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T h e yield of pulp was increased from 43. j per cent to 4 7 . I per cent of t h e weight of wood used or a n increase in t h e o u t p u t of pulp from t h e same q u a n t i t y of wood using t h e same q u a n t i t y of cooking chemical and fuel of over 8 per cent while t h e quality of t h e pulp was improved a n d t h e bleach copsumption lowered from 13 t o 11 lbs. of bleaching powder per I O O lbs. of pulp. I n seeking a n explanation of this phenomenon, it was necessary t o s t u d y t h e conditions in t h e digester during t h e cook. T h e consumption of caustic soda as shown in Fig. 111 was very rapid during t h e first hour a n d a half b u t constantly decreased in r a t e a n d after t h e second hour h a d reached a point where only one-fourth of t h e original caustic was present as such. T h e condensation of s t e a m increased very rapidly during t h e first hour d u e t o t h e fact t h a t t h e contents
caustic soda solution has penetrated t h e chips a t nearly t h e original concentration. It is evident t h a t t h e uncooked inner portions of t h e chips are capable of adsorbing sufficient caustic soda for their reduction, b u t on t h e conversion of this material t o pulp t h e adsorptive power is so reduced t h a t t h e remaining caustic soda passes back t o t h e liquor. T h e increased volume due t o condensation also more effectually removes t h e products of reduction from t h e wood a n d decreases t h e contamination of t h e pulp therefrom. I t is evident, t h e n , t h a t while t h e power of t h e caustic soda t o reduce t h e ligno-cellulose is not diminished, t h e a t t a c k on t h e pulp is considerably decreased
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and t h e coloring of t h e pulp by t h e products of reduction is much less, thereby decreasing t h e bleach necessary t o obtain a s t a n d a r d white. While no tests on a commercial scale ha\-e yet been tried, it seems probable t h a t t h e same advantages would be gained. T h e equivalent of t h e added condensation could he obtained by injecting hot water with t h e steam supplied, by which means perfect control could be comparatirely simple. T h e only disadvantage would b e t h e increased volume of t h e black liquor t h a t ~ o u l d h a r e to be handled in t h e recovery of the soda. With multiple-effect evaporators, however. t h e excess water could be ex-aporated with very small increase in t h e fuel consumption and t h e increased production of pulp mould be attained a t extremely small cost.
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FOREST PRODVCTS
LABOR.4TORY
L f A D I S O S . \vISCOKSIN
THE RATE OF AMMONIA DISTILLATION FROM WATER By F . W. BRUCKMILLER
Received March 21, 1916
I n t h e determination of t h e ammoniacal nitrogen in waters, t h e q u a n t i t y of ammonia obtained depends upon a number of factors, principal among which are t h e volume of t h e distillate sa\-ed a n d t h e r a t e a t which t h e ammonia comes over. Regarding this m a t t e r , Wanklyn,’ t h e originator of t h e method, s a y s : “The recommendation has heen given to nesslerize only the first j o cc. of the free ammonia and to throw away the next I j o cc. Formerly, it was,our custom to nesslerize all four 50 cc. tubes for the free ammonia, but that was a useless trouble, inasmuch as the first j 0 cc. invariably contained three-fourths of the total free ammonia, The rule is, therefore, to nesslerize the first j o cc. of the distillate and then add one-third. In the instance of the albuminoid ammonia, i t is necessary to nesslerize each separate j 0 cc. of the distillate (4) and to add the amounts together in order to arrive at the total albuminoid ammonia.” 1
“Water h n a l p i s . ” 1896, 43.
J u l y , 1916
T H E JOURNAL OF INDL’STRIAL A N D ENGINEERIN G CHEMISTR Y
Mason,’ who has used t h e method extensively, says: “Usually four 50 cc. tubes will be sufficient t o carry off al! the free ammonia, but it is the author’s custom always to distil off six.”
Stocks2 says: “In distilling ordinary waters, practically the whole of the ammonia will be present in the first IOO cc., but with sewages
the whole of the ammonia may not have been obtained even after distilling 300 cc., and it is, therefore, necessary in such cases to allow the retort to cool, make up to the original volume with distilled water and continue the distillation. The albuminoid ammonia being formed by the oxidation of organic matter, is not evolved so quickly as the free ammonia, hence it may be necessary to distil several IOO cc. portions before it ceases to be evolved.” T h e “ S t a n d a r d Methods of Water Analysis” (1912 Edition) recommends t h e collection of t h r e e j o cc. portions for t h e free ammonia, a n d a t least four, pref- ’ erably five, j o cc. portions f o r albuminoid ammonia. This procedure we were using until we saw a n a d vance copy of the Revision of t h e Standard Methods a n d learned t h a t it was recommending a collection of four j o cc. Nessler t u b e s in t h e distillation of t h e free ammonia a n d five in t h e case of albuminoid ammonia. In order t o see what influence this procedure would have upon t h e results obtained, we began a statistical s t u d y of t h e quantities of ammonia collected in each tube, as well as the total a m o u n t obtained. T h e results of this s t u d y are herein contained. We have been following t h e revised procedure f o r several months, using it on all classes of water. T h e total number of waters examined was between j o o a n d 1000;t h e free ammonia varied from 0 . 0 0 2 t o 2 . o parts per million, a n d t h e albuminoid from 0 . 0 0 2 t o 3 . o p a r t s per million. -1compilation of all of t h e results, with regard t o a m o u n t a n d r a t e of ammonia distilling, were made a n d the conclusions obtained were as follows: 76 24 50 20
75 25 30 20
per per per per
~YITROGENA S FREEAMMOXIA Fourth tube averages 5 per cent of t h e total nitrogen cent of t h e waters had 100 per cent nitrogen in 3 tubes cent of t h e waters had 95 per cent nitrogen in 3 tubes cent of t h e waters had 50 t o 5.5 per cent nitrogen in 1 tube cent of t h e waters h a d 65 to 70 per cent nitrogen in 1 tube
per per per per
NITROGEN A S . ~ L B U M I K O I D AXMONIA F i f t h tube averages 5 per cent of t h e total nitrogen cent of t h e waters had 100 per cent nitrogen in 4 tubes cent of t h e waters had 95 per cent nitrogen in 4 tubes cent of the waters had S O t o 60 per cent nitrogen in 1 tube cent of t h e waters had 60 t o 7 0 per cent nitrogen in 1 tube
Those waters which h a d j per cent of t h e nitrogen in t h e last t u b e h a d a total nitrogen content of either free or albuminoid ammonia of I p a r t per million or more of nitrogen. Since ordinary waters, unless grossly polluted, contain less t h a n I p a r t per million of nitrogen as free or albuminoid ammonia, we can conclude t h a t t h e collection of a 4th t u b e in t h e free ammonia determination a n d a 5th in t h e albuminoid determination, under ordinary circumstances, is n o t necessary. Furthermore, t h e average per cent found in t h e last t u b e , including all samples, was only j per cent of t h e total nitrogen. In a water containing less t h a n I part per million t h e maximum error is 0 . o j p a r t per million; in a water containing 4 parts per million, t h e maximum a m o u n t found in t h e waters examined, t h e error is 0 . z p a r t per million. I n other words, in one case we would report o . 9j p. p. m . of nitrogen a n d in t h e other 3 . 8 0 . “Examination of Water,” 1913, 62. “LT-ater Analysis.” 1912, 11.
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However, since t h e ammonia determination is not quantitative a n d t h e results are used only as a basis for determining pollution, t h e question t o be decided is whether or not t h e error of 0 . 0 j p. p. m. in one case a n d 0 . 2 in t h e other, would cause a change of judgment. We t h i n k it would n o t ; t h a t is, a water with I p. p. m. of nitrogen would s t a n d as good a chance of being condemned as one containing 0 . 9 5 p. p. m., if all t h e other evidences pointed towards contamination. We conclude, therefore, from this s t u d y t h a t in order t o get sufficient information upon which t o base a judgment, it is not necissary. in ordinary routine water analysis, t o nesslerize more t h a n three 5 0 cc. portions for free ammonia, a n d four 50 cc. portions for albuminoid ammonia WATGRA X D SEWAGE LABORATORY UNIVERSITYOF KANSAS,LAWRENCE
A MODIFICATION OF McCRUDDEN’S METHOD FOR CALCIUM, FOR THE ESTIMATION OF CALCIUM AND STRONTIUM IN THE PRESENCE OF PHOSPHORlC ACID AND A SMALL AMOUNT OF IRON By 0. B. WINTER Received August 11, 1915
T h e methodl generally used in estimating calcium a n d strontium, when both are present in a solution, is t o precipitate t h e m as t h e oxalates, burn t o t h e oxides, change t o t h e nitrates, separate t h e calcium nitrate from t h e strontium nitrate b y means of absolute alcohol a n d ether, and then determine each element separately. If phosphoric acid and iron are also present in t h e solution with t h e calcium a n d s t r o n t i u m salts, t h e separation becomes much more difficult since calcium, strontium and iron phosphates a r e quite insoluble in a neutral or alkaline solution. I n this latter case, t h e phosphoric acid a n d iron are re moved before, t h e calcium and strontium are determined. This is usually accomplished b y precipitating2 t h e phosphoric acid as ferric phosphate. a n d t h e excess of iron as ferric subacetate. However, when there is a large amount of phosphoric acid in t h e solutibn, this method becomes tedious because t h e bulky, gelatinous precipitate formed causes t h e solution t o filter very slowly, a n d i t is almost i m pbssible t o wash all of t h e calcium a n d strontium salts o u t of this precipitate. McCrudden has worked out a method3 for “ T h e quantitative separation of calcium a n d magnesium in the presence of phosphoric acid a n d small a m o u n t s of iron, devised especially for t h e analysis of foods, urine and feces.” B y this method t h e calcium is precipitated very slowly as t h e oxalate in a boiling solution containing a small amount of free hydrochloric acid. This gives rise t o a condition i n which t h e calcium oxalate comes down very coarsely crystalline, a n d apparently no soluble salts are carried down b y occlusion. The above method was found accurate for t h e estimation of calcium, b u t in trying it out on a strontium U. S. Dept. of Agr., Bureau of Chemistry, Bxll. 162, 44 ?
Perkin, “ M e t h o d s in Qual. Analysis.” p . 76.
J . Bid. Chem.. 7 (I909), 83.
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