AWWA WQTC65982

Filtration processes efficiently remove most organisms but the accumulation and potentialdevelopment of some of these organisms within the filter media can potentially lead to water qualityproblems, such as microbial non-compliance or aesthetic problems of the distributed water. Despitethe fact that the risks related to filter colonization are usually managed by waterprofessionals, little information is available concerning the level of contamination of typical filtermedia used for potable water production. In that context, the objectives of this project were tocharacterize the state of media contamination of a number of filtration plants and to optimize theprocedures applied for media cleaning, in case of abundant colonization. The preliminary resultsobtained among 14 filtration units indicate that all the filter media, regardless of the type of media, arecolonized by various organisms (amoebae, aerobic spores, E. coli, nematodes, etc.), and that the levelof contamination generally depends on the influent water quality. The effectiveness of chlorinatedbackwash is not proven, whereas a higher backwash flow rate tends to improve the removal oforganisms. Site investigations are still in progress and pilot scale trials will be undertaken to definedecontamination procedures. Includes 12 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2007

Number of Pages:

10

File Size:

1 file , 180 KB