Comparative Studies on the Chemo and Biosynthesized Nanomaterials for the Remediation of Pharmaceutical Residues in Wastewater

Abstract

In the present study, comparison was made on the wastewater remediation efficiencies of chemically and biologically synthesized magnetite and zinc oxide nanoparticles. Starchytarpheta indica (snake weed) leaf extract was used as a reducing and capping agent in the green synthesis of magnetite and zinc oxide. The synthesized nanoparticles (NPs) were characterized by X-ray diffraction studies (XRD), Field emission scanning electron microscopy (FESEM) and Fourier transform infra-red spectroscopy (FTIR). These synthesized nanoparticles were further applied in the treatment of industrial pharmaceutical effluent basically comprising amoxicillin, acetaminophen and ascorbic acid. The NPs all performed differently in the removal of these pharmaceutical active compounds. Results showed that the NPs had significant removal efficiencies for acetaminophen, ranging from 67.07 % - 93.59 %, with bio-ZnO having the highest removal efficiency and magnetite giving the least. The range of removal efficiency for ascorbic acid was 54.35 % - 100 %, Magnetite and bio-magnetite showed the highest removal efficiencies whereas bio-ZnO had the least removal rate. Wastewater treatment for the removal of amoxicillin residues with the synthesized nanoparticles was not quite significant, negative removal patterns were observed for wastewater treatment with bio-ZnO and magnetite, a removal rate of 16.82 % was obtained for treatment with bio-magnetite, ZnO NPs had the highest removal efficiency of 49.73 %. Generally, ZnO and bio-magnetite NPs displayed better removal capacities than the other NPs, with overall removal rates of 64.71 % and 48.92 % for ZnO and bio-magnetite NPs respectively.