흄산의 침적에 미치는 금속이온의 영향

In the presence of metal ions(Co(Ⅱ), Ni(Ⅱ), Sr(Ⅱ), Cu(Ⅱ), Fe(Ⅲ), U(Ⅵ)), the sedimentation of humic acid was increased at constant pH with increasing metal concentration and the strength was increased in the following order: Sr < Ni < Co < Cu < Fe < U. At constant metal concentration, Cu(Ⅱ), Ni(Ⅱ), and Co(Ⅱ) ions caused an increase in sedimentation of humic acid as the solution pH increased, whereas Fe(Ⅲ) and U(Ⅵ) ions caused a decrease. Sr(Ⅱ) ions did not affect the sedimentation even with the variation of pH. The analysis of FT-IR spectra for the sediments prepared from the reaction between humic acid and metal ions showed that metal ions were bound to humic acid to form complexes, suggesting that the metal complexation plays an important role in the sedimentation of humic acid. 일정한 pH에서 Co(II), Ni(II), Sr(II), Cu(II), Fe(III) 및 U(VI) 등의 금속이온농도가 증가할 수록 흄산의 침적율이 증가하였으며, Sr