scholarly journals Study on layout optimization of sewage outfalls: a case study of wastewater treatment plants in Xiamen

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cui Wang ◽  
Zhouhua Guo ◽  
Qingsheng Li ◽  
Jing Fang
Keyword(s):  
Wastewater Treatment ◽  
Water Reuse ◽  
Evaluation System ◽  
Evaluation Method ◽  
Wastewater Treatment Plants ◽  
Comprehensive Evaluation ◽  
Ecological Impact ◽  
Layout Optimization ◽  
Marine Environmental

AbstractIn order to protect the offshore environment and strengthen the comprehensive rectification of sewage outfalls, an evaluation method of regional sewage outfalls by combining the marine numerical simulation and comprehensive evaluation technology was constructed, considering the marine environmental capacity and the ecological impact of sewage discharge from outfalls on the marine eco-environment sensitive areas. Then the layout rationality of each outfall was evaluated and the discharge scale was optimized with a case study of existing sewage outfalls in Xiamen. The results show that, the comprehensive evaluation score of Yundang outfall was 3 points in 2025, evaluated as the outfall with irrational layout. In 2035, the comprehensive evaluation scores of Fenglin and Dalipu outfalls were 3 and 2 points respectively, evaluated as the outfall with irrational discharge scale. It is suggested to control the scale of expansion or increase the reclaimed water reuse rate in Jimei and Gaoqi Wastewater Treatment Plants. This method has enriched the evaluation system for layout optimization of sewage outfalls, providing scientific supports for comprehensive improvement of sewage outfalls and marine environmental management.

Evaluation of Highway Traffic Safety Facilities Based on Set Pair Analysis

2015 ◽  
Vol 730 ◽  
pp. 73-76
Author(s):  
Yao Wu ◽  
Jian Lu ◽  
Wan Qiu Zhu ◽  
Hong Tong Qiu
Keyword(s):  
Traffic Safety ◽  
Evaluation System ◽  
Evaluation Method ◽  
Comprehensive Evaluation ◽  
Set Pair Analysis ◽  
Highway Traffic ◽  
Freeway Traffic ◽  
Connection Degree ◽  
Pair Analysis

In order to make a reasonable evaluation of highway traffic safety facilities, a comprehensive evaluation method based on set pair analysis was proposed. An evaluation system of freeway traffic safety facilities was established. Combined with relevant norms and standards, each indicator in the evaluation system was divided and a reasonable threshold has been set. Through the calculation of the connection degree of ‘identicalness, differentness and reverse’, the maximum connection degree criterion was used to judge the evaluation results of freeway traffic safety facilities. Finally a case study was conducted to verify the proposed evaluation method. The case study shows that the selected highway traffic safety facilities are at a good level and this method can provide scientific decision basis for highway traffic facility renovation.

scholarly journals Method of Desulfurization Process Selection Based on Improved Fuzzy Comprehensive Evaluation: A Case Study of Papermaking Desulfurization in China

Processes ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 446 ◽  
Author(s):  
Wang ◽  
Wang ◽  
Zhu ◽  
Gong
Keyword(s):  
Evaluation System ◽  
Evaluation Method ◽  
Comprehensive Evaluation ◽  
Fuzzy Comprehensive Evaluation ◽  
Process Selection ◽  
Evaluation Tool ◽  
Comprehensive Evaluation Method ◽  
Implementation Processes ◽  
Desulfurization Process

With the increasingly prominent global energy and environmental problems, more and more enterprises have been required to desulfurize the exhausted gases. Different enterprises have different demands for the desulfurization process, thus the choice of desulfurization process methods has become a focus of attention. Since the evaluation of the desulfurization process involves many factors, this paper proposes an improved fuzzy comprehensive evaluation method to evaluate the selection of desulfurization process when the traditional evaluation method is not applicable. Firstly, an evaluation system with two rating indicators was constructed, which considers the subjective and objective weights comprehensively. Secondly using the two hierarchical indicators, an effective desulfurization process method was obtained according to the principle of maximum membership degree. Finally, we took a real papermaking factory as an example to illustrate the detailed implementation processes of this method. The result shows that the model could be used as a comprehensive evaluation tool to select desulfurization scheme or optimize the desulfurization process.

Controlling the Settling of Activated Sludge in Pulp and Paper Wastewater Treatment Plants

1999 ◽  
Vol 40 (11-12) ◽  
pp. 223-229 ◽  
Author(s):  
Frédéric Clauss ◽  
Christel Balavoine ◽  
Delphine Hélaine ◽  
Gaëtan Martin
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Pulp And Paper ◽  
Organic Load ◽  
Forest Industry ◽  
Filamentous Bulking ◽  
Mineral Particles ◽  
Mineral Powder

Forest industry wastewaters are difficult to clean: hydraulic and organic load variations, filamentous bulking or pin-point flocs negatively impact depollution processes. The addition of a fine, mineral, talc-based powder, Aquatal, into the aeration tanks of wastewater treatment plants connected to pulp and paper factories has been successfully tested since end of '97. The first case-study presents full results obtained over a period of 18 months in a 20,000 p.e. plant connected to a paper factory. The mineral powder was regularly added to control sludge volume index, thereby ensuring low suspended solids concentration in the outfluent. Plant operators could easily adapt biomass concentration to match organic load variation, thereby maintaining pollution micro-organisms ratio constant. In a second case study, a trouble-shooting strategy was implemented to counteract filamentous bulking. A one-off, large dosage enabled the plant operator to deal effectively with poor settleability sludge and rapidly control sludge blanket expansion. In both cases, the main common characteristics observed were an increase in floc aggregation and the production of heavier and well-structured flocs. The sludge settling velocity increased and an efficient solid/liquid separation was obtained. After a few days, the mineral particles of Aquatal were progressively integrated into the sludge floc structure. When the mineral powder was added to the activated sludge in the aeration basin, chemical interactions frequently encountered with other wastewater treatment additives did not pose a problem. Moreover, with this mineral additive, the biological excess sludge displayed good thickening properties and dewatering was improved. Despite the addition of the insoluble mineral particles, the amount of wet sludge expelled did not increase. Aquatal offers a rapid solution to floc settleability problems which so frequently arise when physical or biological disorders appear in forest industry wastewater treatment plants.

Study of highway asphalt pavement recycling maintenance scheme decision system and decision method

2021 ◽  
pp. 1-10
Author(s):  
Hongjun Jing ◽  
Ping Yao ◽  
Lichen Song ◽  
Jiahao Zhang ◽  
Yanlong Zhao ◽  
...  
Keyword(s):  
Decision Making ◽  
Evaluation System ◽  
Evaluation Method ◽  
Comprehensive Evaluation ◽  
Asphalt Pavement ◽  
Economic Benefits ◽  
Highway Maintenance ◽  
Decision System ◽  
Recovery Index ◽  
Pavement Recycling

With modern economic and social development, the technical and economic requirements of highway maintenance and construction projects have become increasingly complicated. Meticulous and in-depth investigation and demonstration guided by scientific theories and methods are of considerable importance to highway maintenance scheme decision. As basis for the selection of highway asphalt pavement recycling maintenance scheme, the factors influencing the decision are analytically demonstrated and an evaluation system is proposed, including three major decision indexes: applicability of recycling mode, recycled pavement quality recovery index, and economic benefit. According to the principles of data statistics and analysis, this study proposes a calculation method for the recycled pavement quality recovery index, analyzes the economic benefits of decision schemes using economic models such as recycling ratio and cost, and puts forward an optimal evaluation method of engineering cost and its fuzzy score intervals. Index weights are calculated through the analytic hierarchy process, and the comprehensive decision evaluation system and comprehensive evaluation method are established. Subsequently, the decision-making method is analyzed on the basis of the decision system by combining the related data. Results show maximum weight of the pavement quality recovery index and minor differences among four recycling schemes in the quality recovery index and applicability. The decision-making results are simplified with clear hierarchical feature because of the fuzzy score intervals of each index. Findings can provide a reference for the asphalt pavement recycling scheme decision.

scholarly journals Sewer Mining as a Distributed Intervention for Water-Energy-Materials in the Circular Economy Suitable for Dense Urban Environments: A Real World Demonstration in the City of Athens

Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2764
Author(s):  
Argyro Plevri ◽  
Klio Monokrousou ◽  
Christos Makropoulos ◽  
Christos Lioumis ◽  
Nikolaos Tazes ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Circular Economy ◽  
Water Reuse ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Urban Environments ◽  
Treated Wastewater ◽  
Aquifer Recharge ◽  
Treatment Unit ◽  
Plant Nursery

Water reuse and recycling is gaining momentum as a way to improve the circularity of cities, while recognizing the central role of water within a circular economy (CE) context. However, such interventions often depend on the location of wastewater treatment plants and the treatment technologies installed in their premises, while relying on an expensive piped network to ensure that treated wastewater gets transported from the treatment plant to the point of demand. Thus, the penetration level of treated wastewater as a source of non-potable supply in dense urban environments is limited. This paper focuses on the demonstration of a sewer mining (SM) unit as a source of treated wastewater, as part of a larger and more holistic configuration that examines all three ‘streams’ associated with water in CE: water, energy and materials. The application area is the Athens Plant Nursery, in the (water stressed) city of Athens, Greece. SM technology is in fact a mobile wastewater treatment unit in containers able to extract wastewater from local sewers, treat it directly and reuse at the point of demand even in urban environments with limited space. The unit consists of a membrane bioreactor unit (MBR) and a UV disinfection unit and produces high quality reclaimed water for irrigation and also for aquifer recharge during the winter. Furthermore, a short overview of the integrated nutrient and energy recovery subsystem is presented in order to conceptualise the holistic approach and circularity of the whole configuration. The SM technology demonstrates flexibility, scalability and replicability, which are important characteristics for innovation uptake within the emerging CE context and market.

scholarly journals Evaluation of Airport Environmental Carrying Capacity: A Case Study in Guangzhou Baiyun International Airport, China

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Lili Wan ◽  
Qiuping Peng ◽  
Tianci Zhang ◽  
Zhan Wang ◽  
Yong Tian
Keyword(s):  
Carrying Capacity ◽  
Evaluation Method ◽  
Comprehensive Evaluation ◽  
Projection Pursuit ◽  
Indicator System ◽  
Development Mode ◽  
The Sustainable Development ◽  
International Airport ◽  
Environmental Carrying Capacity

In order to clarify the comprehensive operational capabilities of the airport and better plan the sustainable development mode of the airport, this paper studies the evaluation method of airport environmental carrying capacity. First, this paper proposes the concept of airport environmental carrying capacity by taking into account the complex characteristics of airports affected by multiple factors and then selects 16 representative evaluation indicators to construct an indicator system based on the Driving Force-Pressure-State-Response (DPSR) framework. Finally, the accelerated genetic algorithm-projection pursuit model is established to model a comprehensive evaluation index, which is used to calculate the airport environmental carrying capacity (AECC). The results of the case study show that the AECC of Guangzhou Baiyun International Airport (CAN) decreased year by year from 2008 to 2017, which is in line with the coordinated development level of CAN. By analysing the changing mechanism of AECC and indicators, we get 6 key influencing indicators that led to the continuous decline of AECC and put forward some political suggestions to improve the AECC.

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