Abstract

MARTIN-DOMINGUEZ, Alejandra; RIVERA HUERTA, María de Lourdes; PINA SOBERANIS, Martín  and  PEREZ CASTREJON, Sara. INCIDENCE OF THE VELOCITY GRADIENT IN THE ELECTROCOAGULATION EFFICIENCY FOR ARSENIC REMOVAL IN A PLUG-FLOW REACTOR. INCI [online]. 2008, vol.33, n.7, pp.503-509. ISSN 0378-1844.

Studies at laboratory scale were carried out using a plug-flow electrochemical reactor with steel plates that produces iron hydroxide as coagulant in a continuous form. The goals were first to analyze the influence of turbulence over coagulation due to neutralization charges and second, to define the principal factors that are involved in obtaining high efficiencies of electrochemical iron production and in removing the formed flocs. The results revealed that these efficiencies were increased when the mixture velocity gradient (G) and its product by the reactor detention time (Gt) also rose. The iron production decreased according to the reactor operation time; however, the addition of NaCl to reach a conductivity of 600µS·cm^-1 avoided the reduction and increased electrochemical efficiency. The presence of chlorine in water raised considerably the iron removal efficiency, but did not affect the iron production. In this study it was assumed that if more iron is removed after sedimentation the amount of eliminated arsenic in water will be higher. The results showed that there is a good correlation between the elimination of both pollutants.

Keywords : Arsénico ; Electrocoagulación ; Potabilización ; Reactor Flujo Pistón .