rapid removal of phosphorus from sewage by activated sludge

[15. IX. 1959] Kurze Mitteilungen - Brief Reports 339

agglut inins appear in ti le se rum a t a la ter date, viz. 3 weeks af ter inocula t ion when resorpt ion of the t u m o u r is in ful l sway. Cyto tox ins and agglut in ins are poss ib ly dif- ferent antibodies.

The quest ion remains open a s to the role of these ant i - bodies in the resorpt ion of the he tero t ransplant . Re- t r ansp lan ta t ion of the t m n o u r ceils f rom rats to mice shows t h a t a t l eas t .par t of the t u m o u r cells remain viable in the organism which contains cyto toxins .

Resorp t ion of the mice turnout and appearance of cyto- toxins ensues in 2-week old ra ts while tolerance to homo- t r ansp lan ta t ion of skin is stil l demons t rab le (BILLINGHAM and BRENT 6, X~VOODRUFFS).

The capac i ty of 2- and 3-week old ra ts to produce ant i - bodies agains t heterologous tunmurs th rows d o u b t upon the wide ly accepted opinion of ' immunologica l imma- tu r i ty ' of rats of this age.

I t is in teres t ing to compare our da t a and work of HOLLIDAY 10, who has vacc ina ted 10-11-day old rats wi th S. Pul lorum and observed an t ibody product ion.

G. j . SVET-MOLDAVSKY and O. S. FRANKFURT

The L. A . Tarasevich State Control Institute o/ Vaccines and Sera, Moscow, January 27, t959.

Rdsumd

Chez les rats jeunes auxquels on a inocul6 le cancer asci t ique d 'Ehr l i ch 1-2 jours apr6s la naissance, la t umeur a t t e in t une grande d imension et d ispara i t au bout de 14-31 jours. Chez des rats de 14 jours, le s6rnm a une act ion cy to tox ique sur les cellules du cancer d 'Ehr l i ch et agglut ine celles-ci ~ par t i r du 21e jour.

10 R. HOLLIDAY, Prec. R. See. [B] 147, 140 (1957).

Rapid Removal of Phosphorus from Sewage by Activated Sludge

In a s tudy of the growth of plants in the ac t iva ted sludge t a n k by set t ing up w h a t m a y be t e rmed ' hang ing gardens ' , i t was in teres t ing to observe the behaviour of the rice p lan t which showed an ex t r ao rd ina ry vege ta t ive growth, a t t a in ing an unusual he igh t and pu t t i ng for th more t h a n f i f ty t i l lers bu t showing poor fo rmat ion of grain ~. The rice p lan t appeared to suffer f rom def ic iency of cer ta in nutr ients , no t ab ly phosphorus, while i t had an excessive or a b u n d a n t supply of ni trogen. Unde r the con- dit ions of the exper iment , the p lants f loated on the l iquid in the last aera t ion chamber of the ac t iva ted sludge t ank (the plants being in a sui table box equipped to float, con- ta ining a bed of res is tant cellulosic mater ia l such as coir fibre and s t raw bits) and der ived thei r nut r i t ion f rom the liquid. The sewage enter ing the pur i f icat ion t ank con- ta ined a considerable a m o u n t of water-soluble phosphorus, but, as i t a r r ived a t the last aera t ion chamber of the t a n k af ter abou t 4 h of de ten t ion wi th ac t iva ted sludge, the soluble phosphorus was appa ren t l y l i t t le or inadequate . I t was therefore of in teres t to s tudy the rate of removal of phosphorus, par t icu la r ly water -soluble phosphorus, dur ing the pur i f ica t ion process. As there is prac t ica l ly no infer-

1 S. C. PILLAI, CULT. Sci. lO, 85 (1941); Report on Hanging Gardens to Dr. G. J. FowLer, Technical Representative of Messrs. Activated Sludge Ltd., London, for India and the East (1941).

marion on these po in ts in the l i t e ra ture on the subjec t 2, the evidence we have col lected is br ief ly descr ibed in this communica t ion .

22

20"

18

76

14

12

10: e

"~ 0 k~

o---------o

21 "r, ~. 30 8g 80 t20 180 240 390 860 Time in mb

Rate of removal of phosphorus from sewage by activated sludge • , water soluble phosphorus (P); x x total phosphorus (P) ;

if) .......... (2) 3 rain permanganate value,

Expe r imen t s were carr ied ou t by adding v a r y i n g amoun t s of ac t iva t ed sludge to samples of det r i tus-f ree raw sewage (containing general ly 10 to 14 p.p.m, of to ta l phosphorus and 6 to 9 p.p.m, of water-soluble phosphorus as de te rmined by the me thod described by FISKt~ and SUBBAROW 3 and modified by K1NG 4; for the de t e rmina t ion of water-soluble phosphorus the samples were f i l tered f l l rough filter paper No. 44) and b y blowing air th rough these mix tures (in sui table conical flasks) for v a r y i n g periods, general ly up to 6 h, and by examin ing the super- n a t a n t l iquids for thei r water-soluble and to ta l phosphorus contents , as also for the degree of purif icat ion, by cus tomary methods. At the same t ime, the effect of aera t ion o[ samples of sewage only (wi thout the sludge) on thei r phosphorus contents was also studied.

i n one series of exper iments , the sewage samples were aera ted wi th 25% sludge for va ry ing periods, f rom 15 min to 6 h, and the supe rna t an t l iquids (collected a f te r s top- ping the aera t ion a t s t a ted in terva ls and al lowing the con- ten ts of the flasks to se t t le down) were analysed for the i r phosphorus con ten t s and for the e x t e n t of pur i f ica t ion as indicated by the 3-rain oxygen absorp t ion tes t (permanga- na te value) and turb id i ty . These observat ions are g iven in the Figure. In a s imilar series of exper iments , the concen- t r a t ion of sludge was var ied while the period of aera t ion was the sanle (Table).

2 S. H. JENKINS and W. T. LOCKETT, Nature 151, 306 (1943).-- C. N. SAWYER, Sewage Wks. J. I6,925 {1944); J. N. 1.5. Water Works Ass. 61, 905 (194.1).--W. RUDOLFS, Sewage \Vks. J. 19, .13 (1947}.-- F. ZEIIENDER, Prec. intern. Ass. theor, appl. Limnol. 10, 597 (1948); Water Poll. Abstr. 24, 305 (1951). -- E .H. BELCHER, J. Prec. Inst. Sew. Purif. 195l, 348.--C. N. SAVCYER, Sewage industr. Wastes 24, 768 (1950).--R. OwEu, Sewage industr. Wastes 25, 548 (I953).-- K. WUnRMANN, Sewage industr. Wastes °6, l (1954),-T. STONES, ]. Prec. Inst. Sew. Purif. 1956, 404.--N. HAKKNESS and S. H. JEN- KINS, J. Prec. Inst. Sew. Purif. 1958, 85.

a C. H. FISKE and Y, SU~BAROW, J. biol. Chem. 66, 375 (1925). a E. J. KING, Biochem. J. ,°6, 092 (1932).

2.9.:*

340 Br~ves comnmnications - Brevi comunicazioni [EXPERIENTIA VOL. XV/9]

Table.-- Influence of Varying Amount of Activated Sludge on the Removal of Phosphorus from Sewage*

Amount of sludge** (percentage) added to sewage

and aerated for 6 h

Raw sewage only (control) 2-5 5-0 7'5

10.0 15.0 20.0 25.0 30.0

Percentage reduction of turbidity** *

4.5 18-2 27-3 40.9 59.1 72.8 77.3 86.4 90.9

Percentage purification based on 3-rain permanganate

value

6-9 22"8 38-6 62.8 78.7 83.5 88-3 88.3 88-3

Percentage removal of Water soluble Phosphorus

(P)

2-1 21-7 26-1 32.6 43.5 82.6 91 "3 93-2 94-2

Total Phosphorus

(P)

1.9 11.3 17.7 40.4 53.5 78.1 90.5 92.6 93.6

* The analytical figures for the sewage employed are: turbidity (P) 7'7 p.p.m, and total phosphorus (P) 10.3 p.p.m.

** Microscopic examination of the sludge showed the presence of (about 3000 cells per ml) and Epistylis (about 800 cells per nil).

*** Turbidity was determined with the aid of a Klett Summerson

The results given in the Figure and the Table show t h a t dur ing the ac t iva t ed sludge process t he r emova l of phos- phorus, including the water -so luble phosphorus , f rom the sewage closely follows the rap id ra te of clar if icat ion and ox ida t ion of sewage and t h a t t he r ap id i ty of r emova l of the phosphorus , as the pur i f ica t ion process, is d e p e n d e n t on the concen t ra t ion of sludge.

Other observa t ions m a y be summar i s ed as follows :

W h e n the sludge was previous ly hea t ed a t t e m p e r a t u r e s above 40°C for 10 rain and added to sewage, the r emova l of phosphorus , as the pur i f ica t ion of sewage, was adverse ly affected. The sludge h e a t e d a t 50°C for 10 min d id n o t remove the water -so luble phospho rus and did n o t pur i fy the sewage to any appreciable ex ten t . T r e a t m e n t of the mix ture of sewage and sludge wi th small a m o u n t s of chemicals such as mercur ic chloride (4 p .p .m.) also ad- versely af fec ted b o t h the r emova l of phospho rus and the purif icat ion process. Add i t ion of a mixed cu l ture of bacter ia isolated f rom ac t iva t ed sludge (15 ml bacter ia l suspension, each ml con ta in ing 8000 mill ions of bacter ia , added to 85 ml of raw sewage; t he bac te r i a free f rom the culture med ium were ob t a ined by the t echn ique 5 using cel lophane m e m b r a n e on n u t r i e n t agar) caused only a sl ight reduc t ion of water -soluble phosphorus b u t caused an appreciable increase in the to ta l phosphorus , in the p e r m a n g a n a t e value, and in tu rb id i ty , these increases being due to the added suspens ion of bacter ia .

E. G. SRINATtt, C. A. SASTRY, and S. C. ~DILLAI

Department o/Biochemistry, Indian Institute o/Science, Bangalore (India), April 75, 1959.

Rdsumd La plus grande par t ie du phosphore con tenu dans les

eaux d '6gouts y compris le phosphore dissous dans l 'eau a 6t6 r a p i d e m e n t 61imin~e ~ l 'a ide de boue (, activ~e ,, en l ' espace de 6 h. Le l iquide recueilli pa r le proc6d6 de boue (,activ~e~ con t ien t tr~s peu de phosphore . Le t a u x du phosphore 81imin6 sui t de tr~s pros la vi tesse de purif i- ca t ion et d ' o x y d a t i o n des eaux d '6gouts . L 'ac t iv i t~ des bact~ries con tenues dans la vase ne semble pas expl iquer la d i spar i t ion rap ide du phosphore con tenu dans les eaux d '6gouts .

T. R. BHASKARAN, M. SREENIVASAYA, and V. SUBRAHMANYAN, Curr. Sei. 3, 484 /1935).

1~5; 3-rain permanganate value 22 p.p.m.; water-soluble phosphorus

certain protozoa in large numbers, notably the species of Opercularia

photoelectric colorimeter, employing violet filter (420 mlz ).

E f f e c t o f C o b a l t o u s C h l o r i d e

o n t h e B l o o d S u g a r L e v e l

a n d t h e I s l e t C e l l s i n R a t s

Since 1951, when VAN CAMPENHOUT a n d CORNELIS 1 d e m o n s t r a t e d changes in the u-cells of the islets of Langcr- hans in guinea-pigs a f te r in jec t ion of coba l tous chloride. s imilar obse rva t ions have been m a d e in o the r species of an imals such as the r ab b i t and the dog 2-4 Dis tu rbance of t he blood sugar level has been r epo r t ed in a n u m b e r of cases, the change usual ly consis t ing in an increase instead of t he decrease t h a t m i g h t logically be expec ted . CREUTZ- FELDT and SCHMIDT 5 and FODDEN 6 have n o t been able to observe such changes in t he blood sugar or islet cells in rats . MUKHERJEE. DE and MUKERJI 2, on the o the r hand, ob ta ined hype rg lycemia af ter cobal tous chlor ide adminis- t r a t i on (50 mg/kg) , b u t these inves t iga to rs did no t s tudy the islets f rom t h e morphologica l aspect .

% + I00

+=GO

0 - - ~ )C

I I J I f

3 6 2~ 12 2 4 h

Blood sugar changes daring 24 h after injection of eobaltous chloride in percentage of initial value.

x - - x controls ~ ; o o CoC12 45 mg/kg.

1 E. v. CAMPENHOUT and G. CORNELIS, C. R. Soc. Biol. 145, 933 (1951).

2 M. G. GOLDNER, B. W. VOLK, and S. S. LAZARUS, Metabolism 1, 544 (1952}.

S. S. LAZARUS, ]~{. G. GOLDNER, and B. W. VOLK, Metabolism Z, 51,q (1953).

4 B. W. VOLK, S. S. LAZARUS, and M. G. GOLDNER, Proc. Soc. exp. Biol. Med., N.Y. 82, 406 (1953).

5 W. CREUTZFELDT and W. SCHMIDT, Arch. exp. Path. Pharmak. 222, 487 (1954).

6 j . H. FODDEN, Arch. Path. 61, 65 (1956). v S. K. MUKHERJEE, U. N. DE and B. MUKERjI, Indian J. reed.

Res. 45, 337 (1957).