Estudio de estrategias de remoción de peróxido de hidrógeno de agua típicamente usadas en investigaciones referidas a procesos de oxidación avanzada.

Abstract

Hydrogen peroxide (H2O2) has been widely used in industries and water treatment; it presents importance for Advanced Oxidation Processes (AOPs) since it facilitates the generation of hydroxyl radicals (•OH). The remaining H2O2 in water could be problematic in kinetics studies on AOPs. The removal of H2O2 from water can be achieved through three strategies: 1) the addition of manganese dioxide (MnO2), 2) the rise of temperature, and 3) an increase in the pH value. The kinetics of H2O2 degradation for these strategies were studied; the order of reaction was determined/confirmed, and the observed constant rates were obtained for each case. A rise of temperature to 65 ± 5 °C and the increase of the pH value up to 12 allowed removals of 99,965 and 99,957 %, respectively, after 10 min of reaction. Therefore, those strategies allowed higher removal of H2O2. The addition of 10 mg of MnO2 powder to 250 mL of H2O2 solution (708,620 mg L-1) allowed an H2O2 removal of 87,057 % in 60 min. Besides being the less efficient H2O2 removal strategy, the addition of MnO2 could have limitations that may affect the measurement of parameters such as the Chemical Oxygen Demand (COD). Although the rise of temperature and the increment of the pH value allowed a rapid H2O2 removal, the characteristics of chemical compounds (organic pollutants) must be taken into account.