Estudio de la degradación de detergentes en aguas residuales domésticas empleando una celda DiaClean® dotada con electrodo de diamante dopado con boro

Abstract

Surfactants are considered persistent organic pollutants (POP’s) and are not completely degraded by conventional wastewater treatments, so it is necessary to develop new technologies. This research project proposes to study the degradation of surfactants that are the main components of detergents present in domestic wastewater from a WWTP at "Arupos de la Hacienda" housing complex through advanced electro-oxidation. The studies of electrochemical oxidation of surfactants was carried out in a cell DiaClean® with BDD anode. The flow rate (1,5 L/min, 4 L/min and 7 L/min) was ranged, keeping the current constant, and then the current density was varied (7, 14, 20, 30, 40 and 50 mA/cm2) maintaining the constant flow. For each test was monitored surfactants, COD, turbidity, pH, conductivity, temperature and cell potential. Moreover, once found the optimal operating conditions was analyzed COT. The best operating conditions: flow 1,5 L/min and a current density of 50 mA/cm2, an 89.7%, surfactants remission was reached with a kinetic constant of 0.0026 mol/L-min. With respect to cod, 90.7% of the remission was reached with a kinetic constant of 0.0022 mol/L-min; In addition, 94% mineralization (COT) was achieved with a kinetic constant of 0.0076 min-1 and 89.4% turbidity reduction. Finally, the installation cost of the proposed system was $12 460.00 and the operating cost was 0.08 USD L-1. This POA is proposed as a promising alternative for the efficient removal of surfactants and high mineralization of organic compounds present in domestic wastewater.