Environmental assessment of the life cycle of sludge treatment systems of ardabil and khalkhal wastewater treatment plants

With the increasing population growth and the importance of sustainable development, the need for wastewater treatment systems with less environmental load and therefore the economy is felt. The life cycle assessment method, is one of the methods of environmental assessment of products and services. in this study a comparison between two methods of sludge treatment systems, aerated lagoon (Ardabil wastewater treatment plant) and activated sludge (Khalkhal WWTP) were discussed. for this purpose, inputs (materials and energy) and outputs (related pollutants) of each system were determined. Based on the quality parameters data from the water and wastewater company in Ardabil province, the amount of CH4 and CO2 production gases in both systems were calculated, and analyzed with use of simapro 8.2.0 software and basic data of CML2001 and Eco-indicator 99. The results showed that, lagoon system had maximum effects in all impact categories and in contrast, activated sludge system had much less environmental impact than lagoon system. Thus, activated sludge system in the category of toxic effects for humans had the highest contribution (79 %) and in the global warming and photochemical oxidation impact categories had the lowest contribution (0.72 %). So, the results of this research showed that activated sludge system had lowest environmental load and introduced as an alternative method of aerated lagoon system in the development of Ardabil wastewater treatment plant (WWTP).