Environmental Engineering Reference
In-Depth Information
30.3.3 How Many Water Purification Systems Have Been Designed?
Both domestic and collective systems have been designed based on ion-exchange columns
(Figure 30.8). The former are 2-L pitchers and lasks with a funnel in the upper part con-
taining a ZZ cartridge or a load of the product creating a column 10 cm in height and 5 cm
in diameter. The collective systems are more complex for they are connected to the water-
supply pipes and their capacity can be of either 2 or 4 kg of ZZ in one or two columns.
The ZZ water puriication systems (Figure 30.8) were evaluated in accordance with exist-
ing water quality parameters for human consumption [16]. The results indicate that tur-
bidity in well water was reduced to 3 units when treated in a ZZ pitcher (Figure 30.9).
In addition to its ion-exchange properties enabling the release of zinc ions through the
exchange of calcium ions in the water, ZZ has another important property: the adsorption
that reduces excess hardness in water, this being a major cause of sediments in the human
urinary tract. Actually, water hardness is reduced by 60% (Figure 30.10).
The presence of such heavy metals as Cd, Cr, Mn, Ni, and Pb remains at lower levels
than the values established for water intended for human consumption (Table 30.6). The
(a)
(b)
(c)
FIGURE 30.8
ZZ water puriication systems: (a) lask and funnel (2 L); (b) pitcher (1.5 L); (c) collective systems.
240
Initial
Final
160
80
0
0
10
20
30
40
50
Volume (L)
FIGURE 30.9
Water turbidity after treatment with the ZZ system.
