Microalgae Cultivation Using Offshore Membrane Enclosures for Growing Algae (OMEGA)

作     者：Patrick Wiley Linden Harris Sigrid Reinsch Sasha Tozzi Tsegereda Embaye Kit Clark Brandi McKuin Zbigniew Kolber Russel Adams Hiromi Kagawa Tra-My Justine Richardson John Malinowski Colin Beal Matthew A. Claxton Emil Geiger Jon Rask J. Elliot Campbell Jonathan D. Trent 

作者机构：Advanced Organic Methods Penryn USA Department of Chemistry University of California Santa Cruz USA Department of Mechanical Engineering University of Nevada Reno USA Department of Ocean Sciences University of California Santa Cruz USA Dynamac Corporation NASA Ames Research Center Moffett Field USA NASA Ames Research Center Moffett Field USA School of Engineering University of California Merced USA SETI Institute Mountain View USA Universities Space Research Association Columbia USA 

出 版 物：《Journal of Sustainable Bioenergy Systems》 (可持续生物质能源系统（英文）)

年 卷 期：2013年第3卷第1期

页      面：18-32页

学科分类：1002[医学-临床医学] 100214[医学-肿瘤学] 10[医学] 

主　　题：Biofuels Wastewater Treatment Microalgae Photobioreactor CO2 Mass Transfer Fast Repetition Rate Fluorometry Instrumentation and Control 

摘      要：OMEGA is a system for cultivating microalgae using wastewater contained in floating photobioreactors (PBRs) deployed in marine environments and thereby eliminating competition with agriculture for water, fertilizer, and land. The offshore placement in protected bays near coastal cities co-locates OMEGA with wastewater outfalls and sources of CO2-rich flue gas on shore. To evaluate the feasibility of OMEGA, microalgae were grown on secondary-treated wastewater supplemented with simulated flue gas (8.5% CO2 V/V) in a 110-liter prototype system tested using a seawater tank. The flow-through system consisted of tubular PBRs made of transparent linear low-density polyethylene, a gas exchange and harvesting column (GEHC), two pumps, and an instrumentation and control (I&C) system. The PBRs contained regularly spaced swirl vanes to create helical flow and mixing for the circulating culture. About 5% of the culture volume was continuously diverted through the GEHC to manage dissolved oxygen concentrations, provide supplemental CO2, harvest microalgae from a settling chamber, and add fresh wastewater to replenish nutrients. The I&C system controlled CO2 injection and recorded dissolved oxygen levels, totalized CO2 flow, temperature, circulation rates, photosynthetic active radiation (PAR), and the photosynthetic efficiency as determined by fast repetition rate fluorometry. In two experimental trials, totaling 23 days in April and May 2012, microalgae productivity averaged 14.1 ± 1.3 grams of dry biomass per square meter of PBR surface area per day (n = 16), supplemental CO2 was converted to biomass with 50% efficiency, and 90% of the ammonia-nitrogen was recovered from secondary effluent. If OMEGA can be optimized for energy efficiency and scaled up economically, it has the potential to contribute significantly to biofuels production and wastewater treatment.