▎ 摘　　要

NOVELTY - Preparing modified graphene material involves (i) pyrolyzing and carbonizing biomass raw material to obtain biochar under condition of complete or partial hypoxia, (ii) crushing biochar, (iii) cultivating heavy metal-resistant bacteria in culture medium, (iv) adding the prepared biochar to culture medium, mixing and performing fermentation culture to prepare heavy metal-tolerant bacteria biochar fermentation broth, (v) adding chitosan and sodium alginate to heavy metal-tolerant bacteria biochar fermentation broth, stirring, performing cross-linking reaction by squeezing into calcium chloride solution by injection device to obtain heavy metal-resistant bacteria biochar gel particles, (vi) putting nano-titania and graphene oxide solution in container, and stirring to obtain mixture of nano-titania and graphene oxide, and (vii) adding heavy metal-resistant bacteria biochar gel particles to mixture of nano-titania and graphene oxide, uniformly vibrating and stirring. USE - The method is used for preparing modified graphene material for removing heavy metal pollution in soil. ADVANTAGE - The method uses the biological decomposition of heavy metal-resistant bacteria and the photocatalytic decomposition of nano-titania to effectively decompose the adsorbed heavy metals, and avoids the secondary pollution problem of plant enrichment. DETAILED DESCRIPTION - Method for preparing modified graphene material involves (i) pyrolyzing and carbonizing biomass raw material to obtain biochar under condition of complete or partial hypoxia, (ii) crushing biochar to a particle size of less than 1 mm, (iii) cultivating heavy metal-resistant bacteria in culture medium, and waiting for bacteria to expand, (iv) adding the prepared biochar to the culture medium, uniformly mixing, and performing fermentation culture to prepare a heavy metal-tolerant bacteria biochar fermentation broth, (v) adding chitosan and sodium alginate to heavy metal-tolerant bacteria biochar fermentation broth in a weight ratio of 2:1, uniformly stirring, performing cross-linking reaction by squeezing into calcium chloride solution by injection device for 10-48 hours to obtain heavy metal-resistant bacteria biochar gel particles, (vi) putting nano-titania and graphene oxide solution in a container in weight a ratio of 2:1, and uniformly stirring to obtain a mixture of nano-titania and graphene oxide, and (vii) adding the heavy metal-resistant bacteria biochar gel particles to the mixture of nano-titania and graphene oxide, uniformly vibrating and stirring to obtain type of modified graphene material finished product that adsorbs and removes heavy metal cadmium, copper, lead, zinc, mercury and arsenic compound pollution in the soil.