Engineering rheology of electrolytes using agar for improving the performance of bioelectrochemical systems

Navanietha Krishnaraj Rathinam; Abhilash K Tripathi; Alevtina Smirnova; Haluk Beyenal; Rajesh K Sani

doi:10.1016/j.biortech.2018.04.089

Engineering rheology of electrolytes using agar for improving the performance of bioelectrochemical systems

Bioresour Technol. 2018 Sep:263:242-249. doi: 10.1016/j.biortech.2018.04.089. Epub 2018 Apr 24.

Authors

Navanietha Krishnaraj Rathinam¹, Abhilash K Tripathi², Alevtina Smirnova³, Haluk Beyenal⁴, Rajesh K Sani⁵

Affiliations

¹ Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, SD, USA; BuG ReMeDEE Consortium, South Dakota School of Mines and Technology, Rapid City, SD, USA. Electronic address: Navanietha.Rathinam@sdsmt.edu.
² Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, SD, USA.
³ Department of Chemistry and Applied Biological Sciences, South Dakota School of Mines and Technology, Rapid City, SD, USA.
⁴ School of Chemical Engineering and Bioengineering, Washington State University, Pullman, USA.
⁵ Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, SD, USA; BuG ReMeDEE Consortium, South Dakota School of Mines and Technology, Rapid City, SD, USA; Department of Chemistry and Applied Biological Sciences, South Dakota School of Mines and Technology, Rapid City, SD, USA.

PMID: 29751231
DOI: 10.1016/j.biortech.2018.04.089

Abstract

The present study is focused on enhancing the rheological properties of the electrolyte and eliminating sedimentation of microorganisms/flocs without affecting the electron transfer kinetics for improved bioelectricity generation. Agar derived from polysaccharide agarose (0.05-0.2%, w/v) was chosen as a rheology modifying agent. Electroanalytical investigations showed that electrolytes modified with 0.15% agar display a nine-fold increase in current density (1.2 mA/cm²) by a thermophilic strain (Geobacillus sp. 44C, 60 °C) when compared with the control. Sodium phosphate buffer (0.1 M, pH 7) electrolyte with riboflavin (0.1 mM) was used as the control. Electrolytes modified with 0.15% agar significantly improved chemical oxygen demand removal rates. This developed electrolyte will aid in improving bioelectricity generation in Bioelectrochemical Systems (BES). The developed strategy avoids the use of peristaltic pumps and magnetic stirrers, thereby improving the energy efficiency of the process.

Keywords: Bioelectricity; Bioelectrochemical systems; Electrolyte; Rheology; Sedimentation rate.

MeSH terms

Agar*
Bioelectric Energy Sources*
Biological Oxygen Demand Analysis
Electrolytes
Rheology

Substances

Electrolytes
Agar