外源CO_2对鸡粪厌氧消化产甲烷性能的影响

Anaerobic Digestion of Chicken Manure for Production of Methane by Adding Exogenous CO_2

以青岛某养鸡场的新鲜鸡粪为发酵原料,在中温条件下(35℃±1℃)采用一次性进料方式进行厌氧消化处理,研究通入外源CO2和改变原料含固率(TS)对厌氧消化系统处理鸡粪过程中溶解性化学需氧量(sCOD)、氨氮、pH和产甲烷量的影响。结果表明,整个发酵过程中pH稳定在8.3~8.6之间;在TS为5%时,通入CO2∶N2=1∶7混合气体的反应器产甲烷性能达到最优,甲烷日产量在第12天达到峰值2 821mL,累积产气量最终为504.3mL/gVS(以每克挥发性固体计),比通入纯氮气的对照组提高了31.7%。通入CO2∶N2=1∶7混合气体,TS为5%时反应器甲烷含量最高可达72%,甲烷平均含量比通入纯氮气的反应器高8%。该研究表明,适量通入外源CO2可以提高厌氧消化系统的沼气产率和甲烷含量,将为废弃有机物的厌氧处理资源化过程提供有益的指导。

Anaerobic digestion of chicken manure for production of methane was conducted in mesophilic conditions at 35℃±1℃.The effects on the change of sCOD、ammonia nitrogen、pH and methane production was studied by adding exogenous CO2 and changing the total solid levels(TS).The results indicate that the pH value of the whole culture process is finally stable between 8.3~8.6.When the TS is 5%,the performance of the reactor(with CO2:N 2=1:7 mixed gas input)is optimal and the biogas production can reach to 504.3 mL/gVS,showing an increase of 31.7%compare with the control one(without exogenous CO2 input,TS is 5%).Methane content of the reactor under optimum conditions up to 72%,and the average methane content is 8%,which is higher than the control group.This indicates that exogenous CO2 can well improve the methane yield and content.