电场促进畜禽粪便好氧堆肥中DOM演化的光谱学研究

好氧堆肥是畜禽粪便处置和资源化利用的主要途径.传统好氧堆肥（CAC）技术存在堆体温度低、发酵周期长、腐熟效果差等缺陷.最近研究发现，电场辅助好氧堆肥（EAAC）可快速促进堆肥腐熟，缩短堆肥周期，减少温室气体排放，具有潜在的应用前景.然而，电场促进堆肥过程中水溶性有机物（DOM）演化及腐殖化过程尚未清晰.基于此，本文采用紫外-可见光谱（UV-Vis）、傅里叶变换红外光谱（FTIR）和三维荧光光谱（3D-EEM）等多种光谱技术分析了EAAC过程中DOM的演变规律.UV-Vis与3D-EEM分析表明，EAAC过程中，蛋白类物质在3 d内几乎被完全分解，富里酸和腐殖酸类物质在高温期（6~18 d）大量形成.EAAC的腐殖化指数（HI=HA/FA）高于CAC，E₄/E₆低于CAC，说明堆肥过程中DOM芳香化和腐殖化的速度与程度均优于CAC. FTIR分析显示，EAAC过程中DOM的碳水化合物、脂肪类物质逐渐减少，芳香族化合物不断增加，其腐殖化趋势明显比CAC更快.相关性分析显示，P_Ⅴ，n/P_Ⅲ，n与A_240~400、SUVA₂₅₄、E₂₅₃/E₂₂₀等UV-Vis光谱指标呈显著正相关（r>0.8， p<0.05），可以作为评价EAAC腐熟度的重要指标.上述结果表明，电场辅助好氧堆肥可加速DOM中蛋白类物质分解，加快富里酸和腐殖酸类物质形成，促进DOM结构的芳香化.

Spectrum analysis of the evolution of DOM during electric-field assisted aerobic composting for the treatment of livestock and poultry manure treatment

Aerobic composting is the main method for the disposal and resource utilization of livestock and poultry manure. However, the low temperature, long fermentation period, and poor composting effect are practical problems that exist in conventional aerobic composting (CAC) technology. A recent study has found that electric-field assisted composting (EAAC) can accelerate the maturation of aerobic compost quickly, short the composting period, and reduce greenhouse gas emissions, suggesting a great application potential. However, the effects of the electric field on the evolution and humification process of dissolved organic matter (DOM) during composting remain unclear. In this paper, the evolution rule of DOM during EAAC is explored for the first time via the use of the synthetic ultraviolet-visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR), and three-dimensional excitation-emission (3D-EEM) techniques. The UV-Vis and 3D-EEM analysis results indicate that the protein-like materials in the DOM of EAAC were almost completely degraded within 3 days, and large amounts of humic acid (HA)-like and fulvic acid (FA)-like materials were formed during the high-temperature period (days 6~18). The humification index (HI=HA/FA) of EAAC was higher than that of CAC, and the E₄/E₆ ratio was lower than that of CAC, indicating that the speed and degree of DOM aromatization and humification during EAAC were better than those during CAC. The FTIR spectra demonstrate that, in EAAC, the carbohydrates and fatty substances in the DOM gradually decreased and the number of aromatic compounds increased, indicating that the humification during EAAC was faster than that during CAC. The correlation analysis results indicate that P_V,n/P_III,n had significant positive relationships with A_240~400, SUVA₂₅₄, and E₂₅₃/E₂₂₀ (r> 0.8, p<0.05), demonstrating their potential as indicators for the maturity of EAAC. The results confirm that EAAC accelerated the decomposition of protein substances, enhanced the formation of FA-like and HA-like materials, and promoted the aromatization of DOM.