环境中植酸的分布、形态及界面反应行为

Distribution, Species and Interfacial Reactions of Phytic Acid in Environment

肌-肌醇六磷酸(myo-inositol-1,2,3,4,5,6-hexakisphosphate,IHP,myo-IP6)简称植酸(Phytic acid或phytate),是大多数土壤中最为丰富的有机磷,它在环境中的界面反应影响着磷素的迁移、循环、转化、生物有效性以及环境效应.本文简要总结了环境中植酸的分布与形态,并综述了其界面反应,包括铁铝氧化物、粘土矿物、碳酸钙等对植酸的吸附解吸,多价阳离子与植酸的络合反应以及沉淀作用.土壤矿物对植酸的吸附影响其转化和生物有效性,矿物对植酸磷的吸附量一般远高于正磷酸盐.其中,弱晶质铁铝(氢)氧化物对植酸的吸附能力一般较晶形铁铝(氢)氧化物大很多.同时,分析了矿物类型、介质pH、温度、共存离子等环境条件对植酸界面反应的影响,植酸吸附对矿物表面电荷性质、颗粒大小和分散稳定性等的作用,以及植酸在金属污染土壤修复中的应用前景.最后讨论了环境中植酸的主要研究热点和方向.

myo-inositol-1,2,3,4,5,6-hexakisphosphate is called phytic acid or phytate,and commonly abbreviated as IHP or myo-IP6.IHP is the most abundant organic phosphorus in most soils.The mobility,cycling,transport,bioavailability to plants and environmental impact of soil phosphorus are affected by the interfacial reactions of IHP in the environment.This paper briefly summarized the distribution and species of phytic acid in the environment,and interfacial reactions,which including adsorption and desorption of IHP by soil components,such as iron and aluminum oxides,clays,calcium carbonate and so on,complexation reactions and precipitation with polyvalent cations.The transport and bioavailability of IHP are affected by its adsorption on soil minerals.The adsorption capacity of minerals for IHP is much greater than that for orthophosphate.The adsorption capacity of amorphous Fe/Al-（hydr）oxides for IHP is generally higher than that of crystalline Fe/Al-（hydr）oxides.In addition,the effects of environmental conditions,such as the type of minerals,pH,temperature and coexisted ions on the above interfacial reactions are discussed.The impacts of adsorbed IHP on surface charge,particle size and stability against aggregation of the minerals,and the application of IHP for remediation of metal-contaminated soils as well are also involved.Finally,hot spots for future research of IHP in the environment are proposed.