AWWA JAW64706

The turbidity spike that occurs during filter ripeningcan be minimized without additional equipment orchemicals, simply by optimizing backwash steps. However,filter-to-waste (FTW) is still needed to achieveaggressive filter effluent turbidity targets.A study was undertaken at the Central Lake CountyJoint Action Water Agency in Lake Bluff, Illinois, to minimizewater consumption and maximize filter servicelife. Filtration and water use were optimized usingexisting equipment and a method called extended terminalsubfluidization wash, demonstrating that10-year-old biologically active granular activated carbonis still viable. The FTW peak following backwashwas reduced from an average of 0.13 to 0.08 ntu.In addition, results suggest that FTW is not requiredin 96% of filter backwashes. Therefore, automaticFTW following backwash should be discontinued and,instead, FTW should only be used as needed. Includes 54 references, tables, figures.

Product Details

Edition:

Vol. 99 - No. 5

Published:

05/01/2007

Number of Pages:

10

File Size:

1 file , 440 KB