无机离子对光催化降解腐殖酸的影响

Effect of Inorganic Ions on Photocatalytic Degradation of Humic Acid

研究了无机离子对光催化降解腐殖酸的影响。结果表明:Ca2+、Mg2+、HCO3-、H2PO4-都对腐殖酸的降解有一定的抑制作用。Ca2+、Mg2+将与腐殖酸络合形成金属离子—腐殖酸配合体,该配合体易于被TiO2吸附,但这种配合体将比腐殖酸更难降解;HCO3-的加入会严重抑制光催化反应的进行,这是由于HCO3-是较强的.OH清除剂;H2PO4-对腐殖酸的光催化降解有较强的抑制作用,H2PO4-与腐殖酸在TiO2表面会形成竞争吸附,从而抑制TiO2对腐殖酸的吸附,同时也是.OH和h+的清除剂。

The effect of inorganic ions on photocatalytic degradation of humic acid （HA） was studied. The experimental results indicated that Ca2＋ , Mg2＋ , HC03- and H2PO4- could inhibit the degra- dation of HA. The complexation of Ca2＋ and Mg2＋ with HA could form the complex of metal ions and HA. This complex was easy to be absorbed by TiO2, but more difficult to be degraded than HA. The addition of HCO3- could inhibit the degradation process seriously, which was due to that HC03- was a kind of strong scavenger of hydroxyl radical （·OH）. H2PO4- could also inhibit the degradation process. The competitive adsorption of H2PO4 and HA could occur on the surface of TiO2, which inhibited the adsorp- tion of HA. Meanwhile, H2PO4 was the scavenger of ·OH and h＋.