HR: 0800h
AN: H51B-0443    [Abstracts]
TI: Experimental Observation and Modeling of Effects of Precipitation on the Stream-Subsurface Exchange of Copper
AU: * Ruiz, J L
EM: jruiz@even.tamuk.edu
AF: Texas A&M University-Kingsville, 700 University Blvd. MSC 213, Kingsville, TX 78363, United States
AU: Otero, D D
EM: dotero@even.tamuk.edu
AF: Texas A&M University-Kingsville, 700 University Blvd. MSC 213, Kingsville, TX 78363, United States
AU: Ren, J
EM: jren@even.tamuk.edu
AF: Texas A&M University-Kingsville, 700 University Blvd. MSC 213, Kingsville, TX 78363, United States
AB: Assessment of contaminated rivers and effective remediation of streams affected by acid mine drainage require a thorough understanding of the dominant mechanisms controlling the fate and transport of contaminants. Such studies are generally complicated due to the complex coupling of hydrologic and geochemical processes. The importance of hyporheic exchange has become increasingly recognized because of its important role in regulating the transport of particles, contaminants, and ecologically relevant substances. Substantial accomplishments of fundamental understanding of the transport processes have been achieved by several researchers. However, a variety of issues still limit the application of the current process-based transport models in natural streams. One of the critical limitations arises from the fact that a wide range of additional processes such as metal precipitation reactions are also expected to influence contaminant transport in natural streams significantly but have not been adequately represented in any fundamental process-based stream-subsurface exchange models. In this study, laboratory flume experiments were carried out using copper (CuCl2) to examine the effects of pH-dependent metal precipitation on the stream-subsurface exchange process. Batch experiments were conducted to characterize the precipitates formed and the extent of sorption occurring at different pHs. Column experiments were used to determine the mobility of copper precipitates formed. A multi-phase reactive exchange model which accounts for the metal precipitation process was developed and applied to interpret the flume experiment results.
DE: 1871 Surface water quality
SC: Hydrology [H]
MN: 2007 Fall Meeting