Desorption of Trace Inorganic Contaminants from Solids in Drinking Water Distribution Systems
In order to maintain high quality safe drinking water, we need to understand what happens after the water has been cleaned at the drinking water plant and before it gets to the consumer’s house. Even if low concentrations of toxic contaminants enter the drinking water distribution system (DWDS) ther...
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| Format: | Others |
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DigitalCommons@USU
2018
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| Online Access: | https://digitalcommons.usu.edu/etd/7039 https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=8147&context=etd |
| Summary: | In order to maintain high quality safe drinking water, we need to understand what happens after the water has been cleaned at the drinking water plant and before it gets to the consumer’s house. Even if low concentrations of toxic contaminants enter the drinking water distribution system (DWDS) there is potential for contaminants to accumulate and be released by changes in flow or water conditions in high concentrations at the tap. For this study, we collected solid material from Park City, Utah that accumulated within the DWDS, along with a year of monthly monitoring of the DWDS. These solids were tested under five chemical and physical changes to see what contaminants can be released into the drinking water, with focus on eight elements: antimony (Sb), arsenic (As), chromium (Cr), copper (Cu), lead (PBS), and thallium (Tl) termed inorganic contaminants (TICs), also pipe elements iron (Fe) and manganese (Mn). From this study it was found that high concentrations of Sb, As, and Tl could be released under some conditions. Fortunately, we saw that the release of Cr, Cu, and Pb was either unmeasurable or so low that the amount never approached drinking water standards. The factors that were the most influential in producing high concentrations were both high and low pH, high temperature, low Cl2, and CaSO4. The most surprising observation was the very high concentrations of Tl released, reaching up to 90 μg/L, where the safe limit in drinking water is 2 μg/L. This study showed the importance of monitoring changes within the DWDS and that small changes can cause harmful levels of some contaminants to be released into the drinking water. However, monthly monitoring showed under normal conditions no harmful levels were detected. |
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