Water utilities adjust water quality treatment procedures to minimize corrosion and to
remain in compliance with local, state, and federal regulations. Some treatment
changes though can adversely affect tubercle stability and cause red water and/or other
related problems. Therefore, it is important for water quality managers and engineers to
have a conceptual model in place to reasonably predict how such changes will impact
the distribution system. Models require a comprehensive understanding of the
relationships between corrosion of the iron pipe and the effects of the composition of the
bulk waters on scale development and scale stability. Studies evaluating these
parameters are based on the assumption that one or two tubercle types are
representative of tuberculation in the given distribution system. This assumption though
has been based on a limited number of real observations and needs to be further
tested, so modeling predictions can be viewed with a high level of confidence.
Therefore, the main objectives of this study were to perform a comprehensive
assessment of the physio-chemical properties of three iron tubercles from a single pipe
and assess their extent of variability. These results could be utilized to refine sampling
strategies for assessing the effects of treatment changes on a distribution systems
water quality.
One 0.11 m long iron pipe segment was obtained from Utility X. Three
tubercles were removed from the pipe and allowed to air dry for 72 hours to three
months. No visable obvious alteration occurred to the samples during drying. The
samples were then encased in Buehler Epo Thin® Low Viscosity Epoxy and then cut in
half parallel to the length of the pipe with a band saw. One half of each sample was
polished with fine grit sand paper and flushed with distilled deionized water. Subsamples
were collected and ground with a mortar and pestle until they passed through a
200 mesh sieve. Includes 25 references.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 370 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 7 |
| Published : | 06/01/2006 |
