Abstract: The effect of raw materials ratio on the combined anaerobic digestion of food waste and corn straw was studied in a mixture system， with food waste and corn stalks as the digestion raw materials and mature landfill leachate as the digestion medium. The buffer effect of the addition of corn straw on acid inhibition in combined anaerobic digestion system was discussed. The experimental results showed that in the combined anaerobic digestion group of mixture system， the experimental group with a total solid mass ratio of food waste and corn stalks of 1∶3 had the best gas production， the biogas production rate reached 0.35 L/g. The addition of corn stalks increased the gas production and biogas production rate by 98% and 68%， respectively. The results of monitoring the pH and VFA concentrations in the digested effluent showed that the addition of corn straw could alleviate the acid inhibition during the combined anaerobic digestion， and improve the buffering and stability of the anaerobic digestion system of the mixture system. At the same time， the detection results of BOD5 and COD in the digestive fluid of the mixture system indicated that the combined anaerobic digestion could improve the biodegradability of the digestive fluid. Therefore， the addition of corn straw to the mixture system of food waste and leachate could effectively improve the gas production rate and biodegradation efficiency of anaerobic digestion of food waste.

Key words: food waste, corn stalk, leachate, co-anaerobic digestion, acid inhibition