AWWA QTC98331

The purpose of this study was to coagulate at the Baxter Water Treatment Plant at an optimum pH and thereby optimize the coagulant dosing, using two pH adjustment points in the treatment process. This half plant test determined the effectiveness of hydrated lime as a chemical choice as well as examined the performance of feed equipment and chemical dosing design. This study involved two distinct challenges to plant personnel: the construction and operation of a hydrated lime feed system and the operation of two different water treatment trains within one utility. Baxter personnel retrofitted an existing lime slaker to an automatic ratio feed control hydrated lime system along with installing new chemical feed lines to the additional post sedimentation application point. The primary measurement of success was the reduction in the dosage of the coagulant ferric chloride, while maintaining the Partnership for Safe Water combined effluent turbidity goal of less than 0.10 ntu. The secondary measurement of success was TOC and TTHM removal rates. Results have shown a reduction in UV254, TOC and TTHM levels on the south side of the plant when compared to the north side. The "CT" credits due to the reduction in pH nearly double on the south side of the plant for the flocculation/sedimentation process. Test filters have shown no degradation in effluent turbidity or particle counts as a result of the application of hydrated lime just prior to filtration.

Product Details

Published:

01/01/1998

ISBN(s):

0898679796

Number of Pages:

20

File Size:

1 file , 120 KB