Municipal solid waste recycling: Impacts on energy savings and air pollution

In recent years, recycling of municipal solid waste (MSW) has been recognized as one of the most efficient methods of waste management in terms of environmental benefits. This study investigates the energy savings and other environmental benefits of recycling of dry MSW collected in Shiraz, Iran (2018). The impact of different recycling rates (current = 15%, desirable = 50%, ideal = 80%) on environmental benefits and energy savings were assessed. The annual quantity of recycled components were defined as glass (735 tons), plastic carrier bags (555 tons), cardboard (3,874 tons), paper (3,806 tons), disposable plastic containers (287 tons), other types of metals (785 tons), disposable metallic containers (aluminum) (171 tons), other types of plastics (812 tons) and polyethylene terephthalate (PET) (887 tons). The results confirmed that recycling of paper and glass in three different scenarios resulted in a reduction of 1.01, 2.14, and 3.43 million tons of air pollutant emissions, respectively. By improving the recycling rates from 15 to 80%, overall energy savings can improve by between a factor of 3.5 to 5.5. Also, a reduction of approximately 2-3.5% in air pollutant emissions can be achieved by upgrading the current recycling program (15% recycling rate) to favorable and ideal conditions.Implications: In recent years, recycling of municipal solid waste (MSW) has been recognized as one of the most efficient methods of waste management in terms of environmental benefits. This study investigates the energy savings and other environmental benefits of recycling of dry MSW collected in Shiraz, Iran (2018). According to available data, there has been little effort for recycling in developing countries, and waste landfilling is recognized as the most favorable option in MSW management. The aim of this study was to characterize MSW components in Shiraz, Iran, and to quantify the environmental benefits and energy savings as result of paper, glass, and aluminum recycling. This work is novel in that there are no reports to our knowledge of the environmental benefits and energy savings resulting from different recycling scenarios including current (15%), desirable (50%), and ideal (80%) recycling for aluminum, paper, and glass. The results of this work have broad implications both for other regions owing to the pervasiveness of recycling facilities and also for developing countries that can strive towards the infrastructure needed to reach improved recycling scenarios.