Propuesta para la optimización de la eficiencia de remoción de manganeso y hierro por dosificación de permanganato de potasio en la planta de tratamiento de agua cruda Tixán - ETAPA-EP mediante la incorporación de un sistema de aireadores

Abstract

The Tixan water treatment plant has a potassium permanganate dosing system to reduce manganese (II) and iron (II) levels in water to safe levels for human consumption. However, there are operational interferences in the initial metal oxidation process because iron is the element that consumes most of the potassium permanganate and manganese is not oxidized. For this reason, ETAPA EP installed an aerator system to incorporate oxygen and oxidize the iron, leaving the potassium permanganate available to oxidize the manganese. The system consists of 5 pairs of aerators placed in parallel. In this work, an experimental design was proposed to determine the effect of different aerator configurations on the oxidation of manganese and iron, together with the oxidation treatment with potassium permanganate. The monitoring of iron and manganese oxidation was verified by atomic absorption. To determine the efficiency of the treatments, an analysis of variance (ANOVA) was performed at a significance level of 5%. The results indicated that there were statistically significant differences for iron between the raw water collection stage and the distribution to the modules (p value = 2e-16 and 1.56e-4, respectively), due to the fact that the initial concentrations are not constant and there is a variation since it comes from a natural resource and is prone to factors such as leaching, rainfall, etc., thus altering the iron and manganese concentration values. No differences were found between the subsequent stages, since from sedimentation onwards, total iron removal had already occurred. On the other hand, in the analysis of manganese concentrations, significant differences were identified in all stages. Finally, it is assumed that the optimal treatment for the iron and manganese removal process and that, in turn, it has the lowest energy expenditure is the first treatment without aeration system.