Softeners for desalinated waters
What about solutions?
Processes of paper production need a primary water without hardness or with low salinity, obtainable with softening and desalination treatments. Wastewaters hold suspended solids and salts, that can be taken off by application of biological technologies, as the UASB, and physico-chemical processes, as flotation.
The procedure for melting of lignin, furthermore, produces the black liquor, contaminated from chemical substances, that can be treated with evaporation technology: concentrate can sometimes be recycled or valorized as secondary raw material.