Evaluation of the ex-situ bioremediation of the petroleum hydrocarbons contaminated soil

Andjela Stanojevic

Bachelor's thesis

Abstract:

The amount of waste entering the environment at the present time is too large to be removed naturally - by self-purification. One of the technologies that are increasingly used in the world for the remediation of polluted environments, primarily soil, is bioremediation. One of the most effective types of bioremediation is the use of non-pathogenic microorganisms (bioaugmentation) for which organic pollutants are an important source of nutrients. The main objective of this thesis was to answer the question: Is it possible in the applied conditions of bioremediation to successfully purify the soil contaminated with fuel oil? In this study, ex-situ bioremediation of soil contaminated with waste oils from petroleum products consisted from different areas in Serbia was performed. Contaminated soil was delivered to Dobanovci in Serbia. Chemical and microbiological indicators of bioremediation were monitored immediately after the preparation of the bio-pile and at the end of the bioremediation procedure, as well as in a control sample (which was prepared without microorganisms). Standard analytical methods were applied. After bioremediation the tested samples showed a slightly increased alkalinity (pH = 7.0-7.5). The loss of organic substances for all the samples after bioremediation was about 34% and the loss of carbonate was about 36%. The value of n-hexane extractable substance (HES) and total petroleum hydrocarbons (TPH) content in the soil after bioremediation decreased by ~90%. The soil sample at the initial state of bioremediation had a significant presence of hydrocarbons with 17C and 18C atoms (pristane and phytane), while after the completion of bioremediation, a significant decrease in the presence of this petroleum hydrocarbons in the soil was observed. After bioremediation, a significant decrease in the content of total (from ~17% to 1.29%) and organic (from ~17% to 0.53%) carbon, as well as total hydrogen (from ~3% to 0.13%) was registered. However, statistically significant difference in total sulfur content (0.07-0.08%) was not registered. The presence of a large number of microorganisms showed that intense aerobic and anaerobic processes take place in soil samples. Microorganisms had a significant role on the decrease of organic substances, HES and TPH, which indicates a very high efficiency of the applied microorganisms in the process of bioremediation with a very favorable bioremediation potential. The general conclusion and answer to the question posed in this thesis is that the applied bioremediation procedure has successfully cleaned the soil contaminated with fuel oil.

Keywords

fuel oil, pristane, phytane, organic substances, microorganisms, bioaugmentation

Language used: English

Date on which the thesis was submitted / produced: 8. 3. 2022

Thesis defence

• Supervisor: prof. Ing. Jiřina Száková, CSc.
• Reader: Marko Spasic, Ing.

Czech University of Life Sciences Prague

Faculty of Agrobiology, Food and Natural Resources

Bachelor programme:
Environmental Engineering