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Waste Digesting

Page history last edited by Malcolm 5 years, 8 months ago

Anaerobic digestion

From Wikipedia, the free encyclopedia

 

 

 

Anaerobic digestion is a process in which microorganisms break down biodegradable material in the absence of oxygen. The process is widely used to treat wastewater sludges and organic wastes because it provides volume and mass reduction of the input material.1 As part of an integrated waste management system, anaerobic digestion reduces the emission of landfill gas into the atmosphere. Anaerobic digestion is a renewable energy source because the process produces a methane and carbon dioxide rich biogas suitable for energy production helping replace fossil fuels. Also, the nutrient-rich solids left after digestion can be used as fertiliser.

 

The digestion process begins with bacterial hydrolysis of the input materials in order to break down insoluble organic polymers such as carbohydrates and make them available for other bacteria. Acidogenic bacteria then convert the sugars and amino acids into carbon dioxide, hydrogen, ammonia, and organic acids. Acetogenic bacteria then convert these resulting organic acids into acetic acid, along with additional ammonia, hydrogen, and carbon dioxide. Methanogenic bacteria finally are able to convert these products to methane and carbon dioxide.2

 

The technical expertise required to maintain anaerobic digesters coupled with high capital costs and lower process efficiencies have so far limited the level of its industrial application as a waste treatment technology.3 Anaerobic digestion facilities have, however, been recognised by the United Nations Development Programme as one of the most useful decentralised sources of energy supply, as they are less capital intensive than large powerplants.4

 

 

  1. California Cows pass gas to grid 05/03/08
  2. Smart eco disaster toilets  05/08/14
  3. UK Waste Digesting Plants
  4. Duckweed to the Rescue 09/07/08
  5. Microwave turns Plastic to Oil

 

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