Effect of filamentous algae in a microalgal-bacterial granular sludge system treating saline wastewater: Assessing stability, lipid production and nutrients removal

• DOI: 10.1016/j.biortech.2022.127182
• Publication Date: 2022-04-16T05:46:32Z
• Authors: Jinhua Cao; Fanzhen Chen; Zheng Fang; Yue Gu; Hao Wang; Jingfang Lu; Yanmeng Bi; Shaopo Wang; Wenli Huang; Fansheng Meng
• Keywords: Bacteria; Sewage; Nitrogen; Nutrients; Wastewater; Lipids; Waste Disposal, Fluid; 01 natural sciences; Aerobiosis; 6. Clean water; Bioreactors; Microalgae; 0105 earth and related environmental sciences

In this study modified microalgal-bacterial granular sludge (MBGS) was constructed and employed to compare the performance for treating 1%-5% saline wastewater with aerobic granular sludge (AGS). Filamentous algae were found to flourish at 1% salinity when nutrients were temporarily restricted to low level (COD 0, N 10 mg/L, P 0.5 mg/L). A significant improvement of granule stability was detected as the integrity coefficients of MBGS was only 0.12-0.24 rather than 0.19-0.48 of AGS under 1%-5% salinities, which reduced the risk of particle disintegration. Filamentous algae including Leptolyngbya and Geitlerinema occupied 91.2% of identified algae, and were beneficial for enhancing the biomass content and lipid production to about 1.27-1.37, 3.1-5.0 times than AGS. The MBGS had best nitrogen and phosphorus removal efficiencies of 93.4% and 64.6% at 1% salinity, and showed higher resistance to 3%-5% salinities. This study could provide meaningful information for using this modified MBGS technology in practice.