Optimization of flocculation efficiency of Chlorella pyrenoidosa with CaCl2 using the Box-Behnken design of response surface methodology: A cost effective statistical investigation

• Published in: Biomass conversion and biorefinery Vol. 14; no. 3; pp. 3261 - 3273
• Main Authors: Singh, Har Mohan, Tyagi, V. V., Ahmad, Shamshad, Kothari, Richa
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-02-2024; Springer Nature B.V
• Subjects: Algae; Biomass; Biotechnology; Calcium chloride; Chlorella; Cost analysis; Efficiency; Energy; Flocculants; Flocculation; Original Article; Process parameters; Renewable and Green Energy; Response surface methodology; Environmental risk; Flocculation efficiency
• ISSN: 2190-6815; 2190-6823
• DOI: 10.1007/s13399-022-02491-4

The harvesting of microalgae biomass from culture medium is a tedious process that needs high cost and energy. Calcium chloride was utilized as a flocculant for the flocculation process of
Chlorella pyrenoidosa
in an alkaline medium. This study was aimed to optimize the four flocculation process parameters for microalgae by Box-Behnken design of Response Surface Methodology. The maximum flocculation efficiency of
C. pyrenoidosa
was obtained 97.58% at 32.5 °C, pH 9, 37.5 min. and 275 mgL
−1
flocculant dose, out of which 72 (± 2) % of flocculant amount was contributed in the flocculation process. The rest of the 28% flocculant was recovered from the spent medium, which was again utilized for the flocculation process and was achieved 28% flocculation efficiency at pre-optimized conditions. The cost of the flocculation process was analyzed ≈0.10 USD for 1 kg of microalgae biomass which shows a low-cost option compared to conventional chemicals.
Graphical abstract