Mobility of heavy metals after spiking in relation to sediment and metal properties: leaching column study

摘要: Sorption, desorption, and leaching of metals in the sediments aquatic environment are paramount important their bioavailability. Also, behavior these such as riverbed is affected by characteristics grain size, pore size distribution, pH medium. Four with varying properties were artificially contaminated cadmium (Cd), copper (Cu), nickel (Ni), zinc (Zn). Then, using columns, they all subjected to drying wetting phases study competitive binding release metals. Sediment samples collected from 0 10 cm depth Abshineh Ghareh Chai River during dry season. Samples spiked 400 mg Zn kg−1, 200 mg Cu kg−1, Ni kg−1, 50 mg Cd kg−1 (dry weight equivalent) plastic container then after seated at a height column. columns incubated room temperature (22–24 °C) leached 10–20 volumes (PVs) distilled water. The distribution over different extractable fractions was evaluated before leaching. four separated into two classes according leachability. In sediment that contained more clay, commonly mobile like Zn, Ni, Cd appeared be rather immobile Cu unexpectedly quite mobile. observation leachability higher for finer organic matter content indicates presence organically complexes, colloidal particles, may have had major role this mobility copper. Zn strongly governed pH, where typically much greater than under acidic conditions. metal addition caused displacement Ca, Mg, K, Na subsequent leachate columns. Despite spiking inorganic leaching, mobilization water (to mimic rainwater) small relative total amounts each added. This would indicate part added likely bound forms exhibit low potential bioavailability organisms.