Mechanism behind alkaline flocculation of Chlorella sorokiniana and its validation in black water

• Grant number: 18/01218-3
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: June 14, 2018
• End date: December 13, 2018
• Field of knowledge: Engineering - Sanitary Engineering - Water Supply and Wastewater Treatment
• Principal Investigator: Luiz Antonio Daniel
• Grantee: Luan de Souza Leite
• Supervisor: Tomás Brányik
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Institution abroad: University of Chemistry and Technology Prague (UCT Prague), Czech Republic
• Associated to the scholarship: 17/14620-1 - Optimization of Chlorella sorokiniana cultivation in a flat panel photobioreactor and harvest for use as fertilizer, BP.MS

Abstract

The research project abroad aims to study the mechanism behind alkaline flocculation (harvesting) of the freshwater microalgae Chlorella sorokiniana, cultured in defined mineral medium and black water. This harvesting method is considered a cheap way of biomass separation and it is based on either spontaneous or forced pH alteration. The pH shift to alkaline regions (pH 9-12) induces precipitation of calcium phosphate or magnesium hydroxide resulting in cell-precipitate interaction and floc formation. In the context of algae recovery combined with wastewater treatment, it is desirable to recover these algae at low capital and operational costs and energy demand when applied at large scale. For practical applications, the knowledge about the importance of surface charge, surface tension and particle size on flocculation efficacy are required. This research will quantify the effect of independent variables Mg2+, Ca2+ and PO4^(3-) concentrations, pH and ionic strength on the zeta potential (ZP) of both microalgae and inorganic precipitates. The physicochemical interaction model obtained will be used to interpret the flocculation test results and predict the flocculation behavior in real black water. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

LEITE, LUAN DE SOUZA; DANIEL, LUIZ ANTONIO; PIVOKONSKY, MARTIN; NOVOTNA, KATERINA; BRANYIKOVA, IRENA; BRANYIK, TOMAS. Interference of model wastewater components with flocculation of Chlorella sorokiniana induced by calcium phosphate precipitates. Bioresource Technology, v. 286, AUG 2019. (18/01218-3)

POTOCAR, TOMAS; LEITE, LUAN DE SOUZA; DANIEL, LUIZ ANTONIO; PIVOKONSKY, MARTIN; MATOULKOVA, DAGMAR; BRANYIK, TOMAS. Cooking oil-surfactant emulsion in water for harvesting Chlorella vulgaris by sedimentation or flotation. Bioresource Technology, v. 311, SEP 2020. (18/01218-3)