Application of mixed metal oxide anode for the electro-oxidation/disinfection of synthetic urine: Potential of harnessing molecular hydrogen generation.

ABSTRACT

The efficacy of electro-oxidation has been checked for the deterioration of synthetic urine (SU) using mixed metal oxide anode along with the potential of harnessing the commercially useful byproduct i.e. molecular hydrogen gas. The results from batch have been used to execute the scale-up studies for the continuous electro-oxidation treatment of SU in a photovoltaic driven reactor. The effect of different operational variables like pH, time, current density and N/Cl ratio on process efficiency was evaluated in terms of %COD removal and specific energy consumption using response surface methodology. The results showed that 87.25% removal in COD and 85.88% in TOC were achieved in 8.8 h. The complete deactivation of E. coli spiked synthetic urine wastewater was achieved in 45 min only. The main strength lies in the demonstration of the significant reduction in treatment time to 6 h by incorporating dual effect i.e. Photo-electrocatalysis. The anode used was proven to be stable and effective even after 100 recycles (207.5 h). The intermediates formed during the treatment process were analyzed through LC-MS. The techno-economic analysis for the proposed technology under optimized conditions was calculated to be 0.85 $/kg of COD removed.