Stabilisation/solidification of soils contaminated by chlorinated pesticides

Abstract

This article describes laboratory tests carried out to identify an effective stabilisation/solidification method for soils contaminated by chlorinated pesticides at a disused industrial site. The effectiveness of the treatment was evaluated using leach tests. Powdered activated carbon (PAC) was used as the primary amending agent, thanks to the strong affinity for organic molecules and high sorption capacity. For some areas of the site, test results showed that treatment with PAC was decisive in reducing leaching of the pollutants below the prescribed limits. For areas with higher concentrations, treatment with PAC alone was not sufficient, although the reduction was significant. According to a detailed programme, further tests were performed: different percentages of cement were added to the soil–PAC mixture as a binding/solidifying agent. For all the agents, the optimum dosage that led to dissolved phase concentration standards for pesticides was identified. The test results are evaluated in view of possible field applications. Factors to be further addressed for an overall evaluation of the technology are discussed.

Keywords:

• stabilisation
• chlorinated pesticides
• activated carbon
• cement
• laboratory test
• field applicability

Acknowledgements

The authors are gratefully indebted to Fabrizio Leoni of Trevi S.p.A. (Italy) for his contribution about the field applicability of the treatment.

Additional information

Notes on contributors

Giovanna Monti

Currently a graduate student at George Washington University, Washington, DC, USA.