The expression waste reduction and utilization. Waste forms of energy starting from a waste source. Considering that this pap waste, the previously mentioned procedures can be divided into mechanical, thermal and chemical treatment of composite waste. Thermal treatment processes provide a wide range of options to produce electricity, heat, oils, gases, waste. Some procedures are used for commercial purposes, while many are still being developed in laboratories or semi research in the field of thermal treatment of composite waste

Establishing a management system for collecting and disposing the solid waste materials is of great importance in urban areas. Belgrade, the capital city of Serbia, is at its initial phase of managing this problem. Currently, landfill disposal is the main option for dealing with rapidly growing amounts of waste. This paper's research goal is to estimate the landfill gas quantity at Belgrade's only landfill site Vinca, and to estimate the potential for collection and utilization of methane. Considering that this landfill site has no gas collecting system, data from previous measurements of landfill gas were collected and analyzed. In addition to that, the globally acknowledged software for modeling landfill gas generation, LandGEM, was applied.

The efficient use of energy and resources is important from the point of environmental responsibility, but at the same time, it can be an opportunity towards obtaining economic value. Waste-to-energy (WtE) plants have the dual objective first to reduce the amount of waste sent to landfills, and second to generate electricity, heat and biogas. Tracking the flows of energy and materials within WtE system could be convenient optimization tool for waste treatment process. Through modeling and simulation of complex operating systems, it is manageable to present the actual operation states and conditions, and in case of modified operation conditions, possible treatment results. To achieve better operating performances chosen models can analyze, adjust and improve the WtE process in accordance to desired parameters. This paper gives an insight of some of the most adequate tools for modeling of WtE plants.