Preparation-Height-Specific Surface Area of Flower-like ZnO for Norfloxacin Removal in Dialysis Wastewater

Abstract

According to statistics, the number of patients with kidney dialysis is increasing every year, especially in Taiwan. The high content of antibiotics in kidney dialysis wastewater can create an environmental burden if not properly treated. Therefore, in this study, a new design for a flower-like ZnO catalyst that can effectively treat norfloxacin (NF) in dialysis wastewater is presented and its NF treatment efficiency is investigated under different operating parameters (including different dosages, pH, ambient temperatures, and pollutant concentrations). Scanning electron microscope results indicate that the ZnO sample consists of flower-like nanostructures with diameters of about 4.97 μm. The surface area, pore volume, and pore size of the flower-like ZnO were estimated to be 46.45 m2g−1, 0.132 cm3g−1, and 19.50 nm, respectively. The total removal efficiency increased with the increase in the initial pH value of NF, when the initial pH value of NF increased from 3.5 (38.1%) to 7.5 (82.5%). However, the total removal efficiency decreased with an increase in the initial pH value of NF, when the initial pH value of NF increased from 9.5 (79.5%) to 11.5 (32.9%). The second-order kinetic simulation results show that the linear relationship is better than that of the first-order kinetic, and the Rc2 values are all above 0.9.

Keywords

• dialysis wastewater
• norfloxacin
• flower-like ZnO
• photocatalysis