14.- WSP Design Summary (3)

Now solve for n 1 2 3 etc and min stop when m m 3

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Unformatted text preview: M1 = Le(fac) = Unfiltered BOD Un Step 2: Step Calculate retention time in second & subsequent maturation ponds: 1/n θm = {[Ne(fac)/Ne(mat)(1+ kBθM1)]1/n −1}/kB −1 now the retention time in M2, M3 etc. now Solve for n = 1, 2, 3 etc. and min STOP when θm <θm (= 3 days) − assume this STOP happens when n = ñ Step 3: Step Choose most appropriate combination* of min θmat and n, including θmat and ñ including * ie, the one for which their product is a ie, MINIMUM, as this gives the least land area MINIMUM, requirement requirement Now calculate the maturation pond areas taking evaporation into account .... areas For facultative ponds we had: facultative θf = AfD/[(Qi + Qe)/2] ① Qe = Qi – 0.001eAf ∴ θf = 2AfD/(2Qi – 0.001eAf) ② Fac. ponds: Af calc’d first, then θf − so θf corrected for evaporation. For maturation ponds, rearrange ②: maturation Am = 2Qiθm/(2Dm + 0.001eθm) Qi = effluent flow from preceding pond Take Dm = 1 m Mat. ponds: θm calc’d first, then Am − so Am corrected for evaporation. Design temperatures 1. Anaerobic & facultative ponds: − mean air temperature of coldest month 2. Maturation ponds (to achieve ≤10 5 or ≤1000 E. coli per 100 ml): − mean air temperature of coolest month in irrigation season...
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This note was uploaded on 03/07/2013 for the course CIVE 1301 taught by Professor Drborman during the Spring '09 term at Leeds Metropolitan U..

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