| The total output of black agaric in China reached 613.19 million tons in 2015.The output is 303.28 million tons in Heilongjiang Province,which accounts for 49.5% of the country's total output.The output of agaric cultivation waste is about 60 million tons in China every year and it is increasing with the rapid development of edible fungus industry.Most of the agaric cultivation waste are discarded arbitrarily in the fields,rivers,or burned directly.It not only pollutes the environment,but also creates a great waste of resources.So it is meaningful for environmental protection and energy saving,if the agaric cultivation waste is fully resource utilized.Biogas fermentation is a feasible way to improve the efficiency of agricultural waste resource utilization and convert to the clean energy.In order to explore the biogas production characteristics of the agaric cultivation waste by anaerobic fermentation,anaerobic fermentation experiment was carried out on the raw materials with different concentrations of initial dry matter and the paper optimized the optimal fermentation concentration.Because the content of the lignocellulose is higher and the rate of the lignin degradation is mainly in the hydrolysis stage,the aerobic hydrolysis experiment was carried out on the agaric cultivation waste at different time and temperature under the optimum fermentation concentration.Finally,the gas production characteristics were compared and analyzed by aerobic anaerobic two-phase fermentation gas production experiment.The main conclusions are as follows:(1)The anaerobic fermentation of 10% concentration experimental group was the best.The cumulative gas production reached 9450 mL and the cumulative amount of methane produced was 4414.36 mL.VS gas production rate was 211 m L/g and VS methane production rate was 98 m L/g.(2)The degradation rate of organic matter increases first and then decreases with the increase of concentration.The degradation rate was the highest at the 10% concentration.The total sugar was least affected by the concentration of the initial dry matter and the degradation rate was more than 95%.But the degradation rate of lignocellulose in each experimental group was low and the highest degradation rate of the 10% concentration experimental group was only 37.99%.The degradation rate of hemicellulose was generally higher than the cellulose and the lignin was hardly degraded.The biogas microbes mainly used carbohydrates and then fat and protein in the process of the anaerobic fermentation.(3)By analyzing the aerobic hydrolyzable materials at different temperatures,it was found that the degradation rate of lignin was the fastest at 44? with stirring.When the hydrolysis time was 8h,the lignin degradation rate was 19.91% which accounted for 67.05% in the total degradation rate and it was better than the other experimental groups in this period significantly.Besides,the total solid degradation rate was low relatively and the degradation rate was slow.Stirring can promote the progress of hydrolysis and the degradation of lignin effectively at the experimental phase of the aerobic hydrolysis.(4)The optimum aerobic hydrolysis time was determined by analyzing the materials with different hydrolysis time.The results showed that the optimum hydrolysis time was 8 h with 44? and stirring Under this condition,the gas production rates of TS and VS were respectively 186 ml/g and 217ml/g,which was 13.16% higher than that of the control group.The methane production rate of TS and VS was also higher than that of the control and increased by 21.6%.This showed that the optimum temperature for aerobic hydrolysis was 44 ?,the best time was 8h.Under these conditions,the biogas production of agaric cultivation waste achieved the best. |
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