User:Lizhuang97/sandbox

Original - "Bioremediation"

Additives
In some cases, nitrogen, phosphorus, micronutrients, vitamins, and other materials are added to improve conditions for microbial respiration.

Many biological processes are sensitive to pH and function most efficiently in near neutral conditions. Low pH can interfere with pH homeostasis or increase the solubility of toxic metals. Microorganisms can expend cellular energy to maintain homeostasis or cytoplasmic conditions may change in response to external changes in pH. Some anaerobes have adapted to low pH conditions through alterations in carbon and electron flow, cellular morphology, membrane structure, and protein synthesis.

Edit - "Bioremediation"

Additives
In some cases, nitrogen, phosphorus, micronutrients, vitamins, and other materials are added to improve conditions for microbial respiration.

Many biological processes are sensitive to pH and function most efficiently in near neutral conditions. Low pH can interfere with pH homeostasis or increase the solubility of toxic metals. Microorganisms can expend cellular energy to maintain homeostasis or cytoplasmic conditions may change in response to external changes in pH. Some anaerobes have adapted to low pH conditions through alterations in carbon and electron flow, cellular morphology, membrane structure, and protein synthesis.

Limitations
Only biodegradable contaminants can be transformed using bioremediation processes. Some compounds, such as highly chlorinated compounds, heavy metals, and radionuclides are not readily biodegradable. Also, microbes sometimes do not fully biodegrade a pollutant and may end up producing a more toxic compound. For example, under anaerobic conditions, the reductive dehalogenation of TCE may produce vinyl chloride which is a known carcinogen. Therefore, more research is required to see if the products from biodegradation are less persistent and less toxic than the original contaminant. Thus, the metabolic and chemical pathways of the microorganisms of interest must be known. In addition, knowing these pathways will help develop new technologies that can deal with sites that have uneven distributions of a mixture of contaminants.

Also, for biodegradation to occur, there must be a microbial population with the metabolic capacity to degrade the pollutant, an environment with the right growing conditions for the microbes, and the right amount of nutrients and contaminants. The biological processes used by these microbes are highly specific, therefore, many environmental factors must be taken into account and regulated as well. Thus, bioremediation processes must be specifically made in accordance to the conditions at the contaminated site. Also, because many factors are interdependent, small-scale tests must be performed before carrying out the procedure at the contaminated site. However, it is difficult to extrapolate the results from the small-scale test studies into big field operations. Lastly, the process of bioremediation is longer and can be more expensive than other conventional options such as land filling and incineration.

Lizhuang97 (talk) 00:51, 20 November 2017 (UTC)