This powerpoint presentation begins by presenting the motivation for research: corroded mains in drinking water
distribution systems. The
repair option of in situ relining is presented. Study objective was to
determine the water quality and
aesthetic effects of a newly installed,
cement mortar lining material. Testing protocol and water quality test methodology for the following are given:
alkalinity, pH, hardness;
metals leaching;
disinfectant consumption;
disinfection byproduct formation;
total organic carbon; and,
odor. Presentation conclusions indicate that: water types performed similarly for all pH and
disinfectant combinations;
critical point on day 9 - significant decrease in most
leachate release rates;
aluminum concentration driven by available aluminum
silicates in uncured cement, bound in mortar matrix as
curing proceeds;
high pH, alkalinity and Ca values driven by dissolution of
Ca(OH)<sub>2</sub> which is a byproduct of cure reactions;
Mg(OH)<sub>2</sub> precipitation occurs due to high pH;
TOC release rate is low and decreases rapidly after
two days;
DBP formation rates are not high and decrease
rapidly with time;
Cement odor intensity remained moderately high for
first 14 days of testing;
Alkalinity and pH results consistent with
previous AWWARF research (Douglas,
Merrill and Caitlin, 1996);
high pH and alkalinity may result in consumer
complaints to include a detectable off-taste;
odor would be noted by consumers particularly in
low flow or dead end areas;
cement mortar lining may not be best choice with
low alkalinity-low hardness waters; and,
aluminum concentration is elevated during first
week of water contact time. Includes figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 4.4 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 26 |
| Published : | 11/01/2008 |
