Calcite dissolution in two deep eutrophic lakes

摘要: The calcium cycle, in particular carbonate dissolution, was analyzed two deep eutrophic lakes, Lago di Lugano (288 m maximum depth) and Sempachersee (87 m) located Switzerland. A box model approach used to calculate calcite dissolution the water column at sediment-water interface based on various lake monitoring data such as sediment traps, cores, pore-water analysis. for stationary conditions allowing calculation of a given particle size distribution developed. relative values simulated Aux were consistent with trap observations. best fit rate constant sinking same order magnitude (3 . 10(-10) kg(1/3) s(-1)) published laboratory Values this surface controlled process. Both lakes show similar specific precipitation 170 g Ca m(-2) a(-1). diffusive flux across amounts about 15 10% total Lugano, respectively. However, 61% precipitated is dissolved compared only 13% Sempachersee. These results point towards importance grain distributions settling times stratified waters most important factors determining retention sediments hard lakes. Copyright (C) 1999 Elsevier Science Ltd.