One of the most important strategies for suitable management of municipal waste that has been in the spotlight as a first priority in urban waste management in many countries, is waste sorting at the sources. Waste sorting is the process by which waste is separated into different elements. Separating the different elements of waste is essential for enabling the recovery of useful materials and minimizing the amount of material sent to landfill, therefore; effective recycling relies on effective sorting, so that there is a wide range of sorting technologies nowadays.
Developed countries have the different systems of waste sorting and these can vary from town to town. In these kinds of countries, waste sorting schedules are generally distributed to every household in the cities, moreover; Ambitious household waste recycling programs have been introduced during recent decades and many different waste-sorting and collection schemes have been developed. In most Asian countries, 2 methods of waste separation play a significant role for the handling of the waste collection and recycling. The formal and the informal separation and recycling of the materials are known as applicable methods. The formal separation means the separation of the waste in the waste treatment facility after the collection of the waste. The informal separations of the waste can occur in 3 different ways, such as: direct at the source, during the collection, and at the disposal site. Unfortunately, in these kinds of countries the waste pickers separate and collect the waste, because they have private benefits by doing this. They can sell the materials which they collect. It does not happen, because of an existing or raising environmental awareness. This research aimed to assess the amount of separated waste in the 22 districts of Tehran during the years 89-92, using geographical information systems (GIS), therefore; the number of residents, statistical data of waste production and its sorting was utilized for analyzing.
Organic waste with 74.56% of weighted portion, has allocated the largest weighted portion of Tehran’s waste. District 4 with more than 885 thousand and district 22 with less than 135 thousand of residents are considered as the most populous and the least populous of municipal districts at the end of 1392, respectively. Districts 2 and 5 in the during years 89-90 and 91-92 have had the highest waste production respectively, so that, district 5 has produced the waste, more than 6 times of district 13, in the year 92. Among the 22 districts of Tehran, the amount of source separation for districts 4 and 5 was the highest, and the lowest level has obtained for districts 21 and 22. The results show that 15.23%, 14.85%, 14.38% and 15.23% of the total collected waste collected on average at the sources, in the years 89, 90, 91 and 92, respectively, in Tehran. District 12 has had the highest rate of collected separated waste in years 89, 90 and 91, moreover; district 14 with 23.73%, district 1 with 22.7%, and district 8 with 22.42% have been the best districts in this case.