Multifunctional Performance of Bacterial Cellulose Membranes in Saline and Oily Emulsion Filtration

The separation of oil-in-water emulsions from industrial wastewater remains a significant challenge, particularly under saline conditions. This study evaluated bacterial cellulose (BC) membranes from Komagataeibacter hansenii for filtering synthetic effluents with high oil content (ES1) and saline oil-in-water emulsions (ES2). FTIR confirmed the incorporation of lipophilic compounds into the BC matrix. Crystallinity decreased from 78.8% to 40% following ES1 filtration, while a new peak at 2θ ≈ 31.8° appeared in ES2, indicating salt deposition. TGA revealed increased mass loss in the oil-saturated membrane (BCO), whereas the saline-exposed membrane (BCOS) exhibited higher thermal stability. SEM showed fiber compaction and localized deposition of oil and salt, corroborated by EDS, which identified Na, Cl, Ca, and elevated oxygen levels. Mechanical testing indicated that oil acted as a plasticizer, increasing the elongation at break of BCO, while salt crystallization enhanced BCOS stiffness. The membranes removed up to 98% of organic load (BOD and COD), 69% of oils and greases, and reduced turbidity and apparent color by 92%. Partial salt retention (~23%) and a significant decrease in dissolved oxygen were also observed. These results demonstrate the potential of BC membranes as an effective and sustainable solution for the treatment of complex oily and saline wastewater.