Abstract
Cognis, part of the Henkel group, has developed a liquid product with lipophilic characteristics that can be applied to a number of environmental clean-up problems: oil contaminated soils, contaminated coast lines and off-shore drilling sites; and, in the event of large-scaled accidents, it can be combined with physical and mechanical pre-cleaning methods.
The Cognis product emulsifies hydrocarbons, making them disperse in water and thereby promoting biodegradation. With organic bound phosphorous and nitrogen the product also acts as a nutrient source for microbes. It forms a layer around contaminant molecules, thus reducing leaching of nutrients and fixing microbes to the contamiants. It boosts total cell count of local oil-devouring bacteria rapidly so that the natural self-cleaning capacity rises to a multiple acceleration. The product itself is of outstanding eco-compatibility: it is not washed-out into the groundwater, it does not remobilize contaminants, and it's active ingredients have a food and/or fodder permittance.
A large-scaled pilot test has shown that common agricultural fertilizers are not useful for bioremediation, because mineral nutrients were washed-out, and the biodegradation process was not enhanced.
Beside more cost intensive conventional ex-situ and in-situ bioremediation techniques, a special low cost technology was developed in a joint effort with IABG. This technique is especially suitable for contaminated zones located no more than 2 m below soil surfaces (D.R.O.P.: Decontamination and Revitalisation of Oil Polluted Land). While the product is applied by means of sprinkling systems and subsequently mixed into the soil, this technology is even applicable for water protection areas, wetlands or nature reserves. The overall cost of this measure is only a third of other well-known in-situ methods.
