In this research, experimental tests and practical
case studies from U.S. utilities uncovered the importance
of chloride-to-sulfate mass ratio (CSMR). When early
investigations of lead contamination in several U.S. cities
failed to determine the source of the problem, this
work uncovered the first valid explanation for those
specific cases by introducing CSMR of water as a
major cause of lead leaching to water.
The authors conclusively linked higher CSMR to
higher levels of lead release through galvanic corrosion
of lead-tin solder at copper pipe joints. Water
providers may inadvertently alter the CSMR of their
water through their coagulant choice. For example,
switching from a sulfate-containing coagulant to one
containing chloride could increase the CSMR, which in
turn could trigger lead contamination at levels above
the regulatory action level. Because even seemingly
innocuous shifts in water treatment can have unforeseen
repercussions, utilities are advised to undertake
preliminary studies at bench-scale or desktop to help
prevent potential contamination problems in systems
with lead-bearing plumbing. Includes 32 references, tables, figures.
| Edition : | Vol. 99 - No. 7 |
| File Size : | 1
file
, 640 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 14 |
| Published : | 07/01/2007 |
