Analysis of efficacy of the process of remediation of landfill site soil contaminated with leachate using material flow analysis

There are two possible cases concerning non-sanitary municipal solid waste landfills due to failure to meet requirements with respect to impermeability and thickness of geological barrier as well as absence of implementation and use of a waste and leachate management system, and also depending on type and the mineral composition of the geological barrier. In the first case, impermeable clay, kaolinite, is prevailing in the composition of the geological barrier the final outcome of which is the spillage of leachate into the volume of the deposited waste, as well as its outbreak on the surface of the landfill site. In the second case, permeable clay, smectite, is prevailing in the composition of geological barrier with dominant leachate infiltration into the ground flow. In accordance with the first case, using STAN software the substance flow analysis (SFA) was carried out, of cadmium primarily, within three scenarios. Efficacy of remediation of the landfill site soil contaminated with leachate from the aspect of heavy metal reduction, focused primarily on cadmium, using in-situ and ex-situ systems, was presented within Scenario 1 and Scenario 2. Possibility and efficacy of direct treatment of leachate in a corresponding plant for its processing, in case of implementing and using the leachate management system, was presented within Scenario 3. Efficacy of cadmium flow reduction accomplished within Scenario 1, Scenario 2 and Scenario 3 amounts to 99.04 %, 55 % and 99.2 %, respectively. Prevention of landfill site contamination with leachate using the system of its management is an optimum option and a desirable practice, while in the case of the already existing contamination of the landfill site and its immediate environment, using in-situ system of landfill site soil remediation, based on achieved results, high efficacy was achieved contrary to use of the ex-situ system.