Effect of Temperature and Ammonia Inhibition on Methane Fermentation of High Concentrated Chicken Manure

Abstract

 High concentrated chicken manure with about 10% of TS was fed to reactors for continuous mesophilic and thermophilic fermentation to evaluate the performance of biogas production and the ammonia inhibition. Stable mesophilic fermentation was achived even though raw chicken manure was fed as substrate. Thermophilic fermentation was successfully achieved feeding ammonia stripped chicken manure. On the contrary, ammonia inhibition was found to thermophilic fermentation when fed with raw chicken manure. By means of estimating biogas production, ammonia inhibition to mesophilic and thermophilic fermentation began to occur when the concentrations of ammonia were in a range of 4000~5000mg/L and lower than 4000mg/L, respectively. Sharply VFA accumulation occurred when TAN concentration was about 10000mg/L in mesophilic fermentation and 5000mg/L in thermophilic fermentation. In addition, with the increase of TAN concentration, there was a trend that degradation rate of oganic matters decreased. And it was obvious that protein was especially sensitive to ammonia inhibition comparing to the other oganic matters.