The Purification of Seiuage. 



203 



ozonite filter, 'j^ per cent. It should be noted that the 

 above percentages of purification are upon the sewage after 

 settling for 12 to 24 hours, and upon the raw sewage would 

 be some 15 per cent higher. The percentages, therefore, 

 are really of soluble albuminoid ammonia removed. 



The Tables appended will explain themselves, and I 

 hope on another occasion to give some further results from 

 the treatment of ten million gallons per day of sewage at 

 the Salford Works. 



Table I. 



Salford Sewage and Effluents, after treatment zvith Basic Per- 

 sulphate of Iron. 100,000 gallons treated daily iviiii i^ grains 

 per gallon. Results expressed in parts per 100,000 of Albu- 

 mi?ioid Ammotiia. 



Note. — The Crude Sewage, column No. i, was allowed to settle 12 hours before 

 analysis. 

 The Effluents, Nos. 2, 3, and 4 were shaken up before analysis. 



