This sanitary landfill method is the final-stage in physical treatment of solid waste. There are two main types of landfill in general.
2.1) SANITARY LANDFILL, is suitable for non-hazardous solid waste and municipal solid waste.
2.2) SECURE LANDFILL, is suitable for industrial and hazardous solid waste which are pretreated to the stabilization and solidification stage before entering the landfill.
The stabilization and solidification of solid waste mean that the waste is pre-treated with specific process to the minimum or non-hazardous stage. The process will generally remove the acidity or alkalinity stage to the neutralized stage, then process the waste to solid stage and cover the waste with cement as a block. The waste will then be secured inside the cement block and is safety for transportation and landfilling.
Each type of waste will require different stabilization processing method. Therefore before the stabilizing process, each waste will be tested in the laboratory to find its specific property before treatment. For example, the Hg waste will be neutralized by sodium-sulfide. Then it will be mixed with cement to become solid form before disposing to the secure landfill.