The invention belongs to the technical field of
biochar immobilized microorganisms, and particularly relates to a preparation method of a
biochar-based
composite material for efficient immobilization of adaptive microorganisms. The microbial loading capacity is remarkably improved, the
chain structure of the attapulgite layer provides a large number of linear adsorption sites, the porous structure of the
biochar forms a three-dimensional adsorption space, and the
chain structure and the porous structure of the biochar construct a synergistic adsorption mode; when the
ammonium ferric citrate is modified, a
decomposition product of the
ammonium ferric citrate can form new mesopores / micropores in the carrier to enlarge the specific surface area, and the
Fe element can be coordinated with an Si-O bond of the attapulgite and a
carbon skeleton of the
charcoal, so that pore collapse is inhibited, and the cycle stability is improved. And hydroxyl groups on the surface of the attapulgite and
oxygen-containing functional groups of the
charcoal cooperate with each other, so that
electrostatic attraction and
hydrogen bond
binding force to the microorganisms are enhanced. The
microorganism survival microenvironment is optimized, the composite carrier has the
ion exchange capacity of the attapulgite and the water and
fertilizer retention characteristic of the biochar, and a stable buffer environment and
nutrition reserve can be provided for microorganisms.