DBO模式在医疗废物集中处置设施中的应用探讨

我国医疗废物集中处置行业呈现多种投资来源和多种运营模式并存的格局,医疗废物集中处置设施建设和运营主要采用以BOT为主的特许经营模式,部分设施由于模式选择不当,导致产权边界不清、稳定运行困难等问题,一定程度限制了行业的可持续发展。近年来开始应用于我国污水处理设施的DBO模式具有责任主体一致、建设运营效率较高等特点,在环境污染治理领域的应用前景较为广阔。本文通过对DBO模式和BOT模式的所有权归属、责任主体、实施期限等方面进行对比,分析得出DBO模式较BOT模式在设施的运营阶段具有突出优势,应用于医疗废物集中处置设施可以更有效地保证运营效率、节约财政支出、强化政府监管。同时,预期在医疗废物集中处置项目中推行DBO模式可能存在的阻碍,包括政府积极性不高、招商面临一定难度、实施过程的不确定因素较多等,并有针对性提出了在中小城市开展试点、发放环境基础设施建设债券、邻近区域多个项目捆绑招商等建议,以促进DBO模式在医疗废物集中处置设施中的应用。     

如何改进污水处理厂的BOT服务模式

如何更好地让BOT模式服务于污水处理事业？本文提出三条建议：第一,BOT模式不仅适合城市污水处理厂，也适合市政管网的建设；第二，用BOT模式时，应尽可能地选择具有设计污水厂能力的企业；第三，政府要树立让企业盈利、服务和监督企业的观念。     

BOT模式在自来水厂的应用

BOT(建设-经营-转让,build-operte-transfer)模式是将城市基础设施引进民间资本和市场化运作的模式,现已成为吸引国内外直接投资基础设施的有效手段。通过BOT融资模式在某公用事业自来水项目中的具体实践和应用,分析了BOT模式在运营阶段的运用,阐述了新融资模式在现代化水厂运营管理实践中的关键做法。     

DBO模式在污水处理行业的应用研究

DBO模式是PPP模式之一,在国家大力推进PPP模式之际,尝试开展DBO模式在污水处理行业的应用研究,分析污水处理行业发展趋势与问题,DBO模式在污水处理行业应用的适用领域与适用条件、优点,提出DBO模式在污水处理行业的推行路径,希望通过DBO模式解决污水处理行业的问题,促进行业健康发展。本文认为,城镇、乡镇与村庄生活污水处理、工业企业废水治理等领域具有项目设计与建设非标准化、项目需求明确、责任边界清晰、项目运营服务质量和成本容易监测等特点,应用DBO模式具有可行性。这些领域内的项目若有可靠的建设资金来源、稳定的运行费用保障机制、急于改善的区域水环境质量及严格的环保设施运行需求,适合采用DBO模式。DBO模式可以提高这些项目的建设质量和运营质量,节约成本,缩短建设周期,提高抗风险能力。同时,在行业层面,能够解决这些领域面临的项目设计不合理、建设质量不高、运行费用高、运行管理不善、闲置等诸多问题,可以促进先进实用技术和管理经验的应用,提高行业技术和运营管理水平的整体进步。因此,建议政府从开展实施试点、制定行业规范、加大宣传和推广、颁布政策文件等方面大力推进DBO模式在污水处理行业的应用。     

DBO模式在分散型乡镇污水处理项目中的应用

乡镇水环境日趋恶化,污水处理设施建设势在必行,针对乡镇污水处理的特点,提出DBO全周期管理和商业模式,分析了DBO模式在乡镇污水处理项目中的优点,列举了环巢湖生态修复二期项目案例中DBO模式的应用,为乡镇污水处理项目提供参考。     

BOT——投资建设城市污水处理厂的有效方式

本文分析了当前城市污水治理中存在的问题，并通过对BOT项目融资方式和工程建设方式的分析，提出BOT是一种投资建设城市污水处理厂的有效方式。     

采用BOT投资方式建设小型污水处理厂的成功经验——以吉木萨尔县为例

随着城市建设进程的加快,我国城镇水环境污染问题已不容乐观。究其原因是小城镇集中排污主体的污水处理设施不能同步配套建设,或建成后不能正常运行。基于此,本文以吉木萨尔县建设城镇污水处理厂为例,分析了如何采用BOT投资方式建设小型污水处理厂,有效缓解治理城镇生活污水资金不足的问题,亦是对探索BOT公司参与城镇污水处理方式取得...     

BOT项目融资模式在环保项目中的应用

近年来，BOT模式开始进入我国环保领域。文章介绍了BOT模式在国内的应用现状和特点，分析了BOT在应用中存在的问题，并提出了相应建议。     

对城市积存垃圾处理项目的建议

以某市处理积存垃圾为例,从处理方式、技术经济分析、BOT建设方案等方面提出了产业化建议。     

银河水务股份有限公司

银河水务股份有限公司成立于2006年,注册资本3亿元,其前身是青岛银河环保股份有限公司,公司以国际先进技术与自主研发技术相结合为依托,专业从事上水(水源和供水)和下水(工业废水、城市污水处理及再生水)处理,以BOT、BT模式投资、设计、建设、运营和管理城市污水、饮用水、水库及配套设施等大型水务项目。     

A stochastic model for colloid transport and deposition

Profiles of retained colloids in porous media have frequently been observed to be hyper-exponential or non-monotonic with transport depth under unfavorable attachment conditions, whereas filtration theory predicts an exponential profile. In this work we present a stochastic model for colloid transport and deposition that allows various hypotheses for such deviations to be tested. The model is based on the conventional advective dispersion equation that accounts for first-order kinetic deposition and release of colloids. One or two stochastic parameters can be considered in this model, including the deposition coefficient, the release coefficient, and the average pore water velocity. In the case of one stochastic parameter, the probability density function (PDF) is characterized using log-normal, bimodal log-normal, or a simple two species/region formulation. When two stochastic parameters are considered, then a joint log-normal PDF is employed. Simulation results indicated that variations in the deposition coefficient and the average pore water velocity can both produce hyper-exponential deposition profiles. Bimodal formulations for the PDF were also able to produce hyper-exponential profiles, but with much lower variances in the deposition coefficient. The shape of the deposition profile was found to be very sensitive to the correlation of deposition and release coefficients, and to the correlation of pore water velocity and deposition coefficient. Application of the developed stochastic model to a particular set of colloid transport and deposition data indicated that chemical heterogeneity of the colloid population could not fully explain the observed behavior. Alternative interpretations were therefore proposed based on variability of the pore size and the water velocity distributions.     

A European model for waste and material flows

The use of materials and the generation of waste are linked to economic activities and in many projections these are assumed to be a constant ratio of the economic activities. This may be the case considering detailed economic activities and unchanged technology. However, the assumption of constant coefficients is questionable when linking material use and waste generation to aggregated economic activities. Therefore, in this paper, econometrics is used to test the assumption of constant waste coefficients empirically. The analyses show that an assumption of constant waste coefficients is not supported, generally, and a model allowing for trendwise changing coefficients is developed and used for projections of waste and material flows in 25 European countries.     

An ecological planning model

In this article a model is proposed that could be used as a basis for ecological planning of natural resources. The role of people as part of the ecosystem is emphasized, and the various factors that should be considered in such planning are discussed. An understanding of ecological planning is dependent on the study of human activities in, and the nature of, natural ecosystems. It also depends on the fact that people are a part of nature, and as a result nature is of value to humans. Realizing the importance of this principle is a prerequisite to studying nature and also for an understanding of the various steps in the ecological planning approach. Realization of these values is often through a series of activities that may result in a negative environmental impact. Nature is described as an interacting group of natural features and processes. In this study both the features and processes are described as natural resources. The use of these natural resources obviously affects them, and if this use is to continue over a long period, both the activity and the resource must be understood if they are to be maintained in a productive state. In order to limit impact and maintain value, a planning aid called zoning is used to assist in the understanding of the processes involved.     

Dynamic metals demand model

Studies by Nutting, Jacobson and Evans and Georgentalis et al. have all concluded, using panel data sets, that a number of metals appear to share a common demand curve that is stable over time. However, these studies have a number of theoretical and econometric limitations. This paper addresses these concerns and reassesses the hypothesis that some metals share such a common demand curve with the same price elasticity of demand. This is achieved within the framework of a random coefficients model. This model was applied to a dynamic metals demand function (DLR) and various estimation techniques were used including OLS, IV, Empirical Bayes (EB) and Instrumental Variables Empirical Bayes (IV-EB). It was found that each metal had its own individual short run demand function with statistically different own price and industrial activity elasticities of demand. In the long run, each metal appeared to be equally unresponsive to price changes, but had different industrial activity elasticities. The speeds of price adjustment to periods of market disequilibrium differed substantially between metals.     

Developing a collaborative model for environmental planning and management

Methods for involving the public in natural resource management are changing as agencies adjust to an increasingly turbulent social and political environment. There is growing interest among managers and scholars in collaborative approaches to public involvement. Collaboration is conceptually defined and elaborated using examples from the natural resource management field. This paper then examines how collaboration theory from the organizational behavior field can help environmental managers to better understand those factors that facilitate and inhibit collaborative solutions to resource problems. A process-oriented model is presented that proposes that collaboration emerges out of an environmental context and then proceeds sequentially through a problem-setting, direction-setting, and structuring phase. Factors constraining collaboration are also specified, including organizational culture and power differentials. Designs for managing collaboration are identified, which include appreciative planning, joint agreements, dialogues, and negotiated settlements. Environmental managers need new skills to manage collaboration within a dynamic social and political environment. Further research is needed to test the propositions outlined here.     

Development and application of a GIS-based sediment budget model

Accelerated erosion and increased sediment yields resulting from changes in land use are a critical environmental problem. Resource managers and decision makers need spatially explicit tools to help them predict the changes in sediment production and delivery due to unpaved roads and other types of land disturbance. This is a particularly important issue in much of the Caribbean because of the rapid pace of development and potential damage to nearshore coral reef communities. The specific objectives of this study were to: (1) develop a GIS-based sediment budget model; (2) use the model to evaluate the effects of unpaved roads on sediment delivery rates in three watersheds on St. John in the US Virgin Islands; and (3) compare the predicted sediment yields to pre-existing data. The St. John Erosion Model (STJ-EROS) is an ArcInfo-based program that uses empirical sediment production functions and delivery ratios to quantify watershed-scale sediment yields. The program consists of six input routines and five routines to calculate sediment production and delivery. The input routines have interfaces that allow the user to adjust the key variables that control sediment production and delivery. The other five routines use pre-set erosion rate constants, user-defined variables, and values from nine data layers to calculate watershed-scale sediment yields from unpaved road travelways, road cutslopes, streambanks, treethrow, and undisturbed hillslopes. STJ-EROS was applied to three basins on St. John with varying levels of development. Predicted sediment yields under natural conditions ranged from 2 to 7Mgkm(-2)yr(-1), while yield rates for current conditions ranged from 8 to 46Mgkm(-2)yr(-1). Unpaved roads are estimated to be increasing sediment delivery rates by 3-6 times for Lameshur Bay, 5-9 times for Fish Bay, and 4-8 times for Cinnamon Bay. Predicted basin-scale sediment yields for both undisturbed and current conditions are within the range of measured sediment yields and bay sedimentation rates. The structure and user interfaces in STJ-EROS mean that the model can be readily adapted to other areas and used to assess the impact of unpaved roads and other land uses sediment production and delivery.     

A formal model for consensus and negotiation in environmental management

Environmental management decisions typically lie at the interface of science and public policy. Consequently, these decisions involve a number of stakeholders with competing agendas and vested interests in the ultimate decision. In such cases, it is appropriate to adopt formal methods for consensus building to ensure transparent and repeatable decisions. In this paper, we use an environmental management case study to demonstrate the utility of a mathematical consensus convergence model in aggregating values (or weights) across groups. Consensus models are applicable when all parties agree to negotiate in order to resolve conflict. The advantage of this method is that it does not require that all members of the group reach agreement, often an impossible task in group decision making. Instead, it uses philosophical foundations in consensus building to aggregate group members' values in a way that guarantees convergence towards a single consensual value that summarizes the group position. We highlight current problems with ad hoc consensus and negotiation methods, provide justification for the adoption of formal consensus convergence models and compare the consensus convergence model with currently used methods for aggregating values across a group in a decision making context. The model provides a simple and transparent decision support tool for group decision making that is straightforward to implement.     

Ecological scenarios analyzed and evaluated by a shallow lake model

We applied the complex ecosystem model EMMO, which was adopted to the shallow lake Müggelsee (Germany), in order to evaluate a large set of ecological scenarios. By means of EMMO, 33 scenarios and 17 indicators were defined to characterize their effects on the lake ecosystem. The indicators were based on model outputs of EMMO and can be separated into biological indicators, such as chlorophyll-a and cyanobacteria, and hydro-chemical indicators, such as phosphorus. The question to be solved was, what is the ranking of the scenarios based on their characterization by these 17 indicators? And how can we handle high quantities of complex data within evaluation procedures? The scenario evaluation was performed by partial order theory which, however, did not provide a clear result. By subsequently applying the hierarchical cluster analysis (complete linkage) it was possible to reduce the data matrix to indicator and scenario representatives. Even though this step implies losses of information, it simplifies the application of partial order theory and the post processing by METEOR. METEOR is derived from partial order theory and allows the stepwise aggregation of indicators, which subsequently leads to a distinct and clear decision. In the final evaluation result the best scenario was the one which defines a minimum nutrient input and no phosphorus release from the sediment while the worst scenario is characterized by a maximum nutrient input and extensive phosphorus release from the sediment. The reasonable and comprehensive results show that the combination of partial order, cluster analysis and METEOR can handle big amounts of data in a very clear and transparent way, and therefore is ideal in the context of complex ecosystem models, like that we applied.