Leachability of selected construction and demolition (C&D) waste

Abstract

The leaching behaviour of various construction and demolition waste was studied in order to evaluate the potential for disposal at sea. The criteria for the study were based on Directive 2003/33/EC. The aim was to measure the compliance of the wastes with this Directive. Samples of waste investigated included bricks, asphalt, concrete, rock, marble, cement, limestone, clay, roof membrane, paint scrapings, fly ash and bottom ash. Different leaching properties were obtained for the same type of waste due to the presence of other matrices combined with the waste, as well as the disposal condition of the same type of waste. The results showed lower leaching values for the more weathered and degraded waste. Bricks, asphalt and concrete recorded values close to the leaching limit value which could be treated prior to disposal. Bricks exceeded the limit values for cadmium (0.05 mg/kg), chromium (0.57 mg/kg) and nickel (1.04 mg/kg), whereas asphalt had higher values for cadmium (0.23 mg/kg), chromium (0.87 mg/kg), copper (2.05mg/kg) and lead (2.00 mg/kg). Concrete exceeded the values for cadmium (0.11 mg/kg) and nickel (0.63 mg/kg). The leaching behaviour of limestone, clay and roof membrane revealed that they could be disposed at sea as the components leached were below the limit values. Concrete, roof concrete, marble, fly ash and bottom ash could not be disposed as they exceeded the leaching limit values for most of the components.