The invention relates to the technical field of
soil remediation, and particularly discloses a composite
biochar material for adsorbing
heavy metals in soil and a preparation method. The composite
biochar material comprises 30-60 parts of cocoanut active
charcoal, 10-15 parts of nano-hydroxyapatite, 5-10 parts of magnetic
iron oxide / porous
ceramic particles, 10-15 parts of shell
powder and 5-10 parts of sea
sludge. The preparation method comprises the following steps: uniformly mixing the raw materials, granulating and
drying to obtain mixture particles; placing the mixture particles in an
inert gas
atmosphere, heating the mixture particles to 350-750 DEG C, carrying out heat preservation
calcination for 1.5-3 hours, and naturally cooling the mixture particles to
room temperature to obtain carbonized particles; and washing,
drying and sieving to obtain the composite
biochar material. By adopting the coconut shell
activated carbon, the nano-hydroxyapatite, the magnetic
iron oxide / porous
ceramic particles, the shell
powder and the sea
sludge in a specific proportion, the adsorption efficiency of the biochar material on
heavy metals can be improved.