Biostimulation

Source: Wikipedia, the free encyclopedia.

Biostimulation involves the modification of the environment to stimulate existing

herbicides.[1]

The primary advantage of biostimulation is that bioremediation will be undertaken by already present native

microorganisms that are well-suited to the subsurface environment, and are well distributed spatially within the subsurface. The primary disadvantage is that the delivery of additives in a manner that allows the additives to be readily available to subsurface microorganisms is based on the local geology of the subsurface. Tight, impermeable subsurface lithology (tight clays
or other fine-grained material) make it difficult to spread additives throughout the affected area. Fractures in the subsurface create preferential pathways in the subsurface which additives preferentially follow, preventing even distribution of additives.

Recently a number of products have been introduced which allow popular use of bioremediation using biostimulative methods. They may harness local bacteria using biostimulation by creating a hospitable environment for hydrocarbon-devouring microorganisms, or they may introduce foreign bacteria into the environment as a direct application to the hydrocarbon. While the jury is out as to whether either is particularly more effective than the other, prima facie consideration suggests the introduction of foreign bacteria to any environment stands a chance of mutating organisms already present and affecting the biome.

Investigations to determine subsurface characteristics (such as natural groundwater velocity during ambient conditions, hydraulic conductivity of the subsurface, and lithology of the subsurface) are important in developing a successful biostimulation system. In addition, a pilot-scale study of the potential biostimulation system should be undertaken prior to full-scale design and implementation.

However, some biostimulative agents may be used in chaotic surfaces such as open water and sand so long as they are oleophilic, meaning that they bond exclusively to hydrocarbons, and basically sink in the water column, bonding to oil, where they then float to the water's surface, exposing the hydrocarbon to more abundant sunlight and oxygen where greater micro-organic aerobic activity can be encouraged. Some consumer-targeted biostimulants bond possess this quality, others do not.

See also

  • Biotreatment

References

  1. ^ Kanissery, R.G., and G.K. Sims. 2011. Biostimulation for the enhanced degradation of herbicides in soil. Applied and Environmental Soil Science. Volume 2011 (2011), Article ID 843450, doi:10.1155/2011/843450. http://www.hindawi.com/journals/aess/2011/843450/

External links