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Energy from wastewater

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Wastewater in an energy resource[edit]

The treatment of wastewater using conventional methods consumes significant amounts of energy.[1]

However, wastewater actually contains biochemical energy, which is normally thrown away, or worse, discarded as pollution. Biochemical oxygen demandW is a measure of pollution, but also indicates the energy content of the wastewater.

Methods of extracting energy[edit]

Biogas is one method with the potential for use as an appropriate technology.

Various waste-to-energyW technologies including incinerationW can be used to dispose of solid waste. This includes dried sewage sludge.W

Microbial fuel cellsW are a completely new method of energy recovery, and are currently under development. They could be used to produce electricity; also they could produce hydrogen - the BioElectrochemically Assisted Microbial Reactor (BEAMR) method is claimed to yields four times the hydrogen of fermentation alone.[2]

Footnotes[edit]

  1. According to one estimate, "In the USA... 5% of electricity we produce is used to treat water and wastewater." - from Microbial Fuel Cells, B.E. Logan, 2005. Does this include the cost of contructing colleciton and treatment facilities, including the embedded energyW in the materials?[Suggested project]
  2. 2005 Popular Mechanics Breakthrough Awards (published in the November 2005 issue). According to this update (Nov 2007) efficiency has reached 82%. For more information, see Microbial Fuel Cells, by Bruce Logan of Penn State University (2005), who won a 2005 Popular Mechanics Breakthrough Award.[1]