Environmental Engineering Reference
In-Depth Information
Also, there is copper, an element with a proven bactericidal effect against a number
of microorganisms and also an important element to life. Iodine, which is also used
for chemical disinfection of water, cannot eliminate some pathogenic parasites; more-
over, some people have adverse reactions to iodine intake. However, zinc combines both
properties and is more important to life. That is why it was chosen in formulating ZZ
and for use in water puriication systems.
30.1.2 What Are the Bases of the ZZ Project?
ZZ is a new material with microbicidal and ion-exchange properties that can be used to
purify water for human consumption, and as a viable alternative to such traditional proce-
dures as water boiling and disinfection with chemical substances and physical methods.
ZZ makes possible the design of lexible domestic and collective water puriication sys-
tems, which combine the ZZ properties, the simplicity of the systems, and their low cost
with the people's water storage and handling habits.
The objectives of a ZZ Project are
• Effective and eficient water puriication for direct human consumption
• A broad distribution of the water puriication systems to all segments of the popu-
lation in a given country
• Distribution of the water puriication systems to low-income segments of the pop-
ulation lacking the necessary infrastructure for water treatment and distribution
• The use of ZZ in population segments with eating habits limiting the incorpora-
tion of zinc to their nutrition
• The use of ZZ as an active complementary therapy for population segments affected
by infectious diseases demanding zinc
This chapter offers the highlights of the ZZ water puriication systems that can be devel-
oped in the conditions prevailing in Cuba and other countries that need to secure the
quality of the water supplied to the population affected by natural disasters or war con-
licts. These systems share similarities with other domestic water puriication systems and
procedures but offer the additional advantage of zinc supplementation.
30.2 Materials and Methods
A natural clinoptilolite (IUPAC code HEU) from Tasajeras, Cuba, a deposit that meets
Cuban standard NC 625: 2008-Annex A [11], of a natural zeolite for human and animal
health and nutrition, was used as the raw material to obtain puriied natural clinoptilolite
NZ [8]. The particle size of NZ chosen was 1-3 mm. The Zn
2+
-NZ form was obtained in a
pilot plant with a capacity production of 1 ton/day through the hydrothermal ion-exchange
modiication of NZ with 0.5 M dissolution of ZnSO
4
·7 H
2
O USP, at boiling temperature dur-
ing 10 h following the procedure described [12]. The pH, density, sterility, and humidity
of Zn
2+
-NZ were adjusted considering the sanitary properties required for products used
in water puriication treatments recommended by the WHO
Guidelines for Drinking Water
