Catalyst preparation method taking red mud as raw material and process for systematically treating sewage

The invention belongs to the field of solid waste recycling and water pollution treatment, and particularly relates to a catalyst preparation method taking red mud as a raw material and a process for systematically treating sewage. The invention aims to provide a method for preparing a catalyst by taking red mud as a raw material and a process for systematically treating sewage, and the basic principle is that ferric oxide in the red mud is converted into ferric iron which can be utilized by Fenton reaction by utilizing ferric oxide and titanium oxide (in a calcium titanate form) in the red mud; titanium dioxide in the red mud is used for photocatalysis, the red mud is prepared into a ceramsite-form catalyst, and meanwhile, a red mud washing solution and other compounds are added, so that the red mud is finally converted to have the functions of treating organic sewage through Fenton reaction, photocatalysis and adsorption, the purpose of treating waste with waste is achieved, and the process is obvious in en