Reactive Solute Transport Through A Single Fracture

Contaminant transport mechanism in the groundwater environment has important instructional significance on deep underground engineering, groundwater pollution prevention and geological disposal of radioactive nuclear waste. Due to complexity of the solute transport in groundwater environment, most of the migration is not a single substance processing along with biochemical reactions. However, the study of solute transport in fractured media still concentrated in the inert solute. This topic is summarized on the basis of the experimental design of reactive solute transport in a set of single fractures, designed with aniline and1,2-naphthoquinone-4-sulfonate simulate the reactive pollutants, obtained the law of reactive contaminant transport in porous media. Mingling the experimental data and the ADE numerical simulation, we made out the main conclusions that are drawn as followings:(1) In this paper, we take a bold attempt to choose aniline and1,2naphthoquinone4-sulfonate as a representative of the reactive pollutants, that good test results confirmed its feasibility.(2)Analyzing the experimental data, we can find that the concentration of1,2-naphthoquinone-4-sulfonic filled in the fracture decreased to0along with the process of the reaction. The product concentration increased firstly and then decreased, and this clarified that the solute could react with the other completely.(3) After summarizing a series experiments of different velocity、aperture and the coarse number, it could be found that the dispersion coefficient and the water Re number increase with the velocity’s increasing, and the non-fickan phenomena would be more significant. As the aperture increasing, the limit velocity of the non-fickan transport decreased. More rough, easier does the non-fickan transport emerge.(4)When the solute transport followed the Fickan transport, the ADE simulation could fit the BTCs preferably. When the non-Fickan transport emerged with its long tailing BTCS, there was a not good simulation.(5)In the process of the series of reaction experiments, it could be found that1,2-naphthoquinone-4-sulfonic was resolved when it’s exposed slowly under visible light. But this phenomenon couldn’t be found under UV-light. In reverse, the reaction product,named1,2-naphthoquinone-4-aminobenzene (NQAB),was resolved more quickly under UV-light than visible light.