Explicating the importance of aeration and pH for Amaranth degradation and electricity generation in a viable hybrid system of photocatalytic fuel cell and electro-Fenton process

Abstract

Hybrid system of photocatalytic fuel cell (PFC) and electro-Fenton (EF) process emerges as an environmentally sustainable technology for wastewater treatment and energy recovery. The established dual-cell hybrid system can reduce the recombination of electron and hole in photoanode and PFC acts as the power source for EF process. Hence, the optimal conditions for dye degradation synchronized with electricity generation in the dual-cell hybrid system should be determined. The in-situ generation of hydroxyl radicals was the key factor for dye degradation in the system. Hence, the operating parameters such as aeration and initial pH of dye were assessed. Higher decolourization efficiency was attained in aerated PFC (76.6%) and aerated EF process (84.5%). Enhanced power density (1.493 μW cm−2) was achieved in aerated hybrid system through the elevated transfer of electrons from photoanode in PFC to the cathode of EF process. Acidic environment was favoured for the dye degradation in both PFC and EF process. At optimal pH 3, PFC and EF process attained highest colour removal efficiency which were 88.5% and 84.5%, respectively. Consequently, largest power density (2.221 μW cm−2) and maximum current density (0.012 mA cm−2) were achieved in the hybrid system under pH 3 condition in both PFC and EF process.