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Experiments performed in a model pipe
system fed with underground water demonstrated that tap
water exposed to cement-lining gradually lost its corrosive
properties and continued to develop its potential for
calcium carbonate precipitation. This was an indication
that cement components were released from the lining into
the water residing in the pipes. Apart from its main components
(calcium, magnesium and aluminum), the water
contained small quantities of trace elements (zinc, barium,
chromium, lead, nickel and cobalt). The study produced
the following fi ndings: leaching of elements from the cement
lining was enhanced upon exposure to chlorinated
water, and the fi nal concentration values of all the elements
detected in the water after contact with the cement
lining were much lower than those permissible for drinking
water.
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