Programs and Communities
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- Creators: Mihaleva, Galina
- Creators: Rittmann, Bruce
- Creators: Karr, Mandi
expenditure, and environmental risk. Surfactant treatment to disrupt Scenedesmus biomass was evaluated
as a means to make solvent extraction more efficient. Surfactant treatment increased the recovery of fatty
acid methyl ester (FAME) by as much as 16-fold vs. untreated biomass using isopropanol extraction, and
nearly 100% FAME recovery was possible without any Folch solvent, which is toxic and expensive. Surfactant
treatment caused cell disruption and morphological changes to the cell membrane, as documented by
transmission electron microscopy and flow cytometry. Surfactant treatment made it possible to extract wet
biomass at room temperature, which avoids the expense and energy cost associated with heating
and drying of biomass during the extraction process. The best FAME recovery was obtained from highlipid
biomass treated with Myristyltrimethylammonium bromide (MTAB)- and 3-(decyldimethylammonio)-
propanesulfonate inner salt (3_DAPS)-surfactants using a mixed solvent (hexane : isopropanol = 1 : 1, v/v)
vortexed for just 1 min; this was as much as 160-fold higher than untreated biomass. The critical micelle
concentration of the surfactants played a major role in dictating extraction performance, but the growth
stage of the biomass had an even larger impact on how well the surfactants disrupted the cells and
improved lipid extraction. Surfactant treatment had minimal impact on extracted-FAME profiles and,
consequently, fuel-feedstock quality. This work shows that surfactant treatment is a promising strategy for
more efficient, sustainable, and economical extraction of fuel feedstock from microalgae.
The Combined Activated Sludge-Anaerobic Digestion Model (CASADM) quantifies the effects of recycling anaerobic-digester (AD) sludge on the performance of a hybrid activated sludge (AS)-AD system. The model includes nitrification, denitrification, hydrolysis, fermentation, methanogenesis, and production/utilization of soluble microbial products and extracellular polymeric substances (EPS). A CASADM example shows that, while effluent COD and N are not changed much by hybrid operation, the hybrid system gives increased methane production in the AD and decreased sludge wasting, both caused mainly by a negative actual solids retention time in the hybrid AD. Increased retention of biomass and EPS allows for more hydrolysis and conversion to methane in the hybrid AD. However, fermenters and methanogens survive in the AS, allowing significant methane production in the settler and thickener of both systems, and AD sludge recycle makes methane formation greater in the hybrid system.
The ASU School of Dance presents Undergraduate Projects Showing, October 25-26, with works by undergraduate dance students, performed at Margaret Gisolo Dance Studio.
The ASU School of Dance presents School of Dance LIVE!, September 7-9, with works by dance faculty, performed at Galvin Playhouse.
The ASU School of Dance presents Emerging Artists I, February 9-12, with works by guest artists, dance faculty, and students, performed at Dance Studio Theatre, PEBE 132.
The ASU School of Dance presents Rhythms of Life, November 3-5, with works by guest artists performed at Dance Studio Theatre, PEBE 132.
The ASU School of Dance presents Celebrating the Nagrin Legend, September 16-18, with works by dance faculty and visiting artists, performed at the Galvin Playhouse Theatre.
The ASU School of Dance presents New Danceworks II, January 26-29, with works by dance faculty, graduate students, and visiting artists, performed at the Dance Studio Theatre, PEBE 132.