Automatic monitoring of labile copper with special focus for aquaculture installations with and without recycling of the water Copper and other heavy metals can be monitored by sending samples to a laboratory or by automatic and continuous in situ monitoring. The advantages of using automatic monitoring are obvious, but no acceptable method has so far been available. As a result from research in analytical chemistry at The Norwegian University of Science and Technology (NTNU) in Trondheim, Norway, new methods have been developed enabling automatically to monitor heavy metals in waters, and this is patented internationally. The company SensAqua AS in Trondheim and Oppdal takes care of the commercial aspects of this activity. We have worked out a method for continuous monitoring of copper of particular interest for aquaculture with and without reused water. A pilot station has been established at Nofima AS in Sunndalsøra, Norway. This has worked satisfactory in a testing period of about seven weeks.

The SensAqua ATMS600 measuring system The sensor system Silver/silver chloride reference electrode for the reference circuit Platinum counter electrode Working electrode, gold based alloy designed for monitoring low concentrations of copper Analytical cell; test solution + HCl (0.01 M)

Long term measurements of copper Results from measurements over time

Further information: www.sensaqua.com Tel. +47 922 98 478 sensaqua@sensaqua.com SensAqua AS, Norway Voltammogram (system response) for a scan with and without addition of 5 g/l Cu2+ CONCLUSION From the results during the testing period for a tailored measuring system for the aquaculture industry, it is found that the concentration of copper in the water can be monitored continuously with satisfactory results. We experienced electricity breakdowns for some days during the actual period, and the results were then lost, but the breakdown did not affect the stability of the further measurements. Monitoring can be run continuously at least one month before manual attendance is needed. We also tested in the laboratory using ICP-MS, and by comparing after addition of standard copper solution, with satisfactory results. The method was specially designed for copper, but other metals can also be monitored.