Phenol Removal from Aqueous Environments with ZnO Nanoparticles Produced from Onion Peel Wastes by Green Synthesis

Phenolic compounds are important industrial wastes and are classified as hazardous substances polluting seas, streams, stagnant waters, and groundwater resources. Therefore, they must be reduced to the permissible levels before being released into natural environments. The removal of nanomaterials and various pollutants by the adsorption method is gradually becoming more important with new technologies developed. In this study, the phenol adsorption capacity of ZnO nanoparticles (NPs) produced from onion peel wastes by the green synthesis method was investigated. In order to determine the optimum adsorption conditions of phenol to ZnO NPs, the effects of the ambient pH, contact time, initial phenol concentration, and temperature were investigated.