Bioremediation
Bioremediation is defined as the use of microbes to clean up contaminated soil and groundwater. It is a cost-effective, sustainable, natural approach to cleaning up contaminated soil and groundwater through the use of biological agents such as bacteria, microbes, fungi, and other organisms or their enzymes. It is an eco-friendly method of remediating old open waste dumps to permanently achieve near-zero emission of landfill gases and leachate.
MGS Environ Pvt. Ltd. has the requisite expertise and infrastructure to undertake Bioremediation.
How Bioremediation Works?
The bioremediation process is a biological process that stimulates helpful microbes to use harmful contaminants as their source of food and energy. Certain microorganisms eat toxic chemicals and pathogens, digesting them and eliminating through changing their composition into harmless gases like ethane and carbon dioxide. Some contaminated soil and water conditions already have the right counter-microbes. Here, human intervention can speed up the natural remediation by boosting microbial action.
In other cases where the right microbes are low in numbers or entirely absent, bioremediation is introduced by adding amendments — microbial actors like fungi and aerobic bacteria that are mixed into the soil or water. This simple process is called bioaugmentation, and it’s highly effective to correct conditions quickly, as long as the right environmental conditions are present. Critical conditions for bioremediation include:
- Host microbial contaminants that provide fuel and energy to parasitical microbes
- Parasitical microbes that feed off their harmful hosts and destroy them
- Oxygen in sufficient amounts to support aerobic biodegradation
- Water, either in liquid form or in soil moisture content
- Carbon is the foundation of microbial life and its energy source
- Temperature, not too cold or hot for microbial life to flourish
- Nutrients like nitrogen, phosphorous, potassium and sulfur to support microbe growth
- Acid and alkaline proportions or pH ratio in the range of 6.5 to 7.5
When all these conditions are in the right proportions, microbes grow at enormous rates. If the optimum conditions are off-balance, microbial action is too slow or can die off altogether, and the contaminants remain until nature eventually restores a balance. Re-balancing can take a long time in highly polluted conditions. But proper bioremediation processes rectify most situations in relatively short time. That can be anywhere from a few years to several decades.
Bioremediation Classes:
There are two main classifications of bioremediation. This refers to where remediation is carried out, not the actual bioremediation technique classes. Bioremediation is done either:
In situ, where all bioremediation work is done right at the contamination site. This can be polluted soil that’s treated without unnecessary and expensive removal, or it can be contaminated groundwater that’s remediated at its point of origin. In situ is the preferred bioremediation method, as it requires far less physical work and eliminates spreading contaminants through trucking or pumping away to other treatment locations. Bioventing, biosparging and bioaugmentation are the main technique classes.
Ex-situ: means removing contaminated material to a remote treatment location. This classification is less desirable. It involves the big job of excavating polluted soil and trucking it offsite. In the case of contaminated water, ex situ is rare, except for pumping groundwater to the surface and biologically treating it in an enclosed reservoir. Ex situ bioremediation poses a hazard to spreading contamination or risking an accidental spill during transport. Once at an ex situ treatment site, three technique classes can be applied. One is landfarming, where soil is spread and biologically decontaminated. Another is composting, which is an age-old process. The third class involves biopiles: a hybrid of stacking material in silos, then composting as a biological treatment.
The major benefits of bioremediation are:
- The completely natural process with almost no harmful side effects
- Carried out in situ for most applications with no dangerous transport
- Quick turnaround time to make soil and water useful
- Minimal equipment needed except for specialized pieces
- Positive public acceptance due to organic process and little disturbance
- Cost-effective to maintain and economical to input
- Lowers liability, as contaminants are less likely to escape
- Little energy consumed compared to incineration and landfilling
- High acceptance from regulatory authorities