A collaborative effect of solid-phase denitrification and algae on secondary effluent purification

• Published in: Journal of environmental management Vol. 348; p. 119393
• Main Authors: Sun, Xiaoran, Tong, Weibing, Wu, Guiyang, Yang, Guangfeng, Zhou, Jiaheng, Feng, Lijuan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.12.2023
• Subjects: Bacterial-algae symbiosis; Chlorella; Microbial community; Solid-phase denitrification; Solid-phase denitrification; Chlorella; Bacterial-algae symbiosis; Microbial community
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2023.119393

This study explored the collaborative effect on nutrients removal performance and microbial community in solid-phase denitrification based bacteria-algae symbiosis system. Three biodegradable carriers (apple wood, poplar wood and corncob) and two algae species (Chlorella vulgaris and Chlorella pyrenoidosa) were selected in these bacteria-algae symbiosis systems. Results demonstrated that corncob as the carrier exhibited the highest average removal efficiencies of total nitrogen (83.7–85.1%) and phosphorus removal (38.1–49.1%) in comparison with apple wood (65.8–71.5%, 25.5–32.7%) and poplar wood (42.5–49.1%, 14.2–20.7%), which was mainly attributed to the highest organics availability of corncob. The addition of Chlorella acquired approximately 3–5% of promotion rates for nitrated removal among three biodegradable carriers, but only corncob reactor acquired significant promotions by 3–11% for phosphorous removal. Metagenomics sequencing analysis further indicated that Proteobacteria was the largest phylum in all wood reactors (77.1–93.3%) and corncob reactor without Chlorella (85.8%), while Chlorobi became the most dominant phylum instead of Proteobacteria (20.5–41.3%) in the corncob with addition of Chlorella vulgaris (54.5%) and Chlorella pyrenoidosa (76.3%). Thus, the higher organics availability stimulated the growth of algae, and promoted the performance of bacteria-algae symbiosis system based biodegradable carriers. •Higher organics availability of carrier corncob than apple wood, poplar wood.•Carrier corncob achieved better performance of nitrogen and phosphorus removal.•Chlorella vulgaris and Chlorella pyrenoidosa could further favored nitrate removal.•Chlorella further improved phosphorus removal only based corncob carrier.•Higher organics availability of carrier corncob made Chlorella become largest microbe.