Reactive Solute Transport Through Porous Media

Contaminant transport mechanism in the groundwater environment hasimportant instructional significance on deep underground engineering andgroundwater pollution prevention, geological disposal of radioactive nuclearwaste. However, due to the complexity of the groundwater environment, thesolute transport is also very complex, so far, the study of solute transport inporous media concentrated in the inert solute. Take into account the actualsituation, most of the migration is not a single substance, and most of themigration process along with biochemical reactions, but the research in thisarea is still in its infancy. So this article as a starting point, preliminary studyon migration reaction rules of reaction solutes in porous media. This topic issummarized on the basis of the experimental design of reactive solutetransport in porous media, designed plexiglass tube filled with differentparticle size of quartz sand simulate the natural porous media, with aniline and1,2-naphthoquinone-4-sulfonate simulate the reactive pollutants, and in thelight of the detection methods in the literature to detect the concentration ofvarious pollutants, obtained the law of reactive contaminant transport inporous media. Also do the numerical simulation as comparative analysis.Summarize the research ideas and experimental results, the main conclusionsare drawn as followings:(1) In this paper，we take a bold attempt to choose aniline and1,2-naphthoquinone4-sulfonate as a representative of the reactive pollutants,that good test results confirmed its feasibility.(2) Each set of tests are set in three different flow rates in order toanalyze the impact of flow rate changes on reactive solute transport in porousmedia. Comprehensive analysis shows that the time of reaction products tomaximize concentration in advance with the flow rate increases, and the timeto the maximum concentration is very close to inert solute，which shows thatthe chemical reaction did not affect the flow rate.(3) Test constructed three kinds of quartz sand column to simulate theporous media, two of which simulated homogeneous media conditions, another simulated heterogeneous media conditions. From the experimentaldiagrams and numerical simulation diagrams，we analysis that media changesseriously affect the reactive solute transport in porous media.(4) From the graphic of experiment we know that the concentration of1,2-naphthoquinone-4-sodium as the reaction progresses gradually decreases to0, the concentration of aniline gradually increases to the0.2mmol/l, theresultant concentration was first increased and then decreased, it can reach amaximum concentration about0.05mmol/l，it confirmed that because of themedia blocking the chemical reaction can not be fully carried out.(5) ADE fitting the breakthrough curves of bright blue, fitting accuracyof the ADE model is good. Analyze the reactive solute numerical simulation,under the homogeneous conditions, the simulation results are good, but underthe non-homogeneous conditions the simulation results are not ideal, and needto improve.