Microbial fuel cell fed by Barnett Shale produced water: Power production by hypersaline autochthonous bacteria and coupling to a desalination unit

Abstract

Hydraulic fracturing for oil and gas production can generate large volumes of highly saline produced waters that pose a significant disposal challenge and a potential opportunity for reuse. Here, we report on a microbial fuel cell (MFC) fed with produced water (Barnett Shale), which produced power (47 mW/m 2) and accomplished a COD removal efficiency of 68% (influent COD 10,520 ± 1340 mg/L). Bacterial population analysis showed two autochthonous halophilic species colonizing the anode, H. praevalens and M. hydrocarbonoclasticus. In addition, we demonstrated that hypersaline MFCs (100 g/L NaCl) can produce electricity to power a capacitive deionization (CDI) device for desalination, with a salt adsorption capacity of up to 40 mg of salt per g of carbon electrode. This is the first report of a MFC operating with hypersaline produced water, and illustrates the potential to couple MFCs with CDI to enable desalination and reuse of hypersaline wastewaters.

Understanding the cumulative effects of salinity, temperature and inoculation size for the design of optimal halothermotolerant bioanodes from hypersaline sediments

“…Some halophilic and/or thermophilic bacterial species isolated from extreme natural or industrial environments have been reported to display electroactive properties [19,20]. In particular, sediments from salt marsh [7,8], saline microbial mats and salt lakes [21], saline ponds [22], the Red Sea [17], the Great Salt Lake [2], and Sambhar Lake [6] have been investigated to select electroactive bacterial biofilms. In the majority of these studies, a positive correlation between salinity and current generation has been demonstrated.…”

“…However, all these studies were carried out at temperatures lower than or equal to 37°C and so none of this work examined the combined effect of increased salinity and high temperature on the bioanode current production, yet the salinity and thermal tolerance of halothermophilic microorganisms would make it possible to consider the design of halothermotolerant bioanodes that would be truly suitable for the treatment of hot, highly saline wastewater. In addition, the approaches used to improve the performance of bioanodes under saline or thermal conditions have so far been carried out by monitoring the influence of a single factor at a time, by following a single experimental response, which is often only the generation of current [3,6,7,8,15,21,22].These approaches, known as one-variable-at-a-time optimization, do not include the interactive effects between the variables studied. Consequently, this optimization does not depict the effects of all the factors on the response.…”

Alginate‐Encapsulated Bacteria for the Treatment of Hypersaline Solutions in Microbial Fuel Cells

“…Moreover, chemical oxygen demand (COD) removal efficiencies are usually limited in hypersaline conditions, considering a five‐day period as the standard degradation time, with values ranging from 50 to 60 % . Allowing higher retention time could increase COD removal; however, increasing the retention time in a real system would require an increase in the operational volume (assuming a constant rate of solution inlet to be treated), which is not always a feasible approach.…”

Petrochemical Wastewater and Produced Water

“…Microbial fuel cell (MFC) fed with produced water (Barnett Shale) was able to produce power and achieve COD removal (Monzon et al, 2017). The hypersaline MFCs (100 g/L NaCl) could produce electricity to power a capacitive deionization (CDI) device for desalination.…”