Preparation method and application of carbon source for sewage denitrification

The invention relates to a preparation method and application of a carbon source for sewage denitrification, which can effectively solve the problems of low carbon-nitrogen ratio of sewage, insufficient available carbon source for microorganisms, inhibition of denitrification process and low denitrification efficiency, and the technical scheme for solving the problem is as follows: the preparation method comprises the following steps: 1) preparing alkali modified corncob; 2) domesticating a fermentation strain; 3) preparing a carbon source by a fermentation method; according to the method, firstly, corncobs are subjected to alkali modification, so that compact cellulose and hemicellulose structures in the corncobs become loose, full contact of microorganisms with fermentation substrates such as cellulose is facilitated, and the biological fermentation efficiency is improved; secondly, microorganisms in the cow dung are domesticated, the proportion of cellulose degrading bacteria in strains is increased, the b