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 Fe3 O4 have good removal effect on Sb, and are cheap and easy to obtain. We made a filter material by mechanically mixing the manganese sand filter material and ferro-ferric oxide (Fe3 O4 ). The Fe-Mn oxide filter material was analyzed by X-ray diffraction. We studied the filtration of real wastewater from a dyeing wastewater resource recovery facility 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 Fe3 O4 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%, the EBCT is 20 min, and 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%. PRACTITIONER POINTS: A novel and cheap Fe-Mn oxide was developed for Sb removal from dyeing wastewater. A self-designed filter device was designed to verify performance of the low-cost material. Optimal design and operational parameters of the filtration process were determined.
Keywords: antimony removal; dyeing wastewater; dynamic filter; heavy metal; iron and manganese mixture.
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