Table 1. Electrical Energy Requirements and Production for the Two-Stage MFC-AFMBR System.
| characteristic | MFCs | AFMBR | system total |
|---|---|---|---|
| Electrical Energy required | |||
| Energy for Hydraulic Loss | |||
| reactor head loss, cm H2O | 0.5 | 2.5 | |
| reactor influent plus recirculation flow rate, mL/min | 1.1 | 171.1 | |
| hydraulic energy requirement, kWa | 0.001(10–6) | 0.699(10–6) | |
| required pumping energy, kWh/m3b | 0.00001 | 0.0107 | 0.0107 |
| Energy for Permeate Extraction | |||
| average TMP, cm H2O | 50.8 | ||
| permeate flow rate, mL/min | 1.1 | ||
| permeate energy requirement, kW | 0.090(10–6) | ||
| required pumping energy, kWh/m3 | 0.0014 | ||
| total pumping energy required for system, kWh/m3 | 0.00001 | 0.0121 | 0.0121 |
| total electrical energy required for pumps, kWh/m3c | 0.000015 | 0.0186 | 0.0186 |
| Electrical Energy Produced | |||
| MFC maximum power, mWd | 1.28 | ||
| electrical energy production, kWh/m3 | 0.0197 | 0.0197 | |
| electrical energy produced/requirede | 1.06 | ||
a
Energy requirement =9.8QE, where Q (m3/s) is flow rate and E (m H2O) is head loss.1
b
Energy per m3 of wastewater treated.
c
Assume energy efficiency of 65% in conversion of electrical energy to pump energy.1
d
Based on the maximum power produced by the SEA MFCs in series. This maximum power output was quite similar to that obtained during steady operation, and therefore it represents power production that could be obtained during continuous treatment tests (SI Figure S3).
e
The ratio of the electrical energy produced to that required by the MFC-AFMBR system.