The invention relates to the field of
sewage treatment, and provides double-layer
anaerobic bacteria-algal-bacterial symbiotic immobilized particles as well as a preparation method and application thereof. The double-layer
anaerobic bacteria-algal-bacterial symbiotic immobilized particle sequentially comprises a PAN (
polyacrylonitrile)
fiber particle, an
anaerobic bacteria layer, a
polymer film, an algal-bacterial symbiotic layer and a
calcium alginate gel layer from inside to outside. The preparation method comprises the following steps: modifying PAN
fiber particles to enable the PAN
fiber particles to carry positive charges, and putting the modified PAN fiber particles into an anaerobic
bacteria solution for dipping adsorption;
coating a PVDF (
Polyvinylidene Fluoride) solution to form a
polymer film, so as to obtain PAN (
Polyacrylonitrile) fiber particles for immobilizing anaerobic
bacteria; soaking in a
mixed solution of an algal-bacterial symbiotic suspension and
sodium alginate, taking out, putting into a
calcium chloride solution, and cross-linking and hardening to form gel.
Anaerobic microorganisms and aerobic microorganisms in the immobilized particles are subjected to regional division and immobilization, and the inner-layer
anaerobic microorganisms and the outer-layer aerobic microorganisms play a greater role in different regions of a carrier by virtue of a physiological synergistic effect among the microorganisms, so that carbon,
nitrogen and
phosphorus in
sewage are deeply removed.