Device for the in situ depollution of aquifers from organic compounds in which a photoreactor is located in a dry zone created by two barrier walls and the flow of water is gravitational not pumped

摘要

A device for the depollution of aquifers contaminated by organic pollutants comprising a means of channelling the polluted ground water towards an in situ treatment zone which is below, or effectively below, the ground water level and a means of treating the water in a photoreactor located in the zone and a method of water depollution using the device. The means of channelling the ground water consists of two secure walls running from the surface to the bedrock at the base of the aquifer on either side of a gate. The gate comprises an upstream piezometer control, a downstream piezometer control and a treatment well. Both controls incorporate a silica filter body to filter the inlet water and assist the flow of outlet water into the soil. The photoreactor is implanted in a dry zone below the level of the groundwater and is of slightly smaller diameter than the treatment well. Its size is dependent on the rate of flow of the water and the degree of pollution. The presence of the walls causes a rise in the water level on the inlet side and the system operates on a gravitational basis without pumping. It is, however, disclosed that the expression 'effectively below' refers to cases when geological factors may lead to the treatment zone being located above or slightly above the water level with a consequent need for pumping.