不同营养水平沉积物在不同pH下对磷酸盐的等温吸附特征

研究了不同营养水平沉积物在不同pH下对磷酸盐的吸附等温线,分别采用了线性和非线性2种方法拟合吸附等温线,并分析比较了2种方法的适用性.结果表明:①不同营养水平沉积物对磷酸盐的吸附量在接近中性时最大,酸性和碱性条件下均下降,污染严重的沉积物对磷酸盐的吸附受pH影响较污染轻的大;②不同pH下,不同营养水平沉积物对磷酸盐的吸附等温线没有明显规律;③沉积物对磷酸盐的吸附行为采用线性和非线性拟合均存在不足,不能仅仅根据R2和X2的大小进行拟合方程的适用性比较;④为了获得更为真实可靠的拟合结果,可以利用线性和非线性方法分别进行拟合,而每一种拟合方法也要同时采用多种拟合方程,在对多个拟合结果比较的基础上确定更符合实验数据的拟合方程. 

The Sorption Isotherms of Phosphate to Different Nutrient Levels of Sediments in Different pH

The sorption isotherms of phosphate to different nutrient levels of sediments in different pH were studied. The two methods of linear and non-linear fitting were applied to describe the sorption isotherms, and their applicability analyzed and compared. The results were: ① The rate of phosphate absorption to different nutrient levels of sediments was biggest near neutral condition, and was descended in acid and alkaline conditions, the influence of pH on absorption to heavily polluted sediment was greater than that of mestrophic sediments; ② The sorption isotherms of phosphate to different nutrient levels of sediments in different pH did not have clear trend; ③ The two methods of linear and non-linear fitting that were applied to describe the sorption isotherms both have deficiency, and cannot compare the applicability of simulated equation only by R2 and X2; ④ The methods of linear and non-linear fitting can be applied to describe the sorption isotherms respectively in order to obtain an actual and credible fitting result, each method can adopt many fitting equations, and the final fitting equation that more accorded experiment data can be selected on the base of comparison of these fitting results.