Fors Mill, Stora Enso Fors AB

Stora Enso Fors AB is a large pulp & paper plant in mid Sweden. The production is mainly liquid packaging based on CTMP and board pulp produced in the mill. One of the main customers is Tetra Pak. Due to increased production and new outlet demands the existing old activated sludge waste water treatment plant had not capacity to meet the new demands and Stora Enso Fors AB decided to invest in an upgrading of the existing plant.

The upgrading consists of a MBBR/Activated sludge basin as pre-treatment in front of the old Activated sludge plant. Additionally a new aeration system in the first of the existing aeration volumes and a new Dissolved Air Flotation, DAF, plant as post treatment with chemical precipitation, were installed. The contract was signed in May 2010 and the upgraded plant was commissioned and started in March 2011. The wastewater originates from the complete pulp & paper mill, but the main COD load is generated by the CTMP production. After the new biological/chemical waste water treatment plant, the effluent is discharged to a local river.


Technical data

Flow: 14 300 m3/d
CODsoluble:  31 000 kg/d
SS (GF/A):  3 000 kg/d