Cellulose-Cyclodextrin Co-Polymer for the Removal of Cyanotoxins on Water Sources

Abstract

With increasing global water temperatures and nutrient runoff in recent decades, the blooming season of algae lasts longer, resulting in toxin concentrations that exceed safe limits for human consumption and for recreational use. From the different toxins, microcystin-LR has been reported as the main cyanotoxin related to liver cancer, and consequently its abundance in water is constantly monitored. In this work, we report a methodology for decorating cellulose nanofibrils with β-cyclodextrin or with poly(β-cyclodextrin) which were tested for the recovery of microcystin from synthetic water. The adsorption was followed by Quartz Crystal Microbalance with Dissipation monitoring (QCM-D), allowing for real-time monitoring of the adsorption behavior. A maximum recovery of 196 mg/g was obtained with the modified by cyclodextrin. Characterization of the modified substrate was confirmed with Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Photoelectron Spectroscopy (XPS), Thermogravimetric Analysis (TGA), and Atomic Force Microscopy (AFM).

Fabrication of aerogels from cellulose nanofibril grafted with β-cyclodextrin for capture of water pollutants

“…As electrostatic interactions -including polar charged interactions and dispersive forces-are the main driving force in the adsorption of charged molecules like MB onto cellulose, this is predominantly favourable for pristine CNF aerogels [30]. Meanwhile, adsorption into CNF-CD surface needs a different driving force, which is mainly hydrophobic due to the cavities available with the immobilized cyclodextrin, just as observed with the preferent adsorption of the microcystin-LR, and seen on the model surfaces [39].…”

“…These efforts have prompted the development of green materials and processing technologies that aim at replacing widely used fossil fuel-derived analogues. Along these lines, the utilization of bio-based materials to develop sorbents for water treatment is of particular interest [7][8][9][10][11][12][13][14]. Out of various bio-based materials, cellulose nanofibrils (CNF) is considered a versatile substrate due to their wide availability, well-established structures, and chemical reactivity, allowing for their modification to target specific interactions towards particular pollutants of interest [15][16][17].…”

“…In addition to this, multiple emerging contaminants such as dyes, aromatics, or hydrocarbons are complex molecules for which their adsorption on the sorbent could be benefited by the addition of hydrophobic active points on the cellulose nanofibril surface, with straightforward routs such as grafting of β-cyclodextrin. β-cyclodextrin has been shown to improve the adsorption of pollutants when was grafted onto magnetic graphene sheets and porous silica [31], chitosan/graphene sheets [32], carbonaceous nanofibrils [33], biomass/polysulfone/polyethylenimine [34], and cellulosebased materials [35][36][37][38][39].…”

Nanocellulose as a sustainable material for water purification

“…[ 6 ] Flocculants are commonly used materials for the removal of contaminants from wastewater by accelerating agglomeration of these contaminants, causing sedimentation, followed by contaminant removal. [ 7 ] Through the years, polysaccharides have become an attractive alternative option for fabricating a wide variety of high performance and low cost adsorbent membranes, attributed to the ease of their chemical modification. [ 7 ] Membrane‐based water treatment eliminates the requirement of chemical additives, no phase change is involved during the process, and the concept is simple and easy to implement.…”

“…[ 7 ] Through the years, polysaccharides have become an attractive alternative option for fabricating a wide variety of high performance and low cost adsorbent membranes, attributed to the ease of their chemical modification. [ 7 ] Membrane‐based water treatment eliminates the requirement of chemical additives, no phase change is involved during the process, and the concept is simple and easy to implement. Thus, membrane water treatment plays an important role in areas such as seawater and brackish water desalination, and wastewater treatment and reuse.…”