AWWA WQTC71363

In this study the removal of dissolved organic matter (DOC) from soil aquifer treatmentwater, and atrazine and MS2 phages from Delft canal water by a pilot plant combiningceramic microfiltration with a pre-coat of powdered activated carbon (PAC) isinvestigated. Two types of PAC are used, normal sized PAC (NPAC, average size 25mm) and a ground form of the same PAC, sub-micron PAC (SPAC, average size 0.8 mm).The DOC removal with pre-filtered (0.45 mm) for a fixed SPAC pre-coat dose is optimalwhen the flux during pre-coating is greater than or equal to 200 l m^-2 h^-1, probably due to better packing of thePAC. The average DOC removal in a 1 hour filtration cycle increases with increasingSPAC pre-coat dose (14-56 mg/l) and varies from 51 to 70%. Pilot experiments with rawDelft canal water and atrazine show that SPAC is better than NPAC in removing atrazine.Atrazine removal with the pilot plant is better for a SPAC pre-coat than for a NPAC precoat;average removal for a 2 hour filtration cycle is 87% for 20 mg/l SPAC and only41% for 20 mg/l NPAC. As the contact time of the water and PAC is very short (in theorder of 0.4 s), the adsorption of atrazine to the smaller sized SPAC is very fast.Increasing the SPAC concentration to 40 mg/l only slightly increases atrazine removal (to93%). Removal of MS2 phages is 0.3-1.5 log units and depends mainly on the transmembrane pressure increase, and not on the pre-coat type indicating that removal takesplace by size exclusion rather than adsorption. Includes 12 references, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2009

Number of Pages:

9

File Size:

1 file , 800 KB