Universal Journal of Agricultural Research Vol. 12(4), pp. 574 - 582
DOI: 10.13189/ujar.2024.120403
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Evaluating Flocculation Efficiency for Harvesting Chlorella vulgaris Using Different Flocculants: Inorganic Salts, Natural Polymer, Carbon Sources and Probiotic Bacteria

Le Thai Hoang ^1,*, Tran Bui Phuc ¹, Tran Phung Nha Thuyen ¹, Nguyen Nhut ^2
1 Institute of Applied Technology and Sustainable Development, Nguyen Tat Thanh University, Vietnam
² Research Institute for Aquaculture No 2, 116 Nguyen Dinh Chieu, Vietnam

ABSTRACT

Chlorella vulgaris has received considerable attention for various applications, including biofuel production, animal feed, and wastewater treatment. Flocculation is a preferable method for efficient harvesting of Chlorella biomass. In this study, metal coagulants such as AlCl₃, Al₂(SO₄)₃, FeCl₃, FeSO₄, chitosan as a natural polymer, mollasses, wheat flour and Bacillus Subtilis were employed to enhance flocculation efficiency of microalgae. A series of concentrations prepared for each flocculant at different pH values was conducted to determine the optimal conditions for flocculating activities. The results showed that five flocculants - AlCl₃, Al₂(SO₄)₃, chitosan, FeCl₃, and FeSO₄, were found as efficient agents for the flocculation of Chlorella vulgaris, with an efficiency exceeding 98% at the optimal concentrations of 70, 150, 15, 200, and 150 mg/L, respectively. The pH 10 was found as the best condition for flocculation efficiency of Chlorella cells in the culture medium. Among the tested flocculants, chitosan is an effective agent for aggregation of microalgae Chlorella vulgaris due to its nontoxic nature, bio polymer composition and the requirement for a low dosage. Additionally, Bacillus Subtilis, a probiotic bacterium, was found to slightly enhance the flocculation efficiency after 24 hours of incubation with an inoculation percentage of 3% Bacillus culture. Further study to optimize the addition rate and incubation time of Bacillus bacteria is necessary to enhance the flocculation efficiency of microalgae Chlorella vulgaris.

KEYWORDS
Flocculation, Chitosan, Bacillus, Microalgae, Chlorella

Cite This Paper in IEEE or APA Citation Styles
(a). IEEE Format:
[1] Le Thai Hoang , Tran Bui Phuc , Tran Phung Nha Thuyen , Nguyen Nhut , "Evaluating Flocculation Efficiency for Harvesting Chlorella vulgaris Using Different Flocculants: Inorganic Salts, Natural Polymer, Carbon Sources and Probiotic Bacteria," Universal Journal of Agricultural Research, Vol. 12, No. 4, pp. 574 - 582, 2024. DOI: 10.13189/ujar.2024.120403.

(b). APA Format:
Le Thai Hoang , Tran Bui Phuc , Tran Phung Nha Thuyen , Nguyen Nhut (2024). Evaluating Flocculation Efficiency for Harvesting Chlorella vulgaris Using Different Flocculants: Inorganic Salts, Natural Polymer, Carbon Sources and Probiotic Bacteria. Universal Journal of Agricultural Research, 12(4), 574 - 582. DOI: 10.13189/ujar.2024.120403.