▎ 摘　　要

NOVELTY - A leaching agent comprises biodegradable composite material and matrix solvent. The biodegradable composite material comprises disodium edetate and graphene oxide wrapped on the surface of chitosan nanoparticles. The concentration of biodegradable composite material is 0.1-100 g/L. The matrix solvent comprises 0.1-1 pt. wt. fatty alcohol polyoxyethylene ether, 0.5-5 pts. wt. Tween-80 (RTM: polysorbate-80), 15-25 pts. wt. ethyl acetate, 5-20 pts. wt. ethanol, and 49-80 pts. wt. water. USE - Leaching agent for repairing heavy metal/organic composite polluted soil (claimed). ADVANTAGE - The leaching agent is environmentally-friendly and biodegradable, and has excellent synergistic enhanced removal effect of heavy metals, and uses chitosan nanoparticles and graphene oxide to reduce the inhibitory effect of EDTA on soil indigenous flora, activate soil and provide nutrients for soil indigenous flora and uses composite material, which is easy to store and has core-shell structure and high utilization rate, and reduces the consumption of chemicals. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: 1. preparation of the leaching agent, which involves ultrasonically dispersing 0.1-10 g chitosan nanoparticles powder in mixed solution of 50-100 ml of water and ethanol for 0.1-1 hour, adding 2-20 g graphene oxide during the ultrasonic dispersion process, continuously adding disodium edetate chelating agent, controlling the concentration of the chelating agent to be 0.05-0.4 mol/L, stirring and reacting for 2-5 hours, centrifuging, drying to obtain biodegradable composite material, mixing fatty alcohol polyoxyethylene ether, Tween-80 (RTM: polysorbate-80), ethyl acetate, ethanol, and water to obtain a matrix solvent, slowly adding matrix solvent in biodegradable composite material under stirring condition, and controlling the concentration of biodegradable composite material to be 0.1-100 g/L; and 2. application method of the leaching agent, which involves pre-processing the contaminated soil, sorting branches and debris, drying, passing through 10-mesh sieve, and testing the content of each polluted component in the contaminated soil, taking polluted soil into a beaker, placing it in a magnetic stirrer, then adding leaching agent and distilled water to maintain a water-soil ratio of 3:1-10:1, stirring for 2-5 hours, leaving still for 20-50 minutes, performing solid-liquid separation through a funnel to obtain leaching agent loaded with pollutants and soil.