Contributions to predicting contaminant leaching from secondary materials used in roads
- 出版日期：2004.
- 页数：1 v. :
- 第一责任说明：Defne S. Apul.
- 分类号：a875.4
- ISBN：0496031341(ebk.) :
MARC全文
02h0029533 20120621153228.0 cr un||||||||| 120621s2004 xx ||||f|||d||||||||eng | 3144739 0496031341(ebk.) : CNY371.35 NGL NGL NGL a875.4 Apul, Defne S. Contributions to predicting contaminant leaching from secondary materials used in roads [electronic resource] / Defne S. Apul. 2004. 1 v. : digital, PDF file. Adviser: Eighmy, Taylor ; Gardner, Kevin. Thesis (Ph.D.)--University of New Hampshire, 2004. Slags, coal ashes, and other secondary materials can be used in road construction. Both traditional and secondary materials used in roads may contain contaminants that may leach and pollute the groundwater. The goal of this research was to further the understanding of leaching and transport of contaminants from pavement materials. Towards this goal, a new probabilistic framework was introduced which provided a structured guidance for selecting the appropriate model, incorporating uncertainty, variability, and expert opinion, and interpreting results for decision making. In addition to the framework, specific contributions were made in pavement and embankment hydrology and reactive transport, Bayesian statistics, and aqueous geochemistry of leaching. Contributions on water movement and reactive transport in highways included probabilistic prediction of leaching in an embankment, and scenario analyses of leaching and transport in pavements using HYDRUS2D, a contaminant fate and transport model. Water flow in a Minnesota highway embankment was replicated by Bayesian calibration of hydrological parameters against water content data. Extent of leaching of Cd from a coal fly ash was estimated. Two dimensional simulations of various scenarios showed that salts in the base layer of pavements are depleted within the first year whereas the metals may never reach the groundwater if the pavement is built on adsorbing soils. Aqueous concentrations immediately above the groundwater estimated for intact and damaged pavements can be used for regulators to determine the acceptability of various recycled materials. Contributions in the aqueous geochemistry of leaching included a new modeling approach for leaching of anions and cations from complex matrices such as weathered steel slag. The novelty of the method was its simultaneous inclusion of sorption and solubility controls for multiple analytes. The developed model showed that leaching of SO4, Cr, As, Si, Ca, Mg, and V were controlled by corresponding soluble solids. Leaching of Pb was controlled by PbVO4)3 solubility at low pHs and by surface precipitation reactions at high pHs. Leaching of Cd and Zn were controlled by surface complexation and surface precipitation, respectively. Pollutants Environmental aspects. Electronic dissertations. aeBook. aCN bNGL http://pqdt.bjzhongke.com.cn/Detail.aspx?pid=8OzHA7xevpk%3d NGL Bs1589 rCNY371.35 ; h1 bs1204