Neutral or acidic pH for the removal of contaminants of emerging concern in wastewater by solar photo-Fenton? A techno-economic assessment of continuous raceway pond reactors

J A Sánchez Pérez; S Arzate; P Soriano-Molina; J L García Sánchez; J L Casas López; P Plaza-Bolaños

doi:10.1016/j.scitotenv.2020.139681

Neutral or acidic pH for the removal of contaminants of emerging concern in wastewater by solar photo-Fenton? A techno-economic assessment of continuous raceway pond reactors

Sci Total Environ. 2020 Sep 20:736:139681. doi: 10.1016/j.scitotenv.2020.139681. Epub 2020 May 25.

Authors

J A Sánchez Pérez¹, S Arzate², P Soriano-Molina², J L García Sánchez², J L Casas López², P Plaza-Bolaños³

Affiliations

¹ Solar Energy Research Centre (CIESOL), Joint Centre University of Almeria-CIEMAT, Carretera de Sacramento s/n, 04120 Almeria, Spain; Department of Chemical Engineering, University of Almería, Spain. Electronic address: jsanchez@ual.es.
² Solar Energy Research Centre (CIESOL), Joint Centre University of Almeria-CIEMAT, Carretera de Sacramento s/n, 04120 Almeria, Spain; Department of Chemical Engineering, University of Almería, Spain.
³ Solar Energy Research Centre (CIESOL), Joint Centre University of Almeria-CIEMAT, Carretera de Sacramento s/n, 04120 Almeria, Spain; Department of Chemistry and Physics, University of Almería, Spain.

PMID: 32479960
DOI: 10.1016/j.scitotenv.2020.139681

Abstract

As far as the authors know, no in-depth comparison has been made between the different performances of the solar photo-Fenton process for the removal of contaminants of emerging concern (CECs) as a function of pH. To this end, real WWTP secondary effluents were treated in continuous flow mode at pilot plant scale. The effect of hydraulic residence time (HRT), liquid depth and percentage of CEC removal on treatment capacity was studied. At acidic pH (2.8), the iron source was FeSO₄ and at neutral pH (7.0), it was Fe(III)-EDDS. At both pH values, 2250 L m^-2 d^-1 can be treated in 15-cm deep raceway pond reactors at 30 min HRT with 0.1 mM iron and 0.88 mM H₂O₂ in order to achieve 80% CEC removal. Treatment costs were 0.25 € m^-3 and 0.56 € m^-3 at acidic and neutral pH, respectively. This study paves the way for the solar photo-Fenton process to be employed on a commercial scale.

Keywords: Advanced oxidation processes; Cost; EDDS; Organic pollutant; Pilot plant; Wastewater.