bioremediation

It is defined as the process whereby organic wastesare biologically degraded under controlled conditionsto an innocuous state, or to levels belowconcentration limits established by regulatoryauthorities.

Simply:

The use of bacteria and fungi and plants to breakdown or degrade toxic chemical compounds that haveaccumulated in the environment

What is Bioremediation?

COMPOUNDS WHICH CAN BE ELIMINATED BY BIOREMEDIATION

• POLLUTANTS• NATURALLY-OCCURRING

COMPOUNDS IN THE

ENVIRONMENT THAT ARE

PRESENT IN UNNATURALLY

HIGH CONCENTRATIONS.

• EXAMPLES:

• CRUDE OIL

• REFINED OIL

• PHOSPHATES

• HEAVY METALS

• XENOBIOTICS• CHEMICALLY SYNTHESIZED

COMPOUNDS THAT HAVE

NEVER OCCURRED IN

NATURE.

• EXAMPLES:

• PESTICIDES

• HERBICIDES

• PLASTICS

WHY MICROBES ??• TYPICALLY VERY RAPID IF FOOD (CARBON SOURCE) IS PRESENT:

POPULATION DOUBLES EVERY 45 MINUTES

• PRISTINE SOILS CONTAIN 100 TO 1000 AEROBIC BACTERIA PER

GRAM OF SOIL

• INCREASES TO 105

WITHIN ONE WEEK IF CARBON SOURCE IS

INTRODUCED

FUNDAMENTALS OF CLEANUP REACTIONS

• AEROBIC METABOLISM

• MICROBES USE O2 IN THEIR METABOLISM TO DEGRADE CONTAMINANTS

• ANAEROBIC METABOLISM

• MICROBES SUBSTITUTE ANOTHER CHEMICAL FOR O2 TO DEGRADE CONTAMINANTS

TYPES OF BIOREMEDIATION

• THE TWO MAIN TYPES OF

BIOREMEDIATION ARE IN SITU

BIOREMEDIATION AND EX SITU

BIOREMEDIATION. IN ADDITION,

ANOTHER OFFSHOOT OF

BIOREMEDIATION IS

PHYTOREMEDIATION.

IN-SITU VS. EX-SITU REMEDIATIONIN-SITU BIOREMEDIATION TREATS CONTAMINATED SOIL OR

GROUNDWATER IN THE LOCATION WHERE IT WAS FOUND.

USUALLY MICROORGANISMS ARE PUMPED INTO THE SOIL OR

GROUND WATER SO THE CONTAMINATED SOIL AND WATER

CAN BE BROKEN DOWN

Ex-Situ bioremediation needs the contaminated water to be pumped out and the contaminated soil to be removed. The contaminated water and soil are treated with microorganisms and then after the materials are degraded the soil and water are placed in a bed with oxygen and rich nutrients for further degradation.

PHYTOREMEDIATION

Phytoremediation is the use of plants to clean up potentially damaging spills.

The plants work with soil organisms to transform contaminants, such as heavy metals and toxic organic compounds, into harmless or valuable forms.

ADVANTAGES OF BIOREMEDIATION

• BIOREMEDIATION CAN OFTEN BE CARRIED OUT ON SITE, OFTEN WITHOUT CAUSING A MAJOR DISRUPTION OF NORMAL ACTIVITIES.

• BIOREMEDIATION CAN PROVE LESS EXPENSIVE THAN OTHER TECHNOLOGIES THAT ARE USED FOR CLEANUP OF HAZARDOUS WASTE

DISADVANTAGES OF

BIOREMEDIATION

• BIOREMEDIATION IS LIMITED TO THOSE COMPOUNDS THAT

ARE BIODEGRADABLE. NOT ALL COMPOUNDS ARE SUSCEPTIBLE

TO RAPID AND COMPLETE DEGRADATION.

• THERE ARE SOME CONCERNS THAT THE PRODUCTS OF

BIODEGRADATION MAY BE MORE PERSISTENT OR TOXIC THAN

THE PARENT COMPOUND.

CONCLUSION

The reasons bioremediation is sought after as an

effective and responsible method of cleaning up oil

spills is that it is cost effective and environmentally

safe and unlike chemicals and machines the

bacteria not only breakdown the hydrocarbons, it

cleans ups the residue. It’s all natural.