Kvicksilver, kadmium och zink i avfall som förbränns i Kiruna kraftvärmeverk

Abstract: Kiruna Kraft AB is the responsible operator of the Kiruna power and heating plant and the Kiruna waste disposal plant. The company is responsible for the production and distribution of heating and electricity in Kiruna and for heat from the heating plant in Vittangi. In addition, the company takes care of household waste from municipality citizens. The company is authorized to incinerate more than 98 000 tons of waste per calendar year with a maximum of 2,500 tons of hazardous waste. Continuous sampling of the outgoing wastewater from waste incineration in boiler 3 to the recipient Luossajoki has shown elevated levels of the heavy metals mercury, cadmium and zinc. The purpose of this study is to identify where in society mercury, cadmium and zinc are found and to examine the type of waste going to Kiruna power and heating plant which contains the greatest concentration of these heavy metals. A compilation of data from samplings have been made and randomly selected samples of household waste in the municipality of Kiruna have been studied to get a picture of the waste incinerated in boiler 3. The results of tests conducted in 2014 and 2015 show that the Environmental Protection Agency regulations (NFS 2002:28) for the emission of mercury, cadmium and zinc to the receiving water were exceeded in certain quarters in 2014 and 2015 despite high treatment efficiency. The reason behind the elevated metal concentrations to the recipient is likely an increased amount of metals in the incoming waste that is incinerated in boiler 3. The randomly selected samples show that the proportion of non-combustible waste decreased between 2005 and 2006, but that it then gradually increased until 2014. After 2014, the proportion of metal packaging, glass packaging and hazardous waste (hazardous waste, electrical and electronic products) decreased, while the percentage of metal scrap and waste (inert material and other glass) increased. Measures concerning the elevated metal emissions to the recipient have been taken and the company continuously works to minimize the environmental impact. As the operation's treatment efficiency is very high and represents the best technology available in the industry, measures to reduce the levels of particularly mercury and cadmium, but also zinc, in the outgoing wastewater must be directed towards the incoming waste in boiler 3. The reason why the municipality citizens put non-combustible waste in household waste needs to be examined.