Method for preparing biological activated carbon by hydrothermal carbonization of algae residue/algae sludge

The invention discloses a method for preparing biological activated carbon by hydrothermal carbonization of algae residue/algae sludge.The method includes the following steps: (1) mixing the algae residue/algae sludge with water prior to putting the mixture into a reaction kettle, performing heating reaction under the pressure less than 6 MPa and at the temperature of 160-220 DEG C for 2-20 hours, and naturally cooling to the room temperature; (2) subjecting a hydrothermal product obtained in the step (1) to filtration or centrifugal separation to obtain solid, and washing the solid; (3) drying the product obtained after washing in the step (2) at the temperature of 50-60 DEG C to obtain the biological activated carbon.Plenty of algae residue can be disposed highly efficiently as well as be utilized to turn waste into treasure; harm brought by the algae residue and algae toxins is reduced, and high efficiency and environmental friendliness are realized.