Demonstration of energy and nutrient recovery from urine by field-scale microbial fuel cell system

• DOI: 10.1016/j.procbio.2020.11.014
• Publication Date: 2020-11-12T17:05:14Z
• Authors: Priya Sharma; Guruprasad V. Tal...; Srikanth Mutnuri
• Keywords: 01 natural sciences; 7. Clean energy; 6. Clean water; 0105 earth and related environmental sciences

Abstract Scaling-up of Microbial fuel cells (MFC) involves optimizing parameters like the number of units, electrodes and unit size. This study demonstrates the working of a 10 L scale MFC stack for nutrients recovery (struvite as slow phosphorous release fertilizer) and energy recovery from urine over a three-month analysis period. The MFCs employed, a part of three staged systems (pH development, precipitation and treatment), were membrane divided double-chambered, operating in multiple-fed batch mode with a hydraulic retention time of 48 h. The average removal of chemical oxygen demand (COD) achieved was 75.55 ± 2.8 %, with removal rates of 4.252 kg/m3 day. The recovery of Ortho-Phosphates and ammoniacal nitrogen as struvite was 90 ± 1.5 % and 46 ± 2.16 %. The stacked MFC showed an average open-circuit voltage of 3.29 ± 0.68 V with power density of 14.5 mW/m2. Our findings suggest that the proposed three-stage process employing MFC stack achieved acceptable performance concerning nutrient recovery and organics removal.