Section: Methodology and research methods. Models and forecasts
The discharge of wastewater of complex composition containing organic compounds resistant to biological degradation is an acute environmental problem. One of the directions of its solution is the search for new more affordable and effective chemical oxidants. peroxodisulfuric acid (H2S2O8) is a promising oxidizer for organic pollutants in wastewater. The main disadvantage of the reagent in question is its instability in aqueous solutions due to the active course of hydrolysis and, as a result, a short shelf life. We studied the effect of initial concentration, pH, temperature and light on the storage process of H2S2O8. To assess the degree of decomposition of peroxodisulfuric acid during its storage and under the external factors, we proposed a new method for determining the final product of H2S2O8 decomposition – hydrogen peroxide. It has been found that the decomposition of peroxodisulfuric acid slows down significantly with a decrease in temperature and practically stops with ≈30% decomposition of the substance. It is proved that a pH changes in the medium leads to the decomposition of ≈95% of the reagent within 1 week. The almost complete decomposition of peroxodisulfuric acid under heating (93% at 60 оC) and under UV irradiation (82%) suggests the possibility of thermal and UV activation of the formation of sulfate radicals for AOP (Advanced Oxidation Processes). The successful discoloration of the free radical scavenger, which was used as a synthetic methyl red dye, confirms the prospects of peroxodisulfuric acid as an oxidizer of organic pollutants in wastewater.
ISSN 1995-4301
Select viewing options
