Enhancing water recovery through integrated graphene oxide-modified forward osmosis and membrane distillation for real textile wastewater treatment

The textile industry is a highly water-intensive sector, emphasizing the increasing importance of reclaiming clean water from textile wastewater and advancing water recovery towards zero liquid discharge. This study proposes and assesses an integrated forward osmosis and membrane distillation (FO-MD) process for treating real textile wastewater, aiming for enhanced water recovery and robustness towards zero liquid discharge. Firstly, a newly developed graphene oxide (GO)-enhanced FO membrane (GFO) was fabricated by adding GO into the polyamide layer during the interfacial polymerization process. Furthermore, the real textile wastewater treatment performance of the FO-MD process based on the GFO membrane was compared to that of a commercial FO membrane (CFO). The results indicated the GFO-based FO-MD process outperformed due to enhanced antifouling properties and stable water flux. Remarkably, the GFO membrane-based FO-MD system achieved over 80% water recovery and nearly 100% rejections for COD, Na+, K+, Cl-, and S2- during continuous 24-hour filtration. The findings highlighted FO-MD as a viable solution, surpassing individual FO and MD process by overcoming the limitation of FO draw solution dilution and MD membrane wetting challenges. Moreover, a preliminary techno-economic study for a 200 m3 day-1 textile wastewater estimated water production costs of $6.48 m-3 and $5.73 m-3 for CFO-MD and GFO-MD systems. The analysis highlighted maintaining the water flux above ~10 L m-2 h-1 is crucial for economic viability. This work demonstrates the potential of the FO-MD system as a sustainable solution to address the textile wastewater treatment challenges, providing insights for FO-MD system design and optimization.