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Assignment 5: Final Wiki Article Edit

Wastewater Treatment

Methanogens are widely used in anaerobic digestors to treat wastewater as well as aqueous organic pollutants. Industries have selected methanogens for its ability to perform biomethanation during wastewater decomposition thereby rendering the process sustainable and cost-effective.

Bio-decomposition in the anaerobic digester involves a four-staged cooperative action performed by different microorganisms. The first stage is the hydrolysis of insoluble polymerized organic matter by anaerobes such as Streptococcus and Enterobacterium. In the second stage, acidogens breakdown dissolved organic pollutants in wastewater to fatty acids. In the third stage, acetogens convert fatty acids to acetates. In the final stage, methanogens metabolize acetates to gaseous methane. The byproduct methane leaves the aqueous layer and serves as an energy source to power wastewater-processing within the digestor, thus generating a self-sustaining mechanism.

Methanogens also effectively decrease the concentration of organic matter in wastewater run-off and minimizes greenhouse gas emissions. For instance, agricultural wastewater, highly rich in organic material, has been a major cause of aquatic ecosystem degradation. The chemical imbalances can lead to severe ramifications such as eutrophication. Through anaerobic digestion, the purification of wastewater can prevent unexpected blooms in water systems as well as trap methanogenesis within digesters. This allocates biomethane for energy production and prevents a potent greenhouse gas, methane, from being released into the atmosphere.

The organic components of wastewater vary vastly. Chemical structures of the organic matter select for specific methanogens to perform anaerobic digestion. An example is the members of Methanosaeta genus dominate the digestion of palm oil mill effluent (POME) and brewery waste. Modernizing wastewater treatment systems to incorporate higher diversity of microorganisms to decrease organic content in treatment is under active research in the field of microbiological and chemical engineering. Current new generations of Staged Multi-Phase Anaerobic reactors and Upflow Sludge Bed reactor systems are designed to have innovated features to counter high loading wastewater input, extreme temperature conditions, and possible inhibitory compounds.

References

Edits0920 (talk) 07:02, 19 November 2017 (UTC)

Assignment 3: For Critique Use

Original - "Methanogen - Fermentative metabolism" There is no subheading for wastewater treatment. This wikipedia article is a start article with not much information listed. There is no previously written portion to be edited. However, new content is to be added.

The understanding of methanogen metabolism has progressed steadily since the 1930s.[16]

Although most marine biogenic methane is the result of carbon dioxide (CO2) reduction, a small amount is derived from acetate (CH3COO−) fermentation.[17]

In the fermentation pathway, acetic acid undergoes a dismutation reaction to produce methane and carbon dioxide:[18][19]

   CH3COO− + H+ → CH4 + CO2       ΔG° = -36 kJ/reaction

This disproportionation reaction is enzymatically catalysed. One electron is transferred from the carbonyl function (e− donor) of the carboxylic group to the methyl group (e− acceptor) of acetic acid to respectively produce CO2 and methane gas.

Archaea that catabolize acetate for energy are referred to as acetotrophic or aceticlastic. Methylotrophic archaea utilize methylated compounds such as methylamines, methanol, and methanethiol as well.

Edits0920 (talk) 06:48, 9 October 2017 (UTC)

Edit - "Role in Wastewater Treatment" Methanogens has industrial selected to play a key role anaerobic digestion technology because of its ability to metabolize organic matter efficiently. Anaerobic digestion is regarded as a sustainable and cost-effective method to breakdown organic pollutants in incoming wastewater and produces gaseous biomethane as an energy source to power the digester itself. [1] Bio-decomposition in the digester involves staged cooperative action of a variety of microorganisms. Acidogens first converts dissolved organic matter in wastewater to organic fatty acids. [3] Methanogenic archaea then metabolizes the organic acids yielding biogas leaving the aqueous layer as a byproduct.[1] Different types of wastewater can be processed by a variety of diverse methanogens, such as palm oil mill effluent (POME) and brewery waste processed by mostly members of the Methanosaeta genus. [3] The usage of methane-producing archaea in wastewater treatment have brought positive impact environmentally. It not only effectively produces alternative energy but it has also been shown that methanogens have minimized greenhouse gas emissions. [3] Wastewater from agricultural sources that are rich in organic material has been a major cause of aquatic ecosystem degradation and chemical imbalances in these habitats can lead to severe environmentally ramifications such as eutrophication. Through generation of renewable biomass in the anaerobic digestion technology, purification of water mitigates possible damage as well as locks biomethane production within digesters. [3] Advancing systems in wastewater treatment has become an active part of research in the field of chemical engineering. New generations of Staged Multi-Phase Anaerobic reactors and Upflow and Granular Sludge Bed reactor systems are designed to have an innovated feature to counter high loading wastewater input, extreme temperature conditions, and possible inhibitory compounds. [2]

References

1. ^ Lettinga, G (1995). “Anaerobic Digestion and Wastewater Treatment Systems.” Antonie Van Leeuwenhoek. 67 (1): 3–28. doi:10.1007/bf00872193.

2. ^ Lettinga, G; et.al. (1997). "Advanced anaerobic wastewater treatment in the near future" Water Science and Technology. 35 (10): 5 -12. doi: 10.1016/S0273-1223(97)00222-9

3. ^ Tabatabaei, Meisa; et.al. (2010). "Importance of the methanogenic archaea populations in anaerobic wastewater treatments" Process Biochemistry. 45 (8): 1214 -1225. doi: 10.1016/j.procbio.2010.05.017

Edits0920 (talk) 06:04, 8 October 2017 (UTC)