Água de diálise: parâmetros físico-químicos na avaliação do desempenho das membranas de osmose reversa

Physical-chemical analyses of water used in hemodialysis systems are very relevant tools for evaluating such systems. These analyses must be periodically done. For this study 36 water samples collected from hospitals A and B during the summer and winter of 2003 were analyzed. The samples were collected from P1 incoming public treated water from city water mains (18 samples), and from P2 after reverse osmosis treatment (18 samples). Fluoride, sulfate, nitrate and conductivity analyses were performed according to the methodology recommended by Standard Methods for the Examination Of Water And Wastewater, 1995,and by the local standards "Normas Analiticas do Instituto Adolfo Lutz",1985. Bacteria endotoxins were determined in 18 samples from P2 according to the "United States Pharmacopeia". In both services, after reverse membrane osmosis processing during winter and summer significantly decreased the amount of ions fluoride, sulfate, nitrate, and conductivity in the water sample from P3 (p< 0,001), according to RDC No154/2004. During the winter the water conductivity increased in both services, 2.85% in A and 24.23% in B. Bacteria endotoxins were only detected in A service during summer in two samples. These results showed that physical-chemicals parameters were important to evaluate the efficacy of reverse membranes osmosis in both services, as it significantly reduced the studied ions concentration. Providing high quality water to hemodialysis system is an accurate procedure for preventing risks to the patients.