Separation of competitive microorganisms using anaerobic membrane bioreactors as pretreatment to microbial electrochemical cells

Evaluation of limiting factors for current density in microbial electrochemical cells (MXCs) treating domestic wastewater

“…It is expected that air exposure during SS collection (30–45 min) would suppress the activity of anaerobic microorganisms present in SS, so the syntrophic interactions between ARB and non-ARB (fermenters and methanogens) would not be promoted well. In comparison, particulates introduction to the anode together with the domestic wastewater (Run 7) can stimulate the syntrophic interactions (fermenters, H 2 consumers, and ARB) [7], [13], which can efficiently provide substrate available for ARB (e.g., acetate and H 2 ). The current density of 0.5 A/m 2 at Run 7, which is 0.2 A/m 2 higher than that at Run 3 and 4, supports the importance of the syntrophy, since the number of non-ARB would be trivial in the anode for Run 3 and 4 (filtrated wastewater).…”

“…Fermenters proliferated in suspension would better offer acetate and H 2 to ARB at longer HRT. Recent literature presents current increase in MXCs fed with mixture of propionate and acetate at longer HRT due to improved propionate fermentation to acetate and H 2 [7], [13]. However, the increase of planktonic fermenters driven by long HRT will deteriorate effluent water quality (e.g., TCOD and SS).…”

“…There are many parameters that are able to influence current density in MXCs, including microbial community on biofilm anode, pH, temperature, oxygen, separator, cathodic catalysts, biodegradability of substrate, alkalinity, biofilm conductivity and so on [7], [8], [20], [21], [26], [28], [30], [34]. Microbial community would show functional redundancy consistently once kinetically-efficient ARB are well proliferated on biofilm anode [1], [29].…”

Methodology for Fast and Facile Characterisation of Carbon-Based Electrodes Focused on Bioelectrochemical Systems Development and Scale Up

“…Most of these materials present unacceptable initial wettability that may distort the analytical results, meaning that a pre-treatment to mitigate this problem is necessary [27,28]. The pre-treatment consists of sequentially immersing the electrode into 1 M nitric acid, acetone and ethanol solutions with concentrations for 12 h, 30 min and 30 min, respectively [27].…”

“…The pre-treatment consists of sequentially immersing the electrode into 1 M nitric acid, acetone and ethanol solutions with concentrations for 12 h, 30 min and 30 min, respectively [27]. These parameters were established based on previous experiments carried out on carbon felt materials, but proved to be ineffective for air removal from carbon paper electrodes, as shown in Figure 2.…”