Abstract:Effect of mixing on dry thermophilic (55℃) anaerobic digestion of dairy manure was investigated. No significant difference in fermentation performance was observed between continuous mixing speeds of 8~32r/min. Compared to continuously mixing, although 10% less methane was produced with batch slightly mixing. It greatly decreased energy consumption for mixing, and more suitable for dry anaerobic digestion. No significant difference in pH value, concentrations of ammonia, volatile fatty acid and total alkalinity was observed among different mixing conditions during digestion.