Flow-through laminar anodes with variable interlaminar distance to modulate the current density of urine-fed bio-electrochemical systems

PRUDENTE, MARIANO; MASSAZZA, DIEGO A.; PROCACCINI, RAÚL A.; RODRÍGUEZ, NICOLÁS A.; ROMEO, HERNÁN E.

BIOELECTROCHEMISTRY

ELSEVIER SCIENCE SA

Año: 2023

1567-5394

Thre e -dimensiona l (3D) porous anodes used in urin e -powere d bi o -electrochemica l appl ication s us ually lead to th e growth of electr o -active ba cteri a on th e oute r electrod e su rface , du e to li mited micr obial access to th e inte r - na l stru cture an d lack of pe rmeatio n of cu lture medium throug h th e entire porous arch ite cture . In this study, we pr opose th e us e of 3D monolithic Ti 4 O 7 porous electrodes with co ntrolle d la m ina r stru cture s as micr obial anodes fo r urin e -fe d bi o -electrochemica l sy stems . Th e inte rla m ina r di stanc e wa s tune d to mo d ulate th e anod e su rface ar - ea s and, thus , th e vo l ume tri c cu rrent de nsities . To profit from th e true area of th e electrodes , urin e feedin g wa s pe rformed as a co nti n uou s flow throug h th e la m ina r arch ite ctures. Th e sy ste m wa s optimize d accordin g to th e re - sponse su rface methodolog y (RSM). Th e electrod e inte rla m ina r di stanc e an d th e co nce ntr ation of urin e were se - lected as indepe ndent variables, with th e vo l ume tri c cu rrent de nsity as th e ou tpu t response to optimize . Ma x i - mu m cu rrent de nsities of 5. 2 kA.m − 3 were pr oduce d from electrodes with 12 µm -interlaminar di stanc e an d 10 %v / v urin e co nce ntr ations. Th e pr esent stud y demo nstrate s th e existenc e of a trad e -off betwee n th e accesibi lit y to th e inte rna l electrod e stru cture an d th e effe ctive usag e of th e su rface area to ma x imize th e vo l ume tri c cu rrent de nsity when dilute d urin e is used as flowin g -throug h feedin g fuel .