	US 12,420,321 B1
	Method for degrading halogenated polycyclic aromatic hydrocarbons in soil by using cryptomelane
Yanzheng Gao, Nanjing (CN); Pengfei Cheng, Nanjing (CN); Jian Wang, Nanjing (CN); and Wanting Ling, Nanjing (CN)
Filed by Nanjing Agricultural University, Nanjing (CN)
Filed on Oct. 5, 2024, as Appl. No. 18/907,488.
Claims priority of application No. 202410606609.7 (CN), filed on May 16, 2024.
Int. Cl. B09C 1/08 (2006.01)

CPC B09C 1/08 (2013.01)

9 Claims

1. A method for degrading halogenated polycyclic aromatic hydrocarbons in soil by using cryptomelane, comprising the following steps:

S1: preparing cryptomelane

S1-1: dissolving 0.01 mol of MnCl₂and 0.015-0.02 mol of KMnO₄in 95-105 mL of water, stirring at a rate of 140-160 rpm until the MnCl₂and KMnO₄are completely dissolved, after the MnCl₂and KMnO₄are completely dissolved, transferring the water to a high-pressure reaction kettle, putting the high-pressure reaction kettle in a blast oven to react at 155-165° C. for 22-26 hours, thus obtaining a reaction product;

S1-2: centrifuging the reaction product at 7500-8500 rpm for 8-12 min, and adding ultrapure water after pouring out a supernatant;

S1-3: repeating an operation of Step S1-2 for 8-10 times, and drying a bottom solid to obtain a dried solid;

S1-4: adding the dried solid into a Cu(NO₃)₂aqueous solution with a concentration of 0.01-0.1 mol/L, oscillating in a shaker at 180-220 rpm for 10-14 hours to obtain a suspension;

S1-5: centrifuging the suspension at a rotating speed of 7500-8500 rpm for 8-12 min, and adding ultrapure water after pouring out a supernatant;

S1-6: repeating an operation of Step S1-5 for 8-10 times, and drying and grinding to obtain solid cryptomelane;

S2: degrading halogenated polycyclic aromatic hydrocarbons in soil

S2-1: taking a soil sample, and grinding and removing impurities;

S2-2: adding the solid cryptomelane prepared in Step S1, which accounts for 2.5-7.5% of the mass of the soil sample, into the soil sample, uniformly mixing to obtain a mixture, and then transferring the mixture to the shaker with a rotating speed of 190-210 rpm to oscillate for 1-2 hours, thus preparing a soil sample containing cryptomelane; and

S2-3: finally transferring the soil sample containing cryptomelane into a brown glass bottle, adding a halogenated polycyclic aromatic hydrocarbon methanol solution according to situation that a ratio of the soil sample containing cryptomelane to the halogenated polycyclic aromatic hydrocarbon methanol solution is 9-11 mg/ml, oscillating at a rotating speed of 190-210 rpm for 1-1.5 hours, then pouring the soil sample containing cryptomelane into a glass culture dish, and degrading halogenated polycyclic aromatic hydrocarbons at a room temperature.