Environ. Sci. Technol. 2006, 40, 5102-5107
Arsenic Leaching from Mulch Made from Recycled Construction and Demolition Wood and Impacts of Iron-Oxide Colorants TOMOYUKI SHIBATA,† H E L E N A M . S O L O - G A B R I E L E , * ,† BRAJESH DUBEY,‡ TIMOTHY G. TOWNSEND,‡ AND GARY A. JACOBI, JR.† Department of Civil, Architectural, and Environmental Engineering, University of Miami, P.O. Box 248294, Coral Gables, Florida, 33124-0630, and Department of Environmental Engineering Sciences, University of Florida, 218 Black Hall, P.O. Box 116450, Gainesville, Florida, 32611-6450
Mulch made from recycled construction and demolition (C&D) wood has been reported to contain elevated levels of arsenic from inadvertent inclusion of chromated copper arsenate (CCA)-treated wood. Such mulch is also commonly colored with iron oxide, a compound known to bind arsenic. The objectives of this study were to quantify the releases of arsenic from mulch made from C&D wood, to evaluate the impacts of an iron-oxide colorant in potentially decreasing arsenic leaching rates, and to evaluate the relative significance of additional variables on leachate concentrations. A total of 3 sets of mulch samples (0%, 5%, or 100% CCA-treated wood) were prepared containing a sample either with or without colorant addition. Each sample was subjected to two tests: a field leaching test and the Synthetic Precipitation Leaching Procedure (SPLP). Results showed that arsenic concentrations in the field leachate from the 0% treated wood mulches were consistently low (
