Green preparation method and application of biochar loaded nano-iron material

The invention belongs to the technical field of heavy metal pollution repair materials in the environment, and particularly relates to a green preparation method and application of a biochar-loaded nano-iron material. A green preparation method of a biochar-loaded nano-iron material comprises the following steps: (1-1) putting banana peel into an extraction solution, heating and extracting in a water bath, filtering, and collecting a banana peel extraction solution; (1-2) adding charcoal into the banana peel extracting solution, and stirring and mixing to obtain turbid liquid; and (1-3) under the protection of nitrogen, dropwise adding a FeSO4 solution into the suspension, stirring, carrying out suction filtration, cleaning the obtained solid with deionized water, and drying in a vacuum drying box until the weight is constant to obtain the biochar-loaded nano-iron material. In the whole process of the preparation method disclosed by the invention, toxic substances such as sodium borohydride are not used, so t