Two strategies of solar photo-Fenton at neutral pH for the simultaneous disinfection and removal of contaminants of emerging concern. Comparative assessment in raceway pond reactors

Abstract

Abstract For the first time, two strategies of solar photo-Fenton at neutral pH (with FeSO4 and Fe3+-EDDS) are techno-economically assessed. With the target of simultaneous wastewater disinfection and removal of contaminants of emerging concern (CECs), a cost estimation ranging from 0.13 to 0.49 €/m3 as a function of the treatment goal is presented. To this end, the effects of liquid depth (5, 10 and 15\u202fcm) and the iron species were studied at lab-scale. Afterwards, the feasibility of both operating strategies was evaluated and validated outdoors at pilot plant scale in low-cost raceway pond reactors. For the joint-removal of bacteria and CECs, the use of FeSO4 as iron source was cheaper than Fe3+-EDDS. However, it is important to highlight that although bacterial inactivation reached > 3 log, only around 35 % of CEC degradation was achieved with FeSO4, while more than 80 % CEC load was removed with Fe3+-EDDS.