Study On Oxygen Releasing Process Of Bioremediation And Contaminants Transport In Groundwater

Oxygen is often the limited factor for aerobic microbes that capable of biologically degrading contaminants such as petroleum hydrocarbons. Oxygen Release Compounds (ORC) is designed to release oxygen into the subsurface. By accelerating natural attenuation using ORC, in-situ treatment of aquifer contaminants can develop an efficient, simple, cost-effective alternative to traditional technologies. With low capital costs, no operations and maintenance, minimal site disturbance, the ORC can efficiently restore water quality and property values at contaminated sites. So ORC have a bright prospect in the field. In addition, one of the foundations of biologic technology application is knowing the characteristics of soil. The relationship between characteristics of soil and bioremediation is the key of bioremediation application in engineering.The oxygen-releasing property of calcium peroxide (CaO₂) is studied. The results showed that the oxygen-release process of CaO₂ consist of three steps. Also the results showed that the pH value of solution could be significantly increased with the add of CaO₂. In this study, pH value of solution is adjusted by physical and chemical methods. It can control pH in the range of 6.5-8.5, which is suitable for the growth of microorganisms. Growth curve of mixed microorganisms are measured from experiment, which proved that using CaO₂ as oxygen-release source can satisfy regular metabolism of microorganisms.Permeability, dispersion coefficient and retarded factor were determined with the soil column experimental apparatus, and adsorption partition coefficients on MTBE are measured from batch experiments. Through the study on the mechanism of organic chemical transport in groundwater the dynamics model with varying coefficient for the organic chemical transport is developed. The analytical solution is obtained based on the mathematical and physical methods and the sensitivities for the parameters used in the model are analyzed. It is shown that the groundwater velocity and retarded coefficient greatly affect the transport of organic chemicals. This provides the theoretical base for the study on convection-diffusion status of organic chemical transport in groundwater. It can be used for the forecast of contaminants as well as the management and evaluation of groundwater resources.