In this study the possibility to recover nitrogen from agro-industrial digestate using bioelectrochemical systems was investigated: two microbial electrolysis cells (MECs) were fed with both synthetic and real digestate (2.5 gNH4-N/L). Carbon felt and granular graphite (d > 2mm) were used as anodes in MEC-1 and MEC-2, respectively. As to synthetic wastewater, optimal nitrogen load (NL) was determined for MEC-1 and -2 (1.25 and 0.75 gNH4-N/d, respectively); MEC-1 showed better performance in terms of NH4-N removal efficiency (41±5%) and recovery rate (3.5±0.2 kgNH4-N/d/m3), compared with MEC- 2 (15±3% and 1.6±0.4 kgNH4-N/d/m3, respectively). At the optimal NL, lower NH4-N removal efficiencies and recovery rates were observed when real digestate was fed to MEC-1and -2, likely due to the higher complexity of the influent. Results are promising and may contribute in reducing the need for highly expensive and polluting processes for nitrogen synthesis
Ammonium Recovery From Agro-industrial Digestate Using Bioelectrochemical Systems
Carucci Alessandra;Erby Giovannimatteo;Milia Stefano
2021
Abstract
In this study the possibility to recover nitrogen from agro-industrial digestate using bioelectrochemical systems was investigated: two microbial electrolysis cells (MECs) were fed with both synthetic and real digestate (2.5 gNH4-N/L). Carbon felt and granular graphite (d > 2mm) were used as anodes in MEC-1 and MEC-2, respectively. As to synthetic wastewater, optimal nitrogen load (NL) was determined for MEC-1 and -2 (1.25 and 0.75 gNH4-N/d, respectively); MEC-1 showed better performance in terms of NH4-N removal efficiency (41±5%) and recovery rate (3.5±0.2 kgNH4-N/d/m3), compared with MEC- 2 (15±3% and 1.6±0.4 kgNH4-N/d/m3, respectively). At the optimal NL, lower NH4-N removal efficiencies and recovery rates were observed when real digestate was fed to MEC-1and -2, likely due to the higher complexity of the influent. Results are promising and may contribute in reducing the need for highly expensive and polluting processes for nitrogen synthesisI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.