铝型材厂工业污泥中重金属的含量及浸出特性

Contents and Leaching Characteristics of Heavy Metals in Aluminum-Anodizing Sludge

在分析7种来源不同的铝型材污泥试样的含水率、灰分、pH值等基本理化特性的基础上,讨论了铝型材污泥的化学组成、重金属含量及重金属浸出特性.结果表明:铝型材污泥属于中性偏碱性物质,主要由含量在50%以上的Al2O3组成;各试样中Cu、Pb、Zn、Ni、Cd及Cr的总含量的分布趋势基本一致,其中Pb、Cd的含量较低,Cu、Zn、Ni及Cr的含量较高.浸出毒性试验表明铝型材污泥属于非危险废物,污泥中各重金属的浸出特性各不相同,这可能主要与它们在试样中的总含量及浸出液的最终pH值有关.

In this paper, the basic physicochemical properties such as the water content, the ash content and the pH value of 7 sludge samples collected from different aluminum-anodizing plants were analyzed, and the chemical compositions of the samples, as well as the contents and leaching characteristics of the heavy metals in the samples, were investigated. The results show that （1） all aluminum-anodizing sludge samples are slightly neutral to mild basic with more than 50% Al2O3; （2） the total contents of Cu, Pb, Zn, Ni, Cd and Cr in the 7 sludge samples are of similar distribution; and （3） the contents of Cu, Zn, Ni, and Cr are relatively higher than those of Pb and Cd. Moreover, leaching toxicity tests indicate that the aluminum-anodizing sludge is nonhazardous and the heavy metals in it are significantly different in leaching behaviors, possibly due to their total contents and to the final pH value of the leachate as well.