Rapid start-up of a bioelectrochemical system under alkaline and saline conditions for efficient oxalate removal

Tharanga N Weerasinghe Mohottige; Maneesha P Ginige; Anna H Kaksonen; Ranjan Sarukkalige; Ka Yu Cheng

doi:10.1016/j.biortech.2017.11.009

Rapid start-up of a bioelectrochemical system under alkaline and saline conditions for efficient oxalate removal

Bioresour Technol. 2018 Feb:250:317-327. doi: 10.1016/j.biortech.2017.11.009. Epub 2017 Nov 7.

Authors

Tharanga N Weerasinghe Mohottige¹, Maneesha P Ginige², Anna H Kaksonen³, Ranjan Sarukkalige⁴, Ka Yu Cheng⁵

Affiliations

¹ CSIRO Land and Water, 147 Underwood Avenue, Floreat, WA 6014, Australia; Department of Civil Engineering, Curtin University, Bentley, Western Australia 6102, Australia.
² CSIRO Land and Water, 147 Underwood Avenue, Floreat, WA 6014, Australia.
³ CSIRO Land and Water, 147 Underwood Avenue, Floreat, WA 6014, Australia; School of Pathology and Laboratory Medicine, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia.
⁴ Department of Civil Engineering, Curtin University, Bentley, Western Australia 6102, Australia.
⁵ CSIRO Land and Water, 147 Underwood Avenue, Floreat, WA 6014, Australia; School of Engineering and Information Technology, Murdoch University, Western Australia 6150, Australia. Electronic address: kayu.cheng@csiro.au.

PMID: 29179053
DOI: 10.1016/j.biortech.2017.11.009

Abstract

This study examined a new approach for starting up a bioelectrochemical system (BES) for oxalate removal from an alkaline (pH > 12) and saline (NaCl 25 g/L) liquor. An oxalotrophic biofilm pre-grown aerobically onto granular graphite carriers was used directly as both the microbial inoculum and the BES anode. At anode potential of +200 mV (Ag/AgCl) the biofilm readily switched from using oxygen to graphite as sole electron acceptor for oxalate oxidation. BES performance was characterised at various hydraulic retention times (HRTs, 3-24 h), anode potentials (-600 to +200 mV vs. Ag/AgCl) and influent oxalate (25 mM) to acetate (0-30 mM) ratios. Maximum current density recorded was 363 A/m³ at 3 h HRT with a high coulombic efficiency (CE) of 70%. The biofilm could concurrently degrade acetate and oxalate (CE 80%) without apparent preference towards acetate. Pyro-sequencing analysis revealed that known oxalate degraders Oxalobacteraceae became abundant signifying their role in this novel bioprocess.

Keywords: Alkaline industrial wastewater; Alumina; Bayer process; Bioelectrochemical system; Microbial fuel cell; Oxalotrophic.

MeSH terms

Bioelectric Energy Sources
Biofilms*
Electrodes
Graphite
Oxalates*
Oxidation-Reduction

Substances

Oxalates
Graphite