Potential Investigation of Reusing Ardabil Municipal Wastewater Treatment Plant Sludge Based on AHP and TOPSIS Models

Introduction: by ever-increasing of population, shortage of water resources and the necessity of wastewater treatment, large amount of sludge that is a byproduct of wastewater treatment, requires being disposed in safe ways, environmentally. the target of specifying strategic preferences of reusing sludge is going to find the safe way of disposing or beneficial use of sludge.materials and methods: in this study, for selecting the best alternatives for reusing wastewater sludge, two systematic methods will be introduced, in which four alternatives in reusing sludge (using in agriculture, in green space, biogas and desert combat) are introduced and they will be compared with four main parameters including: 1-physicochemical 2-biological 3-economic, social and cultural, and 4-environmental pollution situation, where each one contains some criteria.results: sludge of ardabil municipal wastewater treatment plant, according to standards, and epa regulations is eligible to class b, and due to the chemical, in terms of heavy metals, got special (excellent) quality and contains considerable quantities of organic substance, nutrients and micronutrients that indicates the fertilized value of the sludge.conclusion: the result of these comparisons showed that the application of sludge in green spaces is the most appropriate alternative while using in agriculture, biogas, and desert combat alternatives are placed respectively in second to fourth preferences of reusing sludge that is derived from municipal wastewater treatment plant.