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Dong F.,Peking University | Liu Y.,Peking University | Qian L.,Environmental Development Center | Sheng H.,Peking University | And 3 more authors.
Environmental Modelling and Software | Year: 2014

Nutrient load reduction is a well-recognized requirement for aquatic ecosystem restoration. However, decision making is difficult due to challenges related to uncertainty and the interaction between decision makers and modelers, including (a) the quantitative relationship between risks arising from different aspects and the fact that cost is not usually revealed and (b) the fact that decision makers are not significantly involved in the modeling process. In this study, an interactive optimal-decision procedure with risk-cost tradeoff is proposed to overcome these limitations. It consists of chance-constrained programming (CCP) models, risk scenario analysis using the Taguchi method, risk-cost tradeoff and feedback for model adaption. A hybrid intelligent algorithm (HIA) integrating Monte Carlo simulation, artificial neural networks, and an augmented Lagrangian genetic algorithm was developed and applied to solve the CCP model. The proposed decision procedure and HIA are illustrated through a case study of uncertainty-based optimal nutrient load reduction in the Lake Qionghai Watershed, China. The CCP model has four constraints associated with risk levels indicating the possibility of constraint violation. Sixteen risk scenarios were designed with the Taguchi method to recognize the interactions between multiple constraint risks and total cost. The results were analyzed using the signal-to-noise ratio, analysis of variance, and multivariate regression. The model results demonstrate how cost is affected by risk for the four constraints and show that the proposed approach can provide effective support for decision making on risk-cost tradeoffs. © 2014 Elsevier Ltd. Source


Liu J.,Beijing University of Technology | Shi J.,Environmental Development Center | Li J.,Beijing University of Technology | Yuan X.,Hunan University | Liu C.,Beijing University of Technology
2011 International Conference on Electronics, Communications and Control, ICECC 2011 - Proceedings | Year: 2011

The effects of biosurfactant rhamnolipid and chemical surfactant Tween 80 on ethanol production from waste rice straw by simultaneous saccharification and fermentation (SSF) were investigated. The results showed that ethanol yield was increased to different extents by the two surfactants at the optimal condition. The maximum enhancements were obtained at the reaction time of 72 hours, at which time ethanol yields were 84.8% and 91.7% with presence of 1CMC (Critical Micelle Concentration) of rhamnolipid and Tween 80, and the ethanol yields were 12.2% and 21.3% higher than the control, respectively. The experiment proved that rhamnolipid and Tween 80 could improve the complex system of SSF. Ethanol concentration was also increased remarkably with two surfactants. The stimulatory effects on ethanol yield of Tween 80 were superior to that of rhamnolipid. Tween 80 did not inhibit cell growth in fermentation processes and probably improved the utilization of reducing sugar by yeast. For its complexity of reactive system, many influencing factors, more research is needed to investigate effects of surfactants on yeast. © 2011 IEEE. Source


Liu J.,Beijing University of Technology | Shi J.,Environmental Development Center | Li J.,Beijing University of Technology | Yuan X.,Hunan University
Proceedings - International Conference on Computer Distributed Control and Intelligent Environmental Monitoring, CDCIEM 2011 | Year: 2011

The chemical surfactant Tween 80 and biosurfactant rhamnolipid were added to the solid-state fermentation processes of a strain of actinomycete Streptomyces badius. The extracellular amylase, protease, carboxymethyl cellulose enzyme (CMCase) and xylanase were analyzed during the fermentation process. In addition, the pH of the fermentation substrate, microbial population and the degradation of the organic matter were determined. The results showed that Tween 80 increased the activities of amylase, protease, CMCase and xylanase to different extents while rhamnolipid only had an obvious stimulatory effect on xylanase. Neither Tween 80 nor rhamnolipid had an obvious effect on the pH of the fermentation substrate. As a result of the improved enzyme activities, the degradation rates of organic matter of the treatments with surfactants were higher than that of the control. The results indicated that Tween 80 is a common stimulant for most enzymes, while rhamnolipid can only act with some specific enzyme, such as xylanase. © 2011 IEEE. Source


Hu N.,National Technology Center for Solid Waste and Chemicals Management | Cheng C.M.,Environmental Development Center | Wen X.F.,Environmental Development Center | Chen Y.,National Technology Center for Solid Waste and Chemicals Management | Hu H.L.,National Technology Center for Solid Waste and Chemicals Management
Advanced Materials Research | Year: 2014

Total generation amount of scrap tires in China and the U.S. reach 500 million and total weights are about 10 million tons. Management on scrap tires is the common challenges for both countries. In this paper, generation situations, material flows and management policies of the two countries were analyzed and compared. Comparison results show higher possession of private vehicles and higher retreading ratio for commercial trucks in the U.S. results in relatively higher generation amounts (0.3billion units) and relatively lighter weights (4.4 million tons). Management policies on scrap tires in the U.S. are more comprehensive and stricter than those in China. The successful implementation of economic instruments in the U.S provides practical experiences for China to improve material flows and avoid illegally oil refining. In the U.S. co-disposed as an alternative fuel is the main outlet for scrap tires, while in China they are mainly recycled to produce reclaimed rubber. © (2014) Trans Tech Publications, Switzerland. Source


Chen Y.,Environmental Development Center | Li L.-N.,Environmental Development Center | Yang C.-Q.,Environmental Development Center | Hao Z.-P.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Huanjing Kexue/Environmental Science | Year: 2011

VOC pollution is worsening, not only affects the environment, air quality, but also directly harm human health, and Chinese relevant departments need to improve control measures. U.S. toxic air pollutants (HAPs) control system was studied, and Chinese environment countermeasures were proposed based on pollution features. U.S. recognized sources of hazardous air pollutants in the Clean Air Act (CAA), and reduced their emissions by industrial regulations and regional policies. In urban areas, VOC occupied a great part of toxic air and were controlled as a major project in U.S. Due to relatively weak management and technical base, China should screen some VOC components for priority pollutant control. The feature of Chinese VOC pollution was described as complex components, industry sources widely distributed, strong regional characteristics and processes, and gradual development of regional pollution. It was suggested to carry out investigation assessment activities, enhance cumulative risk assessment and environmental impact assessment management, and strengthen emergency risk prevention. Source

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