Civil Engineering Reference
In-Depth Information
TABLE 23-11. Effect of Coagulation Mechanism on Alum Sludge Properties
Coagulation Conditions
Specific
Resistance,
r
m/kg
10
11
Influent
Turbidity,
NTU
Ultimate Thickened
Solids Conc.,
Percent
Vacuum Dewatered
Solids Conc.,
Percent
Coagulant
Dose, mg / L
Coagulation, pH
Mechanism
40
10
6.2
Adsorption-charge neutralization
6.0
55
42
40
15
6.3
Adsorption-charge neutralization
5.5
60
22
7
40
6.5
Mixed
1.0
95
15
7
75
7.1
Enmeshment
1.0
150
11
7
75
8.1
Enmeshment
0.5
310
9
Source:
Reference 21. (Reprinted from
Journal AWWA,
Vol. 79, No. 6 (June 1987), by permission. Copyright
1987, American Water Works Association.)
