Combined ultrasound and Fenton (US-Fenton) process for the treatment of ammunition wastewater

► Combined ultrasound-Fenton process was the most effective in TOC/COD/color removal. ► Initial TOC, [H2O2]/[Fe2+] ratio, pH, and temperature affected TOC/COD/color removal. ► Low pH and high US intensity improved TOC/COD/color removal. ► Optimal temperature for TOC/COD/color removal was 30 °C. ► Optimal [H2O2]/[Fe2+] ratio for TOC/COD/color removal was 500.