title: Removal of vanadium from industrial wastewater using iron sorbents in batch and continuous flow pilot systems.
abstract: This study investigated the removal of vanadium from real industrial wastewater by using six iron materials: commercial iron sorbent (CFH-12), commercial mineral sorbent (AQM), blast furnace sludge (BFS), steel converter sludge (SCS), ferrochrome slag (FeCr) and slag from a steel foundry (OKTO). Batch tests revealed that CFH-12 (ferric oxyhydroxide) removed vanadium most efficiently, which was explained by its high iron content and the amorphous form of the iron, and that the sorption followed the Langmuir isotherm. With a dosage of 10 g/l and an initial vanadium concentration of 58.2 mg/l, 91-94% removal rates for vanadium were achieved in the studied pH range (3-9). Other sorbents showed significantly lower efficiency than CFH-12, with the exception of BFS at acidic pH (93%). Based on the batch test results, CFH-12 was selected for a pilot study made on site. The pilot study demonstrated the feasibility of CFH-12 to remove vanadium at high temperature (80 °C) from concentrated industrial wastewater with fluctuating water quality (vanadium concentration varied from 51 to 83 mg/l, pH about 9 (at 25 °C)). Leaching of impurities (mainly S, Ca, Mg and K) into the effluent occurred during the first day, but subsequently good quality effluent was produced (e.g. <0.1 mg/l V). During the pilot study, the amorphous iron material of CFH-12 was crystallized into a hematite-like phase (Fe1.67H0.99O3), and goethite (FeO(OH)) with a higher average pore diameter, probably due to the hot process conditions to which CFH-12 was exposed for over five days.
authors.affiliation: University of Oulu, Chemical Process Engineering, P.O. Box 4300, FIN-90014, Oulu, Finland. Electronic address: tiina.leiviska@oulu.fi.
authors.forename: Tiina
authors.initials: T
authors.lastname: Leiviskä
authors.affiliation: University of Oulu, Chemical Process Engineering, P.O. Box 4300, FIN-90014, Oulu, Finland. Electronic address: muhammad.khalid@oulu.fi.
authors.forename: Muhammad Kamran
authors.initials: MK
authors.lastname: Khalid
authors.affiliation: Oulu Water Alliance Ltd, Kaitoväylä 1 F2, 90570, Oulu, Finland. Electronic address: arja.sarpola@oulu.fi.
authors.forename: Arja
authors.initials: A
authors.lastname: Sarpola
authors.affiliation: University of Oulu, Chemical Process Engineering, P.O. Box 4300, FIN-90014, Oulu, Finland. Electronic address: juha.tanskanen@oulu.fi.
authors.forename: Juha
authors.initials: J
authors.lastname: Tanskanen
mesh_terms: D000327:Adsorption; D006801:Humans; D007220:Industrial Waste; D007501:Iron / Q000737:chemistry; D010865:Pilot Projects; D014639:Vanadium / Q000737:chemistry*; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification
chemical_list: D007220:Industrial Waste; D007501:Iron; D014639:Vanadium; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Industrial wastewater; Iron sorbents; Pilot study; Sorption; Vanadium