AWWA WQTC65746

This paper describes astudy that was conducted to investigate the effect of sample preservation and holding time on theresults obtained for percentage removal of total organic carbon (TOC). To investigate the effect of sample preservation and storage, a series of source water and finishedwater samples were collected from the Pittsburgh Water and Sewer Authority (PWSA) DrinkingWater Treatment Plant and were analyzed for TOC content. Multiple samples were collected onday 0. Half of the samples were preserved to a pH level of 2 with either phosphoric or sulfuricacid, while the other samples were not preserved. Acid preservation (pH 2) of 40 ml aliquots ofthis source and finished water required 0.2 ml of either acid. Preserved and unpreserved samplesfrom this series were analyzed for TOC concentration on days 0, 7, 14, 21, and 28 followinginitial sample collection. The percentage removal of TOC was calculated on each analysis dayby subtracting the measured finished water TOC value from the source water value, and thendividing this difference by the original source water TOC concentration.The source water for the PWSA Treatment Plant is the Allegheny River which typically has aTOC content in the regulatory category of >2.0-4.0 mg/L, and an alkalinity of approximately 35mg/L (as CaCO₃). With this source water chemistry, PWSA is required by the Stage 1 D/DBPRule to remove 35.0% of the source water TOC in its conventional treatment process.TOC analyses for this study were conducted in the PWSA Laboratory using a Sievers model 900Portable TOC Analyzer. Includes 4 references, table, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2007

Number of Pages:

7

File Size:

1 file , 150 KB