Civil Engineering - Waste Water Engineering - Discussion

Discussion Forum : Waste Water Engineering - Section 1 (Q.No. 19)
19.
When drainage to sewage ratio is 20, the peak dry weather flow is
20% of the design discharge
slightly less than 5% of the design discharge
slightly more than 5% of the design discharge
none of these.
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
10 comments Page 1 of 1.

Gurjant singh said:   4 years ago
Thanks for explaining @Harsh Sharma.

Irfhan said:   5 years ago
Thanks @Harsh.

Harsh Sharma said:   6 years ago
Qd/Qs = 20.

Qd = 20 Is ---- (1).

In rainy weather;

Q = Qd+ Qs.

from eq (1)-
Q = 21 Qs ----- (2).

In peak dry weather;

Q= Qd + Qs (here Qd = 0 since no storm water).
Hence,
Q= Is ----- (3).

From ek (2) & (3).

Dry weather condition/ Rainy weather condition = (Qs/ 21Qs)*100 = 4.76...

Therefore, the peak dry weather flow is slightly less than 5% of the design discharge.
(7)

Hdhjdje said:   6 years ago
@Rana, Nice explanation.
(1)

Khushwant rana said:   6 years ago
In dry weather only dry weather flow mean drainage flow will occur not the stormwater taken into account if drainage: sewage =1:20 then at dry flow only 1 unit will flow in a total of 21 unit mean % flow as compared to rainy season =1*100/21 = 4.76.

Er Mugundan R said:   7 years ago
Explain it, please.

Raj said:   7 years ago
Please explain it.

RAJESHKUMAR J said:   8 years ago
DWF = total supply of water * % of supply contributing to sewage, so when the ratio of drainage to sewage is high (20), then % of supply will be less, so DWF will be less than the design discharge.

Souvik Kundu said:   8 years ago
Please explain it.

Shreya said:   8 years ago
Anyone explain it please.

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