Bioremediation of areas polluted with chlorinated and non-chlorinated hydrocarbons

摘要

In recent decades, growing awareness of the health risks caused by the presence of toxic compounds in the environment has initiated the development of clean-up technologies. A number of innovative technologies are being used for cleaning up contaminated soils, e.g. in situ bioremediation. This paper discusses three in situ bioremediation projects in the Netherlands.rnAn in situ biological remediation method for hexachlorocyclohexane (HCH)-contaminated soil and groundwater has been developed, which combines an active anaerobic in situ zone with an aerobic on-site treatment. The anaerobic degradation of HCH to benzene and monochlorobenzene is stimulated in the anaerobic zone, and the intermediates formed are completely degraded to harmless compounds under aerobic conditions in a water-treatment plant.rnAt a site that was contaminated with aromatic compounds such as BTEX, a push-pull experiment was performed. Nitrate was added to the groundwater, and measurements of the benzene concentration indicated a stimulated degradation of benzene.rnFinally, the processes at the interface between groundwater and surface water (NA-interface) were studied, as this interface can play an important role in the natural attenuation of organic contaminants. With the methods used, it appeared difficult to distinguish the degradation of micropollutants in the NA-interface from diffusion and dispersion effects. However, according to the results from the model, the total flux of pollutants towards the surface water can be reduced by 55% in steady-state systems, and by 5% in tidal systems.