Bioflocculation and settling studies of native wastewater filamentous cyanobacteria using different cultivation systems for a low-cost and easy to control harvesting process. (15th February 2020)

• Record Type: Journal Article
• Authors: Iasimone, Floriana; Seira, Jordan; Desmond-Le Quéméner, Elie; Panico, Antonio; De Felice, Vincenzo; Pirozzi, Francesco; Steyer, Jean-Philippe
• Is Part Of: Journal of environmental management. Volume 256(2020)
• Publication Date: 2020-02-15
• Subjects: Bioflocculation -- Filamentous cyanobacteria -- Urban wastewater -- Sedimentation model; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2019.109957
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: Bioflocculation phenomena for filamentous cyanobacteria were studied and analysed in two different cultivation systems (i.e. based on air-bubbling and on shaking) and for different initial biomass concentrations. Floc formation and biomass settling were monitored during batch cultivation tests according to an innovative protocol. Results showed that the two cultivation systems enhanced two different flocculation behaviours: air bubbling led to the formation of small and dense flocs, while the shaking table resulted in larger (14 mm 2 vs 4 mm 2 ) but mechanically weaker flocs. Floc analysis evidenced that the different mixing systems also affected the speciation of biomass. A mathematical model was developed to simulate and predict the settling performance during the bioflocculation process of filamentous cyanobacteria. Natural settling was examined at different phases of biomass growth. Optimal conditions were obtained at the end of the exponential growth phase, when 70% of the total cultivated biomass could be recovered. Highlights: Different mixing systems (air bubbles, shaking) induced different bioflocculation behaviour. Flocs formation was influenced by the initial biomass concentration. 70% of the total cultivated biomass was recovered through natural settling in 50 min. A new method to evaluate biomass settling dynamics through image analysis has been developed. A mathematical model has been developed to deeply investigate the bioflocculation dynamics and factors of influence.