Advanced method for clean water recovery from batik wastewater via sequential adsorption, ozonation and photocatalytic membrane PVDF-TiO2/rGO processes

This study aimed to investigate the synthesis of TiO2/rGO nanocomposite particles and incorporate them into PVDF membrane for Batik wastewater treatment. Bentonite adsorption and ozonation were combined to mitigate fouling development during the filtration process. The results proved that the TiO2/rGO nanocomposite successfully narrowed the band gap energy ∼2.9 eV by which enhancing its photo sensitivity within the visible light region. Furthermore, the chemical compatibility of TiO2 with PVDF can be improved with the presence of rGO. PVA coating on PVDF-TiO2/rGO membrane has enhanced hydrophilicity and provided the best performance by giving permeate flux ∼19.3 L.m−2.h−1 and dyes rejection up to ∼90%, respectively. Obviously, pre-treatment using bentonite and followed by ozonation significantly enhanced the permeate flux up to 21 L.m−2.h−1 and overall rejection up to ∼95%. As expected, the addition of TiO2/rGO nanocomposites increased membrane's photocatalytic activity by 30–100%. More importantly, wastewater treatment by combining bentonite adsorption, ozonation, and photocatalytic membrane filtration has successfully improved permeate flux and performance stability, reduced fouling growth, and produced clean water. Therefore, the results of this study offers a new promising advanced wastewater treatment for Batik wastewater treatment to produce clean water.