Reningstekniker för lakvatten från verksamhetskompostering : Analys med avseende på ammoniumkväve, totalfosfor samt BOD

Abstract Purification techniques for leachate from composting activity - analysis in terms of ammonia nitrogen, total phosphorus and BOD Sofia Lundkvist Leachate from compost facilities has a large impact on the environment if is not properly cleaned. Water samples taken at Ragn-Sells compost facility at Dåva in Umeå have had problems with high amounts of BOD (biochemical oxygen demand), ammonia nitrogen and total phosphorus in their leachate and need to lower these. The aim of this work was to investigate the methods available for treatment of these substances, see if there is a variation depending on spring and autumn in the presence of substances in the leachate from Dåva, and to investigate whether there are methods that can complement Ragn-Sells existing facility for the purification of leachate. Water samples were used to test season-differences of BOD, ammonia nitrogen and total phosphorus. Furthermore, I did interviews with persons from other compost facilities around Sweden to identify alternative methods to reduce the amount of those three substances in leachate from Dåva. There were no clear pattern between measurements in spring and autumn, but the analysis from Dåva shows that there is a statistically significant negative correlation between ammonia nitrogen with average temperature. When the temperature drops the concentration of ammonia nitrogen increases. Further analysis shows that Dåvas existing system likely can be supplemented with additional steps to improve purification of BOD, ammonia nitrogen and total phosphorus, but the data I received was not enough to declare witch method works best for Ragn-Sells as the majority of the persons I came in contact with could not account for the measured values of the three substances