COAGULATION AND FLOCCULATION
A Case Study Presented to the
Faculty of the Department of Chemical Engineering
School of Engineering and Architecture
Saint Louis University
In Partial Fulfillment of the Requirements for the Degree
Bachelor of Science in Chemical Engineering
By
Dolique, Bryan
Formarejo, Sidney
Pabito, Jaypee
Ofiaza, Karen E.
Caspe, Diomaika
February 13,2020
COAGULATION AND FLOCCULATION DESIGN
SCREENING
COAGULATION GRIT CHAMBER
&
FLOCCULATION
SEDIMENTATION
AERATION
DISCHARGE NUTRIENT DISINFECTION
REMOVAL
Coagulation and Flocculation
Industrial wine production generates large volume of wastewater from cleaning
their equipment and machinery which are used to process the main raw materials of
wine production. Also, the water used to clean the raw materials and packaging
materials are also considered as waste water from wine production. As a result, the
effluent from wine production is considered as highly contaminated due to ethanol,
organic acids and sugars. In the primary treatment, an extensive amount these organic
substances are removed upon the detachment of most suspended solid. These
suspended are separated through a process called coagulation and flocculation
The effluent from the grit chamber will proceed to the coagulation tank.
Coagulants such as Alum, ferric chloride, limewater, ferric sulfate, and ferrous sulfate,
help to destabilize the dispersion of the colloids and decrease the turbidity of water.
Through flash mixing, the following parameters are shown below.
Table 1..1: Design for Coagulation Tank
Tank Geometry Cylindrical
Height (with freeboard) 0.8017 m
Tank Diameter 0.2806 m
Impeller Diameter (radial) 0.3 m
Detention Time 30 sec
Rotational Speed 81.8766 rpm
Power Requirement (ŋ= 80%) 43.8738 W
The rapid mixing in coagulation process is use for equal distribution of coagulant
throughout the water with a detention time of 30 seconds. After coagulation tank, the
effluent goes to the flocculation tank. In the flocculation process, the tank is divided into
three compartments which will have different impeller velocities to enhance the
efficiency of flocculation. The table below shows the desired design for flocculation tank.
Table 1.2: Design for Flocculation Tank
Tank Geometry Rectangular
Height (with freeboard) 2.52 m
Tank Length .3929 m
Tank Width .0932 m
Impeller Diameter (axial) 1.4 m
Detention Time 30 sec
Rotational Speed 3.0995 rpm
(per compartment) 2.4764 rpm
1.7619 rpm
Power Requirement (ŋ= 80%) .2292 W
.1169 W
.0421 W
Computations:
Coagulation Tank:
Given: Wineries generate 100 m3 of wastewater per day
Q= 100 m3 / day
t=30s
Temperature= 200C
viscosity=1011.4996×10-6 Pa.s
ρ= 997.2113 kg/ m3
G= 1000/sec
Solution:
V=Qt= (100m3/day)(30/86400)day
V= 0.0347m3
P=(1000/s)2 (1011.4996×10-6Pa.s)(0.0347m3)
0.8
P= 43.8738 W (power input)
P=(1000/s)2 (1011.4996×10-6Pa.s)(0.0347m3)
P=35.0990 W (motor power)
Let H/T =2
V= (π /4) (T2)(H)
0.0347 m3 = (π /4) (T2)(2T)
T= 0.2806 m
H=2T=2 (0.2806 m)
H= 0.5612 m
B=1/3 (H)
B= 1/3 (0.5612 m)
B= 0.1871 m
H= 0.7 HT
HT = 0.8017 m
0.3 0.4 0.6 RADIAL
D/T 1.0691 1.4255 2.1383 0.14-0.5
H/D 1.8707 1.4030 0.9353 2-4
H/T 2 2 2 0.28-2
B/D 0.6237 0.4678 0.3118 0.7-1.6
D=0.3 m
Power #= Power / ( ρ)(N)3 (D)5
5.7=35.0990 W / (997.2113kg/m 3) ( N3) (0.3m)5
N= 1.3646 rps
N= 81.8766 rpm
Flocculation Tank:
Given:
Q= 100m3 / day
t=30s
H=3.6 m
L:W ; 4:1
G= 35, 25, 15/s
Solution:
*Two flocculation basin for redundancy max Q is twice the average Q.
Qmax= 100/2 =50 m3 /d
V=50((30s)
V= 0.4167m3
V per tank= 0.4167/3
V per tank= 0.1389m3
V=A×H ;
0.1389 m3= A (3.6m)
A= .0386m2
L=4W
0.0386 =4W × W
.0386= 4W2
W= .0982m
L=.3929m
V = (π /4) (T2)
T= .2217m
B=1/3 (3.6)
B=1.2m
0.8 1.4 2.0 AXIAL
D/T 3.6085 6.3148 9.0212 0.17-0.4
H/D 4.5 2.57 1.8 2-4
H/T 16.2382 16.2382 16.2382 0.34-1.6
B/D 1.5 0.8571 0.6 0.7-1.6
D= 1.4
@ G=35, 25, 15/ s
P= G2 (viscosity) (volume per tank) / 80% efficiency
P= (35)2 (1011.4996×10-6) (.1389) / 0.8 = .2292 W
P= (25)2 (1011.4996×10-6) (.1389) / 0.8 = .1169W
P= (15)2 (1011.4996×10-6) (.1389) / 0.8 = .0421W
Power #= Power/ density (speed rotation) (impeller diameter)
0.31 = .2292 / 997.2113(N3) (1.4)5; N=.0517rps = 3.0995rpm
0.31= .1169 / 997.2113 (N3) (1.4)5; N= 0.0413rps = 2.4764rpm
0.31= .0421 / 997.2113 (N3) (1.4)5; N= .0294rps = 1.7619rpm
COAGULATION TANK DESIGN:
P
H
D B
FLOCCULATION TANK DESIGN:
P1
P2
P3
REFERENCES
Day et al. (2011). Winery Wastewater Management and Recycling (Operational
Guidelines). Grape and Wine Research and Development Corporation, Adelaide, SA
C.S. MAHAJAN, S.D. NARKHEDE, V.A. KHATIK, R.N. JADHAV AND S.B. ATTARDE.
(2010). A REVIEW: Wastewater treatment at winery industry. Asian Journal of
Environmental Science (December, 2009 to May, 2010) Vol. 4 No. 2: 258-265.
Tuset, S. (2020). Wine industry wastewater treatment systems. Retrieved 11 February
2020, from https://blog-en.concorchem.com/wine-industry-wastewater-treatment/
