Keywords
wastewater, environmental systems, multi-criteria decision analysis, conceptual design, modelling, machine learning
Start Date
1-7-2006 12:00 AM
Abstract
The objective of this paper is to present a systematic procedure to support environmental engineers during the evaluation of alternative options, identifying both, the strong and weak points of their decisions. The evaluation of alternative options in the design of environmental systems is complex because several objectives must be considered simultaneously (e.g. environmental, technical, economical, legal), i.e. the problem is multicriteria. The systematic procedure presented consists of three steps: 1) multicriteria decision analysis (MCDA), where the best alternative is selected among the most promising options by evaluating the degree of accomplishment of several design objectives; 2) sensitivity analysis, where multidimensional response surfaces are generated to represent the variation of the selected option with respect to the relative importance of the design objectives; and 3) data analysis through the application of classification trees. The resulting set of rules highlights the relationship amongst the design objectives and the selected alternative without requiring a detailed examination of data values. The capability of this new procedure is demonstrated with a case study where the bioreactor of a wastewater treatment plant is designed to achieve simultaneous carbon and nitrogen removal. The results demonstrate how this new procedure supports the systematic evaluation of alternative options during the conceptual design of environmental processes.
Identification of Alternatives Strengths and Weaknesses during the Conceptual Design of Environmental Systems
The objective of this paper is to present a systematic procedure to support environmental engineers during the evaluation of alternative options, identifying both, the strong and weak points of their decisions. The evaluation of alternative options in the design of environmental systems is complex because several objectives must be considered simultaneously (e.g. environmental, technical, economical, legal), i.e. the problem is multicriteria. The systematic procedure presented consists of three steps: 1) multicriteria decision analysis (MCDA), where the best alternative is selected among the most promising options by evaluating the degree of accomplishment of several design objectives; 2) sensitivity analysis, where multidimensional response surfaces are generated to represent the variation of the selected option with respect to the relative importance of the design objectives; and 3) data analysis through the application of classification trees. The resulting set of rules highlights the relationship amongst the design objectives and the selected alternative without requiring a detailed examination of data values. The capability of this new procedure is demonstrated with a case study where the bioreactor of a wastewater treatment plant is designed to achieve simultaneous carbon and nitrogen removal. The results demonstrate how this new procedure supports the systematic evaluation of alternative options during the conceptual design of environmental processes.
