Independent thesis Advanced level (professional degree), 20 credits / 30 HE credits
The incineration of waste is steadily increasing in Sweden and so is the production of
ashes. The bottom ash has for many years been used as construction material in
landfills. Now many of the nation's landfills are closed and there is a great need to find
another beneficial use for the ash. Bottom ash is a gravel-like material and with its
material properties it can replace natural gravel in parts of roads and surface
constructions. Today this use is only approved within landfill areas where leachate is
collected and checked. Outside the landfill area, authorities are uncertain of the
environmental impact of the bottom ash and of what future risks it entails.
The aim of this work was to investigate market opportunities for bottom ash from
Åmotfors Energy, with the goal to be a background basis for an application of the use of
bottom ash outside the landfill area.
The results of analyzes shows that the bottom ash from Åmotfors Energy is comparable
with bottom ash from the rest of Sweden regarding both the total concentrations and
When the values from the analyses of the ash are compared with the standard values for
total allowed concentrations announced by the Environmental Protection Agency, the
guideline values for almost all parameters are exceeded. If you instead look at the
leaching from bottom ash - almost all parameters pass the guidelines. The reason why
the guideline values for leaching may be withheld while the guideline values for total
concentrations exceeded is that ash has a capacity to bind substances stronger than earth
materials and waste, which the guideline values are set for.
It is possible to find an application for use of bottom ash from Åmotfors Energi outside
the landfill area. It is important to choose a project where the bottom ash is suitable as a
construction material. Examples of these include surface construction near industries or
road constructions where there is no contact with groundwater. Near Åmotfors the
national road 61 is under reconstructions and if bottom ash from Åmotfors Energi
would be allowed in the construction, about 130 000 ton could be useful. This is about
13 years of production. Bottom ash can also be used in parking spaces near shopping
centers which are continuously being expanded in Eda Municipality. For a normal
parking space of 20 000 square meters about 20 000 tonnes of bottom ash is needed.
The results of interviews with landfills in neighboring municipalities gave indications
that there could be a need for bottom ash as a construction material on two of the
landfills. The need was estimated to 5000 - 10 000 tonnes per year over the next few
The ash from Åmotfors Energi is, like bottom ashes from other waste incineration
plants to be seen as a resource. Today, metal is extracted from the ashes because of the
economic benefits, but in the future it is possible that we will see bottom ash as a
resource that can replace of virgin and non-renewable materials.