Wu Xiongwei, Jin Cong, Zhang Chiqian, Li Ping, Huang Jim Junhui, Wu Jing, Wu Jinhua, Hu Zhiqiang
School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; Zhongshan Institute of Modern Industrial Technology of South China University of Technology, Zhongshan 528400, China.
Civil Engineering Program, College of Engineering & Computer Science, Arkansas State University, Jonesboro, AR 72467, USA.
J Environ Sci (China). 2025 Nov;157:366-377. doi: 10.1016/j.jes.2024.06.017. Epub 2024 Jun 19.
Microalgae possess significant advantages in nitrogen and phosphorus removal from nutrient-rich wastewater that are highly efficient and independent of the C/N ratio. However, challenges such as low biomass productivity, high variability in nutrient removal under different trophic types, and difficulty in harvesting biomass limits the large-scale application of microalgae wastewater treatment. This study attempted to employ mixotrophic microalgae biofilm to address these issues. The biomass production, microalgal activity, and nutrient removal of Chlorella pyrenoidosa biofilms with different trophic types were compared for nutrient-rich wastewater treatment. The results showed that the biomass productivity of the mixotrophic microalgal biofilm (0.215 g/(L·d)) was 2.3, 8.6, and 6.0 times higher than that of photoautotrophic microalgal biofilm, heterotrophic microalgal biofilm, and photoautotrophic suspended microalga, respectively. Additionally, the dehydrogenase activity (DHA), indicating microalgal activity, of the mixotrophic biofilm was 2.3 and 16.5 times higher than that of photoautotrophic and heterotrophic biofilms, respectively. Meanwhile, the mixotrophic biofilm removed 96.0 % of NH-N and 99.2 % of PO-P, more efficient than that with other types of biofilms and suspended microalgae. In an open-ended air-lift photobioreactor, the mixotrophic microalgal biofilm produced biomass at 0.12 g/(L·d) and removed 90.0 % of NH-N and 97.6 % of PO-P. This study suggests that the mixotrophic microalgal biofilm shows promise in treating nutrient-rich wastewater and producing microalgal biomass for value-added products.
微藻在从富营养化废水中去除氮和磷方面具有显著优势，即高效且不受碳氮比的影响。然而，诸如生物量生产力低、不同营养类型下营养物去除的高变异性以及生物量收获困难等挑战限制了微藻废水处理的大规模应用。本研究试图采用混合营养微藻生物膜来解决这些问题。比较了不同营养类型的小球藻生物膜在处理富营养化废水时的生物量产量、微藻活性和营养物去除情况。结果表明，混合营养微藻生物膜的生物量生产力（0.215 g/(L·d)）分别比光合自养微藻生物膜、异养微藻生物膜和光合自养悬浮微藻高2.3倍、8.6倍和6.0倍。此外，表明微藻活性的脱氢酶活性（DHA），混合营养生物膜分别比光合自养生物膜和异养生物膜高2.3倍和16.5倍。同时，混合营养生物膜去除了96.0%的NH-N和99.2%的PO-P，比其他类型的生物膜和悬浮微藻更有效。在开放式气升式光生物反应器中，混合营养微藻生物膜以0.12 g/(L·d)的速度产生生物量，并去除了90.0%的NH-N和97.6%的PO-P。本研究表明，混合营养微藻生物膜在处理富营养化废水和生产用于增值产品的微藻生物量方面具有潜力。
