Co-culture of bacteria and microalgae for treatment of high concentration biogas slurry. (June 2021)

• Record Type: Journal Article
• Authors: Li, Dan; Liu, Ruiqing; Cui, Xiaoyu; He, Meilin; Zheng, Shiyan; Du, Weijie; Gao, Meng; Wang, Changhai
• Is Part Of: Journal of water process engineering. Volume 41(2021)
• Publication Date: 2021-06
• Subjects: Biogas slurry -- Consortium -- Pollutant removal -- Fatty acid -- Nutrient proportion; Water-supply engineering -- Periodicals; Saline water conversion -- Periodicals; Seawater -- Distillation -- Periodicals; Sanitary engineering -- Periodicals; Sewage -- Purification -- Periodicals; 627
• DOI: 10.1016/j.jwpe.2021.102014
• Languages: English
• ISSNs: 2214-7144

Abstract

Highlights: Bacteria that can be co-cultured with microalgae were isolated. The co-culture displayed great potential in nutrient removal from biogas slurry. The C/N ratio was the key factor regulating NH4 + -N removal by co-culture. The co-culture used for biogas slurry treatment was suitable for biofuel production. Biogas slurry would be an economical medium for large-scale microalgae cultivation. Abstract: The co-culture of microalgae and specific bacteria is conducive for improving wastewater treatment efficiency. In this study, native bacterial strains isolated from pig biogas slurry were screened for effective biogas slurry treatment when co-cultured with different microalgae. Scenedesmus obliquus and Bacillus megaterium ( So-B ) co-culture was found more efficient in treating high concentration biogas slurry compared with the pure microalgae culture. When the C/N/P ratio in biogas slurry was 106/16/1 and the initial microalgae-bacteria inoculation ratio was 9:1, the co-culture attained the maximum chemical oxygen demand (COD), total phosphorus (TP) and ammonia nitrogen (NH4 + -N) removal rates of 85.98 %, 81.03 % and 65.48 %, respectively. High C/N ratio was favorable for NH4 + -N removal by the co-culture. In addition, co-culture with bacteria markedly increased the ratio of saturated/unsaturated fatty acids in microalgae. These results suggest that the co-culture could efficiently reduce various nutrients in biogas slurry and simultaneously accumulate biomass with higher biofuel characteristics.