DNAPLs污染场区复电阻率动态监测装置的研究

发布时间：2018-05-16 01:30

本文选题：DNAPLs + LabVIEW　；参考：《山东工商学院》2017年硕士论文

【摘要】：土壤有机物污染特别是重非水相液体(Densenon Aqueousphase Liquids,缩写为DNAPLs)污染是当前我国土壤和地下水污染控制的难题之一,探索地球物理动态数据检测新方法与新技术迫在眉睫。为治理DNAPLs土壤污染问题,首先要明确污染的程度和范围,建立有效的污染监测和评价方法十分必要。传统的检测如钻探取样加化学分析,不仅浪费了大量的人力物力和财力,还容易对土壤造成二次污染,且仅为静态检测,不能准确确定污染范围和实时监测,而复电阻率作为物理探测的一种新方法,可以很好的解决上述问题,但在土壤污染检测方面研究还很少,且目前复电阻率污染检测装置尚未成熟,因此迫切需要对复电阻率检测装置进行深入研究。本文研究以解决实际问题为出发点,针对DNAPLs污染土壤,研究复电阻率检测新方法,并设计开发复电阻率监测装置,将地球物理学、环境化学以及计算机与信息科学的相关理论与方法结合在一起,探索适用于DNAPLs污染土壤监测的新途径。本文在分析土壤电性机理和极化机理的基础上,对土壤复电阻率法测量的原理进行分析,设计开发了一套基于LabVIEW的实验系统。该系统实现了复电阻率的实时测量和图形化显示,对采集信号进行频谱分析、相频分析,并实时显示和记录采集波形,实时保存复电阻率数据。利用设计开发的复电阻率测量装置,对DNAPLs污染土壤进行室内实验,实验样品采用细砂和5%膨润土均匀混合来模拟实际土壤,测量在低频下进行,频率范围为2-4--25Hz,结果表明,随着DNAPLs含量的增加,复电阻率幅值明显增大,复电阻率相位得到明显压制,但随着频率的变化其相位变化十分明显,且当污染到达一定程度时,其复电阻率参数到达一稳定值,可以很好的区分污染和未污染土壤。又通过可溶性金属盐溶液污染土壤实验,与DNAPLs污染实验数据分析得到,土壤孔隙中填充物发生改变,其表现出来的极化效应不同,进而使测量得到的复电阻率幅值和相位发生变化,产生差异。说明可以通过污染物性质的不同来检测土壤污染。通过本文研究的复电阻率监测装置能够很好地在室内实验下区分DNAPLs污染与未污染土壤,为野外复电阻率监测提供了基础性资料,同时也为复电阻率监测装置的研究提供了一定的参考和推动作用。
[Abstract]:Soil organic pollution, especially Densenon Aqueousphase liquid (abbreviated as DNAPLs) pollution, is one of the most difficult problems in soil and groundwater pollution control in China. It is urgent to explore new methods and techniques for geophysical dynamic data detection. In order to solve the problem of soil pollution in DNAPLs, it is necessary to define the extent and scope of pollution, and to establish an effective method of pollution monitoring and evaluation. Traditional detection, such as drilling sampling and chemical analysis, not only wastes a lot of manpower, material and financial resources, but also easily causes secondary pollution to the soil, and is only static detection, which can not accurately determine the range of contamination and real-time monitoring. As a new method of physical detection, complex resistivity can solve the above problems well, but the research on soil pollution detection is still few, and the complex resistivity pollution detection device is not mature. Therefore, there is an urgent need for in-depth research on complex resistivity detection devices. In this paper, based on solving the practical problems, a new method of complex resistivity detection is studied in view of DNAPLs contaminated soil, and a complex resistivity monitoring device is designed and developed. The environmental chemistry, computer and information science theories and methods are combined to explore a new approach for soil monitoring of DNAPLs pollution. Based on the analysis of soil electrical mechanism and polarization mechanism, the principle of soil complex resistivity measurement is analyzed in this paper, and a set of experimental system based on LabVIEW is designed and developed. The system realizes real-time measurement and graphical display of complex resistivity, and carries out spectrum analysis, phase frequency analysis, real-time display and recording of acquisition waveforms, and preservation of complex resistivity data in real time. Using the complex resistivity measuring device designed and developed, the laboratory experiment of DNAPLs contaminated soil was carried out. The experimental samples were mixed with fine sand and 5% bentonite to simulate the actual soil. The measurement was carried out at low frequency and the frequency range was 2-4--25Hz. the results showed that, With the increase of DNAPLs content, the amplitude of complex resistivity increases obviously, the phase of complex resistivity is suppressed obviously, but the phase changes obviously with the change of frequency, and when the pollution reaches a certain degree, the complex resistivity parameter reaches a stable value. A good distinction can be made between contaminated and uncontaminated soils. Through the experiment of soil polluted by soluble metal salt solution and the analysis of DNAPLs pollution experiment data, it was found that the filler in soil pore changed, and its polarization effect was different. Furthermore, the amplitude and phase of the complex resistivity obtained by the measurement are different. It shows that soil pollution can be detected by the difference of pollutant properties. The complex resistivity monitoring device studied in this paper can distinguish DNAPLs contaminated soil from uncontaminated soil well in laboratory experiments, which provides basic data for field complex resistivity monitoring. At the same time, it also provides a certain reference and promotion for the research of complex resistivity monitoring device.
【学位授予单位】：山东工商学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X85

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