Antimony Release From the Sediments of the Antimony-polluted River

To investigate the effect of aquatic chemistry on antimony release from Sb-contained sediments,samples from the down-stream of an antimony-polluted reviver were characterized.Their X-ray diffraction patterns,Fourier transform infrared spectroscopy(FTIR) spectra and X-ray fluorescence spectra were collected.Moreover,the effect of pH,sality and concentrations of humic acids on the release of antimony were also investigated.Resultsshow that all sediment samples contained similar mineral phases,surface groups and similar main element contents.Identified phases include quartz,albite,muscovite,calcite and stewartite.Elements at the surface of the sediments follow the order of Si>Al>Fe>Ca>K>Mg>Mn.Batch release experiments show that the amounts of released antimony increase with decreasing pH,increasing concentrations of salinity and humic acids.pH is the most important factor to affect antimony release.The release is caused by pH-related mineral dissolution and desorption,and the final states are an equilibrium of the both processes.At pH=3,the released antimony is positively correlated to the contents of Mn at the surface of sediments.That means that dissolution of stewartite rather than surface adsorption markedly affected the release of antimony.