TII1; TOURNAL OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
18
In conclusion i t should be stated that while the above results show interesting differences in the effect
Jan., 1913
in tending to change or modify the results obtained in the above described research. I ~ s n N r os a I N D U S T X ~ LRBSZ~*PCIL
WASIIINDTON. D. C.
EXAMPLES OF THE EFFICIENCY OF CALCIUM HYPOCHLORITE IN TREATIRG TURBID WATERS' BY E o w a n ~BARTOW
We have recently had the privilege of noting the action of calcium hypochlorite in the purification of turbid waters in some of the plants in the North Central Unitcd States. Results from two of the plants illustrate in different ways the efficiency of the chemical. In one case the chemical was added at the end of a long sedimentation period, during which some reduction had taken place. The chemical reduced the number of bacteria very materially, and filtration was able to effect a still greater reduction. In the other case, owing to failure to receive a shipment 01 the chemical, nonecould be used for six days. There was a t once a decided increase in the number of bacteria, followed by a decrease when the chemical w-as again applied even though the water, as shown by the turbidity. was the worst for years. The results obtained in the first case are skown in Table 1. The colony counts were obtained on gelatine at z o o C The water treated was from the Mississippi River. The number of colonies in the raw water i s shown in the first column. The number of colonies in the efRuent from a settling basin of twenty-four hours' capacity is shown in the second column. As a rule, the number was reduced. The average reduction was 6s per cent. The number of colonies in the water after treatment with calcium hypochlorite and approximately one and one-half hours additional sedimentation is shown in the third column. The number of colonies was further reduced 97.6 per cent. or 99.1 per cent. from the number in the raw water. The number of colonies obtained from the water after filtration is shown in the fourth column. There was a further reduction of 82 per cent. or a total bacterial removal of 99.8 per cent. FIG.I I - B i r u w m - ~
APICPI
1 2 M o ~ n t s Ex~osunr '
TASLEI-COLONIBS
I. Fluxed Bemudez Amhilt: Portion of surface glossy and dark brown, showiw an enclosed w t c h u t about 1 inch diameter, dull and light lxown.
2. Gilsonite Oil Asphalt: Surface biight but rough m d granular. 3. Oil Asphalt:
Smooth, bright, ~IOBSY surface.
4. California Pelmleum Residuum: Smooth surface,glossy and sticky. 5. ReGned Coal Tar: surface drawn and cracked in plnces. Surface black; streak brown. 6. Refined Water Gas Tar: Surface wrinkled and showing large brown Datch of about I/* i n c h diameter. Generrl emstalliue aooearance. .. 7. Refined Mixed Tu: Surface drawn and cracked. Friable black film: streak brown.
of exposure upon characteristic types of bituminous materials, they should not, for practical purposes, be too positively or rigidly interpreted. When these materials are exposed t o a n actual service test in connection with the oarticular Durnose for which thev are t o be used, other factors undoubtedly play a part I
.
Geowwo
Date
G e u n a ~AT 20' c. IN 48 After After sedimenhwo-
Raw
act. 17, 1910 ... . . ... . .
~ 21910 3 .......... . oec.18, 1910 ... Feb.6, 1911 ........... M a y 4 , 1911 . . . . . .. AU.. 15, 1911 .. sept. 12, 1911. a c t . 18, 1911 ... .... ]an. 25. 1912_ . _ ..... . M-. 29. 1912 ....... . . . ~
ON
28,non 2.300 5.600 46,500 26.500
..___.. .... ....... . 13,nnn .... . . .. 19.ann . . . 5.400
tation 9,700 2.200 1,200
chlorite 9s 47 70
11,000 3,300
690
280 s.000 2,800
so
370
HOW9
Filter cfsucnt 75 17 31
.
44 40
8 17 72
37 170
500
17,nno
67.000
22,000
260 -
__
A W W ~ , 21,380
7.448
183
33
- _ _
12
4s
in
Tests for gas forming bacteria were made on the same samples of water and the results correspond very well with the reduction in the number of bacteria. 1 Paper presented at the Eishth International Congress chemisUy. N~~ york. September, 1912.
Of
Applied
T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
Jan., 1913
The results are shown in Table 11. The treatment with calcium hypochlorite has entirely eliminated the gas formers from the 0.1 cc. samples, from 86 per cent. of the I cc. samples and from 50 per cent. of the 19 cc. samples. The filtration has improved conditions b y increasing the removal t o 91 per cent. of the I cc. samples and to 73 per cent. of the I O cc. samples. From these observations we q a y conclude that the calcium hypochlorite acts most efficiently in the removal of free bacteria, t h a t the filters still further reduce the numbers by removing aggregates of bacteria which are surrounded b y or enclosed in sediment. TABLEII
FORMATION O F GAS
DEXTROSEBROTHAT 37'/a0 C. 10 cc. 11411 cc. 20+ 3e0 . 1 cc. 18+ After sedimentation.. . . . . . . . . 10 cc. 10+ 01 cc. 18+ 20 . 1 cc. 14+ 7After hypochlorite ............ 10 cc. 6461 cc. 3 c 18o+ 220 . 1 cc. Filter effluent 10 cc. 3 f 81 cc. Zf 20o+ 220 . 1 cc. IN
R a w . . ......................
................
I n the second example of the efficiency of calcium hypochlorite none of the chemical was used for six days, owing to the failure t o receive a shipment. I n the treatment plant lime and iron sulfate were used TABLE111 CALCIUM HYPOCHLORITE^ Bacteria Gas formation P 7 Partsper million Filter TurbidFilter e0luent chlorine Date, 1912 ity Raw effluent Raw 0.51 Mar. 13 . . . . . . . . . . . 25 1600 3 + 0.51 Mar. 14 . . . . . . . . . . . 25 3900 10 0.55 Mar. 15 . . . . . . . . . . . 210 90000 200 0.45 Mar. 16 ........... 230 400000 275 0.53 Mar. 17 ........... 500 27000 50 0.48 Mar. 18 . . . . . . . . . . . 800 125000 20 Average six days preceding period without hypo- 298 107917 93 loo%+ None 0.50 OPERATING RESULTSWITH
i
AND WITHOUT
+ + + + +
I
li
-
+
chlorite.. . . . . . . . j Mar.20 ............ 300 112000 8400 Mar. 21 . . . . . . . . . . . 400 110000 7500 Mar. 22 60000 2000 150 Mar. 23 . . . . . . . . . . . 825 44000 1700 . Mar. 24 . . . . . . . . . . . 400 56000 2000 Mar. 25 . . . . . . . . . . . 320 20000 3000 Average during period without hypo- 399 67000 4100 All+ chlorite. . . . . . . . . Mar. 26 . . . . . . . . . . . 200 20000 30 Mar. 27 ........... 220 160000 120 Mar. 28 . . . . . . . . . . . 450 75000 80 Mar. 29 . . . . . . . . . . . 4000 300000 120 Mar. 30 ........... 4000 300000 550 Mar. 31 . . . . . . . . . . . 350 250000 200 Average six d a y s ) following period 11537 184170 183 All+ without hypochlorite. ........ 1 Analyses by H. M. Ely, Danville, Illinois.
...........
-
+ + + + + +
+ + + + + +
+ .
+ + + +
83.3%
-
00 00 00
+
None
00 00 00
+
None 0.48 0.57 0.55 0.60 0.47 0.47 0.52
as coagulants. The amounts used were varied in such a way as t o furnish a clear water. The calcium hypochlorite was used as a n adjunct. There is approximately one hour's sedimentation after the lime and iron sulfate are added. The calcium hypochlorite
I9
is added not more than five minutes before the water reaches the filters. The water during the three six-day periods, before, during and after the failure t o receive the calcium hypochlorite, was especially bad (see Table 111) as was shown by the high turbidity and the large number of colonies that developed from the raw water during forty-eight hours on gelatine a t z o o C. After the first two days of the first period the number of bacteria in the raw water were never lower than 2 0 . 0 0 0 . Only once was the turbidity below z o o , reaching a maximum of 4,000 during the latter part of the period. As shown in Table 111, the bacterial removal during the six days preceding the period without calcium hypochlorite was 99.9 per cent. and gas formers were entirely absent in the general effluent from the filters. During the period without calcium hypochlorite the bacterial removal was only 93.9 per cent. and gas formers were present in the effluent with the exception of the test made on the first day without calcium hypochlorite. During the six days following the period without calcium hypochlorite the bacterial removal was again 99.9 per cent. and gas formers were absent in all of the samples tested. These results show very decidedly the advisability of using calcium hypochlorite under conditions similar to those existing in the plants in question. UNIVERSITY O F ILLINOIS
URBANA
COMPOSITION OF THE SALINES OF THE UNITED STATES' 111. Brines from the Ocean and Salt Lakes with analyses by W. H. Ross, A. R . MERZ AND B y J. W. TURRENTINE, R . F. GARDNER Received October 9, 1912
I n the search for deposits of potassium salts in the United States two sorts of deposits have been considered, namely, continental and marine. The former, continental, are those which have resulted from the desiccation of inland seas or lakes; while the latter, marine, are the product of the evaporation of arms of the ocean which have become isolated from the main body of the ocean through the formation of bar reefs. The latter method would be analogous t o t h a t generally proposed t o account for the formation of the Stassfurt deposits. Among the saline deposits in the United States, theoretically, are deposits of both kinds. These have been (or are being) subjected to scrutiny t o discover if there may be potassium salts therein, as well as sodium. The search for continental deposits has confined itself t o those regions which i t is known were once covered by inland seas. This statement connotes the fact that such lakes were of sufficiently recent occurrence for their marks to have remained extant on the face of the country where they existed. It is not sufficient t h a t those areas were submerged by lakes, but for deposits of salt t o have formed, i t is necessary that the lakes shall have disappeared through desiccation rather than through drainage. Continental deposits have been sought in the undrained basins of the western part of the United 1
Published by permission of the Secretary of Agriculture.
