A review on different bioremediation technologies for soil polluted with petroleum hydrocarbons

Abstract

Crude oil and its derivates now has become a threat to environment due to extraction and transportation. Accidental oil spills occur regularly at many locations throughout the world. Contamination / pollution of soil with petroleum hydrocarbons has become a serious problem. Various physical, chemical and biological remediation strategies have been used to restore polluted soils. For bioremediation technology application, it is necessary to know the optimizing ways of the biodegradation process. Even though cost the of soil decontamination is roughly similar in many ways, more and more of pollution research is directed to biotechnological methods based on the ability of microorganisms to degrade certain pollutants under both natural conditions and through anthropogenic intervention meant to shorten the time of ecological reconstruction of polluted sites. Bioremediation can be divided into two basic types: natural attenuation, which can be applied when the natural conditions are suitable for the performance of bioremediation without human intervention, and engineered bioremediation, which is used when is necessary to add substances that stimulate microorganisms. Soil bioremediation technologies could be in situ or ex situ. As bioremediation technologies in situ cand be applied: biostimulation, bioaugmentation, bioventing, stimulation with surfactans, phytoremediation, use of agricultural land, natural attenuation, biobubbling, cometabolism. Ex situ bioremediation technologies could be achieved by bioreactors, hovering the land, biopile, composting.