The Enhancement of Indeno(1,2,3-cd)Pyrene Oxidation by Low Concentration of Cyclodextrin with Fenton Reagent in Aqueous Phase

Fenton reagent,composed of H2O2 and FeSO4,was a vital and efficient oxidant to degrade polycyclic aromatic hydrocarbons(PAHs),especially for the PAHs unavailable to microorganisms,such as indeno(1,2,3-cd)pyrene.The degradation efficiency of indeno(1,2,3-cd)pyrene with Fenton reagent in aquatic phase was studied under different pH,reaction time,H2O2,FeSO4 and low concentrations of cyclodextrin conditions.The results indicated that with the initial indeno(1,2,3-cd)pyrene concentration of 2.5 mg·L-1,the removal efficiency was 62.88% under the condition of 20.0 mmol·L-1 H2O2 and 3.0 mmol·L-1 FeSO4.For efficient degradation of indeno(1,2,3-cd) pyrene,pH should be maintained as 3.With the amendment of cyclodextrin,the solubility of indeno(1,2,3-cd)pyrene could be improved in aqueous phase.Among the four types of cyclodextrins,mainly including hydroxypropyl-β-cyclodextrin(HPCD),β-cyclodextrin(β-CD),methyl-β-cyclodextrin(MCD)and acetyl-β-cyclodextrin(ACD),HPCD was proved to be the best one to increase the solubility of indeno(1,2,3-cd)pyrene at the concentration of 3.0 mg·L-1.With the amendment of HPCD at the concentration of 3 mg·L-1,the removal efficiency of indeno(1,2,3-cd)pyrene was 71.24%,compared to 62.88% without cyclodextrin.Cyclodextrin with a low concentration would be more valuable in practical engineering program,given its high price and inaccessibleness,compared to the high concentration of cyclodextrin.