User:Navid.Saleh/sandbox

Wastewater treatment:
Water treatment often relies on the activity of anaerobically denitrifying bacteria in order to remove nitrate from water. However, due to the absence of oxygen, nitrate cannot be fully reduced to dinitrogen, thus nitrate remains in the water or it is converted to nitrous oxide. Lingering nitrate in drinking water poses a plethora of health risks, and both nitrate and nitrous oxide have major environmental impacts. Some hazards include, carcinogenic nitrate ions in drinking water, or eutrophication caused by oxidized nitrogen seeding Algal blooms. Conversely aerobic denitrification can further reduce oxidized nitrogen in a less specialized environment. For instance, many aerobically denitrifying bacteria from the pseudomonas genus (Pm. stutzeri, Pm. mendocina and Pm. Putida) were shown to be isolated from the Liangshui river in China, and could be further used in bioaugmentation to clear contaminated water. In addition to pseudomas,  Acinetobacter sp. SYF26 was isolated from the Hei He reservoir in China. Genomic analysis revealed a napA gene encoding a periplasmic nitrate reductase, and a nirK and nirS for gene for the nitrite reductase (both enzymes needed in aerobic nitrate denitrification).

Global warming:
Nitrous oxide is a 200-300 times more potent greenhouse gas than carbon dioxide, accounting for 5% of the global green house gas effect. During the reduction of nitrate in wastewater treatment, nitrous oxide is only released in the absence of appropriate oxygen regulation. Some solutions to combat the release of nitrous oxide from wastewater treatment could be to use aerobically denitrifying organisms with the capacity to fully reduce nitrogen. For instance, P. Denitrificans has shown to efficiently reduce nitrate to N2 in cultured media and wastewater. Furthermore, TR2 strains of P. sturzeri and Pseudomonas sp. strain K50 were also shown to have substantially low levels of nitrous oxide production in water treatment. Thus enriching activated sludge for aerobic denitrifying bacteria can be effective in combating the global warming effects of nitrous oxide in wastewater treatment.

Navid.Saleh (talk) 23:38, 11 October 2017 (UTC)