Page 880 - Fundamentals of Water Treatment Unit Processes : Physical, Chemical, and Biological

Appendix F: Alum Data and Conversions 835

TABLE F.1
Data for Dry Aluminum Sulfate a,b
Property Condition Data
Formula 14 waters of hydration Al 2 (SO 4 ) 3 14H 2 O
Common name Name for Al 2 (SO 4 ) 3 14H 2 O dry alum
Molecular weight Approximate-for commercial 594
17
Percent Al 2 O 3
Solubility g=L 1050 b
pH pH versus percent % pH
Al 2 (SO 4 ) 3 14H 2 O by weight 1 3.5 a
10 3.2
20 2.9
30 2.7
40 2.6
50 2.4
Screen size a Standard ground alum E-Mesh size % Retained
8 2
60 78
100 7
Powdered alum 100 3
Ground Powdered
Bulk density-ground lb=ft 3 63–71 b 38–45 a
g=L 1010–1138 609–722
kg=m 3 1010–1138 609–7228
Angle of repose a 438
a
Rate of solution 10 g added to 1000 mL water at Time (s) % dissolved
208C, high-speed stirrer 15 92
30 98
45 100

a
General Chemical (1995).
b
Harringer (1984) states solubility is 105 parts in 100 parts water.

Hopper for alum storage/feed
Pallete for alum sacks
Granular alum
Metered alum feed, i.e., M(alum)
Q(plant)

Belt for metered alum feed Q(alum feed)
Q(alum feed)
Dissolution reactor P C(alum feed)
V(dissolution reactor)
Rapid mix
Metering pump
C(alum-in-plant-flow)
Q(plant)

FIGURE F.2 Metered feed of granular alum—schematic drawing.