جستجوی مقالات مرتبط با کلیدواژه « مدفن زباله » در نشریات گروه « آب و خاک »

Areas where waste is buried based on engineering design, which is one of the waste disposal methods. Leachate accumulation in landfills can adversely affect downstream groundwater resources by infiltrating the aquifer. In this study, we tried to investigate the potential of leachate penetration and the plume contamination caused by leachate pools inside and outside the landfill, respectively, using two methods of electrical resistivity tomography (ERT) and vertical electric sounding (VES). For this purpose, at a distance of 60 and 580 meters from the leachate basin, VES data were collected with a transmitter length of 200 meters and ERT with a length of 120 meters and electrode distances of 2 meters. Examination of geotechnical and VES data in the study area shows an impermeable layer with an alternation of clay-madstone and calcareous-marl layers at a depth of about 10-15 meters the percentage of the clay were increased. The ERT data in profile number 1 shows that at a distance of 32-76 meters from the beginning of the profile at deptt of 9 meters there are areas with low electrical resistivity, which indicates the area of leachate penetration, but in the other section of profile leachate deep penetration are not visible due to the Madstone and Siltstone impermeable layers. However, in the ERT data in profile number 2, the presence of an impermeable layer prevents the infiltration of leachate to the downstream and lower depths, which indicates the proper selection of the landfill. Therefore, contrary to what can be seen in the VES data, the study area is not homogeneous in terms of permeability to leachate in the two dimensions of ERT, but the presence of an impermeable layer prevents the deep transfer and infiltration of leachate to the aquifer.

By performing a series of laboratory tests، different landfill barrier layers alternatives (liners) were investigated. The selected liner materials were tested for molecular diffusive transport and the diffusion coefficient of chloride ion was determined. Three liner alternatives comprising of clay over silt، geosynthetic clay liner (GCL) over silt، and GCL over clay over silt، were evaluated using laboratory models and under chloride ion advective-diffusive transport. Using the chloride diffusion coefficients obtained in the laboratory and the models downward flow velocity، the observed advective-diffusive transport of chloride ion was evaluated against the predicted transport by theoretical model in three landfill liner alternatives. They were then compared as an effective and suitable liner to decrease contaminant transport in the landfill. The comparison of observed and predicted concentrations showed that there is a good agreement between the two and the theoretical model is capable to predict the behavior of the experimental models. The comparison of the observed concentrations in the simulated ground water underneath the modeled liners showed that for the prevailed test conditions in this study، all three selected liners are good barriers in terms of controlling contaminant transport and there is no significant difference between them، and all possess similar performance.