Water quality of runoff from flat panel display glass concrete during modified accelerated aging plus leaching tests.

Abstract

Flat panel display glass (FPDG) from plasma televisions is difficult to recycle due to their heavy metal composition. When crushed, flat panel display glass has similar physical properties to sand and could be used as a recycled aggregate in concrete, if the potentially harmful metals in FPDG can be encapsulated. To replicate leaching from environmental exposure, at periodic points during freeze-thaw tests, samples of concrete with 0%, 10%, and 20% FPDG were exposed to simulated rainwater and the runoff water was analyzed. For the metals detected (arsenic, barium, chromium, and lead), lead concentrations in the leachate/runoff from 20% FPDG samples exceeded the acute ambient water quality criteria after approximately 50-60 cycles; however, no samples exceeded the toxic characteristic leaching procedure limits at any point during freeze-thaw testing. Increases in lead and chromium concentrations over time indicate a need for stabilization, especially since lead exceeded the acute water quality criteria. PRACTITIONER POINTS: TCLP results indicate flat panel display glass is not expected to release RCRA-8 metals at or above regulatory limits. Accelerated aging-leaching tests indicate lead might be released at levels approaching or exceeding the acute ambient water quality criteria. With additional lead stabilization, this study shows flat panel display glass has the potential to be used in concrete.