Sewage and Sewage Effluents. 



193 



REDUCTION OF BACTERIA AT COLUMBUS, OHIO. 

 QOHNSON, ipos.) 



Thumm and Pritzkow (1903), at the Berlin Experi- 

 ment Station, obtained the results tabulated below. 



BACTERIA IN SEWAGE, CONTACT EFFLUENT, AND SAND 

 EFFLUENT AT BERLIN. 



Bacteria 

 per C.C. 



Crude sewage 



Primary contact effluent (coarse coke) . 

 Secondary contact effluent (fine coke) . 



Tertiary sand effluent 



Primary contact effluent (fine coke) . . 

 Secondary sand effluent 



16,900,000 

 12,400,000 

 5,600,000 

 1,100,000 

 7,400,000 

 1,800,000 



At the experiment station of La Madeleine, in Lille, 

 Calmette (1907) reports 5,000,000 bacteria per c.c. in 

 the crude sewage, 2,900,000 in the second contact effluent 

 and 800,000 in the effluent from the trickling bed. Of 

 20,000 B. coH per c.c. applied to the filters, the contact 

 system delivered 4000 and the trickling bed 2000 per c.c. 

 The average results of examinations made three times 



