Page 473 - Fundamentals of Water Treatment Unit Processes : Physical, Chemical, and Biological

428 Fundamentals of Water Treatment Unit Processes: Physical, Chemical, and Biological

TABLE 14.1
Properties of Diatomaceous Earth Filtration Media
Manufacturer a
Celite=World Minerals Inc. Eagle-Picher Minerals, Inc.
Particle Pores Perm b Part. Perm c
c
b
b
Grade Color b d(50) (mm) d(50) (mm) (Darcys) d Grade Color d(50) (mm) (Darcys) d
Filter Cel Grey-natural 7.5 1.5 0.07
Celite 577 Pink-C 12 2.5 0.16
Celite 505 Pink-C 2.0 0.06 Celatom FP-2 Buff=pink 12.8 0.100
Standard Super-Cel Pink-C 14 3.5 0.25 Celatom FP-4 Buff=pink -FC 15 0.300
Celite 512 Pink-C 16 5.0 0.50 Celatom FW-6 Light pink-FC 18 0.480
Hyflo Super-Cel White-FC 22 7.0 1.10 Celatom FW-12 Light pink-FC 24 0.800
Celite 501 White-FC 24 9 1.3 Celatom FW-18 White-FC 31 1.70
Celite 503 White-FC 23 10 1.9 Celatom FW-20 White-FC 33 2.10
Celite 535 White-FC 34 13 3.0 Celatom FW-50 White-FC 42 3.50
Celite 545 White-FC 36 17 4.0 Celatom FW-60 White-FC 48 5.0
Celite 550 White-FC 7.4
Celatom FW-80 White-FC 77 10.0
Celite 560 White-FC 106 22 30
a
All grades are registered trademarks of the companies indicated.
b
Particle d(50), pore d(50), and perm (permeability); data set from http:==www.diatomite.com, Nov. 2002.
c
Particle d(50), and perm (permeability) from Eagle-Picher Minerals, Inc., Celatom Technical Data Sheet (2003); see www.epminerals.com=celatomgrade.
html for current data on grades and properties.
d 2
A permeability of 1 darcy permits a flow of 1 mL of liquid of 1 centipoise viscosity through 1 cm of porous solid 1 cm thick under a differential pressure of
2
1 atm in 1 s (Bell, 1962, p. 1247). To convert to ‘‘intrinsic permeability,’’ ‘‘k,’’ multiply the value given in darcys by 0.987 10 12 m .
t
t
t
Other properties: SG(DE) 2.3 (McIndoe, 1983, p. 6). Dry bulk densities for each grade are: Filter-Cel ¼ 112; C-577 ¼ 128; C-505 ¼ 128; Standard
t
t
t
t
t
t
t
Super-Cel ¼ 128; C-512 ¼ 128; Hyflo Super-Cel ¼ 144; C-501 ¼ 152; C-503 ¼ 152; C-535 ¼ 192; C-545 ¼ 192;
3
t
t
C-550 ¼ 288; C-560 ¼ 313 kg=m (from ‘‘Johns-Manville Celite filter aids for maximum clarity at lowest cost’’). Specific surface areas
t
t
t
t
2
2
2
of representative Celite grades are: Filter-Cel 30,000 cm =g; Standard Super-Cel 20,000 cm =g; Hyflo Super-Cel 10,000 cm =g; Celite-
t
2
t
t
2
2
2
503 8,000 cm =g; Celite-535 7,000 cm =g; Celite-545 6,000 cm =g (from Cummins, 1942, p. 405); divide by 10 to obtain m =kg.
40 Giardia lamblia, and Cryptospordium parvum.
C-545
Black Hawk, Colorado is a 4.3 mL=day (1.15 mgd)
35 C-535
DE plant (Rogers, 1997) that treats water from a low
C-503
30 C-501 turbidity mountain stream, which addresses this
issue; the plant produces effluent turbidities gener-
DE particle size (μm) 25 Hyflow Super-Cel 14.1.4 HISTORY
ally <0.5 NTU with raw water generally <1 NTU.
C-512
20
15
10 Diatomite filtration was used as early as 1893 to clarify beet
sugar solutions, and then from about 1900 by the brewery
Filter-Cel industry to clarify beer (Cummins, 1975, pp. 1–15). An article
5
by Cummins (1942) describes DE filtration with reference to
Standard Super-Cel
0 applications in the sugar industry; there is no reference
0 20 40 60 80 100 to applications involving water treatment. Since DE is an
Percent finer than inert substance, there is no taste or color imparted by its
use for filtration.
FIGURE 14.6 Particle size distribution of several Celitee grades.
(From Johns-Manville, Maximum Clarity at Lowest Cost, Celite 14.1.4.1 1940s’ Military Use of DE Filtration
Filter Aids, FA-84A, 5-81, no date but estimated at 1981
from designation 5-81; Table 1, Celite=World Minerals Inc. With During World War II, the U.S. Army was seeking a more
permission.) suitable technology for the field production of drinking water