Design and Pilot Scale Application of a New Geocomposite for Capping of Contaminated Soil

This paper presents a pilot scale application of a new type Geosynthetic Clay Composite for environmental applications in the treatment of toxic metals contaminated land. The designed new geocomposite was consisted of a thin layer of permeable, attapulgite clay sandwiched between two geotextiles. To demonstrate its effectiveness a pilot scale application was implemented at a public primary school in Lavrion Greece, an area affected by extensive heavy metal soil pollution due to past metallurgical activities. The attapulgite clay in the geocomposite is an effective binder for the sorption/ adsorption of toxic metals, preventing upwards migration of metals from the contaminated subsoil to the top soil during evaporation. Also the used geotextiles ensured encapsulation but allowed downwards water infiltration. An extensive investigation of the physical and mechanical properties of this geocomposite was performed by testing both short and long-term behavior in this specific application. Environmental monitoring results over a three semester period indicated the long-term effectiveness of the applied remediation technique for toxic metal retention.