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Article
Algae Grown on Dairy and Municipal Wastewater for Simultaneous Nutrient Removal and Lipid Production for Biofuel Feedstock
Journal of Environmental Engineering (2009)
  • Ian Woertz, California Polytechnic State University - San Luis Obispo
  • A. Feffer, California Polytechnic State University - San Luis Obispo
  • Tryg Lundquist, California Polytechnic State University - San Luis Obispo
  • Yarrow Nelson, California Polytechnic State University - San Luis Obispo
Abstract
Algae grown on wastewater media are a potential source of low-cost lipids for production of liquid biofuels. This study investigated lipid productivity and nutrient removal by green algae grown during treatment of dairy farm and municipal wastewaters supplemented with CO2. Dairy wastewater was treated outdoors in bench-scale batch cultures. The lipid content of the volatile solids peaked at Day 6, during exponential growth, and declined thereafter. Peak lipid content ranged from 14–29%, depending on wastewater concentration. Maximum lipid productivity also peaked at Day 6 of batch growth, with a volumetric productivity of 17 mg/day/L of reactor and an areal productivity of 2.8 g/m2/day, which would be equivalent to 11,000 L/ha/year (1,200 gal/acre/year) if sustained year round. After 12 days, ammonium and orthophosphate removals were 96 and >99%, respectively. Municipal wastewater was treated in semicontinuous indoor cultures with 2–4 day hydraulic residence times (HRTs). Maximum lipid productivity for the municipal wastewater was 24 mg/day/L, observed in the 3-day HRT cultures. Over 99% removal of ammonium and orthophosphate was achieved. The results from both types of wastewater suggest that CO2-supplemented algae cultures can simultaneously remove dissolved nitrogen and phosphorus to low levels while generating a feedstock potentially useful for liquid biofuels production.
Keywords
  • biofuels,
  • biodiesel,
  • algae,
  • lipids,
  • algal polycultures,
  • wastewater treatment,
  • dairy
Publication Date
November 1, 2009
Publisher Statement

Copyright © 2009 American Society of Civil Engineers. The definitive version is available at http://dx.doi.org/10.1061/(ASCE)EE.1943-7870.0000129.

Citation Information
Ian Woertz, A. Feffer, Tryg Lundquist and Yarrow Nelson. "Algae Grown on Dairy and Municipal Wastewater for Simultaneous Nutrient Removal and Lipid Production for Biofuel Feedstock" Journal of Environmental Engineering Vol. 135 Iss. 11 (2009)
Available at: http://works.bepress.com/tlundqui/2/