Reduction of hydrocarbons and other organic trace materials by a decentralized road runoff treatment system

 In collaboration with the Chair of Water Quality Control and Environmental Technology at Ruhr University of Bochum (RUB) and the company Dr. Pecher AG, a decentralized stormwater treatment system had been developed and modified for the retention of hydrocarbons and other organic trace materials from traffic area runoff.

Lab experiments were conducted in order to evaluate filter materials and filter material combinations for the retention of organic pollutants such as PAH (Polycyclic Aromatic Hydrocarbon), PH (Petroleum Hydrocarbons), ETBE (Ethyl-tert-butylether), and MTBE (Methyl-tert-butylether). Batch and column experiments were carried out to determine the maximum sorption capacities and sorption kinetics of several filter materials. Moreover, the suitability of the modified filter material combination, which was developed during this project, was evaluated for the retention of heavy metals and the influences of de-icing salt applications.

Afterwards, the developed filter material combination was tested in two large-scale treatment plants in Wuppertal and Mönchengladbach to monitor its operation by continuous sampling over a one year period. Simultaneously, further studies were performed at pilot scale to determine the influences of further ions and real preloaded columns on the removal of pollutants. Maintenance intervals of the treatment plants were also evaluated. As a result, a guideline was developed with the aim of implementation and improvement of existing decentralized stormwater treatment systems for the reduction of PH and other organic trace substances from road runoff. Furthermore, the expected operational and investment costs were calculated. For the service time, the retention of dissolved zinc was the limiting factor concerning the lab experiments, whereas the risk of clogging was crucial in the field, where the differences between the two locations were reflected.