Chitosan, the deacetylation derivative of chitin, is well-established as renewable adsorbent material in water treatment applications, in particular for the capture of heavy metal ions due to its outstanding chelation properties. Usually, chitosan is derived by alkaline treatment of crustacean chitin. Whereas in static mode this material shows high affinity to heavy metal ions, unfortunately, direct preparation of membranes by film formation for continuous adsorption, omitting the necessity of dissolving the base material first, is not easily being performed.<br/>Chitin can, however, also be obtained from fungi directly in the form of nanofibrils, comparable to nanocellulose, but without the need of energy extensive processes. In this case, chitin is already a composite material in combination with glucan (chitin-glucan complex, CG), which greatly improves film formation properties. Consequently, also chitosan-glucan (CanG) derived from CG possesses good film formation properties. Thus, direct preparation of chitosan membranes from aqueous suspension is anticipated to be performed via an easy papermaking process.<br/>In this study, we investigated the extraction and characterization of chitosan-glucan derived from <i>Agaricus bisporus</i> (common mushroom) by alkaline deacetylation. This extract was analyzed for its affinity towards heavy metal ions and used for the preparation of membranes by a papermaking process. These membranes were tested for their permeance, pore size, rejection of nanoparticles and continuous adsorption of heavy metal ions. It was found that the adsorption capacity of both CanG extract and membranes was comparable to chitosan from crustaceans with the advantage of being derived from a more sustainable source. Furthermore, those membranes proved to be able to reject nanoparticles the size of viruses, i.e. in the ultrafiltration regime.

Fungal chitosan-glucan in water remediation applications

2019 Spring National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.