Assessment of household reverse-osmosis systems in heavy metal and solute ion removal in real and synthetic samples

In this study, the efficiency of household reverse-osmosis system (HROS) with and without neutralizer accessory was investigated in both real and synthetic samples. The real samples were collected from rural and urban public drinking-water systems with and without primary refinery treatment. The selected areas were situated in the Kurdistan province, Iran. The HROS model RO100GPD with and without neutralizer accessory was used in all experiments to prevent effects of the membrane used, age of devices, and length of time in service. In order to assess sample quality, some more common physico-chemical analyses consisting of hardness, Ca2+, Mg2+, total dissolved solids (TDS), electrical conductivity (EC), alkalinity, Cl-, Br-, SO42-, PO43-, NO3-, NO2-, and heavy metals were performed based on standard methods. The results indicate that HROS and neutralizer accessory have significant effects on the physico-chemical properties of feed water. However, the results indicate the instability of HROS output water quality, but they verify that this instability cannot reduce the output quality. Finally, results emphasize that HROS output water meets standard levels regardless of the input water quality and application of neutralizer accessory.