evaluation of the efficiency of magnetic iron oxide absorbents in the removal of navy blue ce-rn textile dyes from aqueous solutions

background : textile wastewater is the most important pollutant of the environment. navy blue (nb) ce-rn is an important chemical dye widely used in the textile industry. the present study aimed to investigate the removal of nb textile dyes from aqueous solutions using magnetic iron oxide absorbents. methods: in this study, a sample of synthetic wastewater with nb concentration of 50 mg/l was used. the effect of different variables such as contact time, ph, and adsorbent dose was evaluated. magnetic iron oxide absorbent was separated from the solution through centrifuging. dye removal efficiency was evaluated by the color and chemical oxygen demand (cod) concentration of the solution. the size of the magnetic iron oxide absorbent was determined using a scanning electron microscope (sem). findings: nb removal was increased from 74% to 80.4% when the contact time was increased from 10 to 210 minutes. the effect of ph variation from acidic to alkaline was investigated and it was found that the highest removal rate was achieved at a ph of 6. with the increasing of absorbent dose from 1 to 4 g/l, the dye removal efficiency was increased from 73.14% to 93.71%. the cod removal of 78.38% occurred in absorption capacity of 11.8 mg/g. conclusion: the results of the present study showed that maximum absorption was achieved in 210 minutes, ph of 6, and dose of 4 g/l. the magnetic iron oxide absorbent used in this research can be accepted as a method through which a high removal rate of textile nb can be achieved.