AWWA ACE92166

The production of potable water from surface water typically involves a large amount of process equipment including flocculation tanks, clarification basins and sand filters as well as backwash storage tanks and associated backwash equipment. Using the DynaSand filter as a continuous contact filtration plant, which combines coagulation, flocculation and particle separation directly in the filter bed, reduces the required equipment volume by nearly 70%. Due to the continuous cleaning operation of the DynaSand filter, the unit functions without interruptions for backwashing. Also, waters with high levels of impurities and/or requiring high dosages of treatment chemicals can be processed using continuous contact filtration and produce potable quality water. Using the DynaSand filter as a flocculation reactor and particle separator permits a smaller floc size requiring shorter reaction times than conventional treatment trains. Thus, in many cases, the treatment chemical demand is reduced by as much as 30%. The short contact time between the treated water and separated sludge minimizes the risk of dissolution of substances, from the sludge, giving bad taste and odor to the water, as well as, the risk of bacteria transfer. Currently, there are over 250 DynaSand filters in Europe producing potable water through continuous contact filtration. The European installations are producing potable quality water, from raw waters with turbidities to 20 NTU, at loading rates to 3-4 gpm/ft2. In North America, full scale installations and pilot plants have demonstrated the ability to consistently produce potable water, even with raw water turbidities to 50 NTU. Data is presented from existing potable water installations.

Product Details

Published:

01/01/1992

ISBN(s):

0898676525

Number of Pages:

15

File Size:

1 file , 360 KB