A pilot scale study on the treatment of rare earth tailings (REEs) wastewater with low C/N ratio using microalgae photobioreactor

作者：Wang, Haiyu; Liu, Zhuochao; Cui, Dan; Liu, Yuanqi; Yang, Liming^*; Chen, Houxing; Qiu, Genping; Geng, Yanni; Xiong, Zhensheng; Shao, Penghui; Luo, Xubiao

来源：Journal of Environmental Management, 2023, 328: 116973.

DOI：10.1016/j.jenvman.2022.116973

• Microalgae photobioreactor
• REEs wastewater
• NH4+-N
• Field trial
• Community succession

Microalgae appear to be a promising and ecologically safe way for nutrients removal from rare earth tailings (REEs) wastewater with CO2 fixation and added benefits of resource recovery and recycling. In this study, a pilot scale (50 L) co-flocculating microalgae photobioreactor (Ma-PBR) as constructed and operated for 140 days to treat REEs wastewater with low C/N ratio of 0.51-0.56. The removal rate of ammonia nitrogen (NH4+-N) reached 88.04% and the effluent residual concentration was as low as 9.91 mg/L that have met the Emission Standards of Pollutants from Rare Earths Industry (GB 26451-2011). Timely supplementation of trace elements was necessary to maintain the activity of microalgae and then prolonged the operation time. The dominant phyla in co -flocculating microalgae was Chlorophyta, the relative abundance of which was higher than 80%. Tetradesmus belonging to Chlorophyceae was the dominant genus with relative abundance of 80.35%. The results provided a practical support for the scaling-up of Ma-PBR to treat REEs wastewater.

• 单位
  南昌航空大学; 北京工业大学