基于可滲透反應(yīng)格柵的地下水中2，4-二氯酚溶質(zhì)運(yùn)移模擬研究
發(fā)布時間：2019-05-12 17:07
【摘要】：氯酚類化合物(CPs)是一類對人體具有巨大危害的有機(jī)污染物,其特點(diǎn)是難以降解、持久性強(qiáng)。氯酚的難降解性使其在自然環(huán)境中可以長期存留,延長降解周期,很難去除。2,4-二氯酚(2,4-DCP)是其中一種,對地下水環(huán)境具有很大危害,由于人們?nèi)狈?,4-DCP在地下水環(huán)境中遷移轉(zhuǎn)化規(guī)律的認(rèn)識,一些針對性的地下水修復(fù)技術(shù)難以得到很好的應(yīng)用。所以研究地下水中2,4-DCP在多孔介質(zhì)中的遷移轉(zhuǎn)化規(guī)律,探索其遷移轉(zhuǎn)化過程,對治理在地下水環(huán)境中2,4-DCP污染具有重要意義。本文在實(shí)驗(yàn)室地下水原位修復(fù)模擬平臺建立的基礎(chǔ)上,模擬實(shí)際的地下水環(huán)境,保證本次研究試驗(yàn)數(shù)據(jù)的準(zhǔn)確性與可靠性。用海藻酸鈉包覆的粗砂承載零價鐵粉混合填料作為反應(yīng)格柵填料,避免了多孔介質(zhì)中分散脫離現(xiàn)象的發(fā)生。同時,為構(gòu)建2,4-DCP的遷移轉(zhuǎn)化模型,設(shè)計(jì)靜態(tài)吸附試驗(yàn)、連續(xù)流動態(tài)示蹤試驗(yàn)和相關(guān)計(jì)算確定遷移轉(zhuǎn)化模型的參數(shù)。本文通過吸附試驗(yàn)確定粗砂和粗砂承載零價鐵的吸附平衡方程為Freundlich吸附方程,吸附系數(shù)分別為4.45635E-6和0.00846,彌散系數(shù)為0.345 cm2/min,孔隙度為0.38,給水度為0.1,滲透系數(shù)為4.15×10-2cm/s,滲流速度為1.245×10-4cm/s。根據(jù)模擬地下水流場初始條件及邊界條件等,本文分別構(gòu)建地下水流數(shù)學(xué)模型和溶質(zhì)運(yùn)移數(shù)學(xué)模型,運(yùn)用Newton-Raphson迭代法進(jìn)行求解。對TOUGHREACT模型軟件的理論背景和計(jì)算方法進(jìn)行分析,TOUGHREACT進(jìn)行物理化學(xué)數(shù)值模擬過程采用了順序迭代法(SIA),模型先進(jìn)行水流方程的求解,之后水流速度和相飽和度數(shù)值會被直接用于化學(xué)溶質(zhì)運(yùn)移模擬過程。本文構(gòu)建了地下水中2,4-DCP化學(xué)反應(yīng)和溶質(zhì)運(yùn)移耦合模型,運(yùn)用TOUGHREACT模型軟件模擬地下水環(huán)境中2,4-DCP遷移轉(zhuǎn)化過程,PRB反應(yīng)器內(nèi)和出水處2,4-DCP隨時間變化的試驗(yàn)測定值(實(shí)測值)和模型計(jì)算值(模擬值)快速反應(yīng)期能夠較好的擬合,說明模型中很好的處理了2,4-DCP在反應(yīng)介質(zhì)中吸附等化學(xué)反應(yīng)。由于2,4-DCP實(shí)測值干擾因素較多,因此出現(xiàn)2,4-DCP隨時間變化升降趨勢。但整體上,2,4-DCP實(shí)測值和模擬值具有良好的擬合效果。
[Abstract]:Chlorophenol compound (CPs) is a kind of organic pollutant which has great harm to human body, which is difficult to degrade and persistent. Chlorophenol is difficult to degrade, which makes it possible to retain chlorophenol for a long time in the natural environment, prolong the degradation cycle and is difficult to remove. 2, 4-dichlorophenol (2, 4 脳 DCP) is one of them, which is very harmful to groundwater environment. Due to the lack of understanding of the migration and transformation of 2, 4 DCP in groundwater environment, some targeted groundwater remediation techniques are difficult to be well applied. Therefore, it is of great significance to study the migration and transformation law of 2 / 4 DCP in groundwater in porous media and to explore its migration and transformation process in order to control the pollution of 2 / 4 DCP in groundwater environment. In this paper, based on the establishment of laboratory groundwater in situ remediation simulation platform, the actual groundwater environment is simulated to ensure the accuracy and reliability of the test data. The mixed packing of zero valence iron powder coated with sodium alginate was used as the reaction grille packing to avoid the phenomenon of dispersion separation in porous media. At the same time, in order to construct the migration and transformation model of 2, 4 DCP, the static adsorption test, continuous flow state tracer test and related calculation were designed to determine the parameters of the migration and transformation model. In this paper, the adsorption equilibrium equation of coarse sand and coarse sand bearing zero valence iron is determined by adsorption test as Freundlich adsorption equation, adsorption coefficient is 4.45635E-6 and 0.00846, dispersion coefficient is 0.345 cm2/min, porosity is 0.38, The water supply degree is 0.1, the permeability coefficient is 4.15 脳 10 ~ (- 2) cm / s, and the seepage velocity is 1.248 脳 10 ~ (- 4) cm / s. According to the initial conditions and boundary conditions of simulated groundwater flow field, the mathematical models of groundwater flow and solute transport are constructed and solved by Newton-Raphson iteration method. The theoretical background and calculation method of TOUGHREACT model software are analyzed. The physical and chemical numerical simulation of TOUGHREACT is carried out. The sequential iterative (SIA), model is used to solve the water flow equation first. Then the water velocity and phase saturation values will be directly used to simulate the chemical solute transport process. In this paper, the coupling model of chemical reaction and solute transport in groundwater is constructed, and the transfer and transformation process of 2,4 DCP in groundwater environment is simulated by TOUGHREACT model software. The experimental measured values (measured values) and model calculated values (simulated values) of 4 DCP over time in the PRB reactor and at the outlet of the DCP can be well fitted. The results show that the chemical reactions such as adsorption of 2, 4 脳 DCP in the reaction medium are well dealt with in the model. Because there are many interference factors in the measured values of 2, 4 DCP, there is a rising and falling trend of 2, 4 DCP with time. On the whole, the measured and simulated values of 2,4-DCP have good fitting effect.
【學(xué)位授予單位】：北京工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：X523
本文編號：2475535
[Abstract]:Chlorophenol compound (CPs) is a kind of organic pollutant which has great harm to human body, which is difficult to degrade and persistent. Chlorophenol is difficult to degrade, which makes it possible to retain chlorophenol for a long time in the natural environment, prolong the degradation cycle and is difficult to remove. 2, 4-dichlorophenol (2, 4 脳 DCP) is one of them, which is very harmful to groundwater environment. Due to the lack of understanding of the migration and transformation of 2, 4 DCP in groundwater environment, some targeted groundwater remediation techniques are difficult to be well applied. Therefore, it is of great significance to study the migration and transformation law of 2 / 4 DCP in groundwater in porous media and to explore its migration and transformation process in order to control the pollution of 2 / 4 DCP in groundwater environment. In this paper, based on the establishment of laboratory groundwater in situ remediation simulation platform, the actual groundwater environment is simulated to ensure the accuracy and reliability of the test data. The mixed packing of zero valence iron powder coated with sodium alginate was used as the reaction grille packing to avoid the phenomenon of dispersion separation in porous media. At the same time, in order to construct the migration and transformation model of 2, 4 DCP, the static adsorption test, continuous flow state tracer test and related calculation were designed to determine the parameters of the migration and transformation model. In this paper, the adsorption equilibrium equation of coarse sand and coarse sand bearing zero valence iron is determined by adsorption test as Freundlich adsorption equation, adsorption coefficient is 4.45635E-6 and 0.00846, dispersion coefficient is 0.345 cm2/min, porosity is 0.38, The water supply degree is 0.1, the permeability coefficient is 4.15 脳 10 ~ (- 2) cm / s, and the seepage velocity is 1.248 脳 10 ~ (- 4) cm / s. According to the initial conditions and boundary conditions of simulated groundwater flow field, the mathematical models of groundwater flow and solute transport are constructed and solved by Newton-Raphson iteration method. The theoretical background and calculation method of TOUGHREACT model software are analyzed. The physical and chemical numerical simulation of TOUGHREACT is carried out. The sequential iterative (SIA), model is used to solve the water flow equation first. Then the water velocity and phase saturation values will be directly used to simulate the chemical solute transport process. In this paper, the coupling model of chemical reaction and solute transport in groundwater is constructed, and the transfer and transformation process of 2,4 DCP in groundwater environment is simulated by TOUGHREACT model software. The experimental measured values (measured values) and model calculated values (simulated values) of 4 DCP over time in the PRB reactor and at the outlet of the DCP can be well fitted. The results show that the chemical reactions such as adsorption of 2, 4 脳 DCP in the reaction medium are well dealt with in the model. Because there are many interference factors in the measured values of 2, 4 DCP, there is a rising and falling trend of 2, 4 DCP with time. On the whole, the measured and simulated values of 2,4-DCP have good fitting effect.
【學(xué)位授予單位】：北京工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：X523
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