Harnessing Squid Bone for Ultra‐Permeable Water Purification Membranes

As emerging contaminants like nanoplastics, organic dyes, and inorganic particles proliferate, traditional water purification faces significant challenges. Here, a novel solution grounded in sustainability and efficiency: ultra-permeable membranes crafted from carboxylated β-chitin nanofibers derived from squid bone is introduced. The 124-nm-thick membrane exhibits an exceptional pure water flux of 46 207 L·m-2·h-1bar-1 with complete rejection (100%) of 100 nm nanoplastics. The 247-nm-thick membrane achieves 100% rejection of 50 nm nanoplastics, whereas the 1.8-µm-thick membrane attains 99.2% rejection of 1.5 nm rhodamine B dye. The breakthrough performance is attributed to the nanofibers' ultrafine dimensions (1.2 × 2.2 nm) and enhanced porosity resulting from carboxylate-mediated electrostatic repulsion. The mathematical models substantiate that this optimized porosity dramatically enhances filtration efficacy. Moreover, life cycle and techno-economic assessments affirm the approach's sustainability and economic feasibility. By marrying advanced material science with circular economy principles, this squid bone-derived membrane not only tackles global water purification challenges but also exemplifies how nature-inspired innovation can lead to scalable, eco-friendly solutions.