Bioremediation

Author: Shaun O Regan - Eco-Tabs

( Article Type: Explanation )

Bioremediation is the application of a biological treatment (mainly microbes) to clean hazardous contaminants in soil and surface or subsurface waters. These microorganisms can transform contaminants into less harmful forms. The bacteria feed on the contamination, deriving nutrition for growth and for reproduction. Complex chemical reactions occur, and the result of this natural process is that contaminants are used up completely or are converted into an innocuous product such as water and carbon dioxide.

Three factors in deciding whether bioremediation is the appropriate method for site remediation are:
• Whether the contaminants are susceptible to bioremediation by the organisms that could be successfully added to the site.
• Whether the contaminants are accessible to the micro-organism
• Whether any inhibitory environmental conditions exist that may interfere with the growth and reproduction of these microbes (e.g. no oxygen). As an example, in most cases, poor pond, lake, river and dam water is a result of an overload of organic matter, including excess nitrogen, ammonia or phosphorous. This build-up serves as a food supply for algae, cyanobacteria, anaerobic bacteria, and certain weeds, producing algae blooms and scummy conditions accompanied by a bad aroma.

These conditions can be eliminated through a natural biological process called bioaugmentation which introduces natural bacteria and enzymes in large quantities into a polluted system. This results in the correct balance of microbes in those areas where the natural microbes may have been destroyed or exist in low numbers, and a better water quality is achieved without the addition of hard chemicals such as copper or aluminium sulphate. Further, bioremediation can even reduce concentrations of heavy metals like Iron, copper and Manganese (to name a few), along with sufides and other contaminants found in mining waste water.