Direct sludge granulation by applying mycelial pellets in continuous-flow aerobic membrane bioreactor: Performance, granulation process and mechanism

Xiao Xiao; Fang Ma; Shijie You; Haijuan Guo; Jinna Zhang; Xiaotong Bao; Xiping Ma

doi:10.1016/j.biortech.2021.126233

Direct sludge granulation by applying mycelial pellets in continuous-flow aerobic membrane bioreactor: Performance, granulation process and mechanism

Bioresour Technol. 2022 Jan;344(Pt B):126233. doi: 10.1016/j.biortech.2021.126233. Epub 2021 Oct 28.

Authors

Xiao Xiao¹, Fang Ma¹, Shijie You¹, Haijuan Guo², Jinna Zhang¹, Xiaotong Bao³, Xiping Ma⁴

Affiliations

¹ State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, PR China.
² School of Environment, Liaoning University, Shenyang 110036, PR China; College of Energy and Environmental Engineering, Hebei University of Engineering, Handan 056038, PR China. Electronic address: guohaijuan@hebeu.edu.cn.
³ College of Energy and Environmental Engineering, Hebei University of Engineering, Handan 056038, PR China.
⁴ School of Environment, Liaoning University, Shenyang 110036, PR China.

PMID: 34743997
DOI: 10.1016/j.biortech.2021.126233

Abstract

This study provides a sustainable manner for direct cultivation of aerobic granular sludge (AGS) by addition of mycelial pellets (MPs) into continuous-flow aerobic MBR. The results showed that the granulation time in MPs-MBR was shortened by at least 65 days, accounting for enhanced mean size of granules (0.68-0.76 mm), increased mixed liquor suspended solids (MLSS) concentration (12.8 g/L) and improved settling ability (78.1 mL/g), in comparison with that of 0.23-0.28 mm, 9.8 g/L and 102.1 mL/g in control MBR. MPs-MBR demonstrated significant advantages in terms of COD reduction (97.0-99.1%), NH₄⁺-N reduction (100%) and TN reduction (32.27-42.33%). MPs, extracellular polymeric substances (EPS) and filamentous bacteria acted as inducible nucleus, crosslinking matter and supporting skeleton, respectively, in favor of promoting the formation and stabilization of AGS with a four-layered structure. The relevant mechanism was underlined by rheological analysis, indicating that MPs addition enhanced non-Newtonian flow characteristics and network structure of sludge.

Keywords: Aerobic granular sludge; Membrane bioreactor; Mycelial pellets.

MeSH terms

Aerobiosis
Bioreactors
Extracellular Polymeric Substance Matrix
Sewage*
Waste Disposal, Fluid*

Substances

Sewage