油菜秸秆比例对好氧堆肥过程及产品特性的影响

Effect of Rape Straw Ratio on Performance of Aerobic Composting Process and Characteristic of Final Product

摘要:

采用堆肥工艺将农作物秸秆转化为有机肥还田是秸秆资源化利用的有效手段。本研究以油菜秸秆为主要原料，按不同比例同辅料混合（三组实验R1、R2和R3中的油菜秸秆比例（湿重）分别为45、65和85%），研究了油菜秸秆比例对高温好氧堆肥过程及产品特性的影响。结果表明，在72d的堆肥过程中，R1、R2和R3的有机物降解主要发生在堆肥过程前期，堆肥结束时分别达到34.06、35.57和39.78%，且符合一级动力学模型。通过比较三组实验过程中样品的理化性质，可知R3最终样品满足了堆肥腐熟的各项指标，且堆肥过程中氮损失最少；其最终堆肥产品中未检测出NH4+，总N含量、NO3-浓度和GI值分别达到2.17%、1,844.93mg•kg-1干重和102.66%。综上所述，以油菜秸秆为主料添加辅料后进行好氧堆肥是可行的，实验范围内增加油菜秸秆量可以减少堆肥过程氮的损失，提高堆肥质量。

Abstract:

Composting is an effective method to convert crop straw into organic fertilizer. To maximum utilize rape straw, the effect of rape straw ratio on performance of aerobic composting process and final product was investigated. The rape straw proportion in feedstocks in R1, R2 and R3 were 45, 65 and 85% (wet weight), respectively. The results showed that organic matter degradation in R1, R2 and R3 occured mainly in the early stage of composting process, and achieved 34.06, 35.57 and 39.78%, respectively at the end of composting process. In addtion, the degradation of organic matter conformed to the first-order kinetic model. Comparing the physicochemical properties of samples during the composting process, the end-product of R3 satisfied all the maturity indicators recommended by previous references. In the end-product of R3, NH4+ was not detected, and the total nitrogen content, NO3- concentration and germination index (GI) achieved 2.17%, 1,844.93mg•kg-1 (dry weight) and 102.66%, respectively. In conclusion, rape straw with higher addition amount enhanced the utilization efficiency of rape straw, and enhanced the quality of the end-product. Moreover, nitrogen loss reduced with increasing rape straw addition amount in the present experiment scope.