| In a laboratory study, removal of sulfide by ozone and the potential for iron oxide-coated sand (IOCS) from groundwater were examined. Oxidation kinetic tests showed rapid oxidation (15 seconds) of sulfide by ozone at an ozone to sulfide ratio of 4:1. Oxidation of sulfide by ozone decreased with increasing pH in the pH range 6.0--9.0. IOCS and manganese greensand were found to be equally effective in removing sulfide from groundwater. In a downflow column test [200 g (125 ml) of IOCS; empty bed contact time 62.5 minutes], breakthrough bed volume at 0.05 mg/L of sulfide was about seventeen. Regeneration of the IOCS by oxygenated water (20%) or ozonated water (50%) did not produce encouraging results. It appeared preferable to recoat the IOCS with additional iron oxide or to use fresh IOCS in each cycle of run. |
