Ning Wu, You might try high pressure steam oxidation, you could achieve several bar at reasonable temperatures. Steam is a very aggressive oxidant, and something as simple as a pressure cooker might do your job. Easy and cheap to try. Gary Gary Hillman Service Support Specialties, Inc. PO Box 365 9 Mars Court Montville, NJ 07045 Telephone 973-263-0640 extension 35 Fax 973-263-8888