ON THE TREATMENT AND UTILIZATION OP SEWAGE, 



179 



Eemarlcs on the Analyses of the Sewage and Effluent Water from the 

 Irrigation Farms at Tunhridge Wells. 



North Farm. — In 100,000 parts. Samples taken in the proportion of -j-irW 

 part of the flow per minute, by a measure graduated to yi^ of a gallon. 



(Total nitrogen in effluent water 1-99.) 



The se-wage from the main, -while containing a comparatively small amount 

 of total solid matter in solution, contains a very large proportion of 

 "actual" ammonia, and also of " albi«pinoid" ammonia, when both the sus- 

 pended and dissolved matters are taken into account ; it is a rich sewage 

 whether the proportion of nitrogenous matters to the total solids or to the 

 bulk of the sewage itself be considered. The chlorine is in fair average 

 amount, 



Tlie analysis of the average effluent water shows that while the total solida 

 arc diminished in amount, the diminution is due to the retention by the soil 

 and vegetation of the more volatile constituents, as the weight of ash left 

 after ignition of the solid matters was greater in the case of the effluent 

 water than in that of the sewage. This may be due to (1) concentration by 

 the evaporation which takes place from the sewage of the soil and from the 

 plants, or (2) to solution of salts already in the soil : that the latter cause is 

 more probably the true one, we see from the diminished amount of chlorine, 

 which, although it may not necessarily indicate dilution with ordinary sub- 

 soil water to a great extent, stUl would certainly not lead us to conclude that 

 any concentration had taken place. That dilution -with underdrainage water 

 actually docs take place has been already pointed out. 



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