Enhanced Removal of Antimony in Dyeing Wastewater by Mixing Fe3O4 with Manganese Sand Filter Material.

Wastewaters from the printing and dyeing industries contain many contaminants in particular Antimony (Sb) that end up in the environment. Both manganese sand filter and Fe O have good removal effect on Sb, and are cheap and easy to obtain. We made a filter material by mechanic mixing the manganese sand filter material and ferro-ferric oxide (Fe O ). The Fe-Mn oxide filter material was analyzed by X-Ray diffraction. We studied the filtration of real wastewater from a dyeing wastewater treatment plant in Suzhou, China containing Sb at high concentration of 410 μg/L, using dynamic tests in adsorption columns during 7 days. We tested the effects of filter material volume filling ratio, the empty bed contact time (EBCT), pH and back washing on the removal of Sb. Results show that the addition of Fe O enhanced the removal of Sb, reaching 85% of initial Sb. When the initial influent pH of the raw water is 3.0, the volume filling ratio of filter material is 60%, and the EBCT is 20 min, the developed dynamic Fe-Mn oxide filter has the best removal effect on Sb. Daily back washing of the filter keeps a Sb removal rate of about 80%.