沉积物中磷的赋存形态及磷形态顺序提取分析方法

Speciation and Release Mechanism of Phosphorus in Sediments and Analysis Methods for Sequential Extraction

阐述了当前我国水体富营养化的现状,水体的富营养化与水体中磷、氮的浓度以及二者的浓度比值有着密切的关系。水体富营养化时氮和磷的浓度均很高,但没有一个固定的值,是在一个较宽泛的富营养范围内,氮和磷的浓度比值大多在10∶1～20∶1。湖泊沉积物作为湖泊水体中磷的重要蓄积库,是湖泊流域磷循环的重要归属,也是湖泊水体内源性磷的主要来源,沉积物中极少量的稳定磷转化为活性磷就会造成湖泊水体富营养化。文中介绍了沉积物中无机磷形态的分类,评述了欧盟标准局在研制湖泊沉积物磷形态标准物质时比对采用的4种提取方法(Willimas法、Hieltjes-Lijklema法、Ruttenberg法、Golterman法),总结了国内外学者所应用的沉积物中磷的各种形态提取方法和磷各形态的分析测定方法,国内学者应用的方法是在国外学者方法的基础上提出的,阐述了顺序提取方法及其地球化学意义。简要评述了湖泊沉积物中磷的生物释放、物理释放和化学释放三种释放机制,这三种释放机制相辅相成,在一特定的环境条件下某一过程可能占主导地位来控制沉积物磷的释放。最后提出应该加强对沉积物中磷的各种形态的专属提取剂及其提取有效性的分子表征和检测,更加细化对于沉积物中磷形态的分类和创新各种磷形态的分析方法,建立沉积物-水体磷的迁移、循环和转化模型,这对于从根本上解决富营养化问题具有重要意义。

This article introduces the concept of chemical speciation analysis,the current status about eutrophication in China and the relationship between nitrogen and phosphorus in eutrophication.It considers that eutrophication has a close relationship with the concentration of phosphorus and nitrogen and their concentration ratio in water.If eutrophication occurs in one lake,the concentration of nitrogen and phosphorus are very high,but are not a fixed value,but rather in a relatively broad range.Moreover,the ratio of phosphorus and nitrogen is almost between 10-20.As the important accumulation reservoir of phosphorus in lakes,phosphorus in sediments is the main source of endogenous phosphorus,a small amount of stable phosphorus changed into reactive phosphorus could cause lake eutrophication.Therefore,the article discusses the classification and relationship between various speciations of phosphorus and the mechanism of phosphorus on eutrophication in sediments.It analyzes the four phosphorus extractale methods used by the European Commission when they developed the phosphorus reference materials in sediments： namely,the Williams method,Hieltjes-Lijklema method,Ruttenberg method and Golterman method.It summarizes the domestic and foreign scholars applied extractable method and determination method about phosphorus in sediments.The domestic scholars application methods are based on the foreign scholars used methods,expounding the geochemical significance of sequential extraction methods.Also reviewed are the release mechanism of phosphorus in sediments.Establishing sediments-phosphorus in water migration,circulation and transformation model which have great significance has been proposed because it could solve the problem of eutrophication fundamentally.