Removal of Iodide from Wastewater Using Strongly Basic Anion Resin

Iodide anion is found in some brine and wastewater. Iodide recovery from wastewater is beneficial from economic and environmental aspects. Discharge of iodide containing wastewater into surface water may lead to formation of some iodine containing species in drinking water sources. It is a treat for human health. In this study, iodide adsorption from wastewater )1000mg/l (using strongly basic anion exchange resins Amberlite IR400 Cl was investigated. Four common two-parameter models were used for description of isotherm adsorption data. Maximum static capacity of resin was obtained from Langmuir isotherm equation and it was 466.3mg/g. Iodide adsorption in various pH and presence of co-existing ions including SO42- , NO3- and Cl- was investigated too. The maximum obtained capacity was related to neutral pH. Kinetics study showed that the uptake of iodide ions was well described by the pseudo-second-order kinetics. Dynamic capacities of resin were investigated with column study. They were 434.2mg/g and 304.6mg/g for iodide adsorption from iodide solution and iodide solution in presence of co-contaminant ions (SO42- , NO3- and Cl- in concentration of 8mmol/l). The data from breakthrough curve was analyzed with common breakthrough models including Thomas, Dose-response and Yun-nelson models. Morphology of resins was investigated with SEM image and presence of iodide on resin was confirmed by EDS analysis and Raman spectra. The adsorption capacity of resin in comparison with the other adsorbents was considerable.