鸡粪沼渣好氧堆肥颗粒尺度下氧气渗透深度表征

摘要

It is an attempt to characterize of the oxygen penetration depth at the particles scale during chicken manure digestate co-composting wheat straw by Fourier transform infrared microspectroscopy (FT-IRM).It is presented to improve the anaerobic/aerobic co-process mechanism,in order to ensure adequate oxygen supply.The spectral range,spectral resolution and pixel dimensions in the transmission spectra were 750 ～ 4 000 cm-1,16 cm-1 and 6.25 μm × 6.25 μm,and a mean spectrum of 8 scans wasused for the second-derivative analysis with nine smoothing points.Chicken manure digestate aerobic composting samples by freeze-drying treatment should be made into 12 μm slice by using paraffin section technology.Selection of 2 856 cm-1,1 640 cm-1 and 1 568 cm-1,3 001 cm-1 was done to represent aliphatic component and aromaticity,respectively,which were used for deciding the boundary of oxygen penetration depth.The difference curve drops rapidly was regarded as the terminal point of oxygen penetration depth.The oxygen penetration depth of chicken manure digestate particles fluctuated within 7 ～ 20 μm,which was lower than that of pig manure aerobic compost particles.The variation in the oxygen penetration depth can be described by an exponential fitting function.The results indicated that it was feasible to determine the oxygen penetration depth of aerobic composting particles by FT-IRM,but the method and technical parameters should be selected according to the characteristics of different materials.%利用傅里叶变换显微红外光谱技术对鸡粪沼渣好氧堆肥颗粒尺度下氧气渗透深度进行了量化表征.用于表征鸡粪沼渣颗粒氧气渗透深度的显微红外透射光谱法的光谱采集范围为750～4 000 cm-1,光谱分辨率16 cm-1,像素点尺寸6.25 μm×6.25 μm,扫描次数8次.鸡粪沼渣好氧堆肥样品经冷冻干燥处理后,应采用石蜡切片技术制成12 μm薄片,选取2 856 cm-1和1 640 cm-1代表脂肪类化合物,1 568 cm-1和3 001 cm-1代表芳香族化合物作为氧气渗透深度边界判定特征波长,且氧气渗透深度终点定义为差分曲线迅速下降处.鸡粪沼渣颗粒氧气渗透深度较小,介于7 ～ 20 μm范围内动态变化,其符合指数关系式.研究结果表明,采用傅里叶显微红外透射光谱法判定好氧堆肥颗粒氧气渗透深度具有可行性,但应根据不同物料特性,选用适用的方法和技术参数.