Photocatalytic Removal of Cephalexin by UV/ZnO Process from Aqueous Solutions

Conventional wastewater treatment plants are not able to remove effective drugs, such as antibiotics, so eliminating remaining antibiotics from the environment is important. The purpose of this study was to evaluate the efficacy of UV / ZnO photocatalytic process in removing antibiotic cephalexin from aqueous solutions.
This is an experimental-applied study that was performed on a batch scale in a laboratory scale. The variables studied in this study included the initial pH of the solution (11, 9, 7, 5, 3), the dose of nanoparticles (1, 75/0, 0.5, 0.25, 0.1, 0.05 grams per liter), Reaction time (60-50-40-30-20-15-55 minutes) and initial concentration of pollutant (100, 50, 25, 10 mg / l) were investigated. Measurement of cephalexin in samples was performed using HPLC apparatus.
The results showed that by decreasing pH and reducing the initial concentration of cephalexin and increasing contact time, process efficiency increased. But with increasing nanoparticle dosages up to 0.1 grams per liter, the process efficiency increases and more than this amount is reduced.
The results of this study showed that the use of UV / ZnO photocatalytic process in removing humic acid from aqueous solutions can be used as an effective method for cephalexin from aqueous solutions.