GROWTH OF THE CALIFORNIAN RED WORM (Eisenia foetida) IN VERMICOMPOSTING PROCESS OF DIESEL CONTAMINATED SOIL

The goal of this work was to determine the growth and adaptability of the Californian red worm (Eisenia foetida) in a medium contaminated with diesel and to know the efficiency of degradation of the hydrocarbon in the vermicomposting process. Six different diesel concentrations were tested: 1, 5, 10, 15, 20 and 25%. The physicochemical properties of the soil were analyzed in three stages: soil mixed with organic matter (previous to diesel addition), in the soil/organic matter/diesel mixture once the vermicomposting process had started, and at the end of the vermicomposting process. Evolution in the population of the red worm and the removal of contaminant during the process was measured. The highest diesel removal achieved was 97%, reached in the contaminated soil with a 20% pollutant concentration. The results show that the vermicomposting process with Californian red worm represents an efficient alternative for bioremediation of soils contaminated with hydrocarbons.