Biorecovery of Nutrients from Municipal Wastewaters with Co-production of Biofuels and Other Bioproducts

Nutrient pollution of lakes, estuaries, coastal areas and other water bodies frequently results in algae blooms, sometimes toxic, and often leading to anoxia, fish kills and dead zones. Efforts to reign-in nutrient pollution, in particular of phosphorus, P, have been lagging and noxious algae blooms make headlines almost daily all over the US and world. This is a problem attracting increasing attention of the public and politicians, responding to businesses and residents impacted by the algal blooms, from declines in property values to lost tourism and recreation business, to commercial fisheries, and even public health. Current technologies for phosphorus control are expensive, and increasingly stringent regulations on nutrient discharges are raising costs to homeowners, businesses, municipalities, even farmers, but with relatively little effect. These problems provide opportunities for innovative technologies that can provide cost-effective technologies to remove nutrients from both point and non-point sources, such as municipal wastewater treatment plants and agricultural run-off. Microalgae have evolved the capability to effectively capture nutrients, in particular P, from the environment, reducing their levels to essentially non-detectable. Microalgae are also potential sources of biofuels and bioproducts. Using wastewater nutrients has been one approach to reduce costs of microalgae biofuels production. There is an opportunity to use nutrients being discharged into, or even those already present in, the environment, to produce algal biomass for biofuels and bioproducts, while generating revenues from pollution control services provided by such processes. The focus of this proposed project is specifically on remediation of low-levels of P, generally, the main culprit in algal blooms. Stringent regulations on P discharges, which are very costly to meet, provide an opportunity for novel technologies that have lower costs than established processes. An innovative process is described herein that uses filamentous microalgae able to recover P at low concentrations discharged from wastewater treatment plants. Concentrations that, however, still exceed current and prospective regulatory mandates for such effluents. The algae technology would also have future applications for other low-concentration P releases to the environment, and even to remediation of P already present in nutrient polluted waters. The work in Phase I of this SBIR will demonstrate this technology at the proof-of-concept level, through operation of the actual process for extended period. This will allowing for the monitoring and validation of the achievable reductions in low-concentrations of influent P. The biomass produced can be valorized for use in biofuels, biofertilizers and bioplastics.