Purification of groundwater containing pollutants, using chemical reaction and adsorption container

摘要

Purification of groundwater containing pollutants, using chemical reaction and adsorption container, is implemented as simple siphonic arrangement with careful control of relative levels The polluted groundwater level (2) is higher in the extraction region (A) than in the discharge region (E) for purified water. The water table fall is natural, or is promoted between the regions (A, E). The discharge passes into e.g. an outfall ditch, prepared gutter, channel, lower water table or drain. Extraction lowers the water table by height (h), less than the height difference (H) between the regions (A, E), inducing the flow. One or more vessels (1) with inlet openings (11) are located in the extraction region. A pipeline (5) inlet (4) is submerged in the vessel. The outlet opening (6) is maintained constantly below the lowering level (12) in the vessel, with a height difference (a). A container (9) in the sealed line contains reactive substances (10). Line and container are sealed air-tight. The container cross section exceeds that of the line. The method operates siphonically, with no further energy input. Preferred features: The container (9) is preferably located in a readily-accessible position above the water table and/or above ground level. The sealed line includes (manual) flow control valves (7, 13). They are adjusted to set up a quasi-static flow state. At the start (4) or end (6) of the line, a pump is mounted, optionally removably. This produces the lowering (h) in water level, to fill the pipeline and commence operations. The operation may be carried out between a number of different levels. The vessel (1) may take over the function of the pipeline in the extraction region. It is constructed as a percolation pit for water. The outlet openings (6) for cleaned groundwater discharge into one or more groundwater lines, ditches, streams, flows, channels, drains or a combination. The container (9) is filled with an adsorbent, reactive substance and/or aggregate, suitable for active and/or passive conversion of pollutants. The container enables desorption of pollutants, preferably using air under reduced pressure. Whilst the container alone is not resistant to reduced pressures, it is reinforced by its solid filling. Provision for volumetric flowrate and purification efficiency measurement are made in the pipeline. Volumetric flowrate is varied to change the hydraulic head (a) and/or flow control valves are operated to alter flow resistance. Operation is initiated using equipment to fill the line with water, using reduced pressure. The outlet region is so designed that no air can enter the run-off line, especially by formation of a siphon.