In-situ cleaning of contaminated groundwater, comprises saturating groundwater with ozone-oxygen mixture using ozone injection unit and then propagating ozone into the groundwater in flow direction, and controlling dosage of ozone-oxygen

摘要

The method comprises saturating contaminated groundwater with ozone-oxygen mixture using an ozone injection unit (1) and then propagating ozone into the groundwater in a flow direction, and controlling the dosage of ozone-oxygen over a monitoring gauge (2) and subsequently withdrawing the groundwater in a withdrawal unit (3), through which a defined quantity of groundwater is pumped out and is again led back by a clean filtration unit (4), which is present in the flow direction of the groundwater viewed above the ozone injection unit. The ozone-oxygen mixture contains 5-8% of ozone content. The method comprises saturating contaminated groundwater with ozone-oxygen mixture using an ozone injection unit (1) and then propagating ozone into the groundwater in a flow direction, and controlling the dosage of ozone-oxygen over a monitoring gauge (2) and subsequently withdrawing the groundwater in a withdrawal unit (3), through which a defined quantity of groundwater is pumped out and is again led back by a clean filtration unit (4), which is present in the flow direction of the groundwater viewed above the ozone injection unit. The ozone-oxygen mixture contains 5-8% of ozone content. The ozone is produced from oxygen and specially dried air by using an ozone generator and is dosed into the groundwater, so that a microbiological decomposition of the pollutants occurs parallel or in connection to the chemical oxidation. The ozone entry is continuously or discontinuously carried out. The ozone supply is controlled over the monitoring gauge to reach an optimization of the chemical oxidation. The microbiological decomposition of the pollutants is conveyed by the introduced oxygen and by a nutrient addition corresponding to carbon, nitrogen and phosphorous ratio of 100:10:1. The nutrient is supplied by the clean filtration unit over the monitoring level. The withdrawal step is carried out in connection to the chemical oxidation. The pH value adjustment is carried out by a buffer action of the ground during the entire process and no further pH adjustment is necessary. The ozone-oxygen mixture is infiltrated, so that the ozone completely or almost completely dissolves in an aqueous phase and the surplus oxygen guides from the saturated phase to a stripping of volatile pollutants during leakage and then adds to an additional cleaning of the groundwater. The groundwater cleaning is carried out by the combination of several in-situ process units parallely switched one behind the other.