Municipal Wastewater Could Lower Cost Of Biofuel Production

Algae may be useful in supporting the production of biofuels, but the chemicals needed to fertilize the algae are expensive. In a breakthrough, Rice University researchers have found a way to lower those costs by fertilizing the algae with municipal wastewater.

By growing the algae in wastewater, "the water would already contain its own free fertilizer, plus the algae would help clean it up," GizMag reported.

The experiment was conducted in open-air pools at a municipal wastewater treatment plant in Houston. "Although the solids had already been filtered from the water, it still contained the nitrogen and phosphorous that the algae needed to feed upon," Gizmag reported.

The researchers found that this process is effective for removing both nitrates and phosphorous. "The algae effectively removes 90 percent of nitrates and more than 50 percent of phosphorous from the water, two pollutants which wastewater processing plants have not been able to find affordable ways to expel," UPI reported.

The upshot is that this research, recently published in Algae Journal, could lower the cost of making biofuels with algae. "The stable productivity of monocultures suggests that this may be a viable production method to procure algal biomass for biodiesel production," the study said.

Study author Meenakshi Bhattacharjee put the research in context. .

"Biofuels were the hot topic in algaculture five years ago, but interest cooled as the algae industry moved toward producing higher-value, lower-volume products for pharmaceuticals, nutritional supplements, cosmetics and other products," Bhattacharjee said, per a release.

"The move to high-value products has allowed the algaculture industry to become firmly established, but producers remain heavily dependent on chemical fertilizers," Bhattacharjee continued. "Moving forward, they must address sustainability if they are to progress toward producing higher-volume products, 'green' petrochemical substitutes and fuels."