泥炭对磷吸附特性的试验研究

Experiment of the Phosphate Adsorption Characteristics by Peat

通过试验研究了吸附时间、磷初始浓度、pH值、温度、吸附剂量和盐度等因素对磷在泥炭上吸附的影响。结果表明：磷在泥炭上的吸附量在反应的初始阶段（0～2h）增加很快，此后趋于平缓；泥炭对磷的吸附过程遵循准二级动力学模型；随着磷初始浓度的增加，吸附量上升而吸附率下降；泥炭对磷的等温吸附可用Langmuir和Freundlich等温模型拟合，相关性均达到极显著水平（P〈0．01）；随着溶液pH值的升高，分配系数＆和吸附量均降低；泥炭对磷的最大吸附量随着温度的上升而减小，由Langmuir等温方程计算出的最大吸附量qm分别为：2380．95mg／kg（25℃）〉2008．03mg／kg（35℃）〉1848．42mg／kg（45℃）；随着吸附剂量的增加，吸附量下降而吸附率上升；盐度对吸附有一定的抑制作用。

Effect of reaction time, initial concentration of PO4^3-, pH, temperature, amount of adsorbent and solution salinity on the phosphorus adsorption on peat is experimentally studied. The results indicate that the phosphorus adsorption capacity of peat increases rapidly at the beginning of the adsorption process （0 -2 h）, and then decreases slowly. The adsorption kinetics can be described by the pseudo-second order model. The adsorption capacity increases while the adsorption rate declines with the increasing initial PO4^3- concentration. The isothermal adsorption process of phosphate on peat can be fitted by Langrnuir and Freundlich equations with a high correlation coefficient. Both the distribution coefficient and the adsorption capacity decrease as pH increases. The maximal adsorption capacity decreases as the temperature increases in following order： 2 380. 95 mg/kg（25 ℃ ） 〉2 008.03 mg/kg（35 ℃ ） 〉 1 848.42 mg/kg（45 ℃ ）. As the adsorbent amount increasing, the unit adsorption capacity decreases and the adsorption rate increases. The adsorption can be influenced by salinity in a certain extent.