Granulation process in an expanded granular sludge blanket (EGSB) reactor for domestic sewage treatment: Impact of extracellular polymeric substances compositions and evolution of microbial population

Hui Xu; Yanbiao Liu; Yingying Gao; Fang Li; Bo Yang; Man Wang; Chunyan Ma; Qing Tian; Xinshan Song; Wolfgang Sand

doi:10.1016/j.biortech.2018.08.100

Granulation process in an expanded granular sludge blanket (EGSB) reactor for domestic sewage treatment: Impact of extracellular polymeric substances compositions and evolution of microbial population

Bioresour Technol. 2018 Dec:269:153-161. doi: 10.1016/j.biortech.2018.08.100. Epub 2018 Aug 25.

Authors

Hui Xu¹, Yanbiao Liu², Yingying Gao¹, Fang Li², Bo Yang³, Man Wang¹, Chunyan Ma¹, Qing Tian¹, Xinshan Song¹, Wolfgang Sand⁴

Affiliations

¹ Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, College of Environmental Science and Engineering, Donghua University, Shanghai 201620, PR China.
² Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, College of Environmental Science and Engineering, Donghua University, Shanghai 201620, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
³ Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, College of Environmental Science and Engineering, Donghua University, Shanghai 201620, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China. Electronic address: yangbo@dhu.edu.cn.
⁴ Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, College of Environmental Science and Engineering, Donghua University, Shanghai 201620, PR China; Institute of Biosciences, Freiberg University of Mining and Technology, Freiberg 09599, Germany.

PMID: 30172178
DOI: 10.1016/j.biortech.2018.08.100

Abstract

In this study, an expanded granular sludge blanket (EGSB) reactor was used for the treatment of low-strength domestic sewage and the sludge granulation process was systematically investigated. At an optimized hydraulic retention time (HRT) of 5 h, up-flow velocity (V_up) of 1.9 m/h, and organic loading rate (OLR) of 2.16 kg COD/m³/d, the average COD removal efficiency was 71.5 ± 2.3%. Completely granular sludge can be observed after 107 d of continuous operation. Analysis of the distribution and composition of the extracellular polymeric substances (EPS) indicates that the tightly bound EPS (TB-EPS) content shows an increasing trend, while the loosely bound EPS (LB-EPS) content did not significantly alter after the granular sludge was formed. The three-dimensional excitation-emission matrix technique (3D-EEM) confirms that aromatic protein-like substances are of key importance to sludge granulation. High-throughput sequencing analysis indicates that the metabolism shifted from hydrogenotrophic (Methanobaterium) to aceticlastic methanogens (Methanosaeta) during sludge granulation.

Keywords: 3D-EEM; Anaerobic granulation; Extracellular polymeric substances; Granulation mechanism; Microbial community distribution.

MeSH terms

Bioreactors*
Polymers*
Sewage*
Waste Disposal, Fluid

Substances

Polymers
Sewage