Page 128 - Membranes for Industrial Wastewater Recovery and Re-Use
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Industrial waters 103
Figure 3.16 Forest resources in the world (FAO, 2000)
Figure 3.17 Proportion afforest by countrg aspercentage of land area (PAO, 2000)
the turn of the century to between 20 and 30 m3/te today. Naturally, an
important factor affecting the water consumption is the paper grade as well as
the technical age of the paper machine: the more modern the paper machine, the
lower the freshwater consumption.
Traditionally flotation and evaporation have been widely used as separation
and purification techniques in the pulp and paper industry. Since the 1980s
membrane filtration has also been adapted to these applications. Moreover,
along with increasing knowledge and better membranes and modules,
membrane filtration has gradually become a more attractive option through its
versatility, intensity (low footprint), and significantly lower energy consumption
compared to evaporation.
