Rapid static feeding combined with Fe2+ addition for improving the formation and stability of aerobic granular sludge in low-strength wastewater

Tao Song; Wanying Xie; Yong Li; Ji Li; Xiaolei Zhang; Wenyi Dong; Hongjie Wang

doi:10.1016/j.envres.2023.117770

Rapid static feeding combined with Fe²⁺ addition for improving the formation and stability of aerobic granular sludge in low-strength wastewater

Environ Res. 2024 Feb 1:242:117770. doi: 10.1016/j.envres.2023.117770. Epub 2023 Nov 28.

Authors

Tao Song¹, Wanying Xie², Yong Li³, Ji Li⁴, Xiaolei Zhang⁵, Wenyi Dong⁴, Hongjie Wang⁴

Affiliations

¹ School of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen, Shenzhen, Guangdong, 518055, PR China; School of Ecology and Environment, Inner Mongolia University, Hohhot, 010021, PR China.
² College of Civil Engineering and Architecture, Xinjiang University, Urumqi, Xinjiang, 830017, PR China.
³ School of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen, Shenzhen, Guangdong, 518055, PR China.
⁴ School of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen, Shenzhen, Guangdong, 518055, PR China; Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen, 518055, PR China; State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, PR China.
⁵ School of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen, Shenzhen, Guangdong, 518055, PR China. Electronic address: xiaolei.zhang2016@foxmail.com.

PMID: 38029821
DOI: 10.1016/j.envres.2023.117770

Abstract

Aerobic granular sludge (AGS) needs a long start-up time and always shows unstable performance when it is used to treat low-strength wastewater. In this study, a rapid static feeding combined with Fe²⁺ addition as a novel strategy was employed to improve the formation and stability of AGS in treating low-strength wastewater. Fe-AGS was formed within only 7 days and showed favorable pollutant removal capability and settling performance. The ammonia nitrogen (NH₄⁺-N) and chemical oxygen demand (COD) concentration in the effluent were lower than 5 mg/L and 50 mg/L after day 23, respectively. The sludge volume index (SVI) and mixed liquid suspended solids (MLSS) was 37 mL/g and 2.15 g/L on day 50, respectively. Rapid static feeding can accelerate granules formation by promoting the growth of heterotrophic bacteria, but the granules are unstable due to filamentous bacteria overgrowth. Fe²⁺ addition can inhibit the growth of filamentous bacteria and promote the aggregation of functional bacteria (eg. Nitrosomonas, Nitrolancea, Paracoccus, Diaphorobacter) by enhancing the secretion of extracellular polymeric substances (EPS). This study provides a new way for AGS application in low-strength wastewater treatment.

Keywords: EPS; Filamentous bacteria; Heterotrophic bacteria; Settling performance; Sphaerotilus.

MeSH terms

Aerobiosis
Bioreactors / microbiology
Nitrogen
Sewage* / microbiology
Waste Disposal, Fluid
Wastewater*

Substances

Wastewater
Sewage
Nitrogen