In situ process for improvement of microbiological ground water and soil remediation by electrokinetic dispersion effects

Aims

The aim of this project is the stimulation of microbiological groundwater and soil remediation by electro-kinetic dispersion effects to overcome mass transport limitation of the natural degradation process. The nutrients will be transported in the depleted regions to get bioavailable for the remediation process to shorten the contaminated downstream region.

BTEX (Benzene, Toluene, Ethylbenzene and Xylene) and PAHs (polycyclic aromatic hydrocarbons) are typical pollutants of groundwater in the surrounding of gas plants. The aerobic degradation of aromatic hydrocarbons by micro- organisms takes place in a multi step process by successive degradation of each ring. Degradation under consumption of oxygen starts with building of dihydrodiol followed by an cleavage into acids and smaller fragments. The last ring will be degraded by building of salicylic acid and pyrocatechol. At last a mineralization into biomass and carbon dioxide takes place. Toluene will be degraded by formation of benzyl alcohol and benzyl aldehyde. The anaerobic degradation process will be supported by anions like nitrates and sulphates. For the degradation in the soil the bioavailability of each component like pollutant, nutrient and micro-organisms in the same place is very important. Dispersion of the components perpendicular to the flow direction of groundwater is very weak, so that the support of transport in this direction by electro-kinetic processes like, electro-osmosis and electrophoresis and migration of ions is necessary. In that case coincidence of all components takes place to optimize the degradation process.