Estudo da otimização do processo H2O2/UV para degradação do corante remazol vermelho RB 133%

Abstract

Industrial processes that consume excess of water, typically generates a high volume of effluent, where the textile industry is a typical example. The oxidation chemistry is one of the alternative processes for the textile dyes treatment. In this context, the Advanced Oxidation Processes (AOPs) are based on the generation of hydroxyl radicals (.OH) on which are highly oxidizing compounds can decompose quickly and non-selective contaminant solutes, for a partial or complete mineralization. This study investigated the use of advanced oxidation process for degradation of the dye Remazol Red RB 133%. The studies were conducted in two stages. For first step, in the reactor with 710 mL of working volume , were studies the parameters: kinetic effect, hydrogen peroxide dosage, temperature, pH, addition of hydrogen peroxide in the line. The kinetics study decolorization and the inhibitory effect of anions were also studied. The study of kinetic showed that in 250 minutes there was a complete decolorization of the solution using a H2O2 dose of 1% (v/v) through the use of UV radiation, and a 78.41% removal in Chemical Oxygen Demand (COD) was observed. The pH effect not influenced in the decolorization process; however has been influenced in removal of COD. The study of temperature effect showed that for an increase in temperature the decolorization rate increases, but a small improvement in the efficiency of COD removal. The addition of H2O2 during the process increased the efficiency of COD removal. The results of the efficiencies of the end of the process indicated that there was no difference between treatments in the presence of anions in the studied concentration (10 mM) when compared to degradation without the presence of these anions, since the end of all treatments, the solution was colorless. In the second stage, was carried in the reactor with 520 mL of working volume flow studies were performed and power of UV radiation. The studies of flow rate showed that for flow rate of 1.0; 2.0 and 3.0 L/min there was no significant difference in the process decolorization process. The of organic matter concentrations at 480 minutes of experiment for the three flow rates were 36.63%, 51.08% and 48.35% respectively. The increased power of UV radiation caused an increase in the XII efficiency of discolouration and degradation of organic matter. The study showed a real effluent with low efficiency to reduce color and chemical oxygen demand.