A novel anaerobic granular sludge-membrane distillation (AGS-MD) hybrid systems for textile dye wastewater reclamation

For the first time, a 15 wt% polyvinylidene fluoride (PVDF) casting solution in N -methyl-2-pyrrolidone/ethanol (37.5 % v /v) was γ-irradiated prior to casting and phase inversion to fabricate a deep-irradiated membrane distillation (MD) membrane. The resulting membrane exhibited approximately 2.2-fold higher water flux than the conventional MD membrane, attributed to γ-induced chain scission and crosslinking, as confirmed by G3 (MP2) quantum-chemical calculations. Integration into an anaerobic granular sludge–direct contact MD (AGS-DCMD) hybrid system further enhanced operational stability, showing only a moderate flux decline over six days (from 33.01 to 22.38 LMH) compared with the steep loss observed in DCMD alone (from 33.78 to 5.38 LMH). AGS pre-treatment effectively reduced irreversible fouling, resulting in a fouling layer nearly an order of magnitude thinner (32.4 vs. 296.0 μm), while maintaining >99 % color removal and stable flux over 14 days. These findings highlight deep-irradiated MD membranes as a promising approach for sustainable textile dye wastewater treatment. • Deep gamma-irradiated MD membrane was successfully fabricated for dye treatment. • At 2.0 kGy, J w of irradiated MD was 2.2× higher than that of non-irradiated MD. • The mechanism for enhanced J w of deep γ-irradiated MD membrane was investigated. • AGS–DCMD system showed more stable flux than DCMD-only due to less fouling.