Research And Application Of Optimum Selection Method Of Ship Sewage Treatment System

Since January 1,2010, the Resolution MEPC.159 (55) has been come into force, which sets higher criterion for the disposal and discharge of ship sewage. Considering the characteristics of sewage, the paper gives some algorithm used for choosing the optimal treatment system, and makes it out in computer program.First, some suggestions for selection of sewage treatment systems are given, on analysis of pollution characteristics including water quantity and quality, and the treatment of sewage including techniques and conditions.Second, by analyzing the typical ship sewage treatment systems and the plants complied with the latest standards, it shows that the future technology trend is the combination of biological, membrane and UV disinfection treatment.Third, with applying AHP to transform several evaluating indicators into a combined single evaluating indicator and establishing the hierarchical structure evaluating body system within 0.1-0.9 scales, the index weight based on expert's judge is made out; then by the use of the gray-relevancy analysis technique, the paper analyzes the index data and get reliable relevancy grade. For more computational efficiency, the MATLAB is used for hierarchy-relevancy analysis.Finally, the algorithm for optimization analysis made out in Matlab programme is built in C#.net environment which could uses the Xml file to transmit the information of ships and equipment. In C#.net, there are several forms for interaction with people, such as the expert evaluation form and the equipment analysis form.Comparing with the method which is according to the economic data used in system feasibility analysis, the optimization method which takes the benefit of economy, technical performance and management into account makes the evaluating results more scientifically and reasonably. So it has better reference value for the selection of sewage systems.