Integration of Flotation Technologies and Advanced Oxidation Processes for Oil and Gas and Desalination Industries Effluents Reuse

Identifier:  TDX:2587

Handle: https://hdl.handle.net/20.500.11797/TDX2587

Authors:  Jiménez Herrera, Silvia

Abstract:
PW is the aqueous effluent that is brought to the surface along with oil or gas in extraction operations. For its treatment and reuse, integrated processes consisting in a pretreatment followed by an advanced oxidation process (AOP) have been proposed. As pretreatments, settling and enhanced DAF (E-DAF) without air injection showed adequate turbidity and oil and grease (O&G) removals, with eliminations higher than 87% and 90% respectively, employing 70 mg L-1 of FeCl3 and 83 min of settling time; and 57.9 mg L-1 of FeCl3, 300 mg L-1 of microspheres and a flocculation rate of 40 rpm. Pretreated PW with O&G content below the requirements for discharging was obtained, but dissolved organic compounds were not eliminated, so POAs such as photocatalysis, photo-Fenton, Fenton and ozonation were studied to include one of these processes within the integrated treatment solution after the E-DAF or settling. The best results were obtained with 4 g h-1 O3 and 1500 mg L-1 H2O2, at pH 10. After 2 h a 74% of TOC removal was achieved, the acetic acid (the most recalcitrant component) elimination was 77.8% and the components added in the synthetic PW essayed in this work were eliminated. Reverse osmosis membranes cleaning waters were also treated by POAs (Fenton, photo-Fenton and photocatalysis). Highest elimination was achieved with the photo-Fenton process at pH 3, where 79% of TOC removal was obtained with 1400 mg L-1 H2O2 and 70 mg L-1 Fe2+ after 60 min of simulated solar radiation, obtaining suitable effluent for its reuse on irrigation.