A three-dimensional reactive transport model for sediments, incorporating microniches

• DOI: 10.1071/en08006
• Publication Date: 2009-02-09T02:58:26Z
• Authors: Łukasz Sochaczewski; Anthony Stockdale; William Davison; Wlodek Tych; Hao Zhang
• Keywords: 550; 13. Climate action; 01 natural sciences; 0105 earth and related environmental sciences

Environmental context. Modelling of discrete sites diagenesis in sediments (microniches) has typically been performed 1-D and involved a limited set components. Here we present new 3-D model for microniches within traditional vertical sequence redox reactions, show example modelled niches range sizes, close to the sediment–water interface. Microniche processes may have implications understanding trace metal diagenesis, via formation sulfides. The provides quantitative framework examining microniche data concepts. Abstract. Most reactive transport models represented as one-dimensional (1-D) systems solely considered development concentration gradients. However, application recently developed microscale 2-D measurement techniques demonstrated more complicated solute structures some sediments, including localised depleted oxygen, elevated metals sulfide, referred microniches. A reaction that can simulate dynamic gradients occurring was developed. Its graphical user interface allows easy input user-specified reactions flexible schemes prioritise their execution. capability by modelling hypothetical behaviour at organic matter covering sizes. Significant effects on profiles oxygen nitrate are demonstrated. Sulfide is shown be readily generated 1 cm sediment surface, provided diameter material greater than mm. These results illustrate geochemical complexities arise when occur demonstrate need such model. Future use high-resolution should include collection relevant major components, iron manganese oxides, allow full, multicomponent processes.