Efficiency of Reverse Osmosis System in the Removal of Lead, Cadmium, Chromium and Zinc in Feed Water of Dialysis Instruments in Kermanshah Hospitals

Background and The chemical quality of feed water to dialysis instrument is very important، especially in terms of heavy metals which could cause serious health problems for dialysis patients. This study aimed to determine the concentration of selected heavy metals (lead، cadmium، chromium and zinc) in feed water to dialysis instrument and compared that with EPH and AAMI standards in hospitals of Kermanshah province in 2014. A total of 42 samples of feed water، and 42 samples of permeate water (feed water to dialysis instrument) of reverse osmosis systems were collected from Kermanshah province hospitals. The collected samples were analyzed and the concentrations of lead، chromium، cadmium and zinc were determined using ICP (DV-Optima2100 model) according to standard methods. Then، the mean concentrations were compared with AAMI and EPH standards. The mean concentration of lead، cadmium، chromium and zinc in permeate water of reverse osmosis system was 18. 81± 14. 32، 0. 719± 0. 53، 84. 25 ± 2. 46 and 43. 39± 19. 1 ppb، respectively. The efficiency of the settled reverse osmosis system before dialysis instrument was 61. 5 and 2. 1%، in removal of zinc and chromium، respectively. But this system was found inefficient in removal of lead and cadmium. The mean concentrations of lead and chromium in the permeate water from the reverse osmosis system was higher than limited standards of AAMI and EPH، but the mean concentrations of chromium and zinc were lower than mentioned standards in all investigated hospitals. Therefore، the reverse osmosis system was able to decrease zinc in moderate and chromium in lower levels، but it was not effective in the removal of other heavy metals. So، periodic washing and cleaning or replacing the membrane of the reverse osmosis system is highly recommended.