Investigating the Appropriate Method of Sludge Dewatering Technology in Wastewater Treatment Plants Using Analytical Hierarchy Process (Case Study: Wastewater Treatment Plant in the South of Tehran)

In recent decades, the management and treatment of sewage and sludge dewatering process have become crucial due to their high nutrient content. However, choosing the right technology in this area is a big challenge due to the complexities and the existence of many uncertainties. In this article, an analytical hierarchy process is used as a decision-making tool to choose the appropriate dewatering method in the southern Tehran treatment plant, in which the criteria structure and the evaluation process are defined by describing several possible options for sludge dewatering to be compared and weighted. The results were analyzed and evaluated using Expert choice software. According to the results, the belt filter press is the best and most appropriate technology for sewage sludge dewatering among pressure and belt filter press, lagoon, centrifuge, and sludge drying beds. Finally, validation had been done based on the sensitivity analysis method, which shows the effect of changes in input parameters on the results and was carried out for technical, economic, environmental, and management criteria, and the sensitivity of the options to the change in the weight of the main criteria was determined and the results showed that the most sensitivity in the economic criteria refers to the lagoon process, in the technical criteria refers to the centrifuge process, in the environmental criteria refer to the centrifuge process, and in the management criteria refers to the belt filter press process. The results show that this method, due to its simplicity and adaptability to different situations and regions, can be considered at the national level for different decision-makers in the field of selecting processes in water and wastewater treatment.