Zeitschrift für Bioremediation und biologischen Abbau

Abstrakt

Investigation of the Effect of Co-Metabolism on Removal of Dodecane by Microbial Consortium from Soil in a Slurry Sequencing Bioreactor

Majid Nozari, Mohammad Reza Samaei, Mansooreh Dehghani

Background and Objectives: Biodegradation techniques are nowadays widely used for cleaning soil contaminated with oil. The aim of this study is to evaluate the effects of cell metabolism (glucose) on Dodecane removal in slurry sequencing batch reactors (SBR) by a bacterial consortium.

Materials and Methods: In this study, a Slurry Sequencing Batch Reactor (SSBR) was used as a pilot by a bacterial consortium, including bacterium Acinetobacter radioresistens, Bacillus subtilis, and Pseudomonas aeruginosa, in order to remove different concentrations of dodecane (1, 4, 7, and 10 percent). Sampling was performed for four times during the sedimentation step. Then, the samples were analyzed by GC-FID and the results were analyzed statistically.

Results: The results showed that dodecane removal (%) by the microbial consortium was higher in lower initial concentrations; such a way that the biological removal of dodecane was respectively 47.39%, 38.41%, 28.03%, and 17.46% in the concentrations of 1%, 4%, 7%, and 10% on the third day. Moreover, Adding an external carbon source (glucose) in the first and second day increased Dodecane biological removal by 17.12 and 17.41 respectively, which are 1.2 and 1.94 times the amount of biological Dodecane removal in non-cometabolism conditions.

Conclusion: The results showed that SSBR could be used as an exit-situation effective method for dodecane removal in low concentrations through considering the effective factors in its function, such as dissolved oxygen, pH, and temperature. Also, adding the secondary carbon source could be effective in dodecane removal from the soil. Yet, this effect might be different on various days.