Techno-economic feasibility of forward osmosis for sustainable treatment of tartrazine in industrial wastewater

The synthetic colorant tartrazine dye is widely used in various industries, but it is a significant environmental pollutant due to its persistence and toxicity in wastewater. This study examines the removal of tartrazine dye from wastewater using forward osmosis (FO) as a sustainable treatment method. FO operates by using osmotic pressure differences between feed and draw solutions to maximize water flux, dye rejection, and minimize reverse solute flux. The study evaluated the impact of feed solution and draw solution concentrations, as well as the performance in FO and PRO modes. The results show that PRO mode achieved higher water flux compared to FO mode, while both modes exhibited over 98% dye rejection. Additionally, a long-term performance assessment using seawater as the draw solution revealed a gradual decline in water flux but effective rejection. Membrane fouling was managed by freshwater cleaning, restoring approximately 97% of the membrane’s original performance. An economic assessment showed that an FO system treating 200 m³/day of dye-contaminated wastewater has a cost of 0.978 $/m³ with NaCl as the draw solution, and 0.942 $/m³ when using seawater. These results highlight the potential of FO as a cost-effective, efficient treatment method for industrial wastewater, offering a promising perspective for future industrial-scale applications.