Digital Library / STP / STP1033-EB / STP22875S



Leaching Characteristics of Construction Materials and Stabilization Products Containing Waste Materials
van der Sloot, HA
Section head of environmental research, scientific co-worker, and senior technician, Netherlands Energy Research Foundation (ECN),

de Groot, GJ

Wijkstra, J


Pages: 25    Published: Jan 1989


Download this paper for $25 PDF (632K)          View License Agreement
        Click here to download the complete source publication for $70 PDF (8.9M)


Source: STP1033-EB


Abstract

In this work, several construction materials prepared with an admixture of waste material and various stabilized waste products have been subjected to leaching studies in order for the leaching behavior of trace elements from these materials to be characterized. Static and dynamic leach tests have been applied, in which the specimen to be studied is fully immersed in demineralized water. Often the leaching process is governed by outward diffusion of constituents dissolved in the pore water. In some cases, dissolution from the surface of the product is most prominent, and in some materials short-term surface release has been observed. Groups of materials can be distinguished with similarities in the leaching behavior of trace elements.

The alkalinity of the material, the open porosity of the product, and the surface-to-volume ratio prove to be important factors in controlling the release of potential hazardous elements from materials containing waste products. In these studies, leach parameters of trace elements are related to those of sodium. Since the interaction of sodium with the solid phase is usually small, sodium can be used as an indicator for the tortuosity of the product. Elements leached from cement-based waste products are mainly anionic species, like MoO42-, BO33-, VO43-, F-, and SO42-, whereas leaching of metals such as copper, cadmium, zinc, and lead is limited due to the high pH in the pore solution. The leaching experiments have been verified by scanning electron microscopy for major components on field samples and by measuring depth profiles in waste products for trace constituents using an apparatus developed for this purpose.


Keywords:
hazardous elements, waste materials, construction materials, leaching process, leach test, diffusion, element speciation, mobility measurement

Paper ID: STP22875S
Committee/Subcommittee: D34.01
DOI: 10.1520/STP22875S
CrossRef ASTM International is a member of CrossRef.