Soil washing - a sound method to remediate CCA contaminated soil?

Published: 4 October 2007

An investigation of contaminated areas conducted by Swedish County Adminstrative Boards has revealed sites polluted by arsenic. A number of sites are contaminated in such a manner that they possess a negative impact on the surroundings or on human health and thereby, the sites need to be treated by the year 2010.

In wood impregnation industry, chromated cupper arsenates (CCA) were commonly used as wood preservative. Different steps in impregnation process have resulted in soil contaminated with arsenic. Landfilling is a commonly used strategy to remediate As contaminated areas and a great deal of the treatment costs consists of transportation and landfilling fees. Recently, the Landfill Directive, which is setting standards on waste to be landfilled, has been reformed. The reformation has paved the way for new techniques to treat contaminated soil, such as soil washing.

The main of the project is to evaluate if soil washing is a sound technique to remediate CCA contaminated soil. Further, to identify a chemical to enhance the performance of soil washing and to find a suitable strategy to treat As polluted washing solution.

It is not sustainable to landfill soil while reuse of inert-classified treated soil could reduce the use of natural material. The aim of the project is to assure that the washed soil has no negative effect on the ecosystem. This would establish the method as a potential treatment method that can be used by soil remediation companies. Finally, reducing the remediation cost would enable the treatment of more sites within society’s limited budget.

This project is financially supported by the Swedish Research Council for Environment, Agricultural Science and Spatial Planning (FORMAS).

Contact:
Lea Rastas Amofah
Urban water

Tel. +46 (0)920-49 31 49
E-mail lea.rastas(a)ltu.se

Project participants at LTU