To Based On Permeable Reactive Barrier Of 2, 4-DCP Transport Simulation Studies In Groundwater

Chlorophenol compounds(CPs), which is a kind of typical organic pollutant. Even at low concentration it will cause harm to human body. Refractory of the CPs, makes it remain in the environment for a long time with a long degradation period and hard to remove.2,4- dichlorophen(2,4-DCP)is one kind of the CPs, it makes great harm to the groundwater environment, some specific practical groundwater remediation technology is difficult to get a good application because people are lack of understanding with the 2,4-DCP’s rules of underground environment transformation. So, study the rules of the 2, 4-DCP’s transition and transform from porous media in groundwater, and explore its migration transformation process, it is very meaningful for 2,4-DCP pollution treatment in underwater environment.The establishment of the laboratory of groundwater in situ repair simulation platform and the simulation of the actual groundwater environment make sure that the test data of this study will be accurate and reliable. Using sodium alginate coated coarse sand carring zero-valent iron powder mixed packing as reaction grille. It avoid the dispersion in porous media from happening.For building the transformation of 2,4-DCP migration model, it needs to design the static adsorption experiment and continuous flow dynamic tracer test. And needs to identify the calculate to determine the migration transformation parameters of the model. Through the adsorption test we can confirm the adsorption equation of the coarse sand and coarse sand carrying zero-valent iron is the Freundlich equation, adsorption coefficient is 4.45635E-6 and 0.00846, respectively, and dispersion coefficient is 0.345 cm2/min. Porosity is 0.38, specific yield is 0.1. Osmotic coefficient is 4.15×10-2cm/s, seepage velocity is 1.245×10-4cm/s.Analysis the theoretical background and calculation method of TOUGHREACT software, it use sequential iterative method(SIA) through the physical chemical process of numerical simulation, first is the solution of the model to the flow equation, and then flow speed and phase saturation value will be directly applied to solute transport simulation of the chemical process.According to the simulate of the initial conditions and boundary conditions, etc., of the groundwater flow field. Construction the groundwater flow mathematical model and mathematical model of solute transport, respectively, using Newton-Raphson iterative method for solving.Building chemical reactions and solute transport coupling model of the 2,4-DCP in groundwater, using TOUGHREACT software simulate the process of the 2,4-DCP’s migration and transformation in groundwater, find that in PRB reactor and effluent position, 2,4-DCP’s test determination value(measured value) and model calculated value(simulation value) which variation with time at quick reaction period can better fitting, it shows that model in a good deal with 2,4-DCP‘s adsorption chemical reaction in reaction medium, etc. Because 2,4-DCP ‘s measured values have some interference factors, it shows that 2,4-DCP elevating trend over time. But on the whole, the measured value and simulation value of 2,4-DCP have a good fitting effect.