Formation characteristics of algal-bacteria granular sludge under low-light environment: From sludge characteristics, extracellular polymeric substances to microbial community

Zhe Liu; Jingwen Wang; Shumin Zhang; Yiwen Hou; Jiaxuan Wang; Min Gao; Xingdu Chen; Aining Zhang; Yongjun Liu; Zhihua Li

doi:10.1016/j.biortech.2023.128851

Formation characteristics of algal-bacteria granular sludge under low-light environment: From sludge characteristics, extracellular polymeric substances to microbial community

Bioresour Technol. 2023 May:376:128851. doi: 10.1016/j.biortech.2023.128851. Epub 2023 Mar 9.

Authors

Zhe Liu¹, Jingwen Wang², Shumin Zhang², Yiwen Hou², Jiaxuan Wang³, Min Gao⁴, Xingdu Chen², Aining Zhang², Yongjun Liu⁵, Zhihua Li²

Affiliations

¹ School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Yan Ta Road, No. 13, Xi'an 710055, China; Key Lab of Northwest Water Resource, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, China; Yulin Ecological Environment Monitoring Station, High-tech Zone Xingda Road, Yulin 719000, China. Electronic address: zheliu@xauat.edu.cn.
² School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Yan Ta Road, No. 13, Xi'an 710055, China.
³ School of Architecture and Civil Engineering, Xi'an University of Science and Technology, Yan Ta Road, No. 58, Xi'an 710054, China.
⁴ School of Environmental and Chemical Engineering, Xi an Polytechnic University, Jin Hua Nan Road, No. 19, Xi'an 710048, China.
⁵ School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Yan Ta Road, No. 13, Xi'an 710055, China; Key Lab of Northwest Water Resource, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, China.

PMID: 36898567
DOI: 10.1016/j.biortech.2023.128851

Abstract

In this study, the formation characteristics of algal-bacteria granular sludge (ABGS) under low-light environment (80, 110, and 140 μmol/m²/s) were investigated. The findings revealed that the stronger light intensity favored the improvement of sludge characteristics, nutrient removal performances, and extracellular polymeric substance (EPS) secretion at the growing stage, which were more preferential to facilitate the formation of ABGS. However, after the mature stage, the weaker light intensity ensured more stable operation of the system, as shown by contributing to sludge settlement performance, denitrification, and EPS secretion. According to the results of high-throughput sequencing, the dominant bacterial genus of the mature ABGS cultured under low light intensity were all Zoogloe, while the dominant algal genus was different. For the mature ABGS, the 140 and 80 μmol/m²/s light intensity had the most significant activation effect to the functional genes related to carbohydrate metabolism and amino acid metabolism, respectively.

Keywords: Algal-bacteria granular sludge; Extracellular polymeric substances; Low-light environment; Microbial community; Sludge characteristics.

MeSH terms

Bacteria / genetics
Bacteria / metabolism
Bioreactors / microbiology
Extracellular Polymeric Substance Matrix / metabolism
Microbiota*
Sewage* / microbiology
Waste Disposal, Fluid

Substances

Sewage