Rapid degradation of contaminated soil with 2‐methylpropane‐2‐thiol by H₂O₂/KMnO₄/NaClO system: process modeling and optimization

Abstract

2-Methylpropane-2-thiol is a hazardous material, and remediation of soil polluted by this contaminant with a fast method is important to study.In this study, H 2 O 2 /KMnO 4 /NaClO system as a combined system is investigated for 2-methylpropane-2-thiol oxidation because of especial characteristics of each oxidation agent. Central composite design based on response surface methodology was used to obtain appropriate effects of the main factors (initial oxidant concentrations and FeSO 4 to soil ratio) and their interactions on the removal efficiency. Pareto analysis show that initial H 2 O 2 concentration, FeSO 4 to soil ratio, initial NaClO concentration, and interaction between H 2 O 2 and FeSO 4 are the most influential factors on 2-methylpropane-2-thiol removal efficiency (31.82%, 16.85%, 16.24%, and 8.62% respectively). P-value of lack-of-fit (0.621) indicates that suggested model adequately fits the data with high correlation coefficient (R 2 = 97.59%). Investigation of optimum condition suggests that interaction of KMnO 4 with H 2 O 2 drops the removal efficiency and its concentration has to be as low as possible. The concentration of other studied oxidation agents and Fe 2+ ion must be as high as possible in the studied intervals. Verification experiment at optimum condition shows 95.71% for maximum 2-methylpropane-2-thiol removal efficiency that is a good agreement with the predicted value (94.76%).

Enhanced treatment of 2-methylpropane-2-thiol contaminated soil using magno-modified fenton process

“…This efficiency higher compared to some methods like sonication and a modified Fenton process to degrade 2-methylpropane-2-thiol. As represented in Figure 8, a magno-modified Fenton process has a higher removal efficiency compared to sonication and modified Fenton, minimizing the contaminant vaporization and Fe 3 O 4 recovery simultaneously [21,22,55]. CONCLUSION 2-methylpropane-2-thiol has several human, animal and social consequences and its removal from polluted soil is important to study.…”

“…Although there is some published research on 2-methylpropane-2-thiol removal from soil with 82% to 94% removal efficiency [21][22][23], they do not work on soil remediation and vaporization prevention of this contaminant simultaneously. Furthermore, even though there are some studies which couple the Fenton process with other process methods like microwaves for increasing the remediation yield [24], there are a few studies which use a combination of a magnetic field and chemical oxidants.…”