This application proposes a method for preparing gradient-pore structured
biochar for
soil remediation microbial loading, relating to the field of
biomass resource utilization technology. The preparation method includes: pyrolyzing
biomass raw materials at high temperature and then cooling to obtain
biochar embryos; dissolving surfactants in water to prepare an impregnation solution; impregnating the
biochar embryos in the impregnation solution and
drying to obtain a mesoporous template; dispersing
starch in water, heating, and adding the mesoporous template while stirring, reacting, and then cooling,
settling, and
drying to obtain a macroporous template; and calcining the macroporous template under an
inert atmosphere using a gradient heating process to obtain biochar with a gradient-pore structure. This application, through synergistic regulation of
raw material composition, pretreatment process, and programmed
pyrolysis activation process, achieves for the first time a continuous gradient distribution of pore size from the outside to the inside ("
macropore → mesopore → micropore") within a single biochar particle, significantly improving its performance as a microbial carrier.