Effect Of Edta On The Stability And Adsorption Characteristics Of Resin-based Nano-hydrated Ferric Oxide

The HFO-loaded nanocomposite (HFO-D001) was proved to show preferable adsorption for heavy metals and exhibit great potential in disposal of metal-contaminated effluents. The adsorption capability could be apparently decreased in the presence of EDTA through its complexation with and dissolution of Fe(Ⅲ). In the present study, we prepared a polymer supported hydrated ferric oxide (HFO-D001) through chemical liquid deposition technique. Fe(Ⅲ) dissolution of HFO-D001in the presence of EDTA under various experimental conditions, such as EDTA concentration, dissolution time, solution pH and coexisting ions were examined. At pH=3, Fe(Ⅲ) dissolution from HFO-D001was enhanced significantly as EDTA concentration increased. However, under pH=5and7, negligible Fe(Ⅲ) was detected in solution due to the protection of the polymer host and the electrostatic repulsion between EDTA and sulfonic acid groups of D001. Meanwhile, the coexisting cations such as Cu(II) or Ni(Ⅱ)(0-2mg/L) could inhibit Fe(Ⅲ) dissolution to a certain degree. According to batch sorption experiment, the sorption capability of HFO-D001for heavy metals dropped after Fe(Ⅲ) dissolution.