红外光谱结合热重法对3种作物秸秆腐解特征的分析  

Decomposition characteristics of 3 crop straws based on the infrared spectroscopy combined with thermogravimetry

作　　者：陈丽鹃 张锦秀 范伟 粟桂蓉 李伟鹏[2] 谢慧玲 李雨[2] 周喜新 CHEN Li-juan;ZHANG Jin-xiu;FAN Wei;SU Gui-rong;LI Wei-peng;XIE Hui-ling;LI Yu;ZHOU Xi-xin(Key Laboratory of Tobacco Science and Health,Hunan Agricultural University,Changsha,Hunan 410128,China;China Tobacco Jiangsu Industrial Co.,Ltd.,Nanjing,Jiangsu 210019,China;Baoshan Company,Yunnan Tobacco Company,Baoshan,Yunnan 678000,China)

机构地区：[1]湖南农业大学烟草科学与健康重点实验室,湖南长沙410128 [2]江苏中烟工业有限责任公司,江苏南京210019 [3]云南省烟草公司保山市公司,云南保山678000

出　　处：《南方农业学报》2024年第9期2591-2601,共11页Journal of Southern Agriculture

基　　金：湖南省自然科学基金项目(2021JJ30333);湖南省教育厅优秀青年项目(21B0185);云南省烟草公司保山市公司科技项目(2021530000242013);江苏中烟工业有限责任公司科技项目(2024kjc-yc006)。

摘　　要：【目的】通过模拟试验明确3种作物秸秆腐解过程中的物质结构变化规律,为烟田秸秆的合理利用提供理论依据。【方法】以烟草、油菜和水稻3种作物秸秆为研究对象,采用尼龙网袋法模拟腐解180 d,应用傅里叶红外光谱及热重(TG)分析研究3种作物秸秆在干湿交替和淹水2种土壤水分条件下的腐解特性差异。【结果】3种作物秸秆在180d时腐解率达55.69%~69.39%,表现为水稻秸秆>油菜秸秆>烟草秸秆;同一秸秆在2种土壤水分条件下的腐解率表现为干湿交替处理>淹水处理,但差异较小。红外光谱分析结果显示3种作物秸秆的官能团组成存在一定的相似性,在3420、2920、1640、1380、1050和610 cm^(-1)处共有吸收峰,但在某些特征吸收峰和吸收峰相对强度呈现差异,表明这些吸收峰所对应的物质及含量有所不同。烟草秸秆的1640 cm^(-1)/2920cm^(-1)和1640 cm^(-1)/1050cm^(-1)相对强度比值最大,芳香族化合物含量相对较高。随着腐解的进行,3种作物秸秆红外光谱吸收峰及其相对强度发生变化,碳水化合物、酰胺化合物和脂肪族化合物逐步分解,生成了碳酸盐、铵盐、硝酸盐和羧酸盐等,水稻秸秆中元素硅逐步释放形成二氧化硅和硅酸盐。TG分析显示,3种作物秸秆TG-微商热重(DTG)曲线上200~400℃阶段的失重率达55.00%以上,是秸秆挥发分析出的主要阶段。200~400℃和600~700℃阶段失重率分别以油菜秸秆(58.71%)和烟草秸秆(6.38%)最大,水稻秸秆900℃残留质量百分比最高(23.17%)。腐解末期(180 d)3种作物秸秆的固定碳百分比和挥发分质量分数差异显著(P<0.05),但同一作物秸秆在不同水分条件下差异不显著(P>0.05);其中,水稻秸秆固定碳百分比最高(平均值17.32%),挥发分质量分数最低,而油菜秸秆挥发分质量分数较高,固定碳百分比最低,平均值为11.69%。【结论】红外光谱结合热重法可对模拟还田秸秆的降解状况进行分【Objective】Simulated experiments were conducted to clarify the structural characteristics of organic substances of three crop straws during the decomposition process so as to provide theoretical basis for rational utilization of tobacco field straws.【Method】Using tobacco,rape,and rice straws as research objects,the nylon mesh bag method was used to simulate decomposition for 180 d.Fourier transform infrared spectroscopy and thermogravimetric(TG)analysis were applied to study the differences in decomposition characteristics of the three crop straws under two soil moisture conditions of dry wet alternation and flooding.【Result】The decomposition rate of three straws at 180 d reached 55.69%to 69.39%,with rice straw>rape straw>tobacco straw.The decomposition rate of the same straw under two different soil moisture conditions showed wet dry alternation treatment>flooding treatment,but the difference was small.There were similarities in the functional group composition of the three crop straws,sharing absorption peaks at 3420,2920,1640,1380,1050,and 610 cm^(-1) revealed by infrared spectroscopy analysis.However,the relative intensities of some characte-ristic absorption peaks and absorption peaks were varied,showing that the corresponding material and content of these absorption peaks were different.The ratio of relative intensities of 1640 cm^(-1)/2920 cm^(-1)and 1640 cm^(-1)/1050 cm^(-1)in tobacco straw were the highest,indicating a higher content of aromatic compounds of tobacco straw.As the decomposition progressed,the infrared spectrum characteristic absorption peaks and their relative intensities of the three straws changed.Carbohydrates,amide compounds and aliphatic compounds gradually decomposed to form carbonates,ammonium salts,nitrates and carboxylates.The element silicon in rice straw was released to form silicon dioxide and silicates.The TG-DTG curve analysis showed that the weight loss during the 200-400℃stage of the three straws reached over 55.00%,which was the main stage for the release of

关 键 词：作物秸秆 腐解特性 红外光谱分析 热重分析 

分 类 号：S141.1[农业科学—肥料学]