Physical, chemical, and biological treatment of groundwater at contaminated nuclear and NORM sites

Various potential processes for treating radioactively contaminated groundwater are described in this chapter. Filtration will remove particulates including radioactive particles, and is frequently used as a pretreatment step prior to other processes. Reverse osmosis (RO) will retain most of the ions in groundwater, including the radionuclides. The concentrated retentate stream (typically 10-20% of the original volume) from the RO system will contain the radionuclides plus the common ions in groundwater, and will need to be treated for disposal. Air stripping can remove volatile contaminants including radon. Biological treatment is normally used to degrade organic contaminants, but some radionuclides will be retained in the sludge from the process. Chemical treatment methods, such as ion exchange and precipitation, are the most common methods for treating radionuclides in groundwater. The application of these treatment processes to specific radionuclides is described.