赤红壤区粘土矿物对土壤有机质的固存与转化机理的研究

发布时间：2019-04-17 09:14

【摘要】：本文研究了粘土矿物及铁铝氧化物对有机物的短期吸附特征及其受浓度和pH值的潜在影响,采用室内培养法研究了模拟土壤和去除有机质的土壤对葡萄糖、马尾松凋落物添加的呼吸响应,采用扫描电镜方法研究了粘土矿物对有机物的吸附位置,采用傅立叶热红外法研究了有机矿物复合体化学键特征及不同培养阶段有机矿物复合体的化学结构变化,旨在加深对粘土矿物、铁铝氧化物与土壤有机碳化学保护的认识,揭示粘土矿物与有机质吸附的机理。(1)高岭土、蛭石、伊利石、蒙脱石和氧化铝对通过阳离子交换对亚甲基蓝进行吸附,表现为蒙脱石高岭土伊利石蛭石氧化铝。(2)高岭土、伊利石和蒙脱石主要通过氢键和分子间水合作用吸附胡敏酸。具有吸附胡敏酸能力的5种物质对胡敏酸的吸收值表现为：高岭土蒙脱石伊利石二氧化锰氧化铁；随着胡敏酸pH值的增加,高岭土、伊利石和二氧化锰对胡敏酸的吸收量减少。(3)具有吸附淀粉能力的6种矿物质对淀粉溶液的吸收量表现为氧化铁高岭土氧化铝蒙脱石二氧化锰碳酸钙。随着淀粉溶液的pH变大,氧化铁、二氧化锰和氧化铝对淀粉溶液的吸收量都是随着pH值的减小；高岭土、蒙脱石、碳酸钙这三种物质则表现为先增加再减少。(4)添加葡萄糖或马尾松凋落物的模拟土壤里中微生物释放二氧化碳的速率在培养初期,先急剧增加,随着培养时间的进行,模拟土壤中微生物分解释放二氧化碳的速率逐渐减弱直至稳定。三种模拟土壤加入葡萄糖后的累积矿化量依次是：90%矿物50%矿物100%石英砂；三种添加马尾松凋落物的模拟土壤的累积矿化量大小表现为：90%矿物100%石英砂50%矿物。添加葡萄糖后,三种模拟土壤经过3个月的矿化分解后,有烯烃类物质和芳环类物质产生。(5)以石英砂为对照,添加有机物的3种土壤中,微生物分解产生二氧化碳的速率都符合对数函数关系。添加葡萄糖的土壤在整个培养期的10-20左右才能达到培养期间内最大的二氧化碳释放速率,随着培养时间的进行而逐渐减弱直至平稳；添加马尾松凋落物的土壤则是在第3天就可达到最大二氧化碳释放速率,随着培养时间的延长,3种土壤中微生物产生二氧化碳的速率逐渐变小直至稳定。3种土壤添加了葡萄糖后的累积矿化量依次是：页岩花岗岩第四纪红土；添加了马尾松凋落物的土壤的累积矿化量大小同样表现为：页岩花岗岩第四纪红土。添加葡萄后,3种土壤表现出：花岗岩产生了烯类物质；页岩和第四纪红土则是烷烃类物质减少。
[Abstract]:In this paper, the short-term adsorption characteristics of clay minerals and Fe-Al oxides on organic matter and their potential effects on organic matter concentration and pH were studied, and the effects of glucose on organic matter removal by simulated soil and soil with organic matter removal were studied by indoor culture method. The respiration response of Pinus massoniana litter was studied by means of scanning electron microscopy (SEM), and the adsorption sites of clay minerals to organic matter were studied. The chemical bond characteristics of organic mineral complexes and the chemical structure changes of organic mineral complexes in different culture stages were studied by means of Fourier transform thermal infrared (FTIR) method in order to deepen the understanding of the chemical protection of clay minerals, iron and aluminum oxides and soil organic carbon. The adsorption mechanism of clay minerals with organic matter was revealed. (1) Kaolin, vermiculite, Illite, montmorillonite and alumina adsorbed methylene blue through cation exchange. Montmorillonite kaolinite Illite vermiculite alumina. (2) kaolinite Illite and montmorillonite adsorbed humic acid mainly through hydrogen bonds and intermolecular hydration. The absorption of humic acid by five kinds of substances is as follows: kaolin montmorillonite Illite ferromanganese oxide; With the increase of humic acid pH value, kaolin, The absorption of humic acid by Illite and manganese dioxide decreases. (3) the absorption of starch solution by six minerals which have the ability to adsorb starch is as follows: iron oxide kaolin alumina montmorillonite manganese dioxide calcium carbonate. With the increase of pH in starch solution, the absorption of Fe _ 2O _ 2, mn _ 2O _ 2 and Al _ 2O _ 3 to starch solution decreased with the increase of pH value. Kaolinite, montmorillonite and calcium carbonate appeared to increase first and then decrease. (4) the rate of carbon dioxide released by microorganisms in simulated soil supplemented with glucose or litter of Masson pine increased sharply at the beginning of culture. As the culture time went on, the rate of decomposition and release of carbon dioxide in simulated soil decreased gradually and became stable. The cumulative mineralized amounts of the three simulated soils with glucose addition were 90% mineral 50% mineral 100% quartz sand and 90% mineral 100% quartz sand 50% mineral in the simulated soil with the addition of litter of Pinus massoniana. After adding glucose, after three months of mineralization and decomposition, olefin and aromatic ring substances were produced in three simulated soils. (5) compared with quartz sand, organic compounds were added in three kinds of soil. The rate at which microorganisms decompose to produce carbon dioxide conforms to a logarithmic function. The soil supplemented with glucose could reach the maximum rate of CO _ 2 release during the whole culture period at about 10 ~ 20, and gradually weakened to a steady state with the time of culture. The soil added with litter of Pinus massoniana could reach the maximum rate of carbon dioxide release on the 3rd day, as the culture time extended, The rate of carbon dioxide produced by microorganisms in the three soils decreased gradually and became stable. The cumulative mineralized amount of the three soils added glucose was in turn: Quaternary laterite of shale granite; The accumulative mineralized amount of soil added with litter of Pinus massoniana is also shown as follows: shale granite Quaternary red soil. When grape was added, the three soils showed that the granites produced alkenes and the shale and Quaternary red soil were alkanes.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S153.6

【参考文献】