METHOD FOR IMPLEMENTING ZERO EMISSION BIOGAS SLURRY IN PURE STRAW ANAEROBIC DIGESTION

摘要

Disclosed in the present invention is a method for implementing zero emission biogas slurry in pure straw anaerobic digestion, comprising (1) pretreating a pure straw feedstock; (2) adjusting the C/N of the pretreated straw, and feeding; (3) discharging fermentation residues from the anaerobic digestion reactor, and isolating biogas slurry therefrom; (4) performing an aerobic nitrification treatment on the biogas slurry outside the anaerobic digestion reactor; (5) refluxing 100% of the biogas slurry in the straw feeding process, after the aerobic treatment, to the anaerobic digestion system, and performing a denitrification treatment on the biogas slurry in the anaerobic digestion reactor. The method of the present invention combines the in vitro aerobic nitrification and in vivo denitrification of the biogas slurry, thereby effectively reducing the COD and ammonia nitrogen concentration of the biogas slurry, no additional carbon source needs to be added in the denitrification process, and the inhibitory effect of reusing the biogas slurry on the system is eliminated, thereby achieveing zero emission biogas slurry and 100% reuse, and avoiding secondary pollution; at the same time, completely replacing the straw with biogas slurry for feeding regulates water, thereby achieving significant water conservation, reducing operating costs and being capable of maintaining the long-term stable operation of the anaerobic digestion reactor.