Environmental Engineering Reference
In-Depth Information
Bacteria-
containing water
a
b
(a) Stainless-steel body filter
(b) Filter cloth
(c) Teflon sieve
(d) Antimicrobial copolymer
matrix
c
d
Bacteria-
free water
FIGURE 12.2
Schematic diagram of the reill cartridge for water puriication. (Adapted from Tyagi, M. and Singh, H.,
J. Appl.
Polym. Sci.,
76, 1109, 2000.)
N
-halogenated poly(styrene hydantoins) (Figure 12.3a). The inal polymers are amorphous
solids, which are insoluble in water and can be packed into glass. It was observed that
the ilters made from the poly(styrene hydantoin) polymer inactivated numerous species
of bacteria such as
Staphylococcus aureus
,
E. coli
, fungi, and even rotavirus within seconds
of contact time in lowing water.
19, 20
The mechanism of action of the
N
-halamines beads
is not known. It has been proposed that a contact mechanism is involved in which, upon
(a)
(b)
(c)
(d)
N
-
-
-
O
X
O
O
Cl
Cl
Cl
N
+
+
+
N
N
N
N
N
C
12
H
25
C
12
H
25
Cl
Y
n
n
O
n
n
X = Cl, Br; Y = Cl, Br, H
FIGURE 12.3
Structures of the biocidal polymeric beads and resins used: (a) halogenated poly(styrene hydantoin); (b) chlo-
rinated methylated polystyrene hydantoin; (c and d) quaternary ammonium polymeric resins PQ1 and PQ2.
