Balancing carbon/nitrogen ratio to improve nutrients removal and algal biomass production in piggery and brewery wastewaters

• Published in: Bioresource technology Vol. 249; pp. 479 - 486
• Main Authors: Zheng, Hongli, Liu, Mingzhi, Lu, Qian, Wu, Xiaodan, Ma, Yiwei, Cheng, Yanling, Addy, Min, Liu, Yuhuan, Ruan, Roger
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.02.2018
• Subjects: Brewery wastewater; Carbon/nitrogen ratio; Microalga; Piggery wastewater; Brewery wastewater; Carbon/nitrogen ratio; Piggery wastewater; Microalga
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2017.10.057

•Piggery wastewater exhibited low carbon/nitrogen mass ratio.•Brewery wastewater had high carbon/nitrogen mass ratio.•Mixing the wastewaters balanced the carbon/nitrogen mass ratio.•The optimal carbon/nitrogen mass ratio of mixed wastewater was 7.9.•Strategies for enhancing nutrients removal and biomass production were established. To improve nutrients removal from wastewaters and enhance algal biomass production, piggery wastewater was mixed with brewery wastewaters. The results showed that it was a promising way to cultivate microalga in piggery and brewery wastewaters by balancing the carbon/nitrogen ratio. The optimal treatment condition for the mixed piggery-brewery wastewater using microalga was piggery wastewater mixed with brewery packaging wastewater by 1:5 at pH 7.0, resulting in carbon/nitrogen ratio of 7.9, with the biomass concentration of 2.85 g L−1, and the removal of 100% ammonia, 96% of total nitrogen, 90% of total phosphorus, and 93% of chemical oxygen demand. The application of the established strategies can enhance nutrient removal efficiency of the wastewaters while reducing microalgal biomass production costs.