Effluents of radiographic image processing

This study aimed to survey the knowledge produced about effluents of radiographic image processing from health services through literature review; the study was carried out between February/July 2008, using the online data bases Lilacs, Pubmed and others from public agencies. The traditional radiographic processing includes developing; first washing with water; fixing; last washing with water and drying. The effluents of radiographic image processing consist of high silver-concentrated solutions, hydroquinone, quinone, metol, sodium thiosulfate, sodium sulfite, boric acid and cyanide, chloride, iron, total phosphorus, total nitrogen and sulphide. These solutions should be reused, recovered, recycled, or undergo specific treatment and final disposal. The liquid chemical residues must go through specific treatment, and its final disposal cannot be in landfills. It is observed in daily practice that the effluents from diagnostic imaging services do not always have adequate treatment or discard. Some institutions throw out effluents and solid residues in the environment; health services sell fixer, radiographic films to institutions  and throw the developer and washing water out in the sewerage system, or contact enterprises that supply electrolytic separators to split up silver from the fixer, than effluents are thrown in the sewerage system. All the components of the effluent from the radiographic image processing should be treated, including the water from the film washes. Techniques as electrolysis, metallic displacement, chemical precipitation, can be used to remove high concentrations of silver. To remove silver from the film washing water (in lower concentrations), it is possible to use the activated charcoal absorption process. There are also procedures that tries to destroy the photographic developers` residues through advanced oxidative process, using degradation by hydrogen peroxidase, UV/ H₂O₂ and Ultrasound/H₂O₂. The advanced oxidative processes using the Fenton reagent are also efficient and can be applied in treatment of developers.