几种低分子量有机酸和氨基酸对黄棕壤吸附菲的影响

采用批量平衡试验方法,研究了根系分泌物中几种常见的低分子量有机酸(LMWOA)和氨基酸对黄棕壤吸附菲的影响.结果表明,在供试有机酸和氨基酸的影响下黄棕壤对菲的等温吸附曲线仍呈显著的线性关系,分配作用是黄棕壤吸附菲的主导机制,供试LMWOA和氨基酸对黄棕壤吸附菲有抑制作用,且加入量越大,抑制作用越强.与氨基酸相比,LMW...

Effect of low-molecular-weight organic acids and amino acids on the sorption of phenanthrene in Typic Paleudalfs

The sorption of phenanthrene by TypicPaleudalfs with the addition of low-molecular-weight organic acid (LMWOA) and amino acid as representatives of typical root exudates was investigated using a batch experimental method. Phenanthrene sorption isotherms by TypicPaleudalfs could be well described by a linear sorption model irrespective of the addition of organic and amino acids. The addition of organic and amino acids significantly inhibited the sorption of phenanthrene by soil, and the larger amounts of these root exudates added in soil resulted in the stronger inhibition of phenanthrene sorption. Comparing with amino acids, LMWOAs displayed stronger inhibition ability of phenanthrene sorption in soil. The inhibitory ability of test five organic and amino acids for phenanthrene sorption was in the order of oxalic acid > citric acid > malic acid >> alanin > serine. The concentrations of dissolved organic matter (DOM) in equilibrium solution of phenanthrene sorption were detected, and were observed to be higher with the addition of organic and amino acids, while the soil organic carbon (foc) content was observed to be little lower with the root exudate addition. The partition of phenanthrene into DOM in solution was proposed to be the main cause for the decrease of phenanthrene sorption in soil with the addition of test root exudates.