When using biological methods for removing total petroleum hydrocarbons (TPH) the natural nutrients in the soil are soon exhausted by micro-organisms.
Nutrient limitations are the one major factor that hinders the success and speed of bioremediation. Since bioremediation depends on microbial process, there are two major approaches to speed up microbial activities in polluted sites, namely: bio stimulation and bio augmentation.
Bio stimulation involves the addition of nutrients such as Hydra Bio Nutrient Booster to polluted soil in order to stimulate the activities of autochthonous microbes.
As microorganisms are ubiquitous, it is apparent that pollutant degraders are naturally present in polluted sites, their numbers and metabolic activities may increase or decrease in response to pollutant concentration.