Page 149 - Membranes for Industrial Wastewater Recovery and Re-Use

Industrial waters 123

300 3

- 250
"E -
c
= 200
x"
a
E
L
150
3
E
100
3
-
LL
50

Figure 3.25 Nunofiltration of paper machine clear filtrate with PVD-2 membrane in a VSEP L-filter.
Membrane area 465 cm2, pH 7, amplitude 32 mm, temperature 30-40°C. Thefluxes are recalculated to
35°C. PWFb =pure waterflux beforefiltration, PWF, =pure waterfluxafterfiltration (Huuhiloet al., 2001)

/ I

Figure 3.26 Amounts of different extractives found in the membranes C30F. PA 50H and PES 50H after
UFofgrindingroomcirculation water(Huuhi1oet al.. 2002)

The particle shape has a significant impact on membrane flux (Fig. 3.28a).
Microfiltration of the coating colour components with a 0.1 pm Teflon Typar
(Tetratec) membrane reveals that the round calcium carbonate (CaC03)
particles (usually ground limestone or marble) yield a considerably higher flux
than plate-like particles such as clay and talc. Further, the hydrophobic talc
gives a higher flux than clay, whose particles tend to be positively charged under