DISPOSAL OF BRINES, SLUDGES AND RESINS FROM RADIUM AND URANIUM REMOVAL PROCESSES
Providing an environmentally acceptable and safe residuals handling and disposal method is essential when removing radioactive contaminants such as radium, uranium, and radon from drinking water. The revised Radionuclides Rule will require many water systems to install advanced treatment
systems to meet the drinking water standards (United States Environmental Protection Agency [USEPA], December 7, 2000). The concentrations in the residual streams may pose a concern with environmental regulations and related worker safety issues due to radiation exposure. Concerns
over environmental compliance and worker safety exist.
Potential radiation exposure includes gamma radiation exposure at ion exchange (IX), lime softening, and coagulation water treatment facilities. The decay of certain radionuclides removed by media such as IX resins and filter media,
may result in measurable gamma radiation exposure in the vicinity of the process units during operation. Radon inhalation may be a consideration at aeration facilities inside treatment buildings and at facilities that have open water surfaces. Stored wastes containing Radium (Ra)-226 produce
radon gas, which can be released into the air, or if trapped, cause a gamma radiation exposure due to radon progeny. The possible exposure of water treatment personnel is far above any possible exposure to the general population.
This paper outlines the processes and their possible hazards,
that are used for the disposal of brines, sludges and resins employed for the removal of radionuclides from drinking water. The levels of radionuclides measured in the residuals were compared to existing criteria, from both within and outside the water industry. Where water treatment residuals
exhibited potentially radioactive characteristics, prudent disposal practices that minimize the public exposure to these residuals were developed. Where the residuals do not approach radioactive thresholds, more conventional disposal practices were identified.
Field tests were conducted
at 10 drinking water treatment facilities where uranium and radium were removed. Treatment processes that were evaluated included conventional treatment for uranium and radium removal, anion exchange for uranium removal, lime softening for radium and/or uranium removal, and cation exchange
for radium removal.
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