Effectiveness of the policy of circular economy in China: A DEA-based analysis for the period of 11th five-year-plan

As a policy instrument for sustainable development, nationwide circular economy (CE) mode has been implemented for 7 years by the Chinese government, to overcome the dilemma among economic depression, energy shortage and environmental pollution. Unfortunately, few literatures contribute to checking the efficiency of regional CE and exploring the potential reasons in China, which will be practically helpful in guiding China's future development and providing reference for other developing countries that will adopt CE mode. Therefore, this paper puts forward the method of super-efficiency DEA window analysis to dynamically evaluate CE efficiency of 30 regions in China covering the period of 2005–2010. In line with the features of CE, the specific efficiency of three sub-systems, namely resource saving and pollutant reducing (RSPR) sub-system, waste reusing and resource recycling (WRRR) sub-system and pollution controlling and waste disposing (PCWD) sub-system, was assessed and compared regarding time series trend and spatial distribution, based on which, the comprehensive CE efficiency was totally ranked. The results show that, on the one hand, during the period of 2005–2010, Chinese CE efficiency slightly increased, implying a significant policy effect of CE; on the other hand, the efficiency of different sub-systems varies, with RSPR sub-system the lowest, and WRRR and PCWD sub-systems relatively higher. In terms of regional distribution, the efficiency of RSPR sub-system in the east area dominates during the whole period. However, for the other two sub-systems, from 2005 to 2007, the efficiency scores of the east fluctuate, then after 2007, the east area became more efficient than the central and the west areas. Throughout the study period, the RSPR sub-system in the central area stably maintains low efficiency, and so does the WRRR sub-system in the west area. The difference in regional efficiency of three sub-systems reflects the difficulty of carrying out CE policy in China comprehensively, which means that, promoting the adaptability of regional policy for local government and enhancing the coordination among various policies for China's central government are the key concerns for realizing sustainable development.     

Confronting limitations: new solutions required for urban water management in Kunming City

Despite continuous investment and various efforts to control pollution, urban water environments are worsening in large parts of the developing world. In order to reveal potential constraints and limitations of current practices of urban water management and to stimulate proactive intervention, we conducted a material flow analysis of the urban water system in Kunming City. The results demonstrate that the current efficiency of wastewater treatment is only around 25% and the emission of total phosphorous from the city into its receiving water, Dianchi Lake, is more than 25 times higher than its estimated tolerance. With regard to the crisis of water quantity and quality, the goal of a sustainable urban water environment cannot be attained with the current problem-solving approach in the region due to the technical limitations of the conventional urban drainage and treatment systems. A set of strategies is therefore proposed. The urban drainage system in Zurich is used as a reference for a potential best-available technology for conventional urban water management (BAT) scenario in terms of its low combined frequency of sewer overflow.     

基于EBM模型的长江经济带工业用水效率时空差异及影响因素分析

工业化进程的加快使得工业水资源需求不断增加，工业废水排放量也越来越大，如何提高工业用水效率从而缓解水资源压力成为日益严峻的问题。本文选取工业用水量、工业就业人数、工业固定资本和工业废水治理费用作为投入指标，以工业增加值与工业废水排放量作为期望与非期望产出指标。首先利用EBM模型计算长江经济带2008—2017年工业用水效率，其次利用泰尔指数来分析工业用水效率的区域差距，最后利用面板Tobit模型来分析影响不同地区工业用水效率的驱动因素。结果显示，近年来长江经济带的工业用水效率呈波动下降趋势，不同地区效率差异明显；经济发展水平、工业化程度、技术水平、水资源禀赋和政府环境管制力度对长江经济带的工业用水效率都有一定影响，但存在地区差异。     

Assessing the environmental performance of urban wastewater systems using the INSA model: application to the Algés-Alcântara wastewater system, in Portugal

Although the application of complex integrated models to wastewater systems is useful, it is often difficult to implement and not always suitable for the design of new systems or for their rehabilitation. Integrated simple approaches that allow assessing the environmental performance of urban wastewater systems may be advantageous, especially during the initial phases of the system planning process. This paper presents an original, straightforward approach that can be used for planning, design and operation of urban wastewater systems. The INtegrated Simplified Approach (INSA) combines the concepts of performance indicators with mass balances and can be applied to wastewater systems as a management support tool, particularly in situations where there is lack of data, economic limitations or time constraints. The INSA was applied to the Algés-Alcantara wastewater system to evaluate its environmental performance and to simulate the individual or combined impact of the rehabilitation measures proposed, thus defining their priority. The results clearly indicate that, despite the investment already made upgrading the wastewater treatment plant (WWTP), the proposed interventions must be implemented to ensure an acceptable environmental performance of the system. In addition, the results demonstrate the significant pollution loads present in stormwater, frequently higher than the pollution loads discharged into receiving waters during dry weather.     

Virtues of simple hydro-economic optimization: Baja California, Mexico

This paper uses simple hydro-economic optimization to investigate a wide range of regional water system management options for northern Baja California, Mexico. Hydro-economic optimization models, even with parsimonious model formulations, enable investigation of promising water management portfolios for supplying water to agricultural, environmental and urban users. CALVIN, a generalized hydro-economic model, is used in a case study of Baja California. This drought-prone region faces significant challenges to supply water to agriculture and its fast growing border cities. Water management portfolios include water markets, wastewater reuse, seawater desalination and infrastructure expansions. Water markets provide the flexibility to meet future urban demands; however conveyance capacity limits their use. Wastewater reuse and conveyance expansions are economically promising. At current costs desalination is currently uneconomical for Baja California compared to other alternatives. Even simple hydro-economic models suggest ways to increase efficiency of water management in water scarce areas, and provide an economic basis for evaluating long-term water management solutions.     

Evaluation of coastal zone sustainability: an integrated approach applied in Shanghai Municipality and Chong Ming Island

A systems approach has been applied to the examination of sustainable development in the coastal zone. This complex system is envisaged as comprising three sub-systems: environment and resources, economic development and society. A sustainability indicator system based on these three sub-systems has been set up to evaluate the nature of development in the coastal zone. The administrative regions of the Municipality of Shanghai and Chong Ming Island (in the Yangtze Estuary) have been selected as two coastal zones in which to demonstrate the feasibility and effectiveness of the approach. The approach indicated that the development process in Shanghai is one of weak sustainability with relatively rapid social and economic development at the cost of environment and resource degradation. In contrast, social and economic development in Chong Ming County has been limited to protect the regional environment and resources indicating a more sustainable approach to development.     

Regional water flows – Assessing opportunities for sustainable management

Sustainable water management may strongly benefit from an integrated approach. Additionally, an integrated urban water management policy considering the various urban water flows and the possible interactions between the water sector and the remaining urban activities can benefit if based on an urban metabolism based analysis. This article assesses water flows of Lisbon Metropolitan Area considering the conventional water supply system and wastewater treatment system flows and also the hydrological cycle flows, and proposes a global set of indicators to perform a benchmarking analysis of the 18 municipalities of the region. Results highlighted the heterogeneous nature of the Metropolitan area in terms of water management – either in terms of management entities (predominantly public or municipalized), water consumption (varying from 227.4 l/hab.day in Palmela to 402.7 l/hab.day in Seixal), wastewater treatment (10 out of 18 municipalities already undergo secondary or tertiary wastewater treatments), runoff indices (depending on the municipality's level of urbanization), among other. Through the output volumes it was also assessed the potential of the municipalities to reuse wastewater for potable or non-potable urban uses, as well as the potential to harvest and harness rainwater. The main constraints to an integrated water management were identified and some potential solutions were measured and proposed even though they need further assessment, particularly in a cost-benefit perspective.     

Sustainable wastewater management for small communities in the Middle East and North Africa

Accelerated expansion of wastewater services to small communities in the Middle East and North Africa (MENA) is essential in order to address serious concerns over water scarcity and pollution in addition to meeting the demand for convenience and protecting public health. Centralized and conventional wastewater systems are currently the preferred choice of planners and decision-makers in MENA. Water and funding are not available to provide these centralized conventional services to small communities. This paper presents an integrated approach to sustainable wastewater management for small communities in MENA under the severe water resources crisis. The approach calls for a paradigm shift from centralized conventional wastewater systems to decentralized wastewater systems. Management of wastewater in MENA should start at home. Wastewater generation should be reduced through a combination of domestic water conservation measures. On-site systems must be improved and monitored to control pollution and to recover water for non-potable water uses. Should the circumstances not allow the use of on-site systems, wastewater should be transported and managed through a community system applying the principles of decentralized wastewater management and using the settled sewers for wastewater transportation where appropriate. This approach will facilitate the accelerated and sustainable extension of environmentally responsible wastewater services to MENA's small communities. It offers great potential for cost reduction, accommodates the necessary domestic water conservation efforts, reduces freshwater inputs in wastewater transportation thus eliminating unnecessary demand on freshwater, reduces associated environmental risks and increases wastewater reuse opportunities.     

Urban water infrastructure optimization to reduce environmental impacts and costs

Urban water planning and policy have been focusing on environmentally benign and economically viable water management. The objective of this study is to develop a mathematical model to integrate and optimize urban water infrastructures for supply-side planning and policy: freshwater resources and treated wastewater are allocated to various water demand categories in order to reduce contaminants in the influents supplied for drinking water, and to reduce consumption of the water resources imported from the regions beyond a city boundary. A case study is performed to validate the proposed model. An optimal urban water system of a metropolitan city is calculated on the basis of the model and compared to the existing water system. The integration and optimization decrease (i) average concentrations of the influents supplied for drinking water, which can improve human health and hygiene; (ii) total consumption of water resources, as well as electricity, reducing overall environmental impacts; (iii) life cycle cost; and (iv) water resource dependency on other regions, improving regional water security. This model contributes to sustainable urban water planning and policy.     

Participatory Model Calibration for Improving Resource Management Systems: Case Study of Rainwater Harvesting in an Indian Village

While planning resource management systems in rural areas, it is important to consider criteria that are specific to the local social conditions. Such criteria might change from one region to another and are hence best identified using a participatory approach. In this work, we propose a participatory framework to identify such criteria and derive their weights. These identified criteria and their weights are used as parameters to develop a quantitative model for evaluating efficiency of each system. Such a model can serve as a support tool for stakeholders to simulate and analyze “what‐if” scenarios, evaluate alternatives, and select one which best satisfies their requirements. We use existing systems to test the model by comparing efficiencies evaluated by the model to efficiencies perceived by the stakeholders. The model is calibrated by repeating the process until statistically significant correlation is achieved between evaluated and perceived efficiencies. The novelty of the proposed framework lies in treating efficiencies perceived by the stakeholders as the ground truth since they know these systems well and are their ultimate users. The framework is successfully demonstrated using case study of rainwater harvesting (RWH) systems in an Indian village. The resulting calibrated model can be used to plan new RWH systems in this region and similar regions elsewhere. The framework can be used to plan other resource management systems in various regions.     

Performance assessment of integrated energy systems for HVAC applications

In this article, energy and exergy analyses are conducted for two integrated systems which can be used in HVAC applications. These two systems are analyzed for the cases of single generation, cogeneration and trigeneration, and their performances are evaluated through energy and exergy efficiencies. The parametric studies are performed to investigate the effects of using cogeneration and extended to trigeneration on the system performance. To perform the comparisons between the systems for multiple options, the same amounts of outputs (in terms of electricity, heating, cooling) are produced for all systems. The energy analyses of systems 1 and 2 show a great benefit for moving from single generation to trigeneration, with the trigeneration efficiencies of 83.5% and 87.2%, respectively, and single generation efficiencies of 47% for both systems. However, the exergy analyses show that trigeneration may not always become more efficient than single generation, particularly for system 1, due to the fact that the trigeneration exergy efficiency is 38.7% and the corresponding single generation efficiency is 44.3%. For system 2, the trigeneration exergy efficiency is 52.7% while the single generation efficiency becomes 44.3%. Depending on the type of cogeneration or cogeneration design, the system can be more efficient.     

AN IMPLICIT APPROACH TO PRICING AGRICULTURAL WATER TRANSFERS TO URBAN USES1

ABSTRACT: The increased agricultural efficiency of the American farmer has been a substantial impetus to this nation's rapid urbanization. In many western regions where total water supplies are limited, urbanization has required the transfer of heretofore agricultural water rights to the urban use. A major problem in such transfers has been the value or price of the water. A management level model of a typical urban water system was developed to optimize water supply, distribution, and wastewater treatment alternatives. The values of agricultural transfers were determined as the cost advantages of increasing allowable reuse levels of urban effluents which imply the use of a downstream right. This procedure is justified by the economic theory of alternative cost. Results for a test application to the Denver, Colorado area indicate values on the order of $1,000 per acre-foot of transferable water depending on effluent water quality restrictions and operational policies.     

Quantification of potable water savings by residential water conservation and reuse - A case study

To demonstrate the benefits of water conservation at the household level in regional Victoria in Australia, a family house “Sharland Oasis” was designed and built according to an ecologically sustainable design for improved water and energy efficiency. This study has demonstrated that the combined use of alternative water supplies together with water efficient appliances can save up to 77% of total potable water use compared to the average 1990s household water use in the same region considering the location and differing in water use approach. The use of rainwater inside the home alone saved up to 40% of potable water use. In addition to the water savings, there is a significant wastewater discharge saving achieved through the use of water conservation strategies and greywater reuse. A community survey undertaken in regional Victoria revealed that community receptivity for reusing greywater is highest for uses, such as watering gardens and flushing toilets; but it progressively decreased with increasing personal contact with greywater. Positive perception of greywater reuse needs to be encouraged through programs targeted at developing resources, skills and motivation for new water reuse practices and technologies, across a diverse range of social groups.     

WATER SUPPLY AND URBAN GROWTH PLANNING: A PARTNERSHIP1

ABSTRACT As urban expansion outstrips water supplies, the usual solution is to build pipelines to bring in water from sources farther afield. Such water supplies may act as either a leader of urban development or as a follower. In either case, this engineering approach to the provision of water has fostered less than optimal utilization of regional water and land resources for urban growth. More efficient utilization of these resources is achieved when water supply development and urban growth planning are conjoint activities. Water supply planners and land use planners, working together, are able to generate and evaluate the full range of urban development options, including water demand management through conservation. Preferred regional growth plans are achieved using the best mix of water supply and urban growth. The result is a reduced rate of water supply development and a reduction of urban expansion on prime lands. This partnership approach is demonstrated for the Calgary Region under two levels of water conservation.     

Governance of water supply systems in the Palestinian Territories: A data envelopment analysis approach to the management of water resources

This study demonstrates that data envelopment analysis (DEA) can be a useful tool to assess the relative efficiencies of water supply systems and to establish benchmarks with which to measure progress in the management of water resources. Frontier efficiency models measure the efficiency of water use in the Palestinian Territories (West Bank and the Gaza Strip). At the municipality level, sufficient data for the years 1999-2002 were available to estimate efficiency and stability scores. The Gaza Strip efficiency scores were considerably lower than those of the West Bank. Water losses were the major source of the inefficiency as indicated by the large slacks of this input. The relative sizes of the municipalities affect efficiency scores little. Palestinian policy makers should focus on rebuilding the infrastructure of the water networks, beginning with the most DEA inefficient municipalities in order to minimize water losses.     

Life-cycle phosphorus use efficiency of the farming system in Anhui Province,Central China

The rapid increase of phosphorus (P) use in farming has raised concerns regarding its conservation and environmental impact. Increasing the P use efficiency (PUE) is an approach to mitigating these adverse impacts. In this study, we applied substance flow analysis (SFA) to establish a life-cycle P use efficiency model to determine the life-cycle PUE of the farming system used in Anhui Province in 2011, which is typical of the agriculture practiced in central China. Based on this model, the P flows and PUEs of five subsystems were identified and quantified: crop farming, crop processing, livestock breeding, rural living, and urban living. The three largest P flows were found in the crop farming and livestock breeding subsystems; it can therefore be concluded that these subsystems have substantial impacts on the entire farming system. In contrast, the PUEs of crop farming, rural consumption, and livestock breeding subsystems presented the three lowest PUEs (58.79%, 71.75%, and 76.65%, respectively). These results were also consistent with the finding that the greatest P losses occurred in crop farming and livestock breeding. Consequently, the study proposes that great potential exists for increasing PUEs in the farming system of Anhui, and several of the most promising measures could be combined for improving PUEs. Finally, the study assesses data quality and presents a sensitivity analysis for use in interpreting the results. The study also shows that improving PUE and decreasing P losses in farming systems through improved nutrient management must be considered an important issue, and this study represents valuable experience in resource conservation and agricultural development in China.     

THE IMPACT OF WATER QUALITY OBJECTIVES ON URBAN WATER SUPPLY PLANNING1

ABSTRACT: Optimal policies for supplying rapidly expanding urban centers with additional water supplies are shown to be dependent on water quality goals for the urban effluent. As effluents are required to meet increasingly stringent standards, the unit costs associated with adding capacity to existing wastewater treatment systems to renovate some waters for reuse are shown to substantially decrease. A nonlinear elimination algorithm is developed to delineate optimal policies. A model employing the technique was applied to the wastewater treatment system of a typical urban system and the water quality objectives varied. A comparison of costs with and without various levels of reuse were made and unit costs of reused water under these conditions determined.     

中国城市污水集中处理的现状与对策研究

随着我国城市的迅速发展，城市普遍面临着水资源缺乏和水环境恶化的问题，已影响到城市的可持续发展。城市污水集中处理是解决城市水危机的有效方法，也是保护城市水环境的重要防线。分析了当前我国城市污水处理业的现状以及存在的问题，提出了加快污水处理厂技术革新，建设城市污水管网，加快城市污水回用产业化和完善污水处理厂的运营模式等解决办法，以保证我国城市实现可持续发展。     

A MODEL FOR PLANNING AND LOCATION OF ON-SITE WASTE DISPOSAL SYSTEMS1

Abstract: A model that incorportaes performace data about data about several wastewater management systems is discussed. From these data the excepted behavior of an individual wastewater system or group of systems can be product of the performace probabilities of its individual components. The modeel can be used on a regional scale facilitating land use planning by allowing accurate estimates of performance for a prospective wastewater management system. At this scale it can allow the impact evaluation of new wastewater technology on land use in a region.     

提高农业用水有效性的水文学研究

中国北方15个省、区、市耕地面积占全国的55%,灌溉面积占全国灌溉总面积的48%,而水资源总量仅占全国的20%。区域水资源短缺和农业的进一步发展,要求提高农业用水有效性。本文从水文学角度,研究了华北、西北和东北3个地区水土资源特征;分析了作物熟制和适水种植的节水效益、农田供水量与产量的函数关系、农田棵间蒸发量和控制措施,以及提高高产农田用水有效性等水文试验研究结果;介绍了河北省南皮节水农业试验区的研究模式。