Question

It is required that a wastewater flow of 2 MGD with a strength of 300 mg/L BOD5 be treated to remove 90% of the BOD5. To achieve this, a 25-ft deep filter will be constructed and plastic media will be used. A treatability study has shown that n = 0.5 and K= 0.05 min-1 at 20⁰C. If the critical wastewater temperature is expected to be 10⁰C, what size filter should be required? Recirculation will not be used. Use Excel and Eckenfelder equation and the following steps: 1. Correct K for temp. 2. Compute acceptable hydraulic loading 3. Convert flow from MGD to gpm 4. Calculate filter surface area 5. Determine filter diameter.

Answer 1

90g2. 18 m31 dou Depth of filter 8 f D (20'c)し1047 005 I 0477 1o-20 Kolo, c = 00315 mini ラRecirculation will mot be 10 ed .ỦAing eckenfelder equation - KD So So-influent concentration 300mall Se= Effioer + concentration rfter removing gor, al

= 27mall will nemoved In the eflwert 300-27 Se 273loill be oblane Puting all the vales in e we gel 300 300 0-S 0-5 005 0-0993 MGD- GPM x1440 min/day 10 G 10 6 9PMニ1388.88 S 1388 38 9 Pm a' or V 02 81136 m/min = 2X4546 09 294589 m2 R 028136X24X 60

filter diameter flteutae2 45 89 m2 firea TF d2 (엄.nder pls) But for circulor O-olid3 5-985 d2-22-4589 o d337m 6341