The invention belongs to the technical field of
iodine adsorption materials, and provides a method for modifying a pore structure of an
agricultural waste biochar material, a modified porous
biochar adsorbent and application of the porous
biochar adsorbent. Agricultural wastes are crushed and sieved, the obtained
biomass is mixed with
potassium hydroxide and a modified precursor
aqueous solution, the mixture is dried and then subjected to a high-temperature reaction under the condition of air isolation, and the modified biochar adsorbent is obtained. And respectively washing the product with 0.1 mol / L
hydrochloric acid and
ultrapure water, and
drying. When KOH is activated,
urea is added, so that the
iodine capture performance of the
charcoal can be effectively promoted, the capture of gaseous
iodine within 6 hours reaches 3162mg / g, and the capture amount is increased by 55% compared with that of a sample without using
urea. After the dosage of KOH is optimized, the
urea prepared by using walnut shells, apricot shells, durian shells,
sunflower discs, corn straws, corncobs and other
biomass as precursors achieves similar effects in assisting the biochar, and it is proved that urea addition significantly promotes the biochar iodine capture performance. And theoretical support is provided for removal and
recovery of gas-liquid
radioactive iodine.