Differences of enzyme activities and physicochemical indexes in biogas slurry compost and cattle manure compost

In order to evaluate potential nitrogen additives effect of composting from biogas slurry and develop the relevant treatment technology,changes of major enzyme actives and physicochemical indexes in biogas slurry and leaf composting were investigated with cattle manure and leaf compost as control.Result showed that the duration of thermophilic phase over 50 ℃ was 35 days for the biogas compost,which was 8 days longer than that of cattle manure compost.In the meantime,the β-glucosidase activity and alkaline phosphomonoesterase activity for biogas slurry compost have been reduced all the way,with the Schwellenwert of 25.9 U/mL at day 30 and 0.15 U/mL at day 45.The urease activity for the biogas slurry compost was increased initially with a crest value of NH3-N 4.2 mg/(g·24 h)at day 6,then decreased with a Schwellenwert of NH3-N 1.02 mg/(g·24 h)at day 45.The changes for cattle manure compost were different.Its β-glucosidase activity,alkaline phosphomonoesterase activity and urease activity were enhanced at first with a maximum level at day 6,the crest values were 44.2 U/mL,2.93 mg/(g·24 h),0.72 U/mL respectively,then decreased.The process duration for biogas slurry compost maturity were shorter since decomposition of its organic matter were exuberant.