Modified straw-plastic co-pyrolysis biochar as well as preparation method and application thereof

The invention belongs to the technical field of bottom mud remediation, and discloses a preparation method of modified straw-plastic co-pyrolysis biochar, which comprises the following steps: (1) pretreatment: cleaning, drying, crushing and sieving agricultural straws to obtain straw powder; (2) pyrolyzing: mixing the straw powder with plastic particles, pyrolyzing in a tubular furnace, and cooling to obtain co-pyrolyzed biochar; and (3) loading: taking out the co-pyrolysis biochar, washing and drying, putting the co-pyrolysis biochar into a ferrite solution, adding the corn straw liquefied oil, continuously introducing nitrogen, continuously stirring, washing and drying to obtain the modified straw-plastic co-pyrolysis biochar. The function of filler in an electric-permeable reactive barrier technology is further deepened, and besides the traditional adsorption effect, the modified straw-plastic co-pyrolysis biochar and heavy metal are subjected to oxidation and reduction reactions, so that the heavy metal a