Abstracts

Pharmaceutical residues are increasingly found in sewage wastewater and surface waters, and even at low concentrations, they can negatively affect water quality. Copper-cysteamine (Cu-Cys) supported on bacterial cellulose are a new type of catalyst with high potential for the removal of pharmaceutical residues from wastewater. This luminescent and photosensitizing material may be capable of producing reactive oxygen species after interaction with H₂O₂. Furthermore, they can be stimulated by UV light, microwaves, X-rays, and ultrasound to increase the generation of reactive species in the degradation system. Furthermore, Cu-Cys can be synthesized using an easy, fast, and economical synthesis method, providing an excellent cost/benefit ratio.To facilitate recovery of the nanoparticles and avoid possible copper leaching, the Cu-Cys were immobilized in bacterial cellulose, which has a high surface area, chemical stability, and the ability to disperse metal particles over its surface.This work reported a strong catalytic performance of Cu-Cys coupled to bacterial cellulose applied in the Fenton process for the simultaneous removal of two antibiotics, sulfamethazine and sulfadiazine, in purified water. The synthesized material presented phase purity and an XRD diffractogram similar to that reported in the literature. SEM images showed that the Cu-Cys were well distributed in the cellulose fibers, which contributed to the material stability during degradation experiments. Photo-Fenton experiments under UV-LED irradiation in the 365 nm region showed that after 40 min of reaction at natural pH of the solution (pH 8.1), both antibiotics were below detection limit with negligible leaching of copper to the solution, indicating that reaction occurred on material surface. The good stability and catalytic efficiency of Cu-Cys supported on bacterial cellulose make this material a potential candidate for heterogeneous Fenton processes employed for the effective degradation of emerging contaminants.