Treatability by biorecuperation in situ of urban soils contaminated with hydrocarbons

In the Shell-Rios gas station, two hydrocarbon spills occurred: Diesel in 1996 and gasoline in December 1997. The floor of the General San Martín street was tried to decontaminate the floor of the General San Martín street withdrawing it and replacing it with another not contaminated. In May 2001 it was found that soil pollution levels were high. To achieve decontamination to permissible levels, it is necessary to resort to biorecuperation in situ (bis). On the other hand, hydrocarbon spills are frequent in our country, so it is urgent to acquire training in this method of decontamination. Biorrecuperation takes advantage of the ability of microorganisms to detoxify hazardous compounds. Aerobic digestion is carried out by adding oxygen and fertilizers to the digestion mixture to stimulate the growth and oxidative capacity of microorganisms. There are several biorecuperation techniques. The one that is intended to be applied on a real scale is the Biorrecuperation in situ (bis), so that the tests will be done in the laboratory in situations the most similar to the real ones. The general objective of the project is to stimulate the formation of an important population of microorganisms that degrade hydrocarbons to know whether it is possible to apply in an urban area contaminated a biorecuperation in situ. Applying the biorecuperation in situ at hydrocarbons contaminated with contaminant mineralization, that is, hydrocarbons are transformed into CO2 and water. The method to be applied is as follows: using a backhoe, two samples will be taken: one of contaminated soil and one of without contaminating. Samples will be analyzed to determine the concentration and type of hydrocarbons, heavy metal content and NPK. The native microorganisms will be identified and isolated with which the inoculum will be prepared. Inoculum, oxygen, water and nutrients will be added to the contaminated sample and to a sterile witness that will contain a known amount of a mixture of gasoline and diesel. Two other witnesses similar to the previous ones will be prepared except that the inoculum will be added. The pH, temperature and humidity and quarterly TPH and chromatographic profile will be monitored weekly. The process will be suspended after nine months of treatment and the results will be analyzed and discussed.

2nd UNIVERSITY RESEARCH PROJECT COMPETITION