Effects of nutrient composition, lighting conditions, and metal ions on the growth and lipid yield of the high-lipid-yielding microalgae (Chlorella pyrenoidosa) cultivated in municipal wastewater. Issue 6 (December 2021)

• Record Type: Journal Article
• Authors: Han, Wei; Jin, Wenbiao; Ding, Wanqing; Lu, Shuping; Song, Kang; Chen, Chuan; Qin, Changlei; Chen, Yidi; Tu, Renjie; Zhou, Xu
• Is Part Of: Journal of environmental chemical engineering. Volume 9:Issue 6(2021)
• Publication Date: 2021-12
• Subjects: Wastewater -- Chlorella pyrenoidosa -- Lipid yield -- Nutrient composition -- Lighting condition -- Metal ion; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2021.106491
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: Microalgae have attracted wide attention as an alternative raw material for bioenergy. Microalgae cultivated in wastewater can reduce cultivation costs, and wastewater can be treated while the microalgal biomass accumulates. Here, the effects of nutrient composition, lighting conditions, and metal ions on the growth and lipid yield of Chlorella pyrenoidosa cultivated in synthetic wastewater and actual wastewater were investigated. The microalgae treated with NO3 - -N showed the best growth status, and microalgae treated with NH4 + -N exhibited the highest lipid yield. The maximum lipid yield was 0.18 g/L at a total phosphorus concentration of 5 mg/L. The maximum lipid content of C. pyrenoidosa was obtained at 4000 lux and 9:15 h L/D. In the metal ion experiment, the dry weight and total lipid yield in microalgae were highest when the Fe 3+ concentration was 28.8 × 10 −3 mM, and the total lipid yield reached the maximum (0.25 g/L) when the Mg 2+ concentration was 0.5 mM. The seven factors involved in C. pyrenoidosa cultivation were optimised using a uniform-design experiment. According to the model, the optimal culture conditions were as follows: photoperiodicity, 23:1 h L/D; ammonia nitrogen, 125 mg/L; Fe 3+, 0 mM; light intensity, 9000 lux; phosphorus, 14 mg/L; Mg 2+, 0.18 mM; and CO2, 1.3 vol%; furthermore, the maximum theoretical lipid yield was 0.31 g/L. Analysis of the fatty acid composition revealed a similar composition in both real and synthetic wastewater. Graphical Abstract: ga1 Highlights: NO3 - -N was more suitable for microalgal growth, while NH4 + -N for lipid yield. C. pyrenoidosa had a similar growth trend at different light conditions. The culture conditions of C. pyrenoidosa were optimized by uniform design test. Fatty acid composition in both real and synthetic wastewater were similar.