Arsenic Pollution by Chromated-Copper-Arsenate Treated Woody Debris

摘要

The arsenic concentration level was elevated in flood water and sediment indicated by flood water, deposited sediments and soil samples after Hurricane Katrina by USEPA and individual researchers, which suggested the sediments were contaminated with arsenic during Katrina. In the event of flood, Chromated-Copper-Arsenate (CCA) treated woody debris were generated from demolished house, deck, fence, playground, which contributed to the elevated arsenic level in floodwater and sediments/soils. Sediments and soils were exposed to arsenic when debris were soaked in the floodwater. Based on all available measurement data, a mass balance model was set up and calibrated. With model simulations, the amount and leaching rate of arsenic from CCA-treated woody debris were calibrated and compared with the measured values and literature values. The simulation results agree with the measurement in the inundation period. Through this study, it can be found out that arsenic leached from CCA-treated woody debris was the major source leading to the floodwater and sediment contamination with arsenic.