Labor- und Feldversuche zur mikrobiologischen Sanierung von altoelkontaminierten Raffineriestandorten Endbericht

To develop techniques for the microbial on-site (pile) and in-situ reclamation, laboratory and pilot-scale experiments were performed at a contaminated former waste oil refinery site. Concerning the pile experiments, volatile pollutants like chlorinated hydrocarbons and benzene derivatives (BTEX) were stripped almost completely during excavation and soil preparation. The concentrations of lower molecular mass polychlorinated hydrocarbons (PCB) were reduced by about 50% during a pile treatment of more than 1 year. The mineral oil hydrocarbons were reduced by about 70% independent from methods and starting concentrations. The remaining fraction was of high molecular mass, not leachable and not bioavailable. For the microbiological in-situ remediation of saturated aquifers, an optimal oxygen supply of microorganisms is of greatest importance. The electron acceptors tested were hydrogen peroxide (H_2O_2), technical grade oxygen (O_2), and nitrate. H_2O_2 was recommended: it provides the best O_2 supply and caused the highest microbial degradation activity. Nitrate can be applied additionally. Due to a lower mineralisation efficiency compared to H_2O_2, it results in a 'pre-remediation' of the anaerobic areas of the aquifer. Chlorinated hydrocarbons and BTEX were preferentially washed out hydraulically. The result of R and D project were directly transferred into execution plans for the microbial on-site and in-situ remediation at the site. Due to a high H_2O_2 decay and a resulting formation of O_2 bubbles in the aquifer, the technical reclamation will include a pulsed infiltration. A monitoring program was elaborated for the control and optimisation of the in-situ remediation. (orig.)Available from TIB Hannover: F95B2542+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany); Hessische Industriemuell GmbH, Wiesbaden (Germany). Bereich AltlastensanierungsgesellschaftDEGerman