The potential economy both in capital outlay and operating costs makes direct filtration an attractive treatment process. Although the decreased costs associated with reduced chemical consumption and reduced sludge load have been emphasized less than the initial capital economy in plant construction, they represent on-going savings that continue for the life of the plant. Pilot plant investigations are required in order to establish the design criteria for a direct filtration plant. However, pilot plant investigations should not be undertaken unless the raw water can be treated by direct filtration.

The procedure is the following:

Step I-- Determine the raw water turbidity and record.
Step 2-- Filter the raw water through Whatnan #40 filter paper and record.
Step 3-- Fill the four jars with raw water to the 2-liter mark and decide on dosages.
Step 4-- Measure out the coagulant and polymer doses.
Step 5-- With the Phipps & Bird Stirrer at maximum speed, pour in the coagulant and polymer (test to determine sequence); stir at maximum speed for 30 to 40 seconds.
Step 6-- With stirring continuing at about 50 rpm take a 200ml sample.
Step 7-- Filter through Whatman #40 filter paper (discard paper).
Step 8-- After 3 or 4 minutes of the stirring at 50 rpm take another 200 ml sample.
Step 9-- Filter this later sample through Whatman #40 filter paper (discard paper).
Step 10-- Read and record turbidities of all samples.
Step 11-- Plot data on arithmetic scale paper.

Figure 13, Figure 14,

Figure 15

Raw water - 37 NTU
Filtered - 10 NTU

First trial Jars 1 2 3 4 5
Alum Dosages 2 4 6 8 10
Filtered Turbidity NTU 10 10 4 4 0.4


Second trial - Fec13 Dosages 2 4 6 8
Filtered Turbidity 8.4 2.2 0.35 0.20

Third trial - Cationic polymer
dosages 0.1 0.2 0.3 0.4
Filtered Turbidity 8.0 4.0 2.0 0.8

The result of this test is obvious in terms of effectiveness. The polymer is very efficient and wiU produce only a small amount of floc which portends weU for filter runs. The economics of the situation, however, might favor the FeCl3. This would depend on the location of the plant and delivered cost of each coagulant. A well designed dual media or deep, course sand filter would probably perform satisfactorily with any of the coagulants. Pilot filter testing therefore would determine the best and most economical.

Call Toll-Free (800) 955-7621 in Virginia (804) 254-2737

Fax - (804) 254-2955

Email - info@phippsbird.com

Hablamos Español

Disclaimer: The information on this website is presented solely as ‘entertainment’. Visitors/viewers must subscribe to and accept all the provisions listed below as a condition to viewing the material on this site: 1) Visitors are granted access to view and use at their own risk any materials and information presented herein. No claims are made by Phipps & Bird as to the accuracy, currency, validity, or reliability of any materials or information appearing on this website, to include but not limited to pricing information; laboratory procedures and formulas; implied or express product use or effectiveness; etc. 2) All information on this website is copyrighted by Phipps & Bird, Inc. Visitors may copy or print off only for their own use any of the materials on this website. Images and materials may NOT be copied to other websites, redistributed in any form, or republished in any format whatsoever without the written permission of an authorized representative of Phipps & Bird, Inc. 3) Nothing presented on this website shall be inferred nor construed to be a contract, agreement, covenant, promise or binding commitment of any kind. 4) All information, offers, features, pricing, terms, et al, may be changed, withdrawn, discontinued or rescinded at any time without notice. Photographs may or may not be an accurate and current representation of the depicted subject. 5) Phipps & Bird, Inc. is released of any and all liability resulting from the use, misuse, or misinterpretation of any of the information herein presented. This includes scientific formulas, procedures, charts, graphs, et al., the accuracy of which should be independently verified by the user.
© 2017
 Phipps & Bird, Inc.