Simultaneous organic and nutrient removal in wastewater using a revolving algae biofilm reactor

• Published in: Environmental technology & innovation 2025-02, Vol.37, p.103949, Article 103949
• Main Authors: Vo, Thi-Dieu-Hien, Nguyen, Van-Truc, Le, Vu-Anh, Do, Quoc-Hoang, Nguyen, Thi-Yen-Phuong, Nguyen, Phuong-Thao, Lin, Chitsan, You, Sheng-Jie, Visvanathan, Chettiyappan, Bui, Xuan-Thanh
• Format: Article
• Language: English
• Subjects: Chlorella vulgaris; Hydraulic retention time (HRT), removal rate; Revolving algae biofilm (RAB); Symbiotic
• ISSN: 2352-1864; 2352-1864
• DOI: 10.1016/j.eti.2024.103949

This study focused on a revolving algae biofilm (RAB) reactor for the efficient removal of nutrients from synthetic wastewater. Chlorella vulgaris algae species were used in this study. The study examined the reactor performance across various hydraulic retention times (HRTs) ranging from 60 to 30 hours, revealing crucial insights into its operational efficiency. The results demonstrate that HRT significantly influences key performance indicators, including removal rates, removal efficiencies, biomass growth rate, and complete nitrification. Among the tested configurations, HRT-30h emerged as the optimal parameter, exhibiting impressive removal rates of 108 mg/L/day for COD, 35 mg/L/day for ammonia nitrogen, and 1.8 mg/L/day for phosphorus. Furthermore, it achieved the highest levels of suspended and harvested biofilm mass, measuring 1.07 g/L and 7 g, respectively. Notably, HRT-30h displayed exceptional biomass growth rate, reaching up to 3.77 g/m2/day. Therefore, it underscores the promising potential of the RAB reactor as an efficient and adaptable technology for nutrient removal in wastewater treatment. Further exploration and refinement of operational parameters hold the key to harnessing the full capabilities of this innovative wastewater treatment technology. [Display omitted] •The algae-bacteria symbiotic is well illustrated in the development of algae flocs.•HRT of 30 hours was identified as the optimal condition for high removal rates.•The HRT of 30 hours can lead to nitrate accumulation in the reactor.•The reactor showed remarkable biomass productivity, valued at 3.77 g/m2/day.