Smart Nano-materials for Wastewater Treatment: One Step Process to Photodegrade Dyes and Drugs Complexes and Adsorb Their Heavy Metals
Abstract Complexes plays a great rule in chemical industry such as the use of complexes in pharmaceuticals and in dyes. Complexes are normally constructed from central atom (possibly heavy metal) attached to organic ligands. During the preparation of complexes or after use, a considerable amount of their waste are distributed in water streams which cause serious environmental problems. Hence, the total removal of such complexes from waste water is crucial and very challenging. Although, there are several techniques to remove complexes, dyes and/or heavy metals from industrial waste water such as membrane treatment, biological processes, chemical treatment such as oxidation, however, the problem in such techniques is that they need an additional step to completely remove these complexes. The current study aims to prepare several bifunctional material(s) to carry out two steps (adsorption and degradation) in one step to synthesize a new generation of materials can be used with a super efficiency to treat wastewater from undesired complex. These materials consist of inorganic composite contains two materials; adsorbent and photocatalyst. These materials were able to adsorb the complexes on the surface and then photodegrade the organic part (ligands) of the complexes. Furthermore, the central atom of the complex is trapped on the surface of the adsorbent. The materials used as adsorbents are activated carbon, hydroxyapatite, carbon nitride, and mesoporous silica. On the other hand, the used photocatalytic materials are TiO2, ZnO, WO3, and CeO2. The prepared composites were prepared by wet deposition technique. The prepared composites were characterized by means of X-Ray Diffraction (XRD), UVVis spectroscopy, Energy Dispersive X-Ray (EDX) and Scanning Electron Microscopy (SEM). Two model compounds were used during the study, the first is Alican blue dye with Cu as a central atom, and the second is Gadovest drug complex with Gd as a central atom.Results showed that the best materials in the degradation of Alcian blue were CeO2/activated carbon, ZnO/activated carbon, and TiO2/activated carbon composites, where 0 ppm of Cu were found in the solution after treatment. On the other hand, the best composite for removal Gadovist was ZnO/activated carbon, where 0 ppm of Gd was found in the solution after the removal process.