Study of the diel and seasonal variations of the metal pollution in the Leirelva River, Norway

Monitoring of river water can be carried out in different ways. Manual monitoring by regular manual sampling and analyzing after on in laboratories are the most simple and common way. However, recently also other methods have been developed, like passive sampling by use of e.g. DGT, or automatic monitoring with e.g. voltammetric system to follow metal concentrations. These techniques are advantageous compared to manual sampling since they are more user friendly and renders a near real-time monitoring of the river. The interest is to see as quickly as possible any pollution occurring in a river system to be able to act a soon fast or just to study some biological, geological or meteorological cycles. The subject of this internship has been focused on the use of more recent methods for river monitoring in combination with traditional sampling routines to study seasonal and diel variations in the a river system. The work has been carried out at the department of Environmental and Analytical Chemistry, NTNU during the spring semester 2010 under the supervision of the Professor Øyvind Mikkelsen. Selected river was Leirevla in Trondheim, and the scientific task was to: - Observe and explain possible diel cycles - Observe and explain seasonal variations in selected metal concentrations and some other parameters Starting up and maintaining a newly installed automatic monitoring system were also one of the purposes of this internship.