title: Harvesting microalgae grown on wastewater.
abstract: The costs and life cycle impacts of microalgae harvesting for biofuel production were investigated. Algae were grown in semi-continuous culture in pilot-scale photobioreactors under natural light with anaerobic digester centrate as the feed source. Algae suspensions were collected and the optimal coagulant dosages for metal salts (alum, ferric chloride), cationic polymer (Zetag 8819), anionic polymer (E-38) and natural coagulants (Moringa Oleifera and Opuntia ficus-indica cactus) were determined using jar tests. The relative dewaterability of the algae cake was estimated by centrifugation. Alum, ferric chloride and cationic polymer could all achieve >91% algae recovery at optimal dosages. Life cycle assessment (LCA) and cost analysis results revealed that cationic polymer had the lowest cost but the highest environmental impacts, while ferric chloride had the highest cost and lowest environmental impacts. Based on the LCA results, belt presses are the recommended algae dewatering technology prior to oil extraction.
authors: Department of Chemical & Biomedical Engineering, University of South Florida, Tampa, FL, USA.
authors: Innocent
authors: I
authors: Udom
authors: Behnaz H
authors: BH
authors: Zaribaf
authors: Trina
authors: T
authors: Halfhide
authors: Benjamin
authors: B
authors: Gillie
authors: Omatoyo
authors: O
authors: Dalrymple
authors: Qiong
authors: Q
authors: Zhang
authors: Sarina J
authors: SJ
authors: Ergas
mesh_terms: D017756:Aquaculture; D018929:Cell Culture Techniques / Q000191:economics / Q000379:methods*; D003365:Costs and Cost Analysis; D004560:Electricity; D005427:Flocculation; D017752:Greenhouse Effect; D058086:Microalgae / Q000254:growth & development*; D058433:Photobioreactors / Q000382:microbiology; D013816:Thermodynamics; D014865:Waste Disposal, Fluid; D062065:Wastewater / Q000382:microbiology*
chemical_list: D062065:Wastewater