I293
WATER T R E A T M E N T
freed from air by pumping, gave a specific gravity of 5.335 but a powdered portion gave j.60. There t h u s appears no evidence of the existence of a second solid form of cadmium iodide, even at higher temperatures.
Summary
.
By crystallizing cadmium iodide froni solutions in hydriodic acid, products of low specific gravity, in all respects siiiiilar to the so-called “P-cadmium iodide,” were obtained. On analysis these were found to contain hydriodic acid and water in addition to cadmium iodide. 2. A critical examination of Clarke and Kebler’s work leads to the conclusion that there is no valid evidence of the existence of a form of cadmium iodide of lower specific gravity than 5.6. I,
~
SOME REACTIONS DURING WATER TREATMENT.’ BY
EDWARD BARTO\\‘
A I D J . bf. Received J u l y 8, 1907
LIKDLREN.
T h e necessity for a treatment to improve the University of Illinois Water Supply is shown by a variety of unsatisfactory features viz . turbidity forming on exposure to t h e air ; sediment varying in color from black to red according a s the amount of oxidation of the iron salts varies ; trouble from crenothrix in the mains ; soft scale, clogging the feed pipes of boilers aiid trouble in dairying and photography. T h e Champaign and Urbana city water which is drawn froin the same geological forniation, has the same drawbacks and also causes incrustation i n ten-kettles and the clogging of water backs in ranges and furnaces. I n attempting to improve the water by removing the carbonates of calcium and magnesium, the aniounts removed did not correspond tu our calculations. Analysis of the water had been made gravimetrically aiid also by the briefer methods suggested by the American Public Health Association. T h e results of the former analysis are a s follows. ASALYSIS
OF
Ions
Potassiiin:, K Sodiurn, Na .41ntnoiiiuni, NH, Xlagnesiuni, Mg, Calcium, Ca I r o n , Fe Aluminium, A1 Nitrate, NO, Chlorine, C1 Sulphate, SO, Silica, SiO,
WATERFROM URIVERSITYO F ILLINOIS WATHRSUPPLY. Parts per Million
2.6 29.0
2.3 34.9 70. I 1.0
1.3
.7 3.5 2.3 1S.g
Hypothetical Combinations
Potassium nitrate, Potassium chloride, Sodium chloride, Sodium sulphate, Sodium carbonate, Ammonium carbonate, Magnesium carbonate, Calcium carbonate, Iron carbonate, Alumina, Silica, Total,
Pnrts Per 41il lion
IiSO, I. I KCI 2.9 NaCl 3.5 Ka,SO, 3.6 Na,COs 60.j ( NH4),C0, 6. I MgCO, 121.2 CaCO, 175.2 FeCO, 2. I Al,O$ 2.5 SiO, 18.9
G rai 11c Per U. S Gallon
0.06 0.1’7
0.20
0.21
3.5’ 0.36 7.07 IO 2 2
0.12
0.15 I . 10
--
--
397.6
23.1s
Read a t t h e Toronto Meeting of t h e American Chemical Society.
I294
EDWARD BARTOW A N D J . 31. L I N D G R E N
Froin the results of these analyses we calculated the amount of lime necessary to react with the acid carbondtes of calcium and magnesium, and treated the water accordingly. A n analysis of the water after treatment showed that the reduction in alkalinity was less than expected. T h e use of varying amounts of dry water-slacked lime made apparently no change in the speed of the reaction nor in the reduction of the alkalinity. On the supposition that the reaction would be more rapid and more complete if lime water was used, varying amounts were tried but without satisfactory resuits. With a view to explaining the difficulty and determining just what reactions occur on each addition of lime, (calciuni hydroxide) a series of tests was planned. A liter of water was measured into each of 19 twoliter glass stoppered bottles. Varying portions of a saturated solution of lime water, I O cc. of which were equivaleiit to 23 milligrams of calcium carbonate were added to each of the 19 samples. T h e varying amounts of lime water used, with the equivalent in terms of calcium carbonate, are shown in Table I . Since previous experiments had shown that the reaction was practically complete at the end of six hours, the precipitate formed in each bottle was filtered off at the end of that time. In the filtrate the alkalinity to phenolphthalein and methyl orange and the content of magnesium and calcium were determined. T h e results of these deterniiiiations are shown in Table I and a diagrammatic representation is given on Plate I . T.4BLE TREATMENT OF
THE UNIVERSITY OF
I
ILLISOISWATERSUPPLY WITH L I N E
A1kallllit? to Alkalinity to Methyl Calcium Mamesitiiii Pheuolohthaleiii Orange CaO C a C 0 3 as MgCO, Cor. for in z j o Cor. for MglPIO; cor,f o r , Lime Lime Used roluiiie Filtrate cc. w l u n l e f r o m y o l u l n e Water Milligrams Parts per Partspcr Parts per Parts per > f i l i i zoocc. p a r t s p c r million million grams million Milligrs. million so. cc. I
Amount of
'!!:;::
I
O
0
0
0
2
IO
23
1I.j
11.7
46 92 138 I 61 184
10.5
10.7
3 4
5 6 7
s 9
20
40 60 70 80 IO0 I20
IO II
140
I2
I70
13 14
200
r j 16 17 IS 19
160 130 220
240 260 2SO
300
230
276 32 2 365 591 414
460 506 552
598 644 690
16.8 1S.9 12.6 12.6 18.9 31.5 42.0
35.3 47.9
52.5
60.9
65.1 66.3 65.1 58.S
58.8 52.5 50.4 48.3
17.5 20. I
13.5 13.6 20,s
76.2 78.2 78. I 71.7 72.9 63.3 64.5 62.8
$?.j
376.0 354.9 312.9 270.9 256.2 241.5 222.6 212.1
203.7 200.5
193.2 184.8 163.5 138.6 111.3 9S.j 98.7 94.5
387.5 381,s 361.9 325.4 2S7.1 274.1 260.8 244.9 237.6 232.2 232.6 226.0 218.1 196.6 169.1 138.0 124.4 126.3 122.8
:pa'
26. j 27.5 25.8 IS.0 12.9 10.8 9.0
7. I
6.6 5.3 5.7 5.7 5.7 5.5 5.1
4.5 4.4 '7.0 6.3
1SS.7 19S.6 187.5 133.9 97.4 82.3
69 0 54.9 52.6 43.2 46.2 46.7 48.4
46.7 43.9 39.7 3x9 63.9 jS.1
33.1 33.2 333 36.0 40.5 39 4
37.3 34.2 34.5 32.7 31.9 30.4 27.8 23.4 5.3 5.2 7.7 50
4.S
124.4 126.0 IIS.0
131.6 126.0 126.0 121.6 113.6 116.0
112.0 110.8 105.2
99.6 84.4 19.2
19.2 27.6 19.2 19.2
WATER TREATMENT
1295
PLATE 1.-Water Containing Bicarbonates of Alkalies a n d Alkaline E a r t h s Treated With Lime.
T h e reactions with a water of this class apparently take place in four stages. During the first stage, the reaction is between the calcium hydroxide and the free carbon dioxide, during which the alkalinity to phenolphthalein remains negative, the alkalinity to methyl orange and the calcium content increases, and the magnesium content is unaffected. During the second stage, the calcium hydroxide reacts with the calcium acid carbonate. T h e calciunl content and the alkalinity to methyl orange decrease at equal rates ; the magnesium content and the alkalinity to phenolphthalein are practically constant. During the third stage, the calcium hydroxide reacts with the sodium bicarbonate, the alkalinity to methyl orange is unchanged, the alkalinity to phenolphthalein is increased, while the content of calcium and magnesium are constant. During the fourth stage, the calcium hydroxide reacts with the magnesium bicarbonate with the formation of magnesium hydroxide and calcium carbonate accompanied by a decrease of the alkalinity to both methyl orange and phenolphthalein and decrease in the content of magnesium. A fifth stage might be noted when an excess of calcium hydroxide has been added. T h e calcium, and the alkalinity to both methyl orange and phenolphthalein increase. T h e formulas illustrating the reactions during the various stages are as follows :
'Phis is showii to coiitaiii a iarger proportion of sodium bicarbonaLe, but smaller amounts of the bicarbonates of calcium and rnagnesium. T h e other constituents are about t h e same as iii t h e Cniversity of Illinois water supply. Portioiis of this water were treated with lime water as in the previous experiment. T h e results of the treatment are shown iii Table 2 and represented diagranimatically 011 Plate 2 . I t will be noted that the nietli? 1 orange alkalinity cnrve COI respondi:ig t o the reaction betn-eeii calciuiii hydroxide and calciuiii bicarboilate is shorter. Tiir line cleiic,tiiig the reactioii between calciuin hydroxide and so\iiuni bicarbonate is lotiger, while the ciirve where niagnesiuiii is reacted upon is shorter, it1dicatii.g tlie truth of our hypothesis as to tlie order of reaction. Pmcip pita tion wiih Sodi2c in Haidmxia'e.-A series of tests 11 si ii g sod i 11 rii hydroxide instead of calcium hydroside was next carried 011. The University water supply was treated. T h e analytical results are shown in Table 3 and a diagrammatic representation is seen 011 Plate 3. Comparing Plates I and 3 it will be rioted that the stages of the re-
'297
W A T E R TREATMENT
actions with sodium hydroxide correspond to those with lime. T h e first stage, indicated by the increase in alkalinity to methyl orange and the very slight decrease in the amount of calcium, shows reaction between the sodium hydroxide aiid free carbon dioxide. T h e second stage, indicated by the decrease i n the calcium content and of the alkalinity to methyl orange, shows the reaction taking place between the sodium hydroxide and calcium bicarbonate. I t will be noted that the calcium bicarbonate is removed with one-half the equivalent of sodium hydroxide. T h e third stage, indicated by a constant amount of calcium and magiiesiuin implies a reactioti between the sodium bicarbonate arid sodium hydroxide. T h e fourth stage, indicated by a reduction of magnesium shows a reaction between the magnesium bicarbonate and sodium hydroxide. Here it is noted that the magnesium decreases much more slowly than when calcium hydroxide is used, and does not reach a minimum until a larger amount of sodium hydroxide has been added. T h e reactions during the different stages may he writtcn as follows : I. aSaOH aCO, = 2NaHC0,. a. (i4)2xaOH CaCO,H,CO, = Sa,CO, CaCO,. a . (B)Sn,CO, CaCO,H,CO, I-= CaCO, aNaHCO, 2H,O. j. NaOH f NaHCO, = Na,CO,, H,O. 4. 4NaOH -- hlgCO,H,CO, = Mg ( O H ) , 2Na,CO, 2H,O.
+
+ +
+
+
+
TABLE
+
+
2.
TREATMEXT OF WATER FRO31 DEEP IVVELL O F ILLISOIS HOTEI, CO., ~ L O O h l l S G T O S ILLINOIS, , \VITH
3-0
Lime U'ater c,,bic centimetres
rZmOutlt of Lime 1:stci RIilligrams as C a C 0 2 .
I
0
0
0
0
5
2j
3 4 5 6
IO
44 88 132 I 76 264 308 352 396 440 52s 572 616 660 704 748 792
26 39 56
20
7 8
30 35 40
9
45
IO
50 60 65 70 75 80 85 90
I1 I2
13
I4 I5 16 17 IS
IO0
sso
M~~P~o,~>~~T$
Sz:",fp,'
2
15
LIME
Alkalinity to Calcium Magnesium Methyl Orange CaCO Phenolphthalein in Cor. fo", Cor, for Fi:trate Filtrate volume 200 cc. rolume from 2oo volume parts per parts per parts per parts per M i 11 i - Parts per cc. parts per million million million million g r a m ? million milligrs. million Alkalinity to
3s 52
48 69 90
78 '03
122
141
I18
139 129 135 148 I33 161 194
108 109 118 104
124 147 166
178 242
52
222
243 3s;
423 37s 343 309 287 26 I 256 254 245 239 192 I79 162 162 I 78 '94 202
267
13.2
118.1
27.5
5.5
49.9
24.4
93.8
3.4
33.9
20.1
85.2
3.0
30.9
18.8
82.4
3.0
31.9
14.9
2.2
24.2
6.2
67.2 29.1
--
--
2.4
14.5
7.9
92.
1.8
104.2
9.0
298
I
EDWARD B A R T O R ’ A S D J . 11. L I S D G R E N
FLXTE 11.-Water Containing Bicar1)oiiates of Alkalies and Alkaline Earths Treated With Lime. TABLE 3
TREATMENT OF THE USIVERSITY OF ILLINOIS WATER SUPPLY WITH SODILM
Amount of Sodium Sodium Hydroxide Hydroxide Solution rsed milligrams KO cc.
Alkalinity Alkalinity to Phenol- to hfethyl phthalein Orange parts per parts per million million
I
0
0
0
2
I
li 34
0
3
4 5
6 7 8 9 10 11
I2
13 I4 15
16 17 8 9 0
I
2
4 6 7 8 IO 12
14 16 17
IS 20 22
24 26 28
30 32 34
6’3 102
119 136 170
204 238 272
299 316 340 374 40s
442 476 5x0 554 575
HYDROXIDE.
22
26 50 72 90 139 I47 I 9‘3 248 270
266 307 334 369 393 417 463 518 549
386 405 403 3SY 36s 406 426 465
Magnesium Calcinm 1srgco3 CaCO,{ Corrected Cor. for for CaO ill ,.olume ~ r g ? P ? O ~ volutne parts per 2jo CC. parts per fronl 250 CC. milligrams millioti milligrs. million
26.5 26.0
189.1 18j.5
22. I
15j.S
12.8 7.2
91.3 50.4
39.7 39.8 38.3 3s. 1 37.4
5.5
384
36.1
‘09.4
5.4 4.5
38.4 32.0
2S.5 25.3
86.2 76.5
3.0
21.2
15s
47.5
2.9
20.5
6.S
20.4
2. I
Ij.O
3.2
9.7
5.5
2.2
6.6
120.j
120.5 118.8
IIS.5 113.2
511
555 589 609 622 650 673 702
72s 780
813
sjj
893
.8
WATER TKEATMENT
..
.
.
.
129
3
.
In order to try the effect of treatment of a water containing no sodium bicarbonate, the water from a shallow well in Champaign, Illinois, was chosen for experiment.
Analysis slio~redthe follo~riiigininernl cimteiit : .IS.A.I,\~,ilS 0 1 ;
s:~.\I,l,o\v
1 s'J(\i!lIl!, >:,l N;!mv,hiii!i!,
IkIg
c"ii L , i ti111, C.1 Oxiilzh of I r o n anc! S i t 1 ate, S(1.; Clilciri(ie, C ! S U l ~ ~ l l ~ I Lso, ',
AIiinii~i~.,
Silirx, Si( 1:asc..
&;,o
ILibes, Lviiil silic..!
____
.
.;.
('.IT - -. .
l'otiil Jiiiicral M a t t e r ,
-___
.jijc.
3 2 .64
Portions of this water were treatrtl iritli lime as i i i the preceding e x pLriineiits. The re5:ults of tlic analysis of the wntcr a f t u trecttiiieiit iiicliidiii,q deti.riniriatioii of iiicru~taiit.; according t o method of tlie .-li!i. 1~~1). Health .'iss'n, are sho\rii i i i Table 4 aiid :Ldingrainiiiatic re1)reseiitatioii is sliown on Plate 4. ?'he reactions iii this c a w are also i:i stages. T h e first and second correspond to tlie 5:it and secoiiii stages of the preceding esperirrierits. 1Iurii:g the L1iii-d stage 110 change is e~;itlt-ilt. Further d a t a is iiecessary for explaiiatiori. T h e fourth stag-e siio\i.s a reiiiov:il of the niag:iesiuni liicarl)oii~~te, with n correspoiitiiiig decrense oi aiknlinity to methyl orange a n d ~~lieiiolphtlialeiri,The firial stage \There calci u i i i hydroxitle was added i i i c s c e s s , slio\rs increase of the c:i!ciuiii
,.I R K A T X E 4 T 0 F
'r;lI;I,€: 4
lv:\TI,: :
