Development of a computer-generated equilibrium model for the variation of iron and manganese in the hypolimnion of Lake Mendota

作者：Michael Robert Hoffmann, Steven J. Eisenreich · 发表于：Environmental Science & Technology · 年份：1981 · DOI：10.1021/es00085a011 · 被引用次数：10 · 研究领域：Environmental Toxicology and Ecotoxicology、Electrochemical Analysis and Applications

A computer-generated chemical equilibrium model has been developed to predict the unusual seasonal variation of iron and manganese in the hypolimnetic water above the sediments in Lake Mendota. Models for the detailed chemical speciation of Mn and Fe have been developed as functions of pH, redox level, adsorption, and organic complexation. Results indicate that pH is the primary variable controlling the preferential release of Mn due to simultaneous pH dependent dissolution of solid MnCO_3 and desorption of Mn(II) from oxide surfaces. Progressive appearance of Fe is predicted in terms of a pH-dependent dissolution of iron oxides as influenced by organic complexation. Using the maximum observed concentrations of major chemical components as input data, we have reproduced experimentally determined variations of Mn and Fe as a function of pH over the range 8.7-6.9.