1905.] 



with reference to the Petrification of Sewage. 



263 



Table III. — Showing the Course of Oxidation at Successive Depths in 

 Tall and Medium Filters (Vienna). 











Filtrate at successive depths. 



No. 



Date. 



Constituents. 



Sewage. 

















Tap No. 1, 



Tap No. 2, 



Tap No. 3, 



Tap No. 4, 











50 cm. 



100 cm. 



150 cm. 



200 cm. 







Tall fllfo-*. 



xuiiL nicer. 













1 



24.5.01 



Ammoniacal N. 



12 78 



11 -91 



2-27 



0-39 



0-29 



2 



24.5.01 



Oxidised N 







/ 



+ 



+ + 



+ + t 



3 



27.5.01 



Oxidisability* ... 



9-2* 



3-4* 



2 -6* 



3 0* 



2-3* 



4 



27.5.01 







/ 



/ 



No. 2 x 5 



No. 2 x 7 



5 



1.7.01 



Ammoniacal N. 



11 9 



2 5 



0-2 



0-04 



0-06 



6 



1.7.01 



Nitrites 







/ 















7 



1.7.01 









+ 



+ 



+ 



7-8 







Medium filter. 













8 



1.7.01 



Ammoniacal N. 



11 -9 



8-1 



4-12 







9 



1.7.01 









/ 



/ ' 







10 



1.7.01 



Nitrates 







/ 



4-96 







In 2 the test was made with diphenylamine, in 3 the estimations are approximate. 

 The high numbers in filtrate of 8 are due to deterioration in efficiency of the filter following 

 partial clogging. 



f Nitrous N = 6-0, nitric N = 11. 



Table IV. — Munich Continuous Filters from June 24, 1903, to Xovember 27, 

 1903, using Cows' Urine diluted 1 in 100 ; this contained 14 — 17 parts 

 NH 3 per 100,000 and no oxidised nitrogen. In cases marked with an 

 asterisk the urine was only diluted to 1 in 50. 





Tall filter. 



Medium filter. 



Short filter. 



Date. 



NH 3 



Nitrite 



Nitrate 



NH 3 



Nitrite 



Nitrate 



NH 3 



Nitrite 



Nitrate 





per 



re- 



re- 



per 



re- 



re- 



per 



re- 



re- 





100,000. 



action. 



action. 



100,000. 



action. 



action. 



100,000. 



action. 



action. 



26.6.03 



/ 







+ + 



/ 







+ + 



1 



/ 



+ + 



': 30.6.03 



o-i 







+ + 



o-i 





+ + 



2—3 



/ 



+ + 



9.7.03 



0-05 







+ + 



2—3* 



: 



+ + 



1—2 



+ 



+ + 



\ 13.7.03 

 15.7.03 



jo -2 







+ + 



6—7* 



/ 



+ + 



2—3 





+ + 



23.7.03 



0-05 







+ + 



4—5* 



/ 



+ + 



1—2 



+ 



+ + 



24.10.03 



0-05 







+ + 



0-05 







+ + 



o-i 







+ + 



27.11.03 



O-02 







+ + 



-04 







+ + 



0-04 







+ + 



20.1.04 



5-0* 



1 f 



+ + 



8—10* 



+ + 



+ + 



15* 



+ 



+ + 



The ammonia estimations by direct Nesslerisation are only approximate ; nitrites were tested 

 for by acidified starch-zinc-iodide ; nitrates by diphenylamine (only specific if nitrites are absent 

 or inconsiderable). 



