生物型凹凸棒基高分子固沙材料的制备与性能研究

发布时间：2018-06-28 16:57

本文选题：蓝藻结皮 + 苔藓结皮　；参考：《兰州交通大学》2017年博士论文

【摘要】：沙漠化是当今全球面临的主要生态环境问题之一,不但对社会经济效益产生明显的负面影响,还严重威胁到人类的生存和可持续发展。由于生态环境的破坏,目前我国成为世界上沙漠化面积较大及危害程度较严重的国家之一。因此,研制各项新型固沙材料对于沙漠化的防治具有重要的理论及实际意义。生物结皮是由土壤微生物、藻类结皮、地衣结皮和苔藓结皮等与土壤形成的一个复合的生物土壤层,它的存在、发展对于沙漠化环境的改善具有重要价值,如可以加强沙漠化土壤表面的抗侵蚀能力,保持沙漠化土壤水分,改善沙漠化土壤的养分条件,为沙漠化地区植被的恢复创造有利条件等,因此一直是沙漠学研究的重要领域,受到国内外学者的重视。凹凸棒土特殊的链层状晶体结构,该结构使凹凸棒土具有许多独特的物理化学性质,凹凸棒土经酸改性后带有活性羟基,可通过吸附架桥作用引入不同的高分子,生成带有某些特定官能团的高分子,从而赋予凹凸棒土新的性能,使其具有更好的吸水性、保水性和吸附性。由于沙漠地区较高的昼夜气温差异和较大范围的温度波动,使单纯的生物结皮在干燥的环境条件下存活率下降,从而影响其固沙效果。但将制备的复合高分子材料(过硫酸钾-丙烯酰胺-凹凸棒土复合物)与人工生物结皮按一定质量比配比、在系列环境条件下进行复配,是否能制备出对环境无二次污染,更具有营养性及固沙性的新型固沙材料呢?因此,本研究拟以人工培养的沙漠生物结皮、功能化的凹凸棒土及高分子材料为材料,通过实验测定其生物活性和不同环境条件下的自繁殖能力,探索沙漠生物结皮的优化扩增基质和控制因素,确定功能化凹凸棒土与高分子材料的优化复合条件。并根据实验结果,将生物结皮、功能化的凹凸棒土、高分子材料三者进行优化复配,制备具有自繁殖能力的生物型高分子固沙材料。主要研究内容如下:通过将蓝藻结皮和苔藓结皮接种到5种不同的培养液(MS、Knop、Beneck、BG11和BBM)中生长15天,依据蓝藻结皮和苔藓结皮生长状况,用光镜观察细胞的死亡,破损、污染数量和污染程度,确定蓝藻结皮和苔藓结皮的培养基为BBM和MS,然后在光照培养箱中大量培养。通过不同时间、温度和光照强度对蓝藻结皮的叶绿素a含量、丙二醛(MDA)含量、可溶性蛋白含量以及可溶性糖含量的变化分析,得出25℃的温度和120μE·m-2·s-1的光照强度是光照培养箱内适合蓝藻结皮生长的最佳环境条件,在此环境条件下蓝藻结皮受到的环境胁迫最小并且能够快速生长。通过不同时间、温度和光照强度对苔藓结皮的叶绿素a含量、MDA含量、可溶性蛋白含量以及可溶性糖含量的变化分析,得出30℃的温度和120μE·m-2·s-1的光照强度是光照培养箱内适合苔藓结皮生长的最佳环境条件,在此环境条件下苔藓结皮受到的环境胁迫最小并且能够快速生长。通过用1 mol·L-1、2 mol·L-1、3 mol·L-1、4 mol·L-1、5 mol·L-1和6 mol·L-1硫酸改性凹凸棒土,研究其吸水性能、保水性能及pH变化对吸水率的影响,得出4 mol·L-1硫酸改性的凹凸棒土具有最好的吸水性能和保水性能,4 mol·L-1硫酸改性的凹凸棒土的吸水率受pH值的变化影响最大;并进一步用X衍射以及扫描电镜分析其表征,得出3 mol·L-1和4 mol·L-1硫酸改性的凹凸棒土具有最好的吸附性。通过研究不同浓度的硫酸改性凹凸棒基高分子固沙材料的吸水性能、保水性能及pH值变化对吸水率的影响,得出4 mol·L-1硫酸改性的凹凸棒基高分子固沙材料具有最好的吸水性能和保水性能,4 mol·L-1硫酸改性的凹凸棒基高分子固沙材料的吸水率受pH值的变化影响最大;并进一步用X衍射以及扫描电镜分析不同浓度硫酸改性的凹凸棒基高分子固沙材料的表征,得出3 mol·L-1和4 mol·L-1硫酸改性的凹凸棒基高分子固沙材料具有最好的吸附性。通过蓝藻结皮和4 mol·L-1硫酸改性后的凹凸棒基高分子固沙材料以不同质量比复配后的生物活性的研究,得出蓝藻结皮与4 mol·L-1硫酸改性后的凹凸棒基高分子固沙材料以1:3质量比配比生长情况最佳;进一步研究400 g·m-2和500 g·m-2两种喷洒量对结皮生长过程中叶绿素a含量、MDA含量、可溶性蛋白含量和可溶性糖含量产生不同影响,得出喷洒量为500 g·m-2的蓝藻结皮复配4 mol·L-1硫酸改性后的凹凸棒基高分子固沙材料的生理特性最好。通过苔藓结皮和4 mol·L-1硫酸改性后的凹凸棒基高分子固沙材料以不同质量比复配后的生物活性的研究,得出苔藓结皮与4 mol·L-1硫酸改性后的凹凸棒基高分子固沙材料以1:4质量比配比生长情况最佳;进一步研究400 g·m-2和500 g·m-2两种喷洒量对结皮生长过程中叶绿素a含量、MDA含量、可溶性蛋白含量和可溶性糖含量产生不同影响,得出喷洒量为500 g·m-2的苔藓结皮复配4 mol·L-1硫酸改性后的凹凸棒基高分子固沙材料的生理特性最好。通过实验结果,本研究找出了一套生物型复合高分子固沙材料的优化制备方法,制备出了具有自繁殖能力和生物活性的新型的蓝藻型和苔藓型凹凸棒基高分子固沙材料,而且制备需要的原材料丰富、便宜、易得,因此具有广阔的应用前景。
[Abstract]:Desertification is one of the main ecological environmental problems facing the world today. It not only has a significant negative impact on the social and economic benefits, but also seriously threatens the survival and sustainable development of human beings. Because of the destruction of the ecological environment, China has become one of the countries with greater desertification area and serious harm in the world. Various new sand fixing materials have important theoretical and practical significance for the prevention and control of desertification. Biological crust is a composite soil layer formed by soil microorganism, algae crust, lichen crust and moss crust. Its existence and development are of great value for the improvement of desertification environment, such as strengthening the desertification environment. The anti erosion ability of desertification soil surface, maintaining the soil moisture of desertification soil, improving the nutrient conditions of desertification soil, creating favorable conditions for the restoration of vegetation in the desertification area, has been an important field in the study of desert science, and has been paid much attention by scholars at home and abroad. The special chain layer crystal structure of attapulgite soil has made the concave and convex structure. The rod soil has many unique physical and chemical properties. The attapulgite soil has the active hydroxyl group after acid modification. It can be introduced to different polymers by adsorption and bridging to produce polymers with certain functional groups, which endows the attapulgite soil with new properties, so that it has better water absorption, water retention and adsorption. Higher day and night temperature difference and large range of temperature fluctuation make the survival rate of simple biological crust decrease under the dry environment, which affects its sand fixing effect. But the composite polymer material (potassium persulfate acrylamide - attapulgite complex) and artificial biological crust are proportioning to a certain quality ratio in a series of environment. Is it possible to prepare a new type of sand fixing material which has no two pollution to the environment and is more nutritious and sand fixing? Therefore, this study is to use the cultivated desert biological crusts, functionalized attapulgite and polymer materials as materials, and determine their biological activity and self reproduction under different environmental conditions by experiments. The optimized matrix and control factors of the desert biological crust were explored, and the optimized compound conditions of the functional attapulgite and polymer were determined. According to the experimental results, the biological crust, the functional attapulgite soil and the polymer materials were optimized and mixed to prepare the biotype polymer solid sand fixing material with self reproduction ability. The main contents are as follows: by inoculating cyanobacteria crust and moss crust to 5 different cultures (MS, Knop, Beneck, BG11 and BBM) for 15 days, according to the growth status of cyanobacteria crust and moss crust, the cell death, damage, pollution quantity and degree of pollution are observed by light microscope, and the culture medium of cyanobacteria crust and moss crust is determined to be BBM And MS, and then in the light culture incubator, the content of chlorophyll a, the content of malondialdehyde (MDA), the soluble protein content and the soluble sugar content of cyanobacteria were analyzed at different time, temperature and light intensity. The temperature of 25 C and the light intensity of 120 mu E. M-2. S-1 were suitable for cyanobacteria in the incubator. Under the environment conditions, the cyanobacterium crust was subjected to minimal environmental stress and can grow rapidly. The temperature and light intensity were used to analyze the chlorophyll a content, MDA content, soluble protein content and soluble sugar content of moss crust by different time, temperature and light intensity. The temperature of 30 C and 120 E. M-2. S-1 were obtained. Light intensity is the best environmental condition suitable for the growth of lichen crust in a light incubator. Under the environment, the bryophyte crust has the smallest environmental stress and can grow rapidly. The water absorption and water retention properties of the 1 mol. L-1,2 mol. L-1,3 mol. L-1,4 mol. L-1,5 mol L-1 and 6 mol L-1 sulphuric acid modified attapulgite are studied. And the effect of pH change on the water absorption, it is concluded that the attapulgite soil modified by 4 mol. L-1 has the best water absorption and water retention properties. The water absorption of 4 mol. L-1 modified attapulgite soil is affected most by the change of pH value, and the characterization of 3 mol. L-1 and 4 mol. L-1 sulphuric acid modification is obtained by X diffraction and scanning electron microscopy. The attapulgite soil has the best adsorbability. By studying the water absorption properties, water retention property and the influence of the change of pH value on the water absorption of different concentration of sulphuric acid modified attapulgite based polymer sand fixing material, it is concluded that the 4 mol. L-1 modified attapulgite based polymer sand fixing material has the best water absorption and water retention property, and 4 mol. L-1 sulphuric acid modification. The water absorption of the attapulgite based polymer sand fixing material is most affected by the change of pH value, and the characterization of the attapulgite based polymer sand fixing material with different concentration of sulfuric acid modified by different concentrations is analyzed by X diffraction and scanning electron microscope, and the best adsorbability of the attapulgite based polymer sand fixing material of 3 mol. L-1 and 4 mol. L-1 sulphuric acid modification is obtained. The attapulgite based polymer solid sand material based on cyanobacterial crust and 4 mol L-1 sulphuric acid was studied with the biological activity of different mass ratios, and the best of the attapulgite based polymer sand fixing material after the modification of the cyanobacterial crust and 4 mol. L-1 sulfate was obtained with the ratio of 1:3 mass ratio, and the further study of 400 g m-2 and 500 g. M-2 two Different spraying amounts have different effects on the content of chlorophyll a, MDA content, soluble protein content and soluble sugar content during the growth process of the crust. It is concluded that the physiological characteristics of the attapulgite based polymer sand fixing material with 500 g / m-2 of cyanobacteria crust and 4 mol. L-1 sulphuric acid modification is the best. By the moss crust and 4 mol. L-1 sulphuric acid modification After the study of the bioactivity of the attapulgite based polymer sand fixing material with different mass ratio, it is concluded that the attapulgite based polymer sand fixing material after the modification of the moss crust and 4 mol L-1 sulfuric acid is the best in the ratio of 1:4 mass ratio, and further studies the two kinds of spraying amount of 400 g. M-2 and 500 g. M-2 in the growth process of the crust. The content of a, the content of MDA, the content of soluble protein and the content of soluble sugar have different effects. It is concluded that the physiologic characteristics of the attapulgite based polymer sand fixing material with 500 g / m-2 moss crust compound and 4 mol. L-1 sulphuric acid modification is the best. The optimization of a set of biological composite polymer sand fixing materials is found through the experimental results. A new type of cyanobacteria and moss attapulgite based polymer sand fixing materials with self reproduction ability and bioactivity are prepared, and the raw materials for preparation are rich, cheap and easy to obtain. Therefore, it has a broad application prospect.
【学位授予单位】：兰州交通大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：S288

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