Micro/nano-plastic removal from wastewater using cellulose membrane: Performance and life cycle assessment

Globally, micro- and nano-plastics (MNPs) have become a serious environmental threat due to significant pollutions caused by their multitude sources, widespread distribution, persistence, and adverse effects to ecosystem. Although MNPs can act as carriers of heavy metal ions, associated effort on simultaneous separation of MNPs and heavy metal ions is still in their infancy. Herein, we report a simple and green strategy that can simultaneously separate MNPs and heavy metal ions using cellulose membranes. The process takes advantage of vacuum filtration and in situ crosslinking using bacterial cellulose (BC) and attapulgite (APT). The purification efficiency of bacterial cellulose membrane (BAM) for MNPs is higher than 98 % and the adsorption efficiency for heavy metal ion is 97 %. The BAM also exhibits high tolerance on different aquatic conditions (strong acidic, saline and alkaline water) and adaptation to different sizes of MNPs. Life cycle assessment (LCA) is performed to evaluate the overall environmental impact for the bifunctional BAM, showing a low overall impact under 14 categories, which exceeds other filtering membranes on the aspect of environmental friendliness. This study opens an avenue for valorization of bacterial cellulose membranes on water remediation through efficient and simple separation of various types of plastic particles and heavy metal ions.