Effects of Fenton oxidation on soil mineral stability determined by the Taguchi approach

Abstract

Abstract Due to anthropogenic activities, soils are increasingly being polluted with organic pollutants, many of which are hazardous for ecosystems. Fenton oxidation is widely used to remove organic pollutants, owing to the reaction’s excellent capacity for destroying organic compounds. We used the Taguchi approach orthogonal array nine trials (L9OA) on two different clay mixtures to examine the effects of Fenton oxidation relative to three parameters: hydrogen peroxide concentration, ferrous sulfate concentration, and oxidation period. The first clay sample contained kaolinite (96.6%), illite (1.6%), quartz (1%), and muscovite1 (0.8%). The second sample contained montmorillonite (36.7%) and muscovite2 (63.43%). Kaolinite was highly resistant to Fenton oxidation, with a maximum dissolution of only 5.7% in all trials. Illite and montmorillonite were almost completely destroyed by all Fenton oxidation treatments, with some trials resulting in 100% degradation. Percent quartz degradation tended to oscillate between 0% and 100%. Neoformation of muscovite1 was detected. Hydrogen peroxide concentration was the most influential factor affecting degradation of kaolinite, montmorillonite, and quartz, whereas oxidation period was the most influential factor for muscovite2 associated with montmorillonite. Illite destruction was related mostly to the amount of ferrous sulfate.