The small-scale microbial processes for remediation of sediments contaminated with hydrocarbons

Abstract

The accidents caused by the petroleum industry have caused several deleterious effects both in the environmental and economic fields, with the most affected being natural ecosystems. Among these, mangroves has been increasingly a center of great studies because of its great ecological, economic, and social importance and because it is one of the biosystems that suffers the greatest impacts. The use of biological processes to recover natural environments is gaining increasing importance throughout the world, especially in ecosystems affected by oil hydrocarbons. These methods are favored by being environmentally friendly, clear, lower cost, and easier to apply on a large scale and do not alter the balance of ecosystems. Currently one of the most applied biological techniques for the recovery of environments affected by petroleum activities is bioremediation, which consists of the use of microorganisms to decontaminate areas. The success of bioremediation is directly related to the physical and chemical properties of petroleum, the characteristics of the by-products generated by bioremediation processes, and the peculiarities of the affected ecosystems. Results of scientific research have corroborated that the decrease of hydrocarbon concentrations is directly related to the nutrient and microorganism rates present in the environment. However, this chapter presents a series of experiments with oil-contaminated sediments in laboratory scale, using the technique of biostimulation and bioaugmentation.