Chemical synthesis, characterization and application of nanosized ZnO in the treatment of ciprofloxacin formulated aquaculture effluent: COD, kinetics and mechanism

Antibiotics are generally applied for the treatment of infections in humans and animals due to their economic value, easy accessibility, and potency. The use of veterinary pharmaceuticals such as antibiotics for the treatment of various infections in aquaculture cannot be overemphasized; the discharge of aquaculture effluent without necessary remediation techniques leads to the toxicity of the ecosystem. In this work, zinc oxide hexagonal-nanorods were synthesized via a precipitation method and calcined at ۵۰۰۰C in a muffle furnace for the catalytic degradation of ciprofloxacin (CIP) formulated aquaculture effluent. The characterization of nano-sized ZnO (n-ZnO) was conducted using scanning electron microscopy-electron dispersive spectroscopy (SEM-EDS), transmission electron microscopy (TEM), x-ray diffraction (XRD), Fourier transmission infrared spectroscopy (FTIR) and Brunauer, Emmett and Teller (BET) surface area determination. The SEM micrograph depicted both hexagonal and rod-like structures. The TEM micrograph subjected to ImageJ software showed an average particle size of ۴۲.۶۹ nm. The weight percent of the elements from the electron dispersive spectroscopy (EDS) followed the trend of Zn>O>C>Cl. The sharp peak of the Zn-O band was observed around ۴۶۳.۱۲ cm-۱. The results from XRD showed that pure n-ZnO was achieved at a temperature of ۵۰۰۰C with a BET surface area of ۸.۳ m۲/g, pore volume of ۰.۰۷۲ cm۳/g, and pore size of ۱۸۴.۷۷ A۰. The percentage of chemical oxygen demand (COD) removal of CIP formulated aquaculture effluent followed the trend of ۴۲.۸%, ۷۳.۹%, and ۹۴.۸% for the ultrasound (US), US/n-ZnO, and US/n-ZnO/H۲O۲systems.The US/n-ZnO/H۲O۲system showed the highest removal efficiency of CIP from the aquaculture effluent. The kinetics best fit the pseudo-second order, while the mechanism of degradation followed the Langmuir-Hinshelwood model for the US/n-ZnO/H۲O۲system. Hence, the utilization of US/n-ZnO/H۲O۲for the degradation of CIP formulated aquaculture effluent has proven to be a sustainable system that is dependable, faster, less tedious, and does not generate additional waste superior performance compared to individual materials. As such, findings from this study confirmed the performance and effectiveness of the Mg-(OH)۲-Ca-NPs nanocomposite on the removal of Mn from real river water. This will go a long way in curtailing the impacts of Mn in drinking water and further afield.

Keywords:

Sonolysis , Antibiotics , Langmuir-Hinshelwood model , Advanced Oxidation Process