The invention belongs to the technical field of water and soil
pollution restoration, and discloses a
magnesium oxide-rice
husk biological carbon
composite material as well as a preparation method and application of the
magnesium oxide-rice
husk biological carbon
composite material. The preparation method comprises the following steps: cleaning rice husks,
drying the rice husks under a temperature of 80 to 90 DEG C for 10 to 16 hours, carrying out smashing and screening, heating to a temperature of 300 to 400 DEG C under a condition of feeding
nitrogen and isolating
oxygen at the rate of 3 to 8 DEG C per minute, carrying out thermal
cracking for 2 to 4 hours, naturally cooling to a
room temperature, cleaning the smashed rice husks, and
drying the smashed rice husks to constant weight, so as to obtain rice
husk biological carbon; adding the rice husk biological carbon into a
magnesium oxide suspension with the
mass percentage of 0.6 to 3 percent to obtain a mixed material; carrying out uniform stirring and mixing and then ultrasonic reaction for 1 to 2 hours, putting the mixed material under a condition of 85 to 105 DEG C for 20 to 24 hours, and carrying out
thermal treatment at 300 to 400 DEG C for 20 to 60 minutes under a condition of feeding N2 to obtain the magnesium oxide-rice husk biological carbon
composite material. The composite material can be applied to adsorbing and removing
cadmium from
cadmium polluted
wastewater or
cadmium polluted soil.