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Algae Turns Wastewater into Biodiesel


Scientists at the Rochester Institute of Technology are working to use microalgae to clean wastewater and produce biodiesel simultaneously; the school announced in a press release last week.

Purifying wastewater before sending it back into the ecosystem would reduce or eliminate pollutants, such as nitrates, phosphates, bacteria and toxins. Microalgae consume these materials and then the algae - which are less expensive and grow quicker than corn and soybeans - can be converted into biofuel.

“We can start a new batch of algae about every seven days. It's a more continuous source that could offset 50 percent of our total gas use for equipment that uses diesel,” explains one of the researchers.

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And microalgae work quickly too. The scientists say in three to five days, microalgae can clean up 99% of the ammonia, 88% of the nitrate, and 99% of the phosphate in wastewater. Normally, when introduced to rivers and ponds these pollutants can cause toxic blooms that choke out wildlife.

However, biofuel from microalgae poses a problem. Biodiesel freezes at a higher temperature, creating a thick substance that prevents engines from starting, so it may be necessary to mix it with other biofuel, like soy.

But the research still proves promising on two fronts: reducing toxic waste released into the environment and creating low-emission fuels.

Experimenting with new fuels is already taking place. In 2009, a town in Sweden began using biogas due to high gas prices, which at the time were over $7.50 per gallon. And in Norway, they're using sewage as fuel.

Image credit: AgriLife

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