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

Eutrophication with algal blooms growing in water bodies and coastal areas, is a growing national and global problem. Algal blooms develop due to excess nutrients, mainly nitrogen and phosphorus, discharged from wastewater treatment plants, agricultural and other point and non-point sources.Both nitrogen and phosphorus contribute to algal blooms, but it is generally recognized that phosphorus is the main driver in algal bloom formation, as N2-fixing cyanobacteria can provide nitrogen where limiting. Microalgae can accumulate phosphorus and reduce extracellular concentration to very low levels—a few micrograms per liter. The overall Phase I/Phase II approach is to grow conditioned microalgae in controlled pond systems, so that phosphorus can be removed rapidly at the source, thus combining economically and sustainably clean water with biofuels generation. To address environmental pollution, legal levels of nitrogen and phosphorus that can be released into surface waters are being reduced nationwide. Many municipal wastewater treatment plants are not designed to meet these new nutrient-discharge limits and will be forced to completely replace or significantly retrofit their existing treatment systems, often costing the municipality millions of dollars. This situation has created a need for alternative technologies such as MBE’s innovative Phosphorus Uptake and Recovery with Algae (PURA™) system, which is designed to be simply and affordably retrofitted to a municipality’s existing wastewater treatment infrastructure to meet the new discharge limits. MBE and its partner California Polytechnic State University (Cal Poly) are developing a first-in-class, algae-based wastewater treatment process to achieve virtually zero phosphorus emission from wastewater. Our game changing PURA™ process will not only eliminate P pollution at the source, but it could also be deployed to mitigate existing environmental pollution. This is possible, because we fight phosphorus pollution with algae. In Phase I, we demonstrated proof-of-concept for conditioning suspended filamentous algae to remove P within hours from wastewater and then harvest by using low-cost screens. In Phase II, we will create a prototype to demonstrate reliability, affordability and sustainability of PURA™. The algal biomass created in our process can be used for products such as biostimulants, biofertilizers, bioplastics and biofuels for a circular green economy. Customers for our technology are indeed in pain: due to the increasing damage of algal blooms nationwide, with southern states and Florida being only the recent ground zero for these problems, there is increasing regulatory and political pressure for wastewater treatment plants and other identifiable sources of nutrient pollution, and in particular phosphorus, to reduce effluent levels to 0.05 ppm and even lower levels. Currently available technologies do not meet the dual requirements of technical and economic feasibility.