Abstract : In this study, the nanotreatment of industrial wastewater was used, which included industrial machinery cooling waste water, dairy waste water, and copper industry water. Nanoremediation involves the use of nanoparticles of zinc oxide (ZnO). They are water-insoluble particles, which have been highlighted in water treatment including industrial wastewater contaminated with toxic metals. Different concentrations of zinc oxide nanoparticles were used, ranging from (0.1 mg/L) to (1g/100 mL). They were added to solutions of concentrations of each of the following elements: lead (750) mg/ L, copper (250 mg/L), and nickel (500. mg/L), and chromium (250 mg / L) in order to identify the optimal concentration in the process of removing heavy metals. The results were obtained by measuring the remaining concentrations of ions of each of the heavy elements (lead, copper, nickel, chromium), and high removal rates were obtained using nanoparticles of zinc oxide (ZnO).