Abstract

ISARAIN-CHAVEZ, Eloy et al. Response surface applied to the treatment of wastewater with the coupling of DSA and photocatalysis. Tecnol. cienc. agua [online]. 2015, vol.6, n.2, pp.51-67. ISSN 2007-2422.

This study describes a response surface analysis based on a central composite design to evaluate a filter-press electrolytic flow cell coupled with a compound parabolic solar concentrator. This was used to treat 20 l of domestic wastewater with a chemical oxygen demand of 742 to 756 mg l^-1 and total organic carbon of 248 a 253 mg l^-1. The anodes used in the electrolytic cell were IrPbO, IrSnO and RuPbO. They were coated with metallic chlorides on Ti plates and were activated with thermal decomposition. The area of the compound parabolic solar concentrator was 1 m² and was exposed for 4 hours per day, receiving an average radiation of 889 watts m^-2. The addition of TiO₂ in concentrations of 100 to 150 mg l^-1 contributed to the degradation of the pollutants, and the effects from changing the concentration of the electrolyte support from 0.02 to 0.06 M of Na₂SO₄ were not very significant. Tests of the degradation were followed by an analysis of total organic carbon, with degradation percentages between 5 and 30% at the end of treatment when applying currents of 10 to 30 A, with an energetic consumption from 6 to 74 kW m^-3.

Keywords : Dimensional stable anodes; domestic wastewater; compound parabolic concentrator; photocatalysis; anodic oxidation; titanium oxide.