The treatment of food industries wastewater using synthesised zinc oxide nanoparticles

Food and dairy processing industries consume large quantities of clean water for various processes throughout the plant operations and consequently generate large amounts of wastewater. The objective of this study is to treat the wastewater of food and dairy industries using ZnO nanoparticles (ZnO NPs) to control the pH level and reduce contamination levels. The wastewater from three industries was tested for pH, total dissolved solids (TDS), turbidity, Chemical Oxygen Demand (COD), and Biochemical Oxygen Demand (BOD). The ZnO NPs are prepared with an average size of less than 100 nm by using a simple precipitation method. The obtained particles were characterised by X-Ray Diffraction (XRD), and Scanning Electron Microscope (SEM) proving the nano size of Zinc Oxide nano particles. The effluents have been treated with the ZnO NPs by varying doses resulting in reducing all contaminants to an acceptable level as recommended by concerned environmental organisations.