Procedure for cleaning contaminated soil or waste containing hydrocarbons, heavy metals or polychlorobiphenyl (PCB)

摘要

The contaminated material is broken up in a crusher (1) and then mixed with water and a carrier which is micronized or extruded high density copolymer in 3 mm balls. These absorb hydrocarbons and PCB at low temperatures and are then separated from the mixture by decantation and discharged or regenerated until the soil no longer contains PCB The carrier is an absorbent, made of industrial waste such as polymers or copolymers, micronized to between 500 and 600 microns or extruded in 3 mm balls to encourage the activation of the carrier before its use. The used carrier is sent to a centrifuge (7) with sufficient G force for the pollutant to pass through a physical separation phase, allowing the carrier to be re-used. The volatile organic components are catered for by enclosing the installation so they are absorbed by the carrier and held in the mass. After the carrier is separated out, the soil contaminated with heavy metals is sent to a mixer (11) into which is added an ecologically active neutral solution linking with the metals so the soil can be washed clean with water. Between 15 and 20% of the volume of material in the mixer is finally separated from the water by a filter band connected to a vacuum (12), regenerated and cleaned of metals which can eventually be reused. The carrier containing PCB is incinerated in a special incinerator after separation. Installation for carrying out the above process.