Effect of high ammonia on granular stability and phosphorus recovery of algal-bacterial granules in treatment of synthetic biogas slurry

Wei Cai; Peiqi Hu; Zhaohua Li; Qun Kang; Hongbing Chen; Jin Zhang; Shujing Zhu

doi:10.1016/j.heliyon.2022.e09844

Effect of high ammonia on granular stability and phosphorus recovery of algal-bacterial granules in treatment of synthetic biogas slurry

Heliyon. 2022 Jul 3;8(7):e09844. doi: 10.1016/j.heliyon.2022.e09844. eCollection 2022 Jul.

Authors

Wei Cai¹, Peiqi Hu¹, Zhaohua Li¹, Qun Kang¹, Hongbing Chen¹, Jin Zhang¹, Shujing Zhu¹

Affiliation

¹ Hubei Provincial Key Laboratory of Regional Development and Environmental Response, Department of Environmental Engineering, Hubei University, Wuhan, 430062, China.

Abstract

The aim of the study was to investigate the application of algal-bacterial granules in treatment of high ammonia wastewater. Two identical cylindrical reactors, i.e., Rc and Rs was used to develop granular sludge system with synthetic biogas slurry. Rs was run under an artificial solar lamp controlled at 12 h power on and 12 h power off (∼10,000 lux); Rc was operated as control (no light). Results showed that algal-bacterial granules (ABGS) developed in Rs exhibited better structural stability in the face of high ammonia influent. Compared with aerobic granules (AGS), ABGS possessed high proteins (PN) content (145.3 mg/g-VSS) in extracellular polymeric substances (EPS) and better O₂ mass transfer inner granules. Higher phosphorus (P) removal capacity was obtained in Rs even under 400 mg/L NH₃-N which resulted in higher P content in ABGS biomass (56.4 mg/g-TSS). Bioavailable P in ABGS was 44 mg P/g-SS on day 160, approximately 1.53-times higher than that in AGS.

Keywords: Aerobic granular sludge; Algal-bacterial symbiosis; Extracellular polymeric substances (EPS); High ammonia wastewater; O2 mass transfer.