ABSTRACT
After the bioremediation of soils contaminated with mineral oil products, residual contaminants (designated as total solvent extractable material [TSEM]) remain therein. Since limited information is available about the movement and fate of these residual contaminants in the environment, the potential environmental hazards are difficult to assess. The aim of this study was to identify and quantify the relevant transport and transformation processes of the residual contaminants in bioremediated soil such as volatilization, leaching, and further biodegradation and to conduct a mass flow analysis for the TSEM in bioremediated soil for the first year after application as top soil. The results indicate that after 1 year, the major portion (93%) of the TSEM can be recovered in the top soil and 7% of the TSEM was lost. The majority of the total losses (>98%) was due to transformation processes (biodegradation and aging effects), while small amounts escaped into the atmosphere (0.08%), plant uptake was negligible, (<0.001%) and leaching, identified as the major transport process, accounted for only small effects (1.7%).
