论小于63μm粒级作为水体颗粒物重金属研究介质的合理性及有关粒级转换模型研究

RELATION OF AQUATIC PARTICULATE GRAIN SIZE TO HEAVY METALS CONCENTRATIONS IN EASTERN CHINESE RIVERS

粒度是影响水体颗粒物中重金属含量的重要因素。研究了与此有关的两个问题：１．对各种粒度校正方法进行了讨论，论证了以小于６３μｍ粒级作为水体颗粒物中重金属研究介质的合理性：２．由于我国文献中大量资料是关于小于５０μｍ粒级颗粒物的，为使其与小于６３μｍ粒级数据有对比性，我们采集了我国东部自北至南地理、水文条件显著不同的十数条河流共２７个表层沉积物样品，对Ｃｕ、Ｐｂ、Ｚｎ、Ｃｄ、Ｃｏ、Ｎｉ、Ｆｅ、Ｍｎ等７种重金属元素在小于５０μｍ和小于６３μｍ两种粒级中的含量进行了分析，以简约主轴法回归模型Ⅱ建立了两种粒级中重金属含量的回归模型。

Grain size is one of the most significant factors controlling aquatic par-ticulates capacity for collecting and concentrating heavy metals.Therefore,the study of heavy metals in aquatic particulates requires consideration of thegrain size effects. In this paper, the methods for correcting the grain sizeeffects were reviewed and discussed. The<63μm fraction was then recomme- nded as the most appropriate size separation for reconnaiSsance surveys or monitoring studies of heavy metals in aquatic particulate. The relation of theheavy metals concentrations in<50μm fraction to those in <63μm fractionwas studied, for most data in Chinese literature were about <50μm fractions. A total of 27 geographical and hydrological aquatic particulates samples fromthe eastern Chinese rivers were collected, and the concentrations of Cu,Pb,Zn,Cd,Co,Fe,and Mn in both<50μm and <63 μm fractions were ana- lysed. Based on the data set,regression models(Regression Model Ⅱ)ofheavy metals concentrations in these two fractions were reported and tested.