Biological filler, preparation method and application of biological filler in sewage treatment

The invention provides a biological filler, a preparation method and application of the biological filler in sewage treatment.The method comprises the steps that after multi-biological-phase zoogloea is dried and screened, the multi-biological-phase zoogloea is mixed with a sodium alginate solution and potassium hydroxide according to a preset proportion, the mixture is put into a pelletizer to be pelletized, and third filler in a preset shape is obtained; the third filler is put into a sodium alginate solution to be soaked for a first preset time and then fished out, draining treatment is conducted, and fourth filler is obtained; the fourth filler is put into a calcium chloride solution to be soaked for a second preset time and then fished out, air drying treatment is conducted under the natural condition, and the target filler is obtained, specifically, due to the fact that microorganisms in the target filler are multiple in variety, large in biomass and high in microorganism activeness, various pollutants