Iron oxyhydroxide nanoparticles are commonly found in natural aqueous systems and are known to be effective adsorbents for metals due to their high surface area and surface reactivity. Due to varying geochemical conditions which can impact the ionic strength, pH, and temperature of the environment, nanoparticles typically aggregate in natural aqueous systems, which affects their ability to adsorb and retain metals. Along with this, as the particles move through aqueous systems changes in salinity also impact the particles’ potential to adsorb metals. The metals analyzed in this study are copper (Cu2+) and zinc (Zn2+), which can contaminate aquatic systems though mine waste pollution. In a batch metal uptake experiment, synthethic iron oxyhydroxide nanoparticles, at varying aggregated states of pH, ionic strength, and temperature were exposed to dissolved copper and zinc under varying sulfate concentrations ranging from 0.03M SO4 to 0.18M SO4. Each batch is separated into three samples to measure the initial proportion of metal adsorbed by the nanoparticles, the percent uptake after salt is added, and the percent retained when the pH is lowered to 5.0. Supernatants were analyzed with atomic absorption spectroscopy (AA) to analyze the amount of metal uptake at each stage of the experiment. Results will allow interpretation of the role of increasing sulfate concentrations on metal adsorption and retention processes by iron oxyhydroxides.

Cu(II) and Zn(II) adsorption and retention to iron oxyhydroxide nanoparticles: Effects of aggregation state and sulfate concentration

251st National Meeting (2016)

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