What is Bioremediation?
Bioremediation can be defined as a process that uses microorganisms (yeast, fungi, bacteria or their enzymes) to degrade, potentially hazardous substances into ones that are less toxic or non-toxic. Through this technique, a contaminated site can be returned to a natural, balanced and healthy environment. This method of decontamination usually occurs naturally but at a much slower rate, which is known as natural attenuation. For this reason, bioremediation technology looks to speed up this natural process by stimulating the remedial activities of microorganisms.
If they already occur in nature, why are there still contaminated sites?
The slow speed of natural attenuation is caused by bacteria being kept in check by predatory organisms and also they are not always suited to the kinds of wastes they find themselves in. Tough pollutants such as cyanide are not the natural food source for some kinds of bacteria. Therefore, many contaminants spread before the microorganisms have a chance to break down the toxins. If the microorganisms are carefully selected and enhanced, they have an enormous competitive advantage, and are free and able to handle the wastes at a given site.
How does Bioremediation work?
Microorganisms digest organic substances by producing enzymes that break up complex compounds into nutrients and energy for growth and reproduction, releasing gases and water as waste products. Some organic substances harmful to humans and wildlife, such as fuels and solvents can be digested by certain microorganisms, therefore eliminating the contaminant from the environment.
Two methods of in site bioremediation can be used, biostimulation and bioaugmentation. Biostimulation helps the already present microbe population do its job by adding nutrients or by providing more oxygen, through aeration. This allows the existing population to breakdown the contamination quicker. Microbes can also be added when quantities are not sufficient to complete the job, this is known as bioaugmentation. Bioaugmentation takes advantage of specific microbes preferring specific contaminants, therefore, applications can be precisely managed so the contaminated area is cleaned up quickly and efficiently. Combinations of species often provide a more powerful and complete degradation of specific pollutants than individual strains applied alone, because the by-products of one species often serve as another species’ food. Only a correctly balanced formula of bacterial strains, such as our product line, can use this synergistic effect to completely break down pollutants to non-toxic by-products such as carbon dioxide, water and sulfate.
There are some toxic substances that microbes are unable to breakdown such as high concentrations of heavy metals, inorganic salts and highly chlorinated organics. Phytoremediation can then be employed, this process is based on the ability of some plants to bioaccumulate these substances with no or little adverse effects on the plant itself. The plants can then be harvested, incinerated or recycled for industrial use.
What are the applications?
Bioremediation technologies may be utilized in a wide variety of applications (see our Product List). AquaBio specializes in assessment, sales and distribution of micro-organic degraders, cleaners and bionutrients for: bioremediation, bio-dredging, waste treatment municipal and industrial, drain line grease trap remediation, drain lines, lift stations, hydrogen sulfide removal, ammonia control, hydrocarbon and industrial waste. Also we consult and offer services in the remediation of retention basins, lakes, lagoons and aquaculture facilities both fresh and marine environments. Other applications range from bioventing, landfarming, bioreactors and composting.
Advantages and Disadvantages of Bioremediation
• Products attack targeted substances, which can be solid or soluble and applied in water or on land.
• Microorganisms utilize contaminants for growth.
• The by-products of the microbial process include water, carbon dioxide and bacterial biomass, which is rich in protein. These wastes are then converted into natural food for fish and invertebrates.
• Bioremediation is generally less expensive and more efficient then other forms of remediation.
• Cannot be applied to all potentially hazardous material, organic or otherwise – there are some substances that microbes are unable to breakdown.
• The extent of remediation is dependent on the toxicity and initial levels of contaminant.
Although the principles of bioremediation have a long history, the technologies used today have great potential and methodologies are being improved continuously. Bioremediation has the ability to remove potentially harmful substances from the environment in a way that can be both highly economical and less intrusive than previously used methods.