Calcium Carbonate as Active Barrier Component for the Retention of Phosphorus in Sediments

Figure 7: Bioturbation experiments – Influence of chironomid larvae

3 months after the calcite application

4 Discussion

4.1 Efficiency of calcite barriers with respect to the phosphorus retention in


Our results show, that all calcites investigated are suitable materials to reduce phosphorus

release from eutrophic lake sediments. But already QS, which should behave chemically

inert, led to a considerable reduction of the SRP flux of about 50 % (Figure 3). The

high porosity of the coarse QS may physically hinder the diffusion from the silty sediments

or at least decelerate the diffusion. Just an addition of 2 - 3 wt- % of calcite to

quartz sand significantly improved the immobilisation efficiency of the barrier. Hence, the

Figure 8: Influence of bioturbation on the barrier efficiency (incubation experiments with sediment of Lake

Epple, Southern Germany, [16,19]; no barrier; applied stable barrier, 1 cm; bioturbated



More magazines by this user
Similar magazines