渤海采油平台改建鱼礁区悬浮物与磷酸盐的相互作用

发布时间：2018-09-18 06:23

【摘要】：沉积物是自然水体中磷循环的重要媒介,对水体中磷酸盐的浓度有重要影响。有研究表明,渤海富营养化的限制因子为磷,悬浮物和磷酸盐的吸附解吸作用将直接影响渤海中的磷浓度。退役采油平台改建鱼礁后将影响渤海局部海域的水动力条件,进而影响礁区的固体浓度以及颗粒物与水体的接触反应时间。EPC0(临界磷平衡浓度,Zero equilibrium phosphorus concentration)是悬浮物的重要属性,它与水中磷浓度共同决定悬浮物的源汇角色。本文以渤海埕岛油田海域为例,通过吸附动力学和等温实验,探讨了海洋悬浮物与低浓度的磷酸盐相互作用的波动动力学过程和固体浓度对EPC0的影响,并通过悬浮物无机磷的形态分析探讨了波动动力学过程中不同无机磷之间的转化。主要结论如下:(1)悬浮物与高/低浓度溶液中磷酸盐反应的动力学曲线具有明显差异。高磷浓度动力学曲线单调且易于达到反应平衡,而低磷浓度动力学曲线呈波动趋势,所以通过高磷浓度动力学实验得到的平衡反应时间并不能用于低浓度磷吸附等温实验。(2)悬浮物与低浓度磷作用的动力学波动现象可能是沉积物中不同形态的磷相互转化的结果;悬浮物中的铁和钙能促进悬浮物对磷酸盐的吸附,吸附过程也存在波动现象。(3)波动动力学现象的存在,将导致通过吸附等温实验估算EPC0时,选择不同的平衡时间和不同的磷浓度将得到不同的结果,从而影响对水环境中沉积物的源汇判断,所以要根据实际情况选择合适的磷浓度与吸附-解吸反应时间。(4)悬浮物与磷酸盐的相互作用存在明显的固体浓度效应。随着固体浓度的增大,悬浮物与磷酸盐的吸附等温线斜率减小,沉积物的吸附能力和对磷酸盐的缓冲能力下降。固体浓度和EPC0值是正相关关系,但呈非线性变化。(5)渤海埕岛油田区沉积物各种无机形态的磷含量大小顺序为:HCl-PBD-POH-Ploosely-P。沉积物磷形态分析过程中存在固体浓度效应,随着固体浓度的增大,磷形态分析得到的各形态磷含量降低,并且各形态磷所占百分比也将出现变化。
[Abstract]:Sediment is an important medium for phosphorus cycling in natural water, which has an important effect on phosphate concentration in water. Some studies have shown that phosphorus is the limiting factor of eutrophication in Bohai Sea. The adsorption and desorption of suspended solids and phosphate will directly affect the concentration of phosphorus in the Bohai Sea. After decommissioning the reef, the hydrodynamic conditions in the Bohai Sea area will be affected, and the solid concentration in the reef area and the contact reaction time between particulate matter and water body. EPC0 (critical phosphorus equilibrium concentration zero equilibrium phosphorus concentration) is an important attribute of suspended matter). Together with phosphorus concentration in water, it determines the source and sink role of suspended solids. Taking Chengdao Oilfield in Bohai Sea as an example, through adsorption kinetics and isothermal experiments, the wave dynamics of the interaction between suspended solids and low concentration phosphate and the effect of solid concentration on EPC0 are discussed. The transformation of different inorganic phosphorus in the process of wave dynamics was discussed through the speciation analysis of suspended inorganic phosphorus. The main conclusions are as follows: (1) the kinetic curves of the reaction between suspended solids and phosphate in high / low concentration solutions are obviously different. The kinetic curve of high phosphorus concentration is monotonous and easy to reach the reaction equilibrium, while the kinetic curve of low phosphorus concentration shows a fluctuating trend. Therefore, the equilibrium reaction time obtained from the kinetic experiment of high phosphorus concentration can not be used in the adsorption isothermal experiment of low concentration phosphorus. (2) the kinetic fluctuation of the interaction between suspended solids and low concentration phosphorus may be the result of the mutual transformation of different forms of phosphorus in sediments; Iron and calcium in suspended solids can promote the adsorption of phosphate by suspended solids, and the adsorption process is also fluctuating. (3) the existence of wave dynamics will lead to the estimation of EPC0 by isothermal adsorption experiments. Different equilibrium time and different phosphorus concentration will result in different results, which will affect the source and sink judgement of sediment in water environment. Therefore, the suitable concentration of phosphorus and the reaction time of adsorption-desorption should be chosen according to the actual situation. (4) the interaction between suspended solids and phosphate has obvious solid concentration effect. With the increase of solid concentration, the slope of adsorption isotherm between suspended solids and phosphate decreases, while the adsorption capacity of sediment and the buffer capacity of phosphate decrease. There is a positive correlation between the concentration of solid and the value of EPC0, but there is a nonlinear change. (5) the order of phosphorus content of various inorganic forms in the sediments of Chengdao oilfield area in Bohai Sea is: HCl-PBD-POH-Ploosely-Py-P. There is a solid concentration effect in the process of phosphorus speciation analysis in sediment. With the increase of the solid concentration, the phosphorus content of each form of phosphorus species analysis will decrease, and the percentage of phosphorus forms will also change.
【学位授予单位】：青岛大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X145;P734

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