通风量对餐厨垃圾堆肥中氮素转化及N_(2)O释放的影响

The influence of ventilation rate on nitrogen conversion and N_(2)O releasing in composting of kitchen waste

通风量对餐厨垃圾好氧堆肥过程中氮素的演变和氧化亚氮(N_(2)O)释放均有重要影响.研究以通风量作为影响因子,设置3组初始温度均为35℃的餐厨垃圾好氧堆肥化实验,其通风量分别为(A)0.2 L·min^(-1)、(B)0.4 L·min^(-1)、(C)0.6 L·min^(-1),分析餐厨垃圾堆肥过程中温度、pH、NH_(4)^(+)-N、NO_(3)^(-)-N和N_(2)O等参数变化.结果表明:B、C组堆肥均能在50℃保持5 d以上;B、C组氧容量在10.87%~18.62%之间能够满足微生物活动需要;3组实验结束时的pH值在7.32~8.10之间,符合相关堆肥产品的要求;各组NH_(4)^(+)-N与NO_(3)^(-)-N含量分别为0.48、0.68、0.52 g·kg^(-1)和0.09、0.12、0.11 g·kg^(-1);各组N_(2)O总排放量为464.07、293.92、313.99 g.综上所得,通风量0.4 L·min^(-1)能够较好地促进生化反应过程,对氮素进行有效地矿化与保留,对N2O排放取得相对明显的控制效果,可为N_(2)O减排提供参考依据.

The ventilation rate may have an important effect on the evolution of N element and the release of nitrous oxide(N_(2)O)during the aerobic composting process of kitchen waste.The ventilation rate was chosen as the influencing factor in the present study.Three groups of aerobic composting experiments of kitchen waste were conducted that were set at 35℃and with ventilation rate of(A)0.2 L·min^(-1),(B)0.4 L·min^(-1) and(C)0.6 L·min^(-1)respectively.Parameters including temperature,pH,NH_(4)^(+)-N,NO_(3)^(-)-N,N_(2)O were analyzed.The results show that the temperature of group B and group C could be kept over 50℃for more than 5 days.The oxygen capacity of group B and group C ranged from 10.87%to 18.62%which met the needs of microbial activities.The pH of the three groups ranged from 7.32 to 8.10 at the end of the experiments,which met the requirements of relevant composting products.The contents of NH_(4)^(+)-N and NO_(3)^(-)-N were 0.48,0.68,0.52 g·kg^(-1) and 0.09,0.12,0.11 g·kg^(-1) in each group.The total emissions of N_(2)O in each group were 464.07,293.92,313.99 g,respectively.In conclusion,the ventilation rate of 0.4 L·min^(-1) can effectively promote the biochemical reaction process.It can also produce effective mineralization and retention of nitrogen,and provide obvious emission control of N_(2)O.