08 November 2013

Wastewater as an Energy Source

As much as AguaClara likes clean water, we also wanted to do something about the waste that inevitably comes as a result of people using that water. The Anaerobic Wastewater Treatment team was born out a desire to examine and make use of wastewater, whether as a potential source of energy or otherwise treating it.

Originally, two options presented themselves: aerobic and anaerobic digestion. Digestion in this context refers to the process by which bacteria or other microorganisms decompose biodegradable matter, and the Wastewater team wanted to use this process towards treating the organic material present in wastewater.

However, it was found that aerobic digestion (digestion in the presence of oxygen) required too much in the way of resources, with lackluster results. On the other hand, anaerobic digestion captured gainful amounts of methane, a potent greenhouse gas and source of energy. From a review of prior research o, it was discovered that we could capture the methane present in wastewater and not only prevent it from going out and acting as a greenhouse gas, but also do something productive with it.

Above: We currently have six reactors. Only the one that's black is fully operational. The black that you see in the first reactor is actually the bacteria we're using to process the wastewater, and it's commonly referred to as "biomass".

One of the major goals this semester concerns sand. The group hypothesized that by dispersing sand uniformly inside the reactors, under proper conditions, biomass will have more surfaces to grow on and therefore the reactor will treat the wastewater more effectively. Their advisor, Ruth Richardson, is also currently in Indonesia working with the engineers there to figure out the needs of the communities in which this system will be implemented.

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