统分类的基础上,通过对公园地质遗迹保护的现状分析,找出存在的问题和不足,并制定出科学的对策与措施,实现公园的健康和可持续发展。     

RMBR、SMBR、HMBR在中水回用中的应用研究

近年来,随着人们对废水处理和中水回用技术逐渐重视,一种将传统生物处理技术与膜分离技术结合起来的MBR工艺受到青睐。本文通过对RMBR、SMBR、HMBR应用原理及优缺点的分析。为实际应用提供参考。     

印染废水处理回用工艺现状研究

印染废水产生量大、有机物含量高、具有一定的毒害性,因此印染废水的回用是降低印染废水污染和印染用水消耗的重要途径,印染废水回用包括原废水和二级生化出水的处理回用。印染废水主要回用于印染生产过程,在以印染原废水处理回用时,典型工艺是生化处理+膜分离组合工艺;在以印染废水处理后的二级生化出水进行处理回用时,其典型工艺分别是超滤+反渗透组合工艺,工艺出水可回用于印染漂洗、染色等生产过程,实现废水厂内循环利用。     

山西省输电线路工程水土保持措施研究

本文分析了输电线工程水土流失的特点,结合山西省区域地形地貌及气候特点,提出输电线路工程中防治水土流失的一些措施,为山西省输电线路工程建设水土保持工作的进行提供科学依据。     

Analysis of institutional adaptation: integration of biodiversity conservation into forestry

Integrating biodiversity conservation into forest management requires changes in the practices of those public and private actors that have implementing responsibilities and whose strategic and operational opportunities are at stake. Understanding this kind of context-dependent institutional adaptation entails bridging between two analytical approaches: policy implementation and organizational adaptation. This article combines these two approaches by reviewing them, and their caveats, and by summarizing empirical analyses of organizational competences, specialization, professional judgment, and organizational networks in the organizational field of non-industrial private forestry in Finland. Drawing on these theoretical and empirical analyses, the article discloses the broad phenomenon of institutional adaptation in the integration of biodiversity conservation and forest management. The empirical analyses point to the dominance of hierarchical policy implementation over strategic organizational adaptation. Together with the detected isomorphism of professional norms and networks, these contribute to meeting minimum standards but can constrain the ways in which the organizations and professionals respond to the challenge of biodiversity conservation. The detected inertia signals lack of alertness. It is perhaps also an indication of self-sufficiency among the actors. The interpretation of these responses to challenges and responsibilities across the public and private sector boundaries demonstrates the necessity of combining the two traditionally segregated approaches.     

蟒蛇河水源保护区畜禽养殖污染分析及对策

在对盐城市盐都区畜禽养殖业污染源调查的基础上,介绍了蟒蛇河水源保护区内畜禽养殖业的现状,分析了畜禽养殖对环境的危害以及污染环境的原因,提出防治畜禽养殖污染的对策。     

广西北海中国鲎资源现状以及保育工作进展

中国鲎种群数量近年来急剧下降,资源面临枯竭.位于北部湾的广西北海作为中国鲎理想栖息地,是我国中国鲎的主要产地,因此在北海开展中国鲎的保育工作尤为重要.本文调查分析了广西北海地区中国鲎幼体集聚地西背岭潮间带(21°24′30″N-21°25′24″N及109°11′12″E-109°13′14″E)中国鲎幼体分布现状以及...