有机酸对蒙脱石和针铁矿吸附磷的抑制作用

Inhibition of Organic Acids on Adsorption of Phosphorus on Montmorillonite and Goethite

为探究富营养化水体中泥水界面磷的固定是否受到体系pH和共存有机酸的影响,通过静态吸附实验研究了不同pH和不同浓度的柠檬酸、酒石酸与乙酸对蒙脱石和针铁矿吸附磷的影响。结果表明:随pH从3增加到9,磷酸盐在蒙脱石和针铁矿上的吸附量逐渐降低;0~0.8mmol/L有机酸明显抑制磷在蒙脱石和针铁矿上的吸附。随有机酸浓度增加,抑制减弱。大于1.4mmol/L的三种有机酸对蒙脱石上磷的吸附有促进作用;pH3~7时,0.03mmol/L三种有机酸对针铁矿吸附磷的抑制强于蒙脱石,其抑制能力为柠檬酸>酒石酸>乙酸。这表明蒙脱石在应用于固定磷时,可能比针铁矿更能适应富营养化水体的泥水界面的有机酸环境。

To explore whether the stabilization of phosphorus in the mud-water interface in eutrophic water may be affected by the pH and the coexisted organic acids, the effects of citric acid, tartaric acid and acetic acid on the adsorption of phosphorus by montmorillonite and goethite were studied in this paper by static adsorption experiments. The results showed that with the increase of pH from 3 to 9, the adsorption of phosphate on montmorillonite and goethite was gradually reduced;0~0.8 mmol/L organic acid significantly inhibited the adsorption of phosphorus on montmorillonite and goethite. With the increase of organic acid concentration, the inhibition was weakened. The three organic acids greater than 1.4 mmol/L promoted the adsorption on montmorillonite. In the range of pH 3~7, 0.03 mmol/L organic acids had stronger adsorption inhibition on goethite than that on montmorillonite, and its inhibition ability sequence was citric acid>tartaric acid>acetic acid. In summary, when montmorillonite is applied to stabilize the phosphorus, it might be more suitable than goethite for the mud-water interface with acid ligands of eutrophic water.