Solvent extraction often used to recover a component from liquid. It uses a solvent (a fluid that can dissolve another substance) to separate or remove hazardous organic contaminants from sludges, sediments, or soil and does not destroy contaminants. It concentrates them so they can be more easily recycled or destroyed by another technology. Solvent extraction is of major commercial importance to the chemical and biochemical industries, as it is the most efficient method of separation of valuable products from complex feedstocks or reaction products. Some extraction techniques in involve partition between two immiscible liquids, others involve either continuous extractions or batch extractions. The solvent can be a vapour, supercritical fluid, or liquid, and the sample can be a gas, liquid or solid. There are a wide range of techniques used.
The solvent extraction process involves five steps:
1.Preparation (sorting the contaminated material)
2.Extraction
3.Separation of concentrated contaminants from solvent
4.Removal of residual solvent
5.Contaminant recovery, recycling, or further treatment
