Technical, Economical and Environmental Assessment of Municipal Wastewater Treatment Alternatives Using Multi Criteria Decision Making Techniques

One of the main issues before the design and the implementation of every wastewater treatment plant is the selection of the appropriate treatment process, since the wrong selection can have considerable effect in increasing expense, and also led to unattainable and undesired results regarding the key importance of the issue, the current study was carried out to assess the wastewater treatment plants, are developing in cities such as Ardebil ,Tabriz ,and Uremia in order to choose and prioritize most appropriate treatment process. Based on the technical, economical, and environmental criteria and related sub-criteria, the current study used the Analytic Hierarchy Process (AHP) procedure to select the optimal wastewater treatment process in stated cities. In such cities the treatment process involved: Aerated Lagoon, Activated sludge, and Biolak. As a first stage of the current study, to determine the effective criteria and sub- criteria in the selection of the urban wastewater treatment, the formulation and completion of questionnaires were determined by expert groups and reporters. Then, the weighting of the criteria and sub-criteria was performed through “pair comparison”by “Expert Choice” software. In the next stage,after measuring the weight of each parameter; with regard to each parameter; wastewater treatment options were done in two – way “pair comparison”. Then the best choice was selected. The result derived from the current study illustrated the Biolak process with 0.421 weights was selected as the optimal treatment process and Activated Sludge and Aearated Lagoon processes with 0.356 and 0.223 points were respectively placed in the next priorities. Between the criteria, technical criterion with 0.407 weights was determined as the most effective criterion, and environmental and economical criteria were placed in the next priorities