Abstract
The objective of this study was to evaluate the feasibility of combined modular processes to selectively remove Sb from mine-impacted waters in an Arctic environment in order to fulfil local environmental criteria for discharged waters. Novel ion exchange, selective extraction and ultrafiltration, electrocoagulation, and dissolved air flotation technologies were investigated, individually or in combination, from the laboratory- to pilot-demonstration scale. Laboratory-scale testing using Fe2(SO4)3 precipitation, ion exchange resin, selective ion extraction and ultrafiltration, and electrocoagulation with or without subsequent dissolved air flotation indicated that any of the methods are potentially applicable to Sb removal from mine water. The observed differences between Sb and As removal efficiency by ion exchange resin illustrated the need for Sb-specific removal and recovery technologies. Techno-economic analyses showed that treatment of mine water using electrocoagulation-dissolved air flotation yields the lowest comparative life-cycle cost of examined technologies. Results demonstrated increased Sb attenuation efficiency using either electrocoagulation-dissolved air flotation or selective extraction and ultrafiltration, even when treating only 50% of the mine-impacted water, compared with conventional Fe2(SO4)3 precipitation from mine water. Additional investigation is necessary to characterize the long-term stability of the mineral phases in Sb-containing solid residues and to inform selection of Sb recovery methods and utilisation or final disposal options for the residual materials.
Highlights
Antimony is a common trace element contaminant of mineimpacted water, as it is a component of more than 100 different natural minerals (Anderson 2012)
Where Kd is the distribution coefficient, q is the quantity of adsorbate per unit mass adsorbent, C is the equilibrium concentration of adsorptive in solution, n is a correction factor, k is a constant related to binding strength, and b is the maximum quantity of absorptive that can be adsorbed assuming monolayer coverage
Critical evaluation of potential new technologies for Sb removal and recovery, coupled with life-cycle cost analysis based on 10 years of operation at an Arctic mine site discharging 400 m3 water per annum and targeting a maximum Sb concentration of 300 μg/L, indicated that E-Dissolved air flotation (DAF) may be the most cost-effective solution
Summary
Antimony is a common trace element contaminant of mineimpacted water, as it is a component of more than 100 different natural minerals (Anderson 2012). The element Sb typically occurs with S, Cu, Pb, As, and Ag. Wastes containing. Surface waters receiving mining and industrial effluent discharges frequently exhibit Sb concentrations substantially greater than 5 μg/L Sb. the 1976 Council of the European Communities Directive 76/464/EEC identified Sb as a substance with potential to have deleterious effects on the aquatic environment, permissible concentrations for Sb have not been determined (Council of the European Communities 1976). Despite its widespread use in commercial and consumer products, the present understanding of Sb geochemistry in the aquatic environment and its ecotoxicological characteristics remain incomplete (Obiakor et al 2017)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
