Nonylphenol (NP) is a common endocrine disrupting compound that is hazardous to the bio-environment. Microwave peroxide oxidation (MPO) is an energy-efficient technology that can destroy toxic organic compounds in hazardous waste. The objective of this article is to study the rapid degradation of NP in wastewater sludge discharged from a detergent manufactory using MPO with HNO 3 . The major finding is that nearly all NP, over 95% in the sludge, can be degraded in 3 min at a temperature of 423 K using the MPO treatment. The results obtained in this work imply that MPO provides the potential to degrade NP and lower its toxicity. Significant NP degradation efficiency was achieved, showing sufficient toxic level reduction for further sludge reutilization. A useful correlation between degradation efficiency and treatment conditions is proposed based on the experimental data obtained in this study. For engineering applications, the necessary minimum treatment time is solved using a graphic illustration method, by which the minimum treatment time is obtained if the desired degradation efficiency and treatment temperature are known. The treatment time and temperature effects are also discussed in this article.