Removal and recovery of vanadium from alkaline steel slag leachates with anion exchange resins.
Leachable vanadium (V) from steel production residues poses a potential environmental hazard due to its mobility and toxicity under the highly alkaline pH conditions that characterise these leachates. This work aims to test the efficiency of anion exchange resins for vanadium removal and recovery from steel slag leachates at a representative average pH of 11.5. Kinetic studies were performed to understand the vanadium sorption process. The sorption kinetics were consistent with a pseudo-first order kinetic model. The isotherm data cannot differentiate between the Langmuir and Freundlich models. The maximum adsorption capacity (Langmuir value qmax) was 27 mg V g-1resin. In column anion exchange, breakthrough was only 14% of the influent concentration after passing 90 L of steel slag leachate with 2 mg L-1V through the column. When eluting the column 57-72% of vanadium was recovered from the resin with 2 M NaOH. Trials on the reuse of the anion exchange resin showed it could be reused 20 times without loss of efficacy, and on average 69% of V was recovered during regeneration. The results document for the first time the use of anion exchange resins to remove vanadium from steel slag leachate. As an environmental contaminant, removal of V from leachates may be an obligation for long-term management requirements of steel slag repositories. Vanadium removal coupled with the recovery can potentially be used to offset long-term legacy treatment costs.
School of Environmental Sciences, University of Hull, Cottingham Road, Hull, HU6 7RX, UK. Electronic address: h.gomes@hull.ac.uk.
Helena I
HI
Gomes
School of Environmental Sciences, University of Hull, Cottingham Road, Hull, HU6 7RX, UK.
Ashley
A
Jones
School of Environmental Sciences, University of Hull, Cottingham Road, Hull, HU6 7RX, UK.
Mike
M
Rogerson
Department of Chemistry, University of Hull, Cottingham Road, Hull, HU6 7RX, UK.
Gillian M
GM
Greenway
Department of Chemical and Biological Engineering, The University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK.
Diego Fernandez
DF
Lisbona
School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK.
Ian T
IT
Burke
School of Environmental Sciences, University of Hull, Cottingham Road, Hull, HU6 7RX, UK.
William M
WM
Mayes
D000837:Anion Exchange Resins; D004739:England; D052918:Environmental Restoration and Remediation; D006801:Humans; D007220:Industrial Waste; D013232:Steel / Q000737:chemistry*; D014639:Vanadium / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
D000837:Anion Exchange Resins; D007220:Industrial Waste; D014874:Water Pollutants, Chemical; D014639:Vanadium; D013232:Steel
Environmental remediation; Hyperalkaline drainage; Ion exchange resin; Metal recovery; Recycling