The substitution of iron salts by aluminium salts at the Damhusaaen WWTP started in February 2006 and continued until August. The period of substitution was prolonged because of a higher processtime at the plant, but this is due to other reasons than the substitution. The dewatering of the sludge has taken place at Damhusaaen, and at AWS a separate batch of sludge has been incinerated, thus producing lighter bio ash. This ash has been used in concrete at Unicon, and the concrete has a slight tint of light red. The appearance of the concrete has been assessed both subjectively and objectively.
A memo regarding the Chemical composition of European bio ashes has been written as a part of Task 3.
Final report for Task 3 is completed.
Status per 2008.09.25