黄河内蒙古段沉积物对磷的吸附行为及微生物多样性分析

发布时间：2018-04-27 13:37

本文选题：黄河沉积物 + 磷　；参考：《内蒙古师范大学》2017年硕士论文

【摘要】：生源物质磷是组成生物体不可或缺的元素之一。黄河水体环境中,沉积物是磷的积累和再生的重要场所,对磷循环有重要影响。本研究选取黄河内蒙古段乌海、临河、乌拉特前旗、包头、托县和老牛湾六个采样点2013、2014年秋季,2015、2016年夏季共24个表层沉积物为研究对象,测定了沉积物、上覆水的物理化学性质及各形态磷的含量,模拟研究了磷在黄河表层沉积物上的吸附特征,运用吸附动力学模型、等温吸附模型对实验数据进行拟合,分析沉积物理化性质、微生物等因素对其的影响,并选取乌海海勃湾水利大坝对磷通量进行了估算,分析了黄河沉积物中微生物的多样性并简单探讨了磷细菌在磷形态转换过程中的作用。得出结论:(1)沉积物中总细菌量最大值出现在乌海样品中(3.6×109),最低值出现在老牛湾(1.1×109),平均值为2.58×109;磷细菌数目最大值出现在前旗(3.93×105),最小值出现在托县(8.57×104),平均值是1.98×105。上覆水总磷含量高的沉积物样品中总细菌含量也高;沉积物样品中总磷含量高,磷细菌总量高;沉积物样品中有机质含量高,磷细菌总量降低。(2)沉积物中总磷含量范围在954.067~2085.622 mg/kg,平均值是1139.91 mg/kg,各采样点总磷含量存在秋季夏季的季节差异性。沉积物的七种形态磷中,原生碎屑磷和钙结合态磷是沉积物中磷的主要赋存形态,含量范围分别为262.36~962.56 mg/kg和36.32~405.89mg/kg,二者共占总磷含量的74.37%。沉积物中不同形态磷含量与沉积物理化性质之间存在相关性,可交换态磷与阳离子交换量极显著正相关;铁结合态磷与阳离子交换量、沉积物烧失量显著正相关。总细菌利用可交换态磷或铝结合态磷进行生命活动所需含量较多,说明这两种形态磷更易被微生物直接分解利用。磷细菌含量主要与不易被微生物直接利用的磷含量正相关。(3)沉积物对磷吸附动力学遵循Lagergren准二级动力学方程。由拟合准二级动力学方程得出的平衡吸附量Qe与实验中所得吸附量的值较接近。总体来看,黄河沉积物对磷的吸附量夏季大于秋季。(4)沉积物对磷吸附热力学过程符合Langmiur和Freundlich方程,表明吸附介于单层吸附和多层吸附之间。拟合得出不同沉积物的吸附/解吸平衡浓度(EPC0)范围为0.0089~0.1499mg/g,与上覆水中磷浓度进行比较判断沉积物的“源”“汇”属性,并比较各年份EPC0大小及功能差异。利用2016年乌海的EPC0计算出磷通量为62.59kg。沉积物对磷的最大吸附量Qmax的范围0.0331~0.3062 mg·g-1,夏季平均值为0.1887mg·g-1,秋季为0.1557mg·g-1,即夏季秋季。沉积物拟合参数Qmax、Qe与沉积物中总有机碳、阳离子交换量正相关。(5)磷细菌培养实验后样品中,托县沉积物样品微生物种类减少,老牛湾沉积物样品微生物种类增多,两者微生物总量都呈下降趋势;磷细菌分解效率较高,主要促进Al-P转换为Obs-P并增加了生物可利用磷的总量。
[Abstract]:Phosphorus is one of the indispensable elements of living organisms. In the water environment of the Yellow River, sediment is an important place for phosphorus accumulation and regeneration, which has an important effect on phosphorus cycling. In this study, 24 surface sediments of Wuhai, Linhe, Wulat Qianqi, Baotou, Tuoxian and Laoniu Bay in Inner Mongolia section of the Yellow River were collected in 2013, 2015 in autumn 2014, and 24 surface sediments in summer 2016. The physical and chemical properties of overlying water and the contents of phosphorus in various forms were simulated to study the adsorption characteristics of phosphorus on the surface sediments of the Yellow River. The adsorption kinetics model and isothermal adsorption model were used to fit the experimental data to analyze the physical and chemical properties of the sediments. The effects of microorganism and other factors on the phosphorus flux were estimated by selecting the water conservancy dam of Wuhai Haibo Bay. The diversity of microbes in the sediment of the Yellow River was analyzed and the role of phosphorus bacteria in the process of phosphorus transformation was discussed. It is concluded that the maximum of total bacteria in sediment is 3.6 脳 10 ~ (9) in Wuhai, the lowest is in Laoniu Bay (1.1 脳 10 ~ (9), the average is 2.58 脳 10 ~ (9), the maximum of phosphorus bacteria is in Qianqi (3.93 脳 10 ~ (5), the minimum is 8.57 脳 10 ~ (4) in Towang County, the average is 1.98 脳 10 ~ (5). The total bacterial content in the sediment samples with high total phosphorus content in overlying water was also high, the total phosphorus content in the sediment samples was high, the total phosphorus bacteria content in the sediment samples was high, the content of organic matter in the sediment samples was high, The content of total phosphorus in sediment was 954.067 ~ 2085.622 mg / kg, with an average of 1139.91 mg / kg. Among the seven forms of phosphorus in sediments, primary detritus phosphorus and calcium bound phosphorus are the main forms of phosphorus in sediments, with the ranges of 262.36 ~ 962.56 mg/kg and 36.32 ~ 405.89 mg / kg, respectively, which account for 74.37 mg / kg of total phosphorus content. There was a significant positive correlation between exchangeable phosphorus and cation exchange capacity, iron bound phosphorus and cation exchange capacity, and sediment burning loss. The total bacteria need more contents of exchangeable phosphorus or aluminum-bound phosphorus for life activities, indicating that the two forms of phosphorus are more easily decomposed and utilized by microorganisms. Phosphorus bacteria content is mainly related to phosphorus content which is not easily directly used by microbes. 3) the kinetics of phosphorus adsorption by sediment follows the quasi-second-order kinetic equation of Lagergren. The equilibrium adsorption capacity Qe obtained by fitting the quasi second order kinetic equation is close to that obtained in the experiment. In general, the amount of phosphorus adsorbed by Yellow River sediment in summer is larger than that in autumn.) the thermodynamic process of phosphorus adsorption of Yellow River sediment accords with Langmiur and Freundlich equations, which indicates that the adsorption is between monolayer adsorption and multilayer adsorption. The range of adsorption / desorption equilibrium concentration (EPC0) of different sediments was 0.0089 ~ 0.1499mg / g, which was compared with the phosphorus concentration in overlying water to judge the "source" sink "attribute of sediment, and to compare the size and function of EPC0 in different years. The phosphorus flux is 62.59 kg. calculated by the EPC0 of the black sea in 2016. The maximum amount of phosphorus adsorbed by sediment was 0.0331g ~ (-1) 0.3062 mg / g ~ (-1), the average value was 0.1887mg g ~ (-1) in summer and 0.1557mg g ~ (-1) in autumn. The sediment fitting parameter Qmax-Qe was positively correlated with total organic carbon (TOC) and cation exchange capacity (cationic exchange capacity. 5) in the samples cultured with phosphorus bacteria, the species of microbes in sediment samples of Tuo county decreased, and the species of microbes in sediment samples of Laoniu Bay increased. The decomposition efficiency of phosphorus bacteria was higher, which mainly promoted the conversion of Al-P to Obs-P and increased the total amount of available phosphorus.
【学位授予单位】：内蒙古师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X52;O647.3;X176

【参考文献】