Additive Manufacturing of Graphene Oxide/Sodium Alginate–Cotton Microfiber Composite Hydrogels: Structure, Properties, and Adsorption Performance

The high use and improper disposal of chloroquine (CQ) during the COVID-19 pandemic have significantly increased its presence in water bodies, representing an environmental risk. Adsorption is one of the most-used treatments to remove recalcitrant compounds, although there is still a lack of efficient biosorbents. This work aimed to develop an efficient biosorbent using additive manufacturing (AM) to synthesize bionanocomposite hydrogels based on cellulose fibers, sodium alginate (SA), and graphene oxide (GO) for CQ adsorption. The hydrogels were characterized by mechanical, morphological, and physicochemical techniques. Results show that increasing GO content and reducing water contributed to higher yield stress, which is important for maintaining shape fidelity during the printing. SEM images evidenced thin GO layers interacting with the polymer matrix and cellulose fibers, resulting in 3D disordered porous microstructures. The adsorption capacity of the 3D-printed hydrogel samples for aqueous CQ was analyzed by evaluating the pH effect, contact time, and the adsorption equilibrium isotherms, showing notorious potential for CQ removal, with maximum adsorption capacity of ~25 mg∙g−1 at 25 °C. Results show that the tested formulations were stable for producing hydrogels and efficient on chloroquine adsorption, revealing their potential as novel adsorbents for removing emerging organic pollutants from water.