Composting of Town Refuse by the 'Edelmist' Process

Conversion of organic wastes, including night-soil, into manures has been practised for a number of years. Among the methods so far developed, those of Hutchinson and Richards (1921), Waksman and co-workers (1927), Fowler (1930) and Howard and Wad (1931) are most extensively adopted. These methods involve fermentation under essentially aerobic conditions. They are fairly rapid, but they also involve serious loss of both nitrogen and organic matter. Repeated attempts to raise the level of organic nitrogen, at any rate under Indian conditions, in the fermenting heap by the serobic processes have not so far met with much success. Besides this particular aspect which, no doubt, is the most important from the agricultural point of view, there are several others, pertaining to the hygiene of the disposal which need careful study, e.g., (1) prevention of fly-breeding and (2) maintenance of high temperature at least in the early stages to destroy pathogenic and putrefactive organisms. These points are of ?considerable importance where night-soil is added as the source of available nitrogen for the decomposition of town refuse. Attempts to improve the hygiene of disposal and prevention of fly-breeding by chemical sprays have proved costly. Sometimes the chemical used may even have an adverse effect on the course of decomposition by a modification of the micro-flora. Among the other methods, the ' Edelmist ' (hot fermentation) process originally developed by Krantz [Cunningham (1927), Ruschmann (1927), Boctskaul (1927), Fruwith (1928)] is best known. It is claimed to be hygienic and economical in regard to both nitrogen and organic matter. Quite apart from the above considerations, the Edelmist process should be regarded as a decided advance on ordinary methods in that it affords a means of controlling the fermentation of the manure. It was considered desirable therefore to make a systematic enquiry into the possibility of applying this process to the disposal of town refuse in India. The process, in short, consists in allowing the compost heap to ferment a3robical1y till the maximum temperature is attained. It is then pressed and packed tightly and maintained under ana)robic conditions for three to four months after which the manure is ready for application to land. The method is being examined critically under both field and laboratory conditions with a view to standardizing the condition by which the disposal will be hygienic and will, at the