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羟基化矿物表面对磷酸盐的专性吸附机制包括两个方面:即磷酸盐—羟基的表面反应和所吸附磷酸根离子的构型。磷酸盐—羟基表面的反应机制是配位基交换反应,其证据包括吸附和解吸作用的动力学;羟基离子的释放;红外光谱学和立体化学计算。关于磷酸盐吸附在羟基化矿物表面的配位资料总的来说还未能得出肯定性的结论。同位素交换实验和解吸动力学的研究没有提供关于表面配位作用的确定性资料。羟基离子释放的测定和晶格计算提供了支持磷酸根离子的单基表面络合物和双基表面络合物的存在的证据。红外光谱学的研究表明:在干燥的膦酸化针铁矿表面有双核络合物存在。但是,不能由此机械地推知土壤矿物的情况,因为水分的加入有利于单基表面络合物的形成。因此,还需要进一步研究以弄清吸附态磷酸根离子的构型。
The specific adsorption mechanism of phosphates on the surface of hydroxylated mineral includes two aspects: the surface reaction of phosphate-hydroxyl and the configuration of adsorbed phosphate ions. The reaction mechanism of the phosphate-hydroxyl surface is a ligand-exchange reaction, the evidence of which includes the kinetics of adsorption and desorption; the release of hydroxyl ions; the infrared spectroscopy and the stereochemical calculations. There is generally no conclusive conclusion about the coordination of phosphate adsorption on the surface of hydroxylated minerals. Isotopic exchange experiments and desorption kinetics did not provide definitive data on the role of surface coordination. The determination of the hydroxyl ion release and the lattice calculation provide evidence of the presence of mono-based surface complexes and bis-based surface complexes that support phosphate ions. Infrared spectroscopy studies have shown that there is a dinuclear complex on the surface of the dried phosphonated goethite. However, the soil minerals can not be inferred mechanically, because the addition of moisture favors the formation of mono-based surface complexes. Therefore, further research is needed to clarify the configuration of adsorbed phosphate ions.