Refuse Disposal and Sewage Purification. 2 5 



emptied at any time, so that the process is a continuous one. 

 In deahng with a large quanity of sewage there is necessarily a 

 considerable deposit of solid matter, commonly called sludge, 

 and its ultimate disposal involves careful consideration. Practical 

 science is at fault in not determining its utilization as manure. 

 It can be applied to raise the level of low-lying lands which can 

 be afterwards cultivated with advantage, or carried away and 

 dumped into the sea, or pressed, to remove the surplus water) 

 and then burnt in destructor furnaces. The mal-odorous 

 condition of the fore shore of Belfast Lough demands that the 

 sewage should be treated so as to produce a clear effluent. So 

 far back as 1866 Mr. Montgomery, the then Borough Surveyor, 

 considered it to be essential to his able and comprehensive 

 Main Drainage Scheme to prevent any pollution to the shores 

 of the Lough. Had that proposal been carried out as intended 

 22 years ago, there can be no reasonable doubt that the surface 

 soil of our city would have been free from the disease germs 

 that now render some portions of the city unhealthy. 



The adoption of a clarification process requires that the 

 collecting tanks be fitted with a stirring apparatus to thoroughly 

 mix the chemicals used for precipitation of the solid matter. 

 The direct result of such mixture is that the solid particles are 

 thrown into a flocculent state, permeating the entire contents 

 of the tank, which gradually settle down, leaving the liquid 

 clear and innoxious. The chemical combinations necessary to 

 produce this hygienic effect are prepared chiefly from iron 

 oxide, alumina, and lime. All these exist in immense quanti- 

 ties in our own immediate neighbourhood, and under these 

 favourable local conditions it follows that the cost of precipitat- 

 ing materials should be cheaper here than in any other part of 

 the United Kingdom. 



Refuse disposal and sewage purification are pregnant with 

 possibihties for our material welfare. The destructor, while 

 absolutely destroying those germs of evil that are the accom- 

 paniments of disease, will furnish the power for locomotion, 

 lighting, or other useful purposes. A precipitation process 



