The utilization efficiency of hydrogen peroxide on the removal of volatile organic acids in sand columns

Abstract

Effects of hydrogen peroxide (H2O2) on the removal of volatile organic acids were studied with a series of sand columns. Hydrogen peroxide was used as an alternative oxygen source to enhance the removal of volatile organic acids. In the presence of microorganisms, H2O2 was readily decomposed to increase the dissolved oxygen concentrations (DO) in waters. The microorganisms used in this study could tolerate the toxicity of H2O2, even if its concentration reached 450 mg/L. The volatile organic acids used in this study were not chemically oxidized by H2O2. The results indicated that the concentrations of H2O2 required to remove volatile organic acids were higher than those calculated from the theoretical stoichiometry equation. Hydrogen peroxide was not effectively utilized, especially when the concentrations of H2O2 were relatively high. When the concentration of H2O2 was high, oxygen produced from the decomposition of H2O2 might not be effectively utilized by microorganisms and might escape from waters in gaseous form. The ratio of the amount of the volatile organic acid removed to the amount of H2O2 added decreased with an increase in the concentrations of H2O2. Multi-point injection of H2O2 can be used to improve its utilization efficiency, if a higher concentration of H2O2 was required.