title: Higher biomass productivity of microalgae in an attached growth system, using wastewater.
abstract: Although most algae cultivation systems are operated in suspended culture, an attached growth system can offer several advantages over suspended systems. Algal cultivation becomes light-limited as the microalgal concentration increases in the suspended system; on the other hand, sunlight penetrates deeper and stronger in attached systems owing to the more transparent water. Such higher availability of sunlight makes it possible to operate a raceway pond deeper than usual, resulting in a higher areal productivity. The attached system achieved 2.8-times higher biomass productivity and total lipid productivity of 9.1 g m(-2) day(-1) and 1.9 g m(-2) day(-1), respectively, than the suspended system. Biomass productivity can be further increased by optimization of the culture conditions. Moreover, algal biomass harvesting and dewatering were made simpler and cheaper in attached systems, because mesh-type substrates with attached microalgae were easily removed from the culture and the remaining treated wastewater could be discharged directly. When the algal biomass was dewatered using natural sunlight, the palmitic acid (C16:0) content increased by 16% compared with the freeze-drying method. There was no great difference in other fatty acid composition. Therefore, the attached system for algal cultivation is a promising cultivation system for mass biodiesel production.
authors.affiliation: Environmental Biotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, Republic of Korea.
authors.forename: Seung-Hoon
authors.initials: SH
authors.lastname: Lee
authors.forename: Hee-Mock
authors.initials: HM
authors.lastname: Oh
authors.forename: Beom-Ho
authors.initials: BH
authors.lastname: Jo
authors.forename: Sang-A
authors.initials: SA
authors.lastname: Lee
authors.forename: Sang-Yoon
authors.initials: SY
authors.lastname: Shin
authors.forename: Hee-Sik
authors.initials: HS
authors.lastname: Kim
authors.forename: Sang-Hyup
authors.initials: SH
authors.lastname: Lee
authors.forename: Chi-Yong
authors.initials: CY
authors.lastname: Ahn
mesh_terms: D056804:Biofuels; D018533:Biomass; D019149:Bioreactors; D005227:Fatty Acids / Q000378:metabolism; D058086:Microalgae / Q000378:metabolism*; D062065:Wastewater / Q000737:chemistry*
chemical_list: D056804:Biofuels; D005227:Fatty Acids; D062065:Wastewater