The water circuit of the process is almost totally enclosed, and water consumption amounts to barely 3 m3 / tonne of pulp. The water used is drawn from the Urola River. A sewage/waste water treatment plant treats the
waste water so that it can be re-used and the remainder discharged, reducing the negative impact. It initially passes through a pre-treatment by roughing and decantation for the removal of solids until it reaches the homogenisation
pond where it undergoes primary treatment by dissolved air flotation process for separating the particles. Then, the waste water is taken to a secondary treatment where the organic material is degraded using an IC technology anaerobic
biological digester and an aerobic biological oxygenation reactor with latest generation equipment.
Finally, the effluent is sent to a tertiary treatment by decantation prior to being discharged to the river. The sludge generated
from the treatment is dehydrated mechanically through centrifugation. This process has involved much hard work, both technical and economical, ensuring that the water is returned to its natural cycle while generating minimal impact
on the environment.
In the efficient and responsible production process less than 3 m3 of water is used per tonne of pulp produced.
The waste water is treated at the treatment plant. This consists of a pre-treatment, a physical-chemical
process for removing sludge; internal circulation anaerobic biological digester, a latest generation oxygenation aerobic biological reactor with sludge thickening for decantation and tertiary treatment.
The sludge generated
as a sub-product is dehydrated through centrifugation.