Environmental Engineering Reference
In-Depth Information
humanitarian projects in South American countries are intended to provide a supplement
of zinc salts to combat epidemics and infections; however, the unstable supply of zinc
reduces the effectiveness of these campaigns [9,10]. The continuous and measured com-
bination of water with a zinc supplement only takes place in the ZZ puriication systems.
The ZZ water puriication systems based on the physical, chemical, and microbicidal
properties of ZZ have been designed for use right before water consumption by humans
or animals as they remove pathogenic microorganisms, clean turbid water, soften hard
water, and add zinc—a crucial element to life. They are simple and reliable, and can be
operated at no risk. Taking into account the habits of the different population groups, the
authors have basically conceived them for use with previously treated water destined
for human and animal consumption that may have contaminated along the distribution
network, and for underground or elevated water tanks. They can also be used with non-
treated surface water from rivers, lakes, and water reservoirs, and with water from wells
or springs.
30.1.1 Why ZZ and Not a Salt or Zinc Compound?
Salt and zinc compounds are objected because of the anion or the part of the compound
that is not zinc. In general, that part can have other effects or somehow remain linked
to zinc, limiting its eficacy. It can also alter the taste of water, making it unpleasant (not
palatable). ZZ only contributes the zinc ions—as the zeolitic material is not soluble in
water—while absorbing the excess of calcium and magnesium (hardness) as well as the
contaminants. ZZ can be used inside the puriication systems for a more eficient action
or added directly to water. A necessary condition is to ensure adequate contact with the
water to be puriied and then wait the short time required for the zinc to remove the patho-
genic microorganisms.
Zinc is one those elements well distributed in the human body, just like carbon, hydro-
gen, oxygen, nitrogen, and phosphorous found in organs and biological functions. It is
well documented that zinc is involved in about 200 biochemical processes. The quest for
the biological role of this element leads us to the very source of man's life, his growth, and
reproduction. Zn is responsible for DNA synthesis at the cell's nucleus, hence the acceler-
ated cell division associated with zinc deiciency. These cells can be spermatozoans and
the cells involved in the immunological and healing system.
The organs of the human reproductive system are rich in Zn with a maximum concen-
tration in the seminal luids; thus, a zinc deiciency can cause malformations in the fetus
and sterility in adults. The mother's milk is the richest source of zinc. High concentrations
of zinc can be found in the retina; therefore, night vision impairment and low adaptation
to darkness have been found to be related to zinc deiciency. The production of insulin in
the pancreas and its functioning also depend on zinc, and the immunologic system relies
heavily on a good supply of zinc. This element blocks the points of attack to the free radi-
cals that can cause death or changes in the cells leading to cancer.
The effects of zinc deiciency on health are as follows:
• Severe deiciency: Pustular-bullous dermatitis, chronic and severe diarrhea, alope-
cia, slow growth and development, slow sexual maturity, swollen liver or spleen,
immune system depression, mental disturbance, recurrent infections, anorexia,
night blindness, impaired healing, alteration of the sense of taste, and behavioral
disorder.
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