Kan kväve bevaras i dräneringsvatten från åkermarksom lagras i dammar?
ett laboratorieförsök
The aim of this thesis was to examine if it is possible to keep nitrogen in the form of nitrate(NO3-) in ponds from one season to another by keeping a high concentration of oxygen in thepond water. This hypothesis was tested by doing a lab experiment where two systems werecompared according to nitrate concentration. One system had high concentration of oxygen inthe water and one had low concentration of oxygen. Before the main experiment wasconducted I did a pilot study to test the system setup and included parameters. The result fromthis study and the main study did not show the same result. In both studies the nitrateconcentration decreased in the beginning of the experimental period. In the main study theconcentration of nitrate remained close to zero. While in the pilot study the nitrateconcentration increased back up close to the starting level in the system with high oxygenconcentration. From this result it is not possible to come to any conclusions regarding theinfluence of oxygen concentration on nitrate concentration. One possible reason why the twoexperiments showed different results is that the microbial activity was different in the twosystems.