Biological groundwater treatment of BTEX and PAH

The contaminated groundwater is pumped via wells with direct oil extraction. The water is then aerated, whereby volatile hydrocarbons (VOC) are outgassed and separated by means of activated carbon (AK) filters. The pre-aerated water is then passed over gravel filters for de-icing and removal of suspended solids.

The main contaminants are removed in a fully automatic controlled biological high-performance stage. For this purpose, activated carbon filters are used on which microorganisms settle and break down the organic pollutants.

The non-biodegradable cyanides are then safely removed by means of ion exchangers. Most of the purified process water is then reintroduced into the soil via a nozzle infiltration system in order to flush out the source of damage. Due to the proximity of the residential building, the facility is located in soundproof containers. The system availability is 98%.

Since autumn 2022, the plant has been supplemented with an overgrown soil filter, which removes the high ammonium content in the treated groundwater. The downstream plant treatment plant enables the use of the purified groundwater for irrigation of the lawns and beds as well as for feeding the neighborhood pond in the Ernst-Thälmann-Park, which threatened to dry out in the increasingly hot summers and prolonged dry periods.

The addition of the overgrown soil filter with about 70m3 of storage space for irrigation and overflow to the Kiezteich pond makes it possible to save drinking water, which was previously used, and improves the microclimate and well-being of visitors to the Ernst-Thälmann-Park due to the evaporative cooling of the reed bed of the wetland. The use of this unconventional water resource (purified groundwater from a contaminated site) is thus an innovative response to climate change and contributes to the conservation of groundwater in the capital region.