چكيده به لاتين
Waste landfill as one of the inevitable components of waste management system been a concern for researchers and scholars in environmental engineering for years. In developing countries, this option is more appropriate than other final disposal options such as waste incineration, compost or anaerobic digestion in terms of financial and technical conditions. Estimating the amount of leachate produced is one of the important factors in the efficient management of leachate from such landfills. Designing leachate treatment processes and also determining each unit operation dimensions and specifications, also the possibility of recirculating leachate in the landfill depends on the amount of leachate production. A problem with developed models is that they are established for the specific climate conditions and geographic ranges and may not be suitable for developing countries especially in Middle East and other dry regions. Furthermore, preferential channels which are created by the combination of empty spaces in the waste are disregarded by layer and balance models. In the recent study by the use of rock wool, sand and copper pipe percolation through the waste body has been simulated physically. In other words, it is assumed that waste in each landfill has three different phases: Preferential channels, waste body with specific field capacity and permeability and finally impermeable sections. In order to recognize these phases and the volume and capacity of impermeable zones and also preferential channels, real leachate data of Kahrizak cells in Tehran was used. After calibration, this real data with the final results of this investigation the volume of impermeable sections in landfill obtained 15.05% in each cubic meter. 10% of this section will be activated in recirculation and intensity precipitations. In addition, the results indicate that the ratio of discharge leachate through preferential channels to the total discharge is 0.26. According to the waste permeability and the height of the landfill, the lag time of percolation through the waste body is approximately 37 days. Utilization of these useful results leads to a more accurate estimation of leachate generation and the pick time of discharge.
