Reusable and Biodegradable Separation Membranes Prepared from Common Mushrooms for the Removal of Oily and Particulate Contaminants from Water

Mushroomchitin membranes with controllable pore structures werefabricated through a simple process with naturally abundant Agaricus bisporus mushrooms. A freeze-thaw methodwas applied to alter the pore structures of the membranes, which consistof chitin fibril clusters within the glucan matrix. With tunable poresize and distribution, mushroom chitin membranes could effectivelyseparate stable oil/water emulsions (dodecane, toluene, isooctane,and chili oil) with various chemical properties and concentrationsand particle contaminants (carbon black and microfibers) from water.Chitin fibrils tightly pack with each other to form a dense membrane,leading to no permeation of contaminants or water. An increasing numberof applied freeze-thaw cycles confers more tortuous pore structuresthroughout the mushroom chitin membranes, leading to higher flux whilemaintaining rejection performance. The 3D simulation constructed bythe X-ray computed tomography and GeoDict software also demonstratedcapturing a considerable amount of contaminants within the membranes'pores, which can be easily removed by water rinsing for further successivefiltration. Furthermore, mushroom chitin membranes were almost completelybiodegraded after approximately a month of being buried in the soilor kept in a lysozyme solution while possessing mechanical durabilitydemonstrated by consistent filtration performance for repeated usageup to 15 cycles under ambient and external pressure. This researchis a proof of concept that mushroom-derived chitin develops functionaland biodegradable materials for environmental applications with scalability.

Automated summary

In this study, controllable pore structures were achieved in mushroom chitin membranes by utilizing a simple process with readily available Agaricus bisporus mushrooms. The freeze-thaw method was applied to modify the pore structures of the membranes, which consist of chitin fibril clusters embedded in a glucan matrix. These mushroom chitin membranes demonstrated effective separation of stable oil/water emulsions with different chemical properties and concentrations, as well as particle contaminants from water. By increasing the number of freeze-thaw cycles, the membranes exhibited more intricate pore structures, resulting in higher flux while maintaining rejection performance.