Geographic Analysis of the Feasibility of Collocating Algal Biomass Production with Wastewater Treatment Plants

Abstract

Resource demand analyses indicate that algal biodiesel production would require unsustainable amounts of freshwater and fertilizer supplies. Alternatively, municipal wastewater effluent can be used, but this restricts production of algae to areas near wastewater treatment plants (WWTPs), and to date, there has been no geospatial analysis of the feasibility of collocating large algal ponds with WWTPs. The goals of this analysis were to determine the available areas by land cover type within radial extents (REs) up to 1.5 miles from WWTPs; to determine the limiting factor for algal production using wastewater; and to investigate the potential algal biomass production at urban, near-urban, and rural WWTPs in Kansas. Over 50% and 87% of the land around urban and rural WWTPs, respectively, was found to be potentially available for algal production. The analysis highlights a trade-off between urban WWTPs, which are generally land-limited but have excess wastewater effluent, and rural WWTPs, which are generally water-limited but have 96% of the total available land. Overall, commercial-scale algae production collocated with WWTPs is feasible; 29% of the Kansas liquid fuel demand could be met with implementation of ponds within 1 mile of all WWTPs and supplementation of water and nutrients when these are limited.

Beyond land application: Emerging technologies for the treatment and reuse of anaerobically digested agricultural and food waste

“…Furthermore, Chlorella and Scenedesmus may also be mixotrophic, consuming CO 2 via photoautotrophic metabolism while simultaneously consuming VFAs from AD effluent via heterotrophic metabolism Perez-Garcia et al, 2011). Despite the advantages of using freshwater strains, substantial freshwater requirements may limit process economics and sustainability (Fortier and Sturm, 2012). To combat these issues, marine strains could be cultivated in AD effluent diluted with seawater or brackish water.…”

Low algal diversity systems are a promising method for biodiesel production in wastewater fed open reactors

“…There were twelve, 2,270-L (2.43 m diameter, 61 cm deep) open-top plastic tanks that were operated as continuous-flow reactors (seven day hydraulic residence most of the limitations of chemical treatment and provide cost effective removal of nutrients mainly nitrogen (N) and phosphorus (P) from the water in a process that would create fuels while reducing high nutrient loads in downstream watersheds (Banerjee and Yadav 2009, Park et al 2011, Pittman et al 2011, Rawat et al 2011). Many microalgae have been screened with potential for biodiesel production and nutrient removal from treated municipal sewage (Chisti and Yan 2011, Odlare et al 2011, Fortier and Sturm 2012.…”

Interactions of marine mammals and birds with offshore membrane enclosures for growing algae (OMEGA)

“…Given the pressing need for liquid fuels, the importance of sustainable alternatives to fossil oil that do not compete with agriculture [3,57-59], and the evidence that microalgae are the most promising feedstock for such sustainable alternative fuels [60-62], it seems likely that large-scale OMEGA systems will someday be deployed in coastal waters [4]. The OMEGA system uses wastewater from coastal cities, which dispose of their wastewater offshore.…”

“…Indeed, microalgae species grown on domestic wastewater avoid competing for freshwater and fertilizer [2,3]. Large-scale algae cultivation in the proposed OMEGA system, which grows algae on wastewater and is located offshore, also avoids competing for land [4].…”