Multiphase Flow And Transport Characteristic In In-Situ Bioremediation Of Contaminative Soil

Environmental pollution which resulted from the progress of the global industrialization has caused people's great attention. The aspect of the crude oil and petroleum pollution during being transported and deposited has become more and more serious. There exist many remediation methods on the oil pollution, and the bioremediation is a promising one. The bioremediation can be classified as three kinds, namely, in-situ bioremediation, on-site bioremediation and bioreactor. The bioremediation have many advantages, such as economical, no secondary pollution, higher efficiency, simpler operation, less toxicity, less influence on environment, can eliminate many kinds of pollution and so on. So it applied in many aspects on the pollution removed. There were many polite and engineering experiments in foreign, meanwhile less in our country. In this paper, in-situ bioremediation was used in modeling and experiment, and the air-liquid two phase flow in the soil was researched in a visual experiment. The main contents were listed as follow: Above all, the testing systems were put up and the soil parameters, such as the soil permeability, the porosity, particle diameter and so on, were measured. Secondly, in this paper, the liquid flux characteristic experimental system was set up. The infiltration gallery was endowed with a new function, that is, which could make the saturation break when it met with two different parameter layers. Used the experimental system, the water flux, the water saturation's distribution, the water film thickness'distribution are all measured. The experimental results revealed that the liquid flux would increase when the thickness of the infiltration gallery bottom material decreased or the liquid height which was in the infiltration gallery increased. The liquid saturation's and the liquid film thickness'distribution had the same trend, that is, the value would increase when the liquid flowed downwards. The soil water flow characteristic was calculated by two parameters, namely, the Renault number and the Fanning coefficient. The experimental results showed that experimental data were tallied with the fitting curve f = 1000 Re. Thirdly, forecast the trend of the experimental, a model on the liquid flowing in the soil pore space was made. The experimental value on the model was built to validate the model's results. The calculation results revealed that the liquid flux would increase while the height of the water in the infiltration gallery increased or the thickness of the bottom material in the infiltration gallery decreased. And the distribution of the water saturation in the soil would increase when the water flowed downwards. The distribution of the water film thickness in the soil had the same trend. The distribution of the pollution concentration was calculated and the remediation efficiency was calculated, too. Further more, the air injected, air-liquid two phase flow experimental system was built. In this experiment, the liquid flux, the saturation gallery distribution and the liquid film thickness distribution were measured respectively. The experimental results revealed that the liquid flux had the similar trend comparing with the former but the value would decrease obviously. The saturation and the liquid film thickness would increase when the liquid flowed downwards, but the gradient would decrease. Finally, a model was built to forecast the trend of the liquid flux, the saturation's and water film thickness'distribution. In the model, the liquid flux was calculated above all. The calculation results revealed that the model predication had the similar trend with the experimental data. The calculation results revealed that when the air injected the liquid flux reduced obviously comparing with the same condition. Meanwhile, the water height and the bottom material thickness in the infiltration gallery were both influence the water flow, and the trends were similar contrast to no air injected system. The saturation's and the water film's thickness gradient distribution in the soil become smaller comparing with no air injected system, while the trends were similar.