Removal of organochlorine insecticide endosulfan in water and soil by Fenton reaction with ascorbic acid and various iron resources

An assortment of Fenton (or Fenton-like) reaction treatment systems using various iron resources such as ferrous sulfate, ferric nitrate, commercial zerovalent iron (mZVI), or self-made ZVI (Fe-nanowire) were evaluated to effectively remove α- and β-isomers of endosulfan (ED) from contaminated water and soil. Ascorbic acid (AA) was added as a chelation reagent to maintain the aqueous reaction of soluble iron. In the aqueous experiment, a combined treatment of 1% mZVI, 0.01 M AA, and 0.1 M H 2 O 2 was determined to be the most effective method, showing 98–100% of ED removal within 24 h. The mZVI/AA/H 2 O 2 treatment method was finally applied to ED-contaminated soil samples, and the application removed significant ED residues from both soil slurries (65–73%) and immobile soils containing small amount of moisture (64–66.2%). Overall results showed that the mZVI/AA/H 2 O 2 treatment can be utilized as a potential technique to remediate both water and soil contaminated with ED.