## Calculate the surface dimensions of sedimentation tank, Civil Engineering

Assignment Help:

Calculate the surface dimensions of Sedimentation Tank

A treatment plant upgrade calls for design of sedimentation basins to handle a flow rate of 8 MGD. The basins are for a Type I suspension with an overflow rate (q0) of 650 gpd/ft2 a length to width ratio of 4:1, a weir overflow rate (qw) of 20,000 gpd/ft, The minimum settling zone depth is 10 ft and 1.5 ft is allowed for freeboard.

(a)  If 3 tanks are chosen, what are the surface dimensions of each tank?

(b)  What is the required weir length for each tank?

(c)  What is the detention time

(a) As = settling zone surface area, ft2 Q = flow rate = 8,000,000 gal/d

q0 = overflow rate =650 gpd/ft2

Surface area of settling tank As = Q/q0 = 8*106 / 650= 12307 ft2

As = L w and Given L = 4 w

Since 3 tanks are used, As per tank = 12307 / 3 = 4102 ft2 = LW= (4W)W = 4W2

W=32f t L = 4W = 128 ft Thus, L = 128 ft and W = 32 ft

(b) Overflow weir length Lw = (Q/tan K)/qw

Lw = overflow weir length (ft)

qw = weir overflow rate (gpd//ft)

Q/tank = flow rate per tank (gpd) = 8MGD/3 = 2.67 MGD

Lw = (Q/tan K)/qw = 2.67 * 106 gpd/ 20000 gpd/ft = 133.4 ft

(c) detention time = V/Q = [128*32*10 ft3] /2.67MGD

= 40960 ft3 / [2.67*106 gal/day* ft3 /7.48gal]

= 0.11475 days = 2.75 hours

#### Closing and opening of expansion joints and contraction join, Question ...

Question In case of for unreinforced concrete carriageway, what will succession of closing and opening of expansion joints and contraction joints? Answer Take a case t

#### Define rotation - actions in pot bearings, Define Rotation - Actions in POT...

Define Rotation - Actions in POT Bearings? POT bearings are associated with large rotations which are accommodated by the deformation of elastomeric pad. Large cyclic rotations

Types of beams

#### Sanitary, Design a sewer network

Design a sewer network

purpose

design procedure

#### Calculate the poissons ratio, Calculate the Poissons Ratio: In separat...

Calculate the Poissons Ratio: In separate experiments, Young's Modulus and Rigidity Modulus of a material have been determined as 120 GPa and 50 GPa respectively. Calculate th

#### Slope protection, what is the type of slope protection that use rocks and p...

what is the type of slope protection that use rocks and put cements between those rocks??the concept is same as brick layer

#### Bituminous macadam, What is the working capacity of a road paver per hour f...

What is the working capacity of a road paver per hour for bituminous macadam  