磷酸盐在土壤中的竞争吸附与解吸机制

本文概述了近年来国内外有关磷酸盐的竞争吸附与解吸的研究成果。土壤中许多阴离子都能与磷竞争吸附点位,使得磷的吸附下降。有机质可促进或抑制磷的吸附,pH是影响竞争吸附的主要因子。磷被吸附后大多固持在表面而难于解吸,往往呈现明显的滞后现象。通常只有拟物理吸附的磷能被解吸,化学吸附的磷因与表面金属离子作用形成双齿配位而极难被淋洗下来。解吸受多种因素的影响,其中解吸剂的类型是主要因子之一。

Mechanisms of competitive adsorption and desorption of phosphate in soil

Research results about competitive adsorption and desorption of phosphate (P) in recent years are summerized in this paper. Many anions in soils are able to compete the adsorptive sites with P, resulting in a decrease in the amount of P adsorbed. Organic matter either promotes or inhibits P adsorption, and pH is one of the main factors affecting P adsorption. Most of P fixed on soil surface through adsorption is hard to be desorbed, and the process of P desorption has an evident lagging phenomenon. Generally, only physically adsorbed P can be desorbed, and chemically adsorbed one forms two coordination bonds with metal cations, very hard to be desorbed by leaching. There are many factors affecting P desorption, one of which is the type of desorptive reagents.