Determination of Free Nickel Ion Concentrations Using the Ion Exchange Technique: Application to Aqueous Mining and Municipal Effluents

Abstract

Free metal ion concentration is generally considered a useful indicator of a metal's bioavailability and ecotoxicity to aquatic biota. This article reports the speciation of nickel in mining and municipal effluents from Sudbury (Ontario, Canada), and also in model solutions containing a fully characterized laurentian fulvic acid (LFA) at environmentally relevant concentrations. A column ion exchange technique (IET) using a cation exchange resin (Dowex 50W-X8) was applied to determine free nickel ion concentrations. In model solutions, reasonable correlation was found between the predictions of an equilibrium-based computer speciation code, Windermere Humic Aqueous Model (WHAM) VI, and the results obtained by IET at low nickel-to-fulvic acid ratios. However at higher mole ratios, the WHAM VI predicted higher free nickel ion concentrations than IET. Only three out of six effluent samples showed reasonable agreement between the IET and the WHAM VI results, indicating the need for further development of IET for application to effluent waters.

Determination of Free Cd, Cu and Zn Concentrations in Lake Waters by In Situ Diffusion Followed by Column Equilibration Ion-exchange

“…in laboratory solutions containing various inorganic and organic ligands, including fulvic acid (Fortin and Campbell 1998;Fortin and Caron 2000;Néron et al 2006;Vigneault and Campbell 2005). This technique has been used by others as well (Cantwell et al 1982;Doig and Liber 2007;Ge et al 2005a, b;Gopalapillai et al 2008;Holm et al 1995;Sweileh et al 1987;Worms and Wilkinson 2008), and its capacity to measure the free ion species was demonstrated in complex solutions (some containing natural organic matter) either by comparing the results with thermodynamic equilibrium calculations (Cantwell et al 1982;Fortin and Campbell 1998;Sweileh et al 1987;Worms and Wilkinson 2008) or with values obtained with a different technique such as ion-selective electrodes when natural organic matter was present (Ge et al 2005a, b;Sweileh et al 1987). …”

Speciation of Co, Ni and Cu in the coastal and estuarine sediments: Some fundamental characteristics

“…The chemistry of trace metals and their interaction with natural ligands (such as, dissolved organic matter) are well studied in aquatic system as reflected by the large numbers of publications available in the literature (Achterberg and Braungardt, 1999;Bayen et al, 2006;Chakraborty, 2010;Chakraborty and Chakrabarti, 2008;Chakraborty et al, 2007;Chakraborty et al, 2009;Gopalapillai et al, 2008;Groschner and Appriou, 1994;Guthrie et al, 2005;Nicolau et al, 2008). However, the knowledge of speciation of trace metals and their interactions with heterogeneous binding sites present in sediments are not well understood.…”

Assessing toxicity of mining effluents: equilibrium- and kinetics-based metal speciation and algal bioassay

“…A detailed explanation of the WHAMVI parameters used in the present work has been provided earlier. [19] Results and discussion Nickel speciation Major cation and anion concentrations and trace metal concentrations in the Sudbury effluent samples were reported previously. [19] Crean Hill Mine and Garson Mine aqueous effluents have elevated total nickel concentrations of 1.76 and 2.33 µM, respectively.…”

“…IET involves a simple concept in which the ions in the sample solution exchange with ion exchangers of a strong acid cation resin, by which a relationship between the concentrations of metal adsorbed to the resin and the free metal ion can be established. [23] Gopalapillai et al [19] have provided a detailed account of IET theory and procedure.…”

“…[18] The objective of the present research was to assess the toxicity of nickel-contaminated aqueous mining effluents to aquatic freshwater organisms using algal bioassays, and both equilibrium-and kinetics-based estimates of nickel speciation, which has rarely been done earlier. Free ion concentration in the Sudbury mining effluent samples was evaluated by the Ion Exchange Technique (IET), [19] and a computer speciation code, Windermere Humic Aqueous Model (WHAM ) VI, and the labile metal concentration was determined by the Competing Ligand Exchange Method (CLEM). An additional objective of the present study was to test the hypothesis that BLM (WHAM VI ) is a satisfactory model to predict toxicity to freshwater biota in complex natural waters containing multi-metal mixtures and dissolved organic matter.…”