The study of structure of anaerobic granules and methane producing pathways of pilot-scale UASB reactors treating municipal wastewater under sub-mesophilic conditions

Isaac Owusu-Agyeman; Özge Eyice; Zeynep Cetecioglu; Elzbieta Plaza

doi:10.1016/j.biortech.2019.121733

The study of structure of anaerobic granules and methane producing pathways of pilot-scale UASB reactors treating municipal wastewater under sub-mesophilic conditions

Bioresour Technol. 2019 Oct:290:121733. doi: 10.1016/j.biortech.2019.121733. Epub 2019 Jul 2.

Authors

Isaac Owusu-Agyeman¹, Özge Eyice², Zeynep Cetecioglu³, Elzbieta Plaza⁴

Affiliations

¹ Department of Chemical Engineering, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
² School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom.
³ Department of Chemical Engineering, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden. Electronic address: zeynepcg@kth.se.
⁴ Department of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.

PMID: 31301569
DOI: 10.1016/j.biortech.2019.121733

Abstract

This study was carried out to investigate the relationship between the methane producing pathways and the characteristics of anaerobic granules treating municipal wastewater. For this purpose, two pilot scale upflow anaerobic sludge blanket reactors with different granule size distribution (1-2 mm and 3-4 mm) were investigated at operating temperatures of 20 °C and 28 °C for 239 days. There was an increased and stable biogas production when temperature was elevated to 28 °C likely due to reduction in methane solubility. Larger granules had multi-layered internal microstructures with higher acetoclastic methanogenic activities (250-437 mL CH₄ g^-1 VS d^-1) than smaller granules (150-260 mL CH₄ g^-1 VS d^-1). The relative abundance of acetoclastic methanogens of larger granules was higher, confirming acetoclastic methane producing pathway was more prominent. However, there was no significant difference in the performance of the two reactors because they were operating below their capacities in terms of organic loading rate to volatile solids ratio.

Keywords: Anaerobic granules; Methanogenesis; Microbial community; Municipal wastewater; UASB.

MeSH terms

Anaerobiosis
Bioreactors
Methane*
Sewage
Waste Disposal, Fluid
Wastewater*

Substances

Sewage
Waste Water
Methane