Bioremediation

Soil Bioremediation

Through bioremediation, soil lightly contaminated with petroleum hydrocarbons is inoculated with a nutrient and engineered bacteria that combine to break down the contaminants. The bacteria access the nutrients, which have attached to the hydrocarbons, and quickly and thoroughly degrade the contaminants. The average time needed to reduce contaminants to acceptable levels through bioremediation is approximately 7 to 14 days. The bioremediation process provides substantial cost savings when compared to
thermal desorption or chemical fixation, and is typically used on soil with lower levels of contaminants. Materials treated through bioremediation are typically beneficially re-used as fill material.

This Video about Soil Remediation !!!

Soil contamination

Soil contamination is caused by the presence of man-made chemicals or other alteration in the natural soil environment. This type of contamination typically arises from the rupture of underground storage tanks, application of pesticides, percolation of contaminated surface water to subsurface strata, oil and fuel dumping, leaching of wastes from landfills or direct discharge of industrial wastes to the soil. The most common chemicals involved are petroleum hydrocarbons, solvents, pesticides, lead and other heavy metals. This occurrence of this phenomenon is correlated with the degree of industrialization and intensity of chemical usage.
The concern over soil contamination stems primarily from health risks, both of direct contact and from secondary contamination of water supplies.
In North America and Western Europe the extent of contaminated land is most well known, with many of countries in these areas having a legal framework to identify and deal with this environmental problem; this however may well be just the tip of the iceberg with developing countries very likely to be the next generation of new soil contamination cases.
The United States, while having some of the most widespread soil contamination, has actually been a leader in defining and implementing standards for cleanup. Other industrialized countries have a large number of contaminated sites, but lag the U.S. in executing remediation. Developing countries may be leading in the next generation of new soil contamination cases.
Each year in the U.S., thousands of sites complete soil contamination cleanup, some by using microbes that “eat up” toxic chemicals in soil, many others by simple excavation and others by more expensive high-tech soil vapor extraction or air stripping. At the same time, efforts proceed worldwide in creating and identifying new sites of soil contamination, particularly in industrial countries other than the U.S., and in developing countries which lack the money and the technology to adequately protect soil resources.