Pilot Study of Radionuclide Removal: Using Conventional Iron‐ and Manganese‐removal Equipment

Abstract

This article discusses a pilot study that examined the feasibility of using Fe‐ and Mn‐removal equipment to remove natural radionuclides from drinking water. The goal was also to identify removal techniques that should be studied further, and to specify whether any technical changes should be made to improve removal efficiencies. The study concluded that, although removals of various nuclides are not always complete, removal may be sufficient to meet regulatory requirements. Using aeration and filtration equipment, 222Rn removal was often insufficient because of high 222Rn concentrations, and because an insufficient amount of air was applied with the removal equipment. Removal of 226Ra using manganese greensand filtration and a cation exchanger was efficient, and 238U removal was efficient using an anion exchanger.

Health Effects of Naturally Radioactive Water Ingestion: The Need for Enhanced Studies

“…In estimating retrospective cumulative intake, authors have assumed constant uranium concentrations in water over time, although these actually vary widely depending, for instance, on carbon dioxide partial pressures, pH of the source aquifer, and season ( Ribera et al 1996 ). Water radionuclides mitigation was considered in one study of uranium ( Zamora et al 1998 ) but not of radium, although most were based on public water supply measurements, and water softening is known to decrease radium concentrations substantially ( Vesterbacka and Salonen 2008 ). The physicochemical nature of the contaminant, that is, determining its chemical speciation in water and biological fluids, was not accounted for.…”

Technology for the removal of radionuclides from natural water and waste management: state of the art

“…It is recommended that iron and manganese removal filters should be backwashed about once a week to allow the backwash water to discharge into the sewer. The same is valid for the regeneration liquids of anion and cation exchange resins if the filters are regenerated about once a week [25,31].…”

“…These findings also apply to the special case of radium. The efficiency of iron and manganese removal was examined in 12 households in Finland whose water supply was known to contain some amounts of natural radionuclides [25]. The equipment (typically aerator + filter (anthracite-sand or anthracite-greensand media)) to remove only iron and manganese from household water had been installed at these homes before the radionuclide removal studies began.…”

Prevention measures against radiation exposure to radon in well waters: analysis of the present situation in Finland

“…Iron and manganese removal units that are based on aeration-oxidation normally do not produce a sufficient amount of air to effectively strip radon and hence cannot be recommended for radon removal (Vesterbacka & Salonen 2008). …”