Optimization of photocatalytic performance of the modified zeolite with ZnO nanoparticles for removal of acetaminophen-codeine from aquatic media using Response Surface Methodology (RSM)

Nowadays, the compounds known as emerging pollution are increasing in the environment. Pharmaceutical compounds are one of the most important substances in this group. Due to the complexity of chemical structure of pharmaceutical compounds and their metabolites, removal of these is important. Removal of these compounds by conventional water and wastewater treatment methods is not possible. In the present research, the performance of a hybrid of synthesized zeolite and ZnO nanoparticles for photocatalytic degradation of acetaminophen-codeine from aqueous solutions was investigated. To remove acetaminophen-codeine from aqueous solution, ZnO-Zeolite under UV and solar radiations was used. Final concentration of drug was measured using by HPLC in λmax = 214 nm. The optimal conditions of pH, catalyst dosage, drug initial concentration and reaction time were determined, based on Response Surface Methodology (RSM). Reusability test was finally performed for this synthesized composite. The results indicated that maximum removal of acetaminophen under UV radiation (48W/m2) was related to 14 mg/L of initial concentration in the neutral pH and a catalyst concentration of 1.7 g/L after 167min and that under the solar radiation (1200W/m2) was related on 5.5 mg/L of initial concentration in the neutral pH and a catalyst concentration of 1.2 mg/L after 143min of reaction start. Optimal initial concentration for codeine remove was 7.5 mg/L in the neutral pH. The maximum removal under UV and solar radiations was related to 1.5 and 1 g/L of composite after 192 and 170 min for codeine photocatalytic degradation. Photocatalytic degradation using this synthesized composite under optimal conditions, is able to completely remove the drug compounds (>99%) under UV and solar radiation. The photocatalytic method of ZnO-Z to remove acetaminophen and codeine from aqueous solutions is recommended. Synthesized composite in this research is a suitable material with reusability. Its efficiency also is acceptable under sunlight.