Many solid waste management systems employ mechanical and biological treatment (MBT) prior to waste disposal. The waste is separated into recyclables and landfill.
Recyclable materials such as metals, plastics, and glass are usually removed early in the process with screens, conveyors, shredders, and mechanical separators. This physical unit can be designed to extract specific types of waste which can be used in thermal combustion power plants and cement kilns.
The back end of the system employs biological processes to treat the output from the physical unit. Common biological treatment units include anaerobic digestion, composting and bio drying. Here the wastes are decomposed for further use. Anaerobic digestion uses microorganisms to break down the components in the waste. Composting is a form of aerobic digestion. In the bio drying process the wastes are heated in order to extract refuse derived fuels.
The solid waste is directly fed inside the physical equipment. A mechanical sorting process separates biodegradables and recyclables. The biodegradables are processed in the biological unit into delivers vapors, gas, liquid and/or humus. Some output from this unit is landfilled.
Mechanical and biological treatment units serve as invaluable parts of waste management systems. You can also configure the system depending on your needs. The MBT system is used worldwide to get rid of solid wastes. The recyclable stream is used by the cement industry and thermal power stations in Europe. The agriculture industry can often use the output from the biological unit in this MBT system as it can increase the fertility of the soil.
The MBT system adopts simple process to treat wastes. The physical unit focuses in the separation of recyclables and the biological unit breaks down the biodegradable components into fertilizer.