Spårning av tungmetaller i Västra strandens avloppsreningsverks ledningsnät

Sewage sludge contains several important nutrients that can be utilized byrecycling to arable land. This is especially important for phosphorus which is a finite resource and an important nutrient in agriculture. It is, however, important that the sewage sludge is free from high concentrations of harmful substances. In the spring of 2013 passive samplers (ecoscope) were used to track sources of metals in the waste water system of Västra strandens waste water treatment plant in Halmstad. The results showed differences in the level of metal contaminants in terms of both individual metals and the total load of metals. The results suggest that there is a possible source of cadmium upstream the measuring point that is called KärlekenANB 492. This is supported by the measurement at point (P2) downstream that also showed the presence of high levels of cadmium. Silver at two sampling points (P2 and KarlXIANB 465) have elevated values compared to other sampling points. The measurements performed in combined systems have probably been affected by the snow melting and the winter conditions that prevailed during the exposure period. High levels of zinc occurred mainly in areas with combined systems which indicate that surface water is a likely source for this metal.Further investigations have to be done to track specific sources of heavy metals so that measures can be taken to reduce them