"Adsorption by organic matter, Fe hydroxide association, and sulfide precipitation are primary mechanisms for Pb and Zn removal from neutral pH mine drainage by constructed wetlands. A mathematical model was developed with the geochemical modeling tool PHREEQC to simulate the constructed wetland processes, including both kinetic and equilibrium aspects of the above removal mechanisms...This research provides a quantification method to evaluate removal mechanisms of a constructed wetland and is also a direct support for previous research on wetland removal mechanisms"--Abstract, page iii.