COMBINED REMOVAL OF OIL, TOXIC HEAVY METALS AND ARSENIC FROM POLLUTED SOIL

摘要

The data from this study showed that it was possible to achieve an efficient simultaneous removal of oil, toxic heavy metals and arsenic from heavily polluted soils using bioremediation by heap or in situ techniques. It was also possible to enhance the oil biodegradation by inoculating the soil with laboratory-bred microorganisms possessing a high activity toward the most refractory components of the oil. The indigenous and laboratory-bred microorganisms rapidly formed a stable community in the polluted soil. The growth and activity of this microbial community were maintained at high levels by suitable changes in the levels of some essential environmental factors such as water, oxygen and nutrient contents in the soil. The bioremediation markedly depended on the temperature of the soil. The presence of an impermeable geological barrier below the polluted soil is necessary for the application of the in situ technique. Both the heap and in situ techniques are connected with the construction of systems to collect the pregnant soil effluents as well as of systems to clean up these effluents.