城市生活垃圾堆肥胡敏酸动态光谱特性研究

利用城市生活垃圾中降解部分，采用工厂化工艺进行堆肥，对堆肥过程中胡敏酸动态光谱特性进行了分析。结果表明，随着堆肥进行，胡敏酸在短波长的荧光强度明显降低，并且主体峰位置发生改 变，逐渐靠近土壤胡敏酸的主峰位置。红外光谱解析显示，胡敏酸结构中多糖类脂类等小分子化合物随着堆肥时间的延长而减少，而芳族类化合则呈增加的趋势。紫外扫描光谱进一步证实，在堆肥过程中 ，胡敏酸分子共轭作用、缩合度增加，腐殖化程度明显。但与土壤胡敏酸的E₄/E₆值、光谱特性比较表明，堆肥后的胡敏酸具有相对简单的分子结构，活性较高。

Study on Dynamic Spectral Characteristics of Humic Acid in Municipal Solid Wastes Composting

In the present study, the compost consisted of residual MSW with metal, plastic and glass removed. The composting process was assisted using industrial technology. During the composting, humic acid (HA) was extracted and purified. The spectroscopic characteristics of the HA were determined by using UV, FTIR, and fluorescence spectroscopy. During the composting process, the HA fluorescence spectra exhibited a sharp reduction in relative fluorescence intensity at the short wavelength region, and the primary peak shifted from 335 nm at the initial stage to 458 nm at the final stage of composting, thereby approaching the main peak at 460-480 nm for HA in soil. The FTIR spectra exhibited a reduction in polysaccharides and aliphatic components, and a relative increase in aromatic components; while the HA UV spectra revealed an increase in conjugation and the degree of humification. However, compared with the E4/E6 value and the spectroscopic characteristics of HA in soil, the HA in the MSW compost has a relatively low molecular weight, a simpler structure and a relatively low degree of aromatic condensation, which also implies that the HA in compost is highly active.