Attenuation of trace organic compounds (TOrCs) in bioelectrochemical systems

Craig M Werner; Christiane Hoppe-Jones; Pascal E Saikaly; Bruce E Logan; Gary L Amy

doi:10.1016/j.watres.2015.01.013

Attenuation of trace organic compounds (TOrCs) in bioelectrochemical systems

Water Res. 2015 Apr 15:73:56-67. doi: 10.1016/j.watres.2015.01.013. Epub 2015 Jan 17.

Authors

Craig M Werner¹, Christiane Hoppe-Jones¹, Pascal E Saikaly¹, Bruce E Logan², Gary L Amy³

Affiliations

¹ Water Desalination and Reuse Center, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
² Department of Civil and Environmental Engineering, Pennsylvania State University, University Park, PA 16802, USA.
³ Water Desalination and Reuse Center, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia. Electronic address: gary.amy@kaust.edu.sa.

PMID: 25644628
DOI: 10.1016/j.watres.2015.01.013

Abstract

Microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) are two types of microbial bioelectrochemical systems (BESs) that use microorganisms to convert chemical energy in wastewaters into useful energy products such as (bio)electricity (MFC) or hydrogen gas (MEC). These two systems were evaluated for their capacity to attenuate trace organic compounds (TOrCs), commonly found in municipal wastewater, under closed circuit (current generation) and open circuit (no current generation) conditions, using acetate as the carbon source. A biocide was used to evaluate attenuation in terms of biotransformation versus sorption. The difference in attenuation observed before and after addition of the biocide represented biotransformation, while attenuation after addition of a biocide primarily indicated sorption. Attenuation of TOrCs was similar in MFCs and MECs for eight different TOrCs, except for caffeine and trimethoprim where slightly higher attenuation was observed in MECs. Electric current generation did not enhance attenuation of the TOrCs except for caffeine, which showed slightly higher attenuation under closed circuit conditions in both MFCs and MECs. Substantial sorption of the TOrCs occurred to the biofilm-covered electrodes, but no consistent trend could be identified regarding the physico-chemical properties of the TOrCs tested and the extent of sorption. The octanol-water distribution coefficient at pH 7.4 (log DpH 7.4) appeared to be a reasonable predictor for sorption of some of the compounds (carbamazepine, atrazine, tris(2-chloroethyl) phosphate and diphenhydramine) but not for others (N,N-Diethyl-meta-toluamide). Atenolol also showed high levels of sorption despite being the most hydrophilic in the suite of compounds studied (log DpH 7.4 = -1.99). Though BESs do not show any inherent advantages over conventional wastewater treatment, with respect to TOrC removal, overall removals in BESs are similar to that reported for conventional wastewater systems, implying the possibility of using BESs for energy production in wastewater treatment without adversely impacting TOrC attenuations.

Keywords: Bioelectrochemical systems; Biotransformation; Sorption; Trace organic compounds.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adsorption
Biodegradation, Environmental
Bioelectric Energy Sources*
Bioreactors*
Biotransformation
Electrodes
Electrolysis
Waste Disposal, Fluid / methods*
Water Pollutants, Chemical / metabolism*
Water Purification / methods*

Substances

Water Pollutants, Chemical