Table 1. Effect of the Solvent Type and Oxidant Mixture on the UAOD Efficiency.

operating condition	feedstock	oxidant mixture	solvent	type and content of sulfurous compounds	removal efficiency (%)	refs
75 °C, 3 rounds of extraction for different times	diesel oil	tetradactyl ammonium bromide + phosphotungstic acid + hydrogen peroxide	acetonitrile	various types and contents	98.5	Mei et al.23
70 °C with ultrasonication for 10 min	diesel fuel	hydrogen peroxide + acetic acid + iron sulfide	acetonitrile	various types and contents	98	Ibrahim et al.24
50 °C, 4 rounds of extraction for 3 h	model diesel	cadmium oxide catalyst + hydrogen peroxide + acetic acid	acetonitrile	various types and contents	99.5	Zhao et al.25
ultrasonication for 10 min	kerosene	formic acid + hydrogen peroxide	acetonitrile	various types and contents	95	Babushkina et al.26
ultrasonication for 76 min and 4 rounds of extraction	kerosene	phosphotungstic acid supported on active carbon + hydrogen peroxide	acetonitrile	various types and contents	99	Gildo et al.27
70 °C	model diesel fuel	hydrogen peroxide + acetic acid	N, N-dimethylformamide	dibenzothiophene	98	Margeta et al.28
40 °C with ultrasonication for 15 min	diesel fuel	hydrogen peroxide + acetic acid + iron sulfide	N, N-dimethylformamide	dibenzothiophene	98	Dai et al.29
62 °C with ultrasonication for 17 min and 3 rounds of extraction	gasoil	hydrogen peroxide + acetic acid + iron sulfide + isobutanol	methanol	dibenzothiophene	90	Shayegan et al.17
90 °C with ultrasonication for 9 min and 3 rounds of extraction	diesel oil	hydrogen peroxide + acetic acid	methanol	dibenzothiophene	80	Duarte et al.30
50 °C	diesel oil	hydrogen peroxide + acetic acid + phosphotungstic acid + tetradactyl ammonium bromide	sodium hydroxide	dibenzothiophene	86	Shamseddini et al.31