General Cleanup Technology

Soil remediation with amino acids – crude oil decontamination

The described process for the in situ remediation of soils contaminated with crude oil is based on the degradation of pollutants by microbial action stimulated by the addition of oxygen and nutrients. The use of amino acids as nutrients results in a significant enhancement or short term acceleration of petroleum hydrocarbon degradation. The mixture of amino acids and peptides is considered environmentally benign since it is organic in nature.

Summary

Crude oil contamination occurs mainly along pipelines with leakages as well as due to accidents. The remediation of soils contaminated with PHC (petroleum hydrocarbons) is frequently achieved by excavation and landfilling (“dig and dump”). In remote areas, however, in situ remediation can be an appropriate alternative. One such method is “natural spot remediation”, which stimulates natural microbial degradation by addition of oxygen and nutrients.
The project concept involved supplying nutrients as a mixture of amino acids and peptides (AA/P). Since amino acids contain both hydrophobic and hydrophilic groups, they act as detergents and emulsify oil constituents, which can then be better degraded by the bacteria. Trials were conducted in the laboratory and in the field.

Results:

  • Column tests demonstrated that injection of an AA/P mixture in the soil resulted in a higher remediation rate (80%) than if no AA/P mixture was applied. A combination of AA/P application and aeration further enhances/accelerates PHC remediation (remediation rate of 87%).
  • While PHC degradation in soils in which an AA/P mixture has been injected is initially faster, this becomes relative as the time period increases.
  • Further trials showed that samples with a sand component of 20 kg / 5 l soil achieve remediation rates of 9-21%. Samples with a sand component of 5 kg / 40 l soil achieve a rate of 27-37%.
  • As pore volume increases, the impact of aeration or AA/P application on the remediation rate drops; when pore volume decreases, the inverse effect is observed.
  • During field trials, PHC degradation in unsuitable soils could be increased by using a solar powered bioventing module.

Project Participants

Implementing Institutions

Chemisches Institut Pforzheim GmbH (CIP)

Cooperation Partner

Universität Hamburg - Universitätsklinikum Hamburg-Eppendorf - Institut für Experimentelle und Klinische Pharmakologie und Toxikologie

Russian Academy of Sciences - Institute of Basic Biological Problems

More Project Information

Project title: Verbundprojekt: Zukunftsweisende Verfahrenstechniken zur Sanierung kontaminierter Böden - Teilprojekt 2: Rohöldekontamination

Project number: 02WS0212

Project period: 2002 - 2005Text

Project region: Germany (Baden-Württemberg), Russia

Project contact:

Herr Dr. Eberhardt

View Publication

Source: German National Library of Science and Technology Hannover (TIB)