EVALUATION OF BIODEGRADATION IN THE SOIL OF OIL RESIDUES FROM A PETROLEUM REFINARY

Abstract

Innumerable types of treatment systems exist to promote the degradation of oil residues. One of the best known and most used systems is landfarming, which consists of the aerobic biodegradation of residues that are applied in the soil and incorporated into the superficial layers. The process of landfarming uses the activity of the microorganisms in the soil to degrade and/or to immobilize many components of the residues. This study was developed in the Superior Center for Technological Education - CESET/UNICAMP, with the objective of verifying the biodegradation of oily dregs resulting from the oil refinery process, and the biological sludge that results from the industrial effluent treatment process of the Refinery of Paulínia, SP, in landfarming soil. Through the analysis of the results obtained, it was verified that when oily dregs were added to the soil, the biodegradation was more efficient. Applying only the biological sludge in the same rate as the oily dregs, the breathing that was caused by the biodegradation did not undergo quantitative differences. Mixing the application of oily dregs and biological sludge in a ratio of 1:1, an improvement was observed in the breathing efficiency, however this did not surpass that emitted by the ground when only the oily dregs were applied. It was concluded that the landfarming system has indigenous microorganisms able to degrade several compounds existing in the residues of oil refinery. To improve the efficiency of the biodegradation, the rate of application of the residues in the ground is a limiting factor.