Accomplishing a N-E-W (nutrient-energy-water) synergy in a bioelectrochemical nitritation-anammox process

Abstract

This study reports an investigation of the concept, application and performance of a novel bioelectrochemical nitritation-anammox microbial desalination cell (MDC) for resource-efficient wastewater treatment and desalination. Two configurations of anammox MDCs (anaerobic-anammox cathode MDC (AnA mox MDC) and nitration-anammox cathode MDC (NiA mox MDC)) were compared with an air cathode MDC (CMDC), operated in fed-batch mode. Results from this study showed that the maximum power density produced by NiA mox MDC (1,007 mW/m 3 ) was higher than that of AnA mox MDC (444 mW/m 3 ) and CMDC (952 mW/m 3 ). More than 92% of ammonium-nitrogen (NH 4 + -N) removal was achieved in NiA mox MDC, significantly higher than AnA mox MDC (84%) and CMDC (77%). The NiA mox MDC performed better than CMDC and AnA mox MDC in terms of power density, COD removal and salt removal in desalination chamber. In addition, cyclic voltammetry analysis of anammox cathode showed a redox peak centered at −140 mV Vs Ag/AgCl confirming the catalytic activity of anammox bacteria towards the electron transfer process. Further, net energy balance of the NiA mox MDC was the highest (NiA mox MDC-0.022 kWh/m 3 >CMDC-0.019 kWh/m 3 >AnA mox MDC-0.021 kWh/m 3 ) among the three configurations. This study demonstrated, for the first time, a N-E-W synergy for resource-efficient wastewater treatment using nitritation-anammox process.

Resource recovery from low strength wastewater in a bioelectrochemical desalination process

“…It should be noted that the microbial desalination cells are based on the same fundamental bio‐electrochemical principle as in microbial fuel cells. The individual and interactive effects can vary depending on the process configuration, nature, and characteristics of the process streams and operating conditions .…”

Co-existing Anammox, Ammonium-Oxidizing, and Nitrite-Oxidizing Bacteria in Biocathode-Biofilms Enable Energy-Efficient Nitrogen Removal in a Bioelectrochemical Desalination Process

“…The simulated wastewater was enriched with a nutrient buffer solution (pH 7.0) containing 0.13 g/L KCl, 0.31 g/L NH 4 Cl, 2.45 g/L NaH 2 PO 4 •H 2 O, and 4.58 g/L Na 2 HPO 4 ) with 468.7 mg/L glucose (COD equivalent to 500 mg/L) as a supplemental organic carbon source and trace minerals. 19,20 Anammox Cultures and Medium Composition. Anammox biomass sludge with an initial MLSS concentration of 100 g/L was obtained from a wastewater treatment plant.…”

“…Both membranes were preconditioned based on a previous method. 20 Carbon cloth pieces, wrapped on a supporting material (stainless steel mesh), were used as both anode and cathode electrodes. Both the electrodes have approximately the same surface area of about 11.2 cm 2 .…”

Transitioning Wastewater Treatment Plants toward Circular Economy and Energy Sustainability

“…Scenario 6 is based on the anerobic treatment of wastewater for COD removal in the anode compartment and partial nitritation/anammox based nitrogen removal in the cathode. 49 Details of this process were presented in our previous study. 49 A COD concentration of 500 mg/L and ammonium and nitriate ion concentrations of 70 mg/L were used in that study with a dentention time of 72 h. Finally, in all cases, the net energy ratio is calculated as the ratio of the enregy produced to the amount of energy consumed in the process.…”

“…The net energy ratio for S6 is based on laboratory-scale experimental results presented in our previous study. 49 A comparison of Scenario 6 with Scenario 3 and one other study is shown in Table 1 . Overall, an analysis based on Figure 4 and Figure 5 shows that both energy consumption and energy recovery should be optimized to gain higher net energy ratios.…”