SILVER CONCENTRATIONS IN RADIOGRAPHIC PROCESSING WASH WATER AND WASTE MINIMIZATION

Federal, state, and local governments are imposing stricter limits on silver in radiographic effluents. Many users are concerned about silver carried out of the fixer tank, within the film, into the wash tank. Some codes require the waste wash water to be contained and the hauled away for treatment. This paper presents evidence of the relatively low silver content in the wash water and ways to reduce both silver content and total water volume. There are many factors that affect silver carry-forward. This includes chemical quality, processor quality in squeegee rollers, wash water flow rate, temperature, film feeding practices, and the mix of film type, size, and percentage of exposure. To be able to meet regulations in the least expensive manner, it is important to understand the circumstances or levels of compliance and ways to maintain or meet compliance.