Effects of crosslinking and thermal annealing modifications on the performance of nanohybrid PSf-ZnO membranes for the treatment of raw and ozonated petroleum refinery wastewater by Kusworo, Tutuk Djoko, Kumoro, Andri Cahyo, Aryanti, Nita, Utomo, Dani Puji, Qoyyimah, Qoyyimah, Hasbullah, Hasrinah, Alexandro, Samuel Rajaguguk