褐煤添加对羊粪有机肥发酵过程中水溶性有机物光谱学变化特征的影响

Effects of Lignite Addition on the Spectral Characteristics of Dissolved Organic Matter During Fermentation of Sheep Manure Organic Fertilizer

研究添加褐煤对羊粪有机肥中水溶性有机物(DOM)光谱学特性的影响,为高腐殖酸有机肥的腐熟度评价提供依据。以内蒙古褐煤、羊粪为原料,添加10%褐煤进行羊粪有机肥发酵,对不同阶段有机肥样品的DOM进行紫外可见光谱、荧光光谱、FTIR的表征。紫外-可见吸收光谱分析显示,有机肥样品的E4/E6值随着有机肥发酵的进行呈现出先下降后上升的趋势,由有机肥开始时的9.110 4降至最低为4.647 7,再升为有机肥结束时的5.390 1;A1呈现先减小后增大趋势,A2和A3均呈现先增大后减少的趋势,峰值出现在12d。同步荧光光谱显示,荧光峰光强的比值(I470/I435)由有机肥起始的0.452 8上升至有机肥结束的0.655 2;AHLR/AFLR呈现上升趋势,从有机肥开始的0.673 9上升至有机肥结束的1.040 8。经过18d的有机肥发酵后,有机肥发酵结束后样品荧光强度小于有机肥起始时的荧光强度,而且10%褐煤添加的羊粪有机肥的相对荧光强度明显高于未添加褐煤的荧光强度。FTIR显示,18d的有机肥发酵过程中DOM中的碳水化合物、蛋白质被逐渐分解,而羧基、含苯环的物质含量明显增加。随着发酵的进行,DOM中的非腐殖质物质转化为类腐殖质,不饱和结构的多聚化或联合程度变大,稳定度增加;添加褐煤可以有效促进羊粪中木质素类物质的分解,提高羊粪有机肥DOM的芳构化程度,促进羊粪有机肥腐熟。

Effects of adding lignite on the spectral properties of dissolved organic matter(DOM)in sheep manure organic fertilizer were obtained,which provided a basis for the evaluation of the maturity of high humic acid organic fertilizer.Inner Mongolia lignite and sheep manure were used as raw materials,10%lignite was added to ferment organic fertilizer of sheep manure,and the DOM extracted from organic fertilizer samples at different stages was analyzed by UV-visible spectrum analysis,fluorescence spectrum analysis and Fourier Transform infrared spectroscopy.Ultraviolet-visible absorption spectroscopy analysis showed that the E465/E665value of organic fertilizer samples decreased first and then increased with the fermentation of organic fertilizer. From 9.110 4at the beginning of organic fertilizer to a minimum of 4.647 7,and then to 5.390 1at the end of organic fertilizer, A1showed a decrease and then increased,and both A2and A3showed a trend of increasing first and then decreasing,and the peak appeared at 12d.Synchronous fluorescence spectroscopy showed that the ratio of fluorescence peak intensity(I470/I435)increased from 0.452 8starting from organic fertilizer to 0.655 2at the end of organic fertilizer,and AHLR/AFLRshowed an upward trend,rising from 0.673 9for organic fertilizer to 1.040 8for organic fertilizer.After 18dof organic fertilizer fermentation,the fluorescence intensity of the organic fertilizer after fermentation was lower than that of the organic fertilizer at the beginning,and the relative fluorescence intensity of the 10%lignite-added sheep manure organic fertilizer was significantly higher than that of the un-added lignite.Fourier transform infrared spectroscopy showed that carbohydrates and proteins in DOM were gradually decomposed during the fermentation of organic fertilizer for 18d,while the content of carboxyl groups and benzene ring-containing substances increased significantly.With the progress of fermentation,the non-humus substances in DOM are converted into humus- like substances,the degree of polymerization or aggregation of unsaturated structures becomes larger,and the stability increases. The addition of lignite can effectively promote the decomposition of lignin substances,improve the degree of aromatization of DOM and accelerate the maturity of organic fertilizer.