水溶性有机物荧光特性是评价有机废弃物堆肥腐殖化程度的重要手段之一。 针对现有方法大都局限于腐殖化程度的定性表征等问题, 基于投影寻踪方法, 该研究开展了堆肥腐熟程度分级评价的定量表征。 通过对不同来源有机废弃物堆肥过程中样品水溶性有机物(DOM)荧光特性参数获取, 采用统计分析表明, 荧光参数I436/I383, FLR, PHA/Pro, A4/A1, r(A,C)两两之间显著相关(p<0.01), 可作为综合评价指标。 在此基础上, 确定完全腐熟(Ⅰ级)、 较腐熟(Ⅱ级)、 基本腐熟(Ⅲ级)、 未腐熟堆肥(Ⅳ级)4个腐熟等级荧光参数取值区间。 模型运算得到各等投影值分别为2.01～2.22(Ⅰ级)、 1.21～2.0(Ⅱ级)、 0.57～1.2(Ⅲ级)、 0.10～0.56(Ⅳ级)。 模型验证证实, 各样品的实际腐熟度等级与模型所得到腐熟与未腐熟样品的评价结果准确率为100%, 因此, 该评价方法对有机废弃物的实际堆肥具有重要的指导意义。

The characteristics of fluorescence spectra of dissolved organic matter (DOM) derived from composting is one of the key ways to assess the compost maturity. However, the existing methods mainly focus on the qualitative description for the humification degree of compost. In this paper, projection pursuit classification (PPC) was conducted to quantitative assess the grades of compost maturity, based on the characteristics of fluorescence spectra of DOM. Eight organic wastes (chicken manure, swine manure, kitchen waste, lawn waste, fruits and vegetables waste, straw, green waste, and municipal solid waste) composting were conducted, the germination percentage (GI) and fluorescence spectra of DOM were measured during composting. Statistic analysis with all fluorescence parameters of DOM indicated that I436/I383 (a ratio between the fluorescence intensities at 436 and 383 nm in excitation spectra), FLR (an area ratio between fulvic-like region from 308 to 363 nm and total region in emission spectra), PHA/Pro (a regional integration ratio between humic acid-like region to protein-like region in excitation emission matrix (EEM) spectra), A4/A1 (an area ratio of the last quarter to the first quarter in emission spectra), r(A,C) (a ratio between the fluorescence intensities of peak A and peak C in EEM spectra) were correlated with each other (p<0.01), suggesting that this fluorescence parameters could be considered as comprehensive evaluation index system of PPC. Subsequently, the four degrades of compost maturity included the best degree of maturity (Ⅰ, GI>80%), better degree of compost maturity (Ⅱ, 60%