Mulyati, RikeAwaluddin, AmirSophia, Halida2016-10-192016-10-192016-10-19wahyu sari yenihttp://repository.unri.ac.id/xmlui/handle/123456789/8728Methylene blue (MB) is a useful dye, which is commonly used in texstil, paint and biology. Methylene blue is toxic to living organism because methylene blue in environment is difficult to degradation and requires a long time. Methods Advanced Oxidation Processes (AOP) has been applied succesfully to remove methylene blue. This research focuses on the use of manganese oxide cryptomelane structure to the degradation methylene blue using AOP tecnique. Manganese oxide was synthesized by sol-gel method using KMnO4 and citric acid. The characterization results X-ray diffraction (XRD) indicated manganese oxide obtained was cryptomelane. Scanning emission misroscopy (SEM) result sample has diameter of 2-10 μm and shape cotton. The best performance cryptomelane catalyst for degradation MB was using cryptomelane catalyst 100 mg, with the percent degradation methylene blue was 79.23% at 120 minutes.enAdvanced OxidationCryptomelaneDegradation and Methylene Bluestudent Paper Post Degree