寒旱区湖泊沉积物中有机磷的地球化学特征研究

发布时间：2019-02-27 06:29

【摘要】：有机磷是湖泊生态系统的重要组分,是营养物质生物地球化学循环和生命过程的重要环节,也是沉积磷的主要形态,对湖泊富营养化具有重要作用和贡献。本研究以寒旱区特征显著、湖泊类型差异明显的乌梁素海和呼伦湖为研究对象,以有机磷形态研究为基础,以有机磷的生物有效性研究为主线,厘定了寒旱区不同类型湖泊有机磷的地球化学特征,表征了不同类型湖泊沉积物中的有机磷化合物,阐释了有机磷的时空分布特征及机制,采用31P-NMR分析了有机磷化合物在沉积柱芯中的分布规律,综合判识和评价了寒旱区不同类型湖泊有机磷的生物有效性,对阐释水环境中有机磷的环境行为,积累我国湖泊生态系统中有机磷研究的基础资料,加强暖湿区与寒旱区湖泊有机磷生物有效性的对比研究等均有重要的理论与现实意义。主要进展如下：1.采用化学连续提取法,开展了2个湖泊沉积物中有机磷的地球化学特征研究。结果表明,乌梁素海沉积物中有机磷的主导形态为盐酸提取态有机磷(HCl-OP)和残渣态有机磷(Re-OP),呼伦湖沉积物中残渣态有机磷(Re-OP)为主导形态；2个湖泊沉积物中存在活性有机磷(LOP)中活性有机磷(MLOP)非活性有机磷(NLOP)的含量序列。2.采用31P-NMP,厘定了2个湖泊沉积物中的有机磷化合物组分。结果显示,2个湖泊表层沉积物中有机磷化合物的信息相对丰富,随着沉积深度增加,稳定性不高的有机磷成分不再检出。3.研究发现,乌梁素海柱芯活性有机磷(LOP)与氧化还原电位(ORP)存在较好的对应关系,揭示有机质降解对LOP的释放作用；呼伦湖沉积柱芯中,铁磷(Fe-P)/总有机碳(TOC)与盐酸提取态有机磷(HCl-OP)/NaOH提取有机磷(NaOH-OP)呈显著正相关,表明了铁氧化物固定有机磷的能力,揭示NaOH提取有机磷和盐酸提取态有机磷的相互转化是沉积物有机磷形态转化和再分布的主要驱动力。4.研究了乌梁素海水-沉积物界面磷的扩散机制及冰封期乌梁素海冰体中磷的形态分布,为寒旱区湖泊中磷在不同界面的环境地球化学行为研究积累了基础资料。5.在集成已有研究成果的基础,综合分析了我国典型湖泊沉积物中有机磷形态分布的差异机制。结果表明,蒙新高原和青藏高原湖泊沉积物中各形态有机磷的含量水平显著低于长江中下游及云贵高原湖泊,反映了不同湖区在自然地理环境、气候条件及区域经济社会发展水平等方面存在的差异。
[Abstract]:Organophosphorus phosphorus is an important component of lake ecosystem, an important link of nutrient biogeochemical cycle and life process, and also the main form of phosphorus deposit. It plays an important role and contributes to eutrophication of lakes. In this study, Wuliangsuhai and Hulun Lake, which have obvious characteristics in cold and arid areas and obvious differences in lake types, were taken as the object of study, based on the study on the forms of organophosphorus, and the main line was the study on the bioavailability of organophosphorus. The geochemical characteristics of organophosphorus compounds in different types of lakes in cold and arid areas were determined, the organophosphorus compounds in sediments of different types of lakes were characterized, and the spatial and temporal distribution characteristics and mechanisms of organophosphorus were explained. The distribution of organophosphorus compounds in sediment core was analyzed by 31P-NMR, the bioavailability of organophosphorus compounds in different lakes in cold and arid areas was comprehensively identified and evaluated, and the environmental behavior of organophosphorus in water environment was explained. It is of great theoretical and practical significance to accumulate the basic data of organophosphorus studies in lake ecosystems in China and to strengthen the comparative study on the bioavailability of organophosphorus in lakes in warm and wet areas and cold and arid areas. The main developments are as follows: 1. The geochemical characteristics of organophosphorus in sediments of two lakes were studied by chemical continuous extraction. The results showed that the dominant forms of organophosphorus in the sediments of Wuliangsuhai were hydrochloric acid extracted organic phosphorus (HCl-OP) and residual organophosphorus phosphorus (Re-OP), and the residual organophosphorus (Re-OP) in the sediment of Hulun Lake was the dominant form. The content sequence of active organophosphorus (MLOP) inactive organophosphorus (NLOP) in two lake sediments exists in active organophosphorus (LOP). The organophosphorus compounds in the sediments of two lakes were determined by 31p / NMP. The results showed that the information of organophosphorus compounds in the surface sediments of the two lakes was relatively abundant, and the unstable organophosphorus components were no longer detected with the increase of deposition depth. It was found that there was a good correspondence between the active organophosphorus (LOP) and the redox potential (ORP) in the core of Wuliangsu Sea, which revealed the release of LOP by the degradation of organic matter. In the core of Hulun Lake, iron phosphorus (Fe-P) / total organic carbon (TOC) was positively correlated with hydrochloric acid extracted organophosphorus (HCl-OP) / NaOH extraction of organophosphorus (NaOH-OP), indicating the ability of iron oxide to immobilize organophosphorus. It is revealed that the mutual transformation of organophosphorus extracted by NaOH and hydrochloric acid is the main driving force for the transformation and redistribution of organophosphorus species in sediments. 4. The diffusion mechanism of phosphorus at the sea-sediment interface of Wuliangsu and the speciation distribution of phosphorus in the sea ice body of Wuliangsu during the ice sealing period were studied, which accumulated the basic data for the study of the environmental geochemical behavior of phosphorus at different interfaces in the lakes in the cold and arid areas. 5. On the basis of integrating existing research results, the differential mechanism of organophosphorus speciation distribution in sediments of typical lakes in China was comprehensively analyzed. The results showed that the contents of various forms of organophosphorus in lake sediments of the new and Qinghai-Xizang plateau were significantly lower than those in the middle and lower reaches of the Yangtze River and in the Yungui plateau, reflecting the physical and geographical environment of the different lakes. Climate conditions and regional economic and social development level and other aspects of differences.
【学位授予单位】：内蒙古大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：X142

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