A phenolic soil pollution remediation material, its preparation method and application

Abstract

A phenolic soil pollution remediation material, its preparation method, and its application are disclosed. First, dried willow branch fragments and iron-containing sludge particles are uniformly mixed to obtain a mixed raw material. Then, the mixed raw material is placed in a tubular furnace for anaerobic pyrolysis to obtain a phenolic soil pollution remediation material. The obtained phenolic soil pollution remediation material is added to phenol-contaminated soil to enhance the bioremediation of phenol-contaminated soil. After completion, the residual phenol concentration and microbial community in the soil are tested to evaluate the pollution remediation effect. This invention utilizes iron-containing sludge discharged from the Fenton treatment unit of waste paper manufacturing industry wastewater and waste willow biomass for co-pyrolysis to prepare a composite soil remediation material that enhances the remediation of phenol-contaminated soil, while achieving low cost and waste-to-pollution technical effects.

Description

Technical Field

[0001] This invention belongs to the field of environmental protection technology, and specifically relates to a phenolic soil pollution remediation material, its preparation method, and its application. Background Technology

[0002] Phenolic compounds are widely used in various industries such as pharmaceuticals, petroleum, coatings, explosives, papermaking, wood processing, and agrochemical manufacturing. Based on the number of hydroxyl groups directly attached to the aromatic ring, phenolic compounds can be further classified into mono-, di-, and poly-phenols. Due to the ionization of phenolic hydroxyl groups, phenolic pollutants are typically acidic, corrosive, and biotoxic. Phenolic compounds are protoplasmic poisons and are strictly controlled toxic organic pollutants globally. Phenol is the simplest and most typical phenolic compound, and is an important raw material for the production of various downstream products such as ketol oils, phenolic resins, caprolactam, and bisphenol A. With the increasing production of phenols, the resulting environmental pollution problems are receiving growing attention. Soil is a significant source of pollutant accumulation, and soil environmental safety is closely related to human health; therefore, the soil pollution caused by phenol urgently needs to be addressed.

[0003] Soil is a natural reservoir of microorganisms. Engineering techniques that promote the degradation of organic pollutants by soil microorganisms are a cost-effective and environmentally friendly pollution control technology, and a competitive and preferred approach for remediating phenol-contaminated soil. However, due to the biotoxicity of phenolic pollutants, their toxic inhibition of microorganisms often leads to slow remediation rates. To accelerate the bioremediation process, technologies such as adding nutrients and electron acceptors (e.g., oxygen) to contaminated media have emerged. Biochar materials prepared from agricultural biomass, due to their unique structural characteristics (large specific surface area and porous structure) and surface functional groups (containing oxygen, nitrogen, and sulfur functional groups), possess multiple functions and broad application potential. Adding functional biochar materials to contaminated soil can stimulate the activity of indigenous microorganisms, thereby accelerating the degradation of organic pollutants.

[0004] In recent years, research has focused on modifying biochar materials through techniques such as adding oxygen-containing functional groups, acid modification, and alkali modification in order to obtain new materials with the function of accelerating soil pollution remediation. However, modification measures mean increased costs, which limits their application and promotion.

[0005] Biochar, with its favorable physical structure and abundant specific surface area, has gradually become an emerging environmental remediation material and is widely used in environmental remediation and governance. The raw materials for biochar production are diverse, including many agricultural and forestry wastes (such as straw, willow branches, and rice husks) and organic wastes (such as manure and sludge). Fenton chromatography is a commonly used technology for the deep treatment of wastewater in the waste paper and papermaking industry. The iron-rich sludge it discharges is characterized by high iron content (mainly in the form of Fe(OH)3 and Fe2O3) and low content of other common heavy metals (below the national standard limits for heavy metals in agricultural fertilizers). This iron-rich sludge contains high levels of iron and biomass, and can be used to prepare iron-sludge-based biochar materials through pyrolysis, demonstrating high potential for resource utilization. Chen Tianlai used iron-rich sludge as raw material and prepared a manganese-modified iron sludge-based carbon material by impregnation pyrolysis. The results showed that the material could effectively reduce the concentration of heavy metals in the soil and improve the enzyme activity of the soil ([1] Chen Tianlai. Study on the remediation of cadmium and arsenic in water and soil environment by manganese-modified iron sludge-based carbon material [D]. Nanning Normal University, 2023). In addition to heavy metal pollution, many studies have also analyzed the performance of iron-rich sludge biochar as an adsorbent for organic pollutants. For example, Lin Taicheng et al. prepared iron-rich sludge-based biochar at a pyrolysis temperature of 900℃ using iron-rich sludge as raw material, and used it to adsorb tetracycline in water ([2] Lin Taicheng, Lin Jinhua, Li Yihua, et al. Study on the adsorption performance of iron-rich sludge-derived magnetic biochar for tetracycline [J]. Chemical Technology and Development, 2024, 53(07):73-78.). Zhang Yanping et al. combined iron-rich sludge with walnut shells, pyrolyzed it at 900℃ for 2h to prepare biochar and used it to remove methylene blue from dyeing and printing wastewater ([3] Zhang Yanping, Fan Xuteng, Peng Xiangshi, et al. Study on the adsorption performance of iron-rich sludge biochar for methylene blue [J]. Applied Chemical Industry, 2022, 51(9): 2553-2557.). *Salix psammophila* is a widely planted vegetation for desertification control. It is a shrub with bushy branches that are resistant to sand burial. However, *Salix psammophila* needs to be coppiced every 3-5 years to grow better. The biomass from the coppiced *Salix psammophila* is rich in lignin, cellulose, and hemicellulose, possessing excellent properties for biochar production. Biochar can be made from the remaining *Salix psammophila* branches after high-temperature, oxygen-limited pyrolysis, which avoids the waste of biomass resources and can adsorb pollutants, thus remediating contaminated soil and wastewater. Wen Junfeng et al. studied the adsorption performance of phenolic substances in simulated wastewater using high-temperature activated *Salix psammophila* as a biosorbent. The results showed that the maximum adsorption capacity of phenol in simulated wastewater by the high-temperature activated *Salix psammophila* reached 243.90 mg·g⁻¹. -1([4] Wen Junfeng, Liu Xia, Gao Liguo, et al. Study on the adsorption performance of *Salix psammophila* biosorbent for phenol-containing wastewater [J]. New Chemical Materials, 2018, 46(8), 276-280.). Zhang Jing produced biochar from the remaining *Salix psammophila* branches after coppicing through high-temperature oxygen-limited pyrolysis, and used it for soil remediation of heavy metal pollution in mining areas. The results showed that *Salix psammophila* biochar had a good inhibitory effect on the migration of heavy metals in soils with different pollution levels ([5] Zhang Jing. Study on the improvement effect of *Salix psammophila* biochar on copper pollution [D]. Inner Mongolia Agricultural University, 2017.).

[0006] The above studies indicate that both iron-rich sludge and *Salix matsudana* waste are excellent materials for preparing biochar and using it for contaminated soil remediation and phenolic pollutant adsorption. However, current research on iron-rich sludge and *Salix matsudana* biochar primarily focuses on heavy metal pollution remediation, with limited studies on phenolic pollutant adsorption. Furthermore, there are currently no published studies on the combined use of *Salix matsudana* biomass and iron-containing sludge to prepare phenolic soil pollution remediation materials. Summary of the Invention

[0007] To overcome the shortcomings of the existing technology, the present invention aims to provide a phenolic soil pollution remediation material, its preparation method, and its application. The method involves co-pyrolyzing iron-containing sludge from the Fenton treatment unit of waste paper manufacturing wastewater with waste *Salix psammophila* biomass to prepare a composite soil remediation material. This material enhances the remediation of phenolic contaminated soil while achieving low cost and waste-to-pollution treatment effects. The co-pyrolysis of iron-containing sludge and *Salix psammophila* biomass forms an environmentally safe composite material with magnetic properties and multiple functional groups containing iron and oxygen. This material adsorbs phenolic pollutants through electrostatic attraction, π-π interactions, complexation, and electron transfer, and also utilizes Fe... 2+ / Fe 3+ Redox-driven processes accelerate electron transport and enhance metabolic activity in indigenous microorganisms, thereby achieving enhanced technical effects in the remediation of phenol-contaminated soils.

[0008] To achieve the above objectives, the present invention employs the following technical solution: A phenolic soil pollution remediation material, the raw materials of which include willow branch fragments and iron-containing sludge particles in a mass ratio of 1:4 to 2:1; The iron-containing sludge was taken from the wastewater Fenton treatment unit of a paper mill and stored in a sealed low temperature after collection. Before preparing biochar, the iron-containing sludge was naturally settled, centrifuged and dehydrated, dried overnight, and after the moisture was fully removed, it was ground into 1-2 mm particles. The sand willow branch fragments were collected from desertified areas, air-dried after collection, and stored at room temperature; before preparing biochar, they were dried overnight and then ground into 1-2 mm fragments.

[0009] After drying, the iron-containing sludge particles have an ash content of 68.8-76%, a carbon content of 6.8-8.4%, and an Fe content of 42.6-47.6%.

[0010] After drying, the ash content of the sand willow debris is 12.5-17.5%, the carbon content is 75.5-82.5%, and the Fe content is 0-0.02%.

[0011] A method for preparing a phenolic soil pollution remediation material includes the following steps: S1. The dried sand willow branch fragments and iron-containing sludge particles are uniformly mixed at a mass ratio of 1:4 to 2:1 to obtain the mixed raw materials; S2. Place the mixed raw materials obtained in step S1 into a tube furnace for anaerobic pyrolysis under the following conditions: initial temperature set at 35~45℃, and pyrolysis at 9~11℃ / min. -1 A phenolic soil pollution remediation material was prepared by heating the material to 400-600℃, holding it for 1-1.5 hours, and then allowing it to cool naturally to room temperature.

[0012] The prepared phenolic soil pollution remediation material had a yield of 50.22%–78.38%, an ash content of 41.57%–72.36%, a pH of 7.89–9.21, and a specific surface area of ​​80.90–90.05 m². 2 ·g -1 It has a pore size of 4.63~5.17nm and is magnetic.

[0013] A phenolic soil pollution remediation material was prepared with H / C < 0.4 and O / C < 0.4, which meets the standards for biochar materials as soil conditioners proposed by the European Biochar Foundation (EBC), and has good aromaticity and stability.

[0014] A phenolic soil pollution remediation material was prepared with an Fe content of 54.82–60.18% and a Ca content of 7.14–8.31%, and exhibited a characteristic Fe=O peak (580 cm⁻¹) in infrared spectroscopy. - ¹Near metal-ligand vibration peaks) and characteristic structural peaks of aromatic compounds (850 cm⁻¹) - ¹Out-of-plane bending peak of the nearby monosubstituted benzene ring =CH, 2900 cm⁻¹ - ¹Near CH2-asymmetric stretching vibration peak and 3100 cm⁻¹ - ¹Near the stretching vibration peak of the benzene ring -CH=CH2.

[0015] A phenolic soil pollution remediation material was prepared, exhibiting rapid adsorption of phenol, with an adsorption equilibrium time of 50–180 min and a maximum adsorption capacity of 7.82–8.71 mg·g⁻¹. -1 .

[0016] An application of a phenolic soil pollution remediation material involves adding the prepared phenolic soil pollution remediation material to phenol-contaminated soil to enhance the bioremediation of phenol-contaminated soil. After completion, the residual phenol concentration and microbial community in the soil are tested to evaluate the pollution remediation effect.

[0017] A method for applying a phenolic soil pollution remediation material includes the following steps: Step 1: Add 4-6% (w / w) of a phenolic soil pollution remediation material to 100 mg·kg⁻¹ -1 Phenol-contaminated soil, mix thoroughly; Step 2: Samples were taken on days 1, 2, and 3 to test the concentration of residual phenol in the soil and assess the phenol remediation effect; Samples were taken on days 1, 2, and 3, and changes in soil functional microbial genera were analyzed using 16S rDNA high-throughput sequencing technology.

[0018] The final remediation effect was that 98.75% of phenol was removed within 2 days. The prepared phenolic soil pollution remediation material significantly stimulated the degradation of phenol. Exiguobacterium and Variovorax Fungal proliferation, among which Exiguobacterium These are magnetite-loving microorganisms; on days 1 and 3 of the remediation process, Exiguobacterium and Variovorax The abundance percentages increased from the initial 0.64% to 18.46% and 18.05%, respectively, which were significantly higher than the 0.34% and 0.03% without any additions.

[0019] Compared with the prior art, the present invention has the following beneficial effects: This invention utilizes iron-containing sludge from wastewater treatment units in waste paper mills (Fenton treatment units) and waste biomass from *Salix psammophila*, a common crop used in desertification control, as raw materials. Through co-pyrolysis, it prepares low-cost environmental functional materials with magnetic properties and phenolic pollutant adsorption capabilities, which can be used to accelerate the bioremediation of phenol-contaminated soil. Significant advantages and technical effects include: ① It achieves resource-based reuse of iron-containing sludge and waste biomass, achieving the technical effect of treating pollution with waste; ② It eliminates the need for secondary modification of the pyrolysis-prepared biochar material. By setting parameters, it can directly prepare functional materials with a large specific surface area, magnetic properties, and compliance with the European Biochar Foundation (EBC) standards for use as soil conditioners, offering high quality at a low cost; ③ Through technical parameter control, it prepares composite functional materials rich in iron, oxygen, and organic functional groups, giving them phenol adsorption properties, enabling large-scale adsorption of phenol in a short time; ④ Adding an appropriate amount of the composite biochar material prepared in this invention to phenol-contaminated soil can activate the proliferation of bacteria with phenol-degrading capabilities, thereby significantly accelerating the remediation rate of phenol-contaminated soil. Attached Figure Description

[0020] Figure 1 Example 1 describes the preparation of a phenolic soil pollution remediation material, SFB500, to enhance the bioremediation effect of soil pollution.

[0021] Figure 2 Example 1 describes the changes in the microbial community of SFB500, a phenolic soil pollution remediation material, for enhanced soil pollution bioremediation. Detailed Implementation

[0022] The present invention will now be described in detail with reference to the embodiments and accompanying drawings.

[0023] Example 1: A phenolic soil pollution remediation material SFB500, the raw materials of which include willow branch fragments and iron-containing sludge particles in a mass ratio of 1:1; The iron-containing sludge was taken from the wastewater Fenton treatment unit of a paper mill and stored in a sealed low temperature after collection. Before preparing biochar, the iron-containing sludge was naturally settled, centrifuged and dehydrated, dried overnight, and after the moisture was fully removed, it was ground into 1-2 mm particles. After drying, the iron-containing sludge particles had an ash content of 72.4%, a carbon content of 7.6%, and an Fe content of 45.1%. The sand willow branch fragments were collected from the desertified area of ​​Yulin, air-dried after collection and stored at room temperature; before preparing biochar, they were dried overnight and then ground into 1-2 mm fragments. After drying, the ash content of the sand willow debris was 15.0%, the carbon content was 80.5%, and the Fe content was 0.02%.

[0024] A method for preparing a phenolic soil pollution remediation material SFB500 includes the following steps: S1. The dried sand willow branch fragments and iron-containing sludge particles are uniformly mixed in a mass ratio of 1:1 to obtain the mixed raw materials. S2. Place the mixed raw materials obtained in step S1 into a tube furnace for anaerobic pyrolysis under the following conditions: initial temperature set at 40℃, and pyrolysis rate at 10℃·min. -1 The temperature was raised to 500℃, held for 1 hour, and then naturally cooled to room temperature to obtain a phenolic soil pollution remediation material, SFB500.

[0025] The prepared phenolic soil remediation material SFB500 had a yield of 58.26%, an ash content of 69.90%, a pH of 8.81, and a specific surface area of ​​90.05 m². 2 ·g -1 It has a pore size of 4.63 nm and is magnetic.

[0026] The prepared phenolic soil pollution remediation material SFB500 has an H / C ratio of 0.03 (<0.4) and an O / C ratio of 0.26 (<0.4), which meets the standards for biochar materials as soil conditioners proposed by the European Biochar Foundation (EBC) (i.e., H / C<0.4 and O / C<0.4), and has good aromaticity and stability.

[0027] The prepared phenolic soil pollution remediation material SFB500 has an Fe content of 59.67% and a Ca content of 7.70%, and exhibits the characteristic Fe=O peak (580 cm⁻¹) in infrared spectroscopy. - ¹Near metal-ligand vibration peaks) and characteristic structural peaks of aromatic compounds (850 cm⁻¹) - ¹Out-of-plane bending peak of the nearby monosubstituted benzene ring =CH, 2900 cm⁻¹ - ¹Near CH2-asymmetric stretching vibration peak and 3100 cm⁻¹ - ¹Near the stretching vibration peak of the benzene ring -CH=CH2.

[0028] The prepared phenolic soil pollution remediation material SFB500 exhibits rapid adsorption of phenol, with an adsorption equilibrium time of 50 min and a maximum adsorption capacity of 8.71 mg·g⁻¹. -1 .

[0029] An application of a phenolic soil pollution remediation material involves adding a prepared phenolic soil pollution remediation material, SFB500, to phenol-contaminated soil to enhance the bioremediation of phenol-contaminated soil. After completion, the residual phenol concentration and microbial community in the soil are tested to evaluate the pollution remediation effect.

[0030] Example 2, a phenolic soil pollution remediation material SFB600, whose raw materials include willow branch fragments and iron-containing sludge particles in a mass ratio of 1:4; The iron-containing sludge was taken from the wastewater Fenton treatment unit of a paper mill and stored in a sealed low temperature after collection. Before preparing biochar, the iron-containing sludge was naturally settled, centrifuged and dehydrated, dried overnight, and after the moisture was fully removed, it was ground into 1-2 mm particles. After drying, the iron-containing sludge particles had an ash content of 72.4%, a carbon content of 7.6%, and an Fe content of 45.1%. The sand willow branch fragments were collected from the desertified area of ​​Yulin, air-dried after collection and stored at room temperature; before preparing biochar, they were dried overnight and then ground into 1-2 mm fragments. After drying, the ash content of the sand willow debris was 15.0%, the carbon content was 80.5%, and the Fe content was 0.02%.

[0031] A method for preparing a phenolic soil pollution remediation material SFB600 includes the following steps: S1. The dried sand willow branch fragments and iron-containing sludge particles are uniformly mixed at a mass ratio of 1:4 to obtain the mixed raw materials. S2. Place the mixed raw materials obtained in step S1 into a tube furnace for anaerobic pyrolysis under the following conditions: initial temperature set at 45℃, and pyrolysis rate at 11℃·min. -1 The temperature was raised to 600℃, held for 1 hour, and then naturally cooled to room temperature to obtain a phenolic soil pollution remediation material, SFB600.

[0032] The prepared phenolic soil remediation material SFB600 had a yield of 78.38%, an ash content of 72.36%, a pH of 9.21, and a specific surface area of ​​80.90 m². 2 ·g -1 It has a pore size of 5.17 nm and is magnetic.

[0033] The prepared phenolic soil pollution remediation material SFB600 has an H / C ratio of 0.09 (<0.4) and an O / C ratio of 0.32 (<0.4), which meets the standards for biochar materials as soil conditioners proposed by the European Biochar Foundation (EBC) (i.e., H / C<0.4 and O / C<0.4), and has good aromaticity and stability.

[0034] The prepared phenolic soil pollution remediation material SFB600 has an Fe content of 60.18% and a Ca content of 8.31%, and possesses the characteristic Fe=O peak (580 cm⁻¹) in infrared spectroscopy. - ¹Near metal-ligand vibration peaks) and characteristic structural peaks of aromatic compounds (850 cm⁻¹) - ¹Out-of-plane bending peak of the nearby monosubstituted benzene ring =CH, 2900 cm⁻¹ - ¹Near CH2-asymmetric stretching vibration peak and 3100 cm⁻¹ - ¹Near the stretching vibration peak of the benzene ring -CH=CH2.

[0035] The prepared phenolic soil pollution remediation material SFB600 exhibits rapid adsorption of phenol, with an adsorption equilibrium time of 50 min and a maximum adsorption capacity of 7.82 mg·g⁻¹. -1 .

[0036] An application of a phenolic soil pollution remediation material involves adding a prepared phenolic soil pollution remediation material, SFB600, to phenol-contaminated soil to enhance the bioremediation of phenol-contaminated soil. After completion, the residual phenol concentration and microbial community in the soil are tested to evaluate the pollution remediation effect.

[0037] Example 3, a phenolic soil pollution remediation material SFB400, whose raw materials include willow branch fragments and iron-containing sludge particles in a mass ratio of 2:1; The iron-containing sludge was taken from the wastewater Fenton treatment unit of a paper mill and stored in a sealed low temperature after collection. Before preparing biochar, the iron-containing sludge was naturally settled, centrifuged and dehydrated, dried overnight, and after the moisture was fully removed, it was ground into 1-2 mm particles. After drying, the iron-containing sludge particles had an ash content of 72.4%, a carbon content of 7.6%, and an Fe content of 45.1%. The sand willow branch fragments were collected from the desertified area of ​​Yulin, air-dried after collection and stored at room temperature; before preparing biochar, they were dried overnight and then ground into 1-2 mm fragments. After drying, the ash content of the sand willow debris was 15.0%, the carbon content was 80.5%, and the Fe content was 0.02%.

[0038] A method for preparing a phenolic soil pollution remediation material SFB400 includes the following steps: S1. The dried sand willow branch fragments and iron-containing sludge particles are uniformly mixed at a mass ratio of 2:1 to obtain the mixed raw materials. S2. Place the mixed raw materials obtained in step S1 into a tube furnace for anaerobic pyrolysis under the following conditions: initial temperature set at 35℃, and pyrolysis rate at 9℃·min. -1 The temperature was raised to 400℃, held for 1 hour, and then naturally cooled to room temperature to obtain a phenolic soil pollution remediation material, SFB400.

[0039] The prepared phenolic soil remediation material SFB400 had a yield of 50.22%, an ash content of 41.57%, a pH of 7.89, and a specific surface area of ​​85.57 m². 2 ·g -1 It has a pore size of 4.81 nm and is magnetic.

[0040] The prepared phenolic soil pollution remediation material SFB400 has an H / C ratio of 0.02 (<0.4) and an O / C ratio of 0.37 (<0.4), which meets the standards for biochar materials as soil conditioners proposed by the European Biochar Foundation (EBC) (i.e., H / C<0.4 and O / C<0.4), and has good aromaticity and stability.

[0041] The prepared phenolic soil pollution remediation material SFB400 has an Fe content of 54.82% and a Ca content of 7.14%, and possesses the characteristic Fe=O peak (580 cm⁻¹) in infrared spectroscopy. - ¹Near metal-ligand vibration peaks) and characteristic structural peaks of aromatic compounds (850 cm⁻¹) - ¹Out-of-plane bending peak of the nearby monosubstituted benzene ring =CH, 2900 cm⁻¹ - ¹Near CH2-asymmetric stretching vibration peak and 3100 cm⁻¹ - ¹Near the stretching vibration peak of the benzene ring -CH=CH2.

[0042] The prepared phenolic soil pollution remediation material SFB400 exhibits rapid adsorption of phenol, with an adsorption equilibrium time of 120 min and a maximum adsorption capacity of 7.93 mg·g⁻¹. -1 .

[0043] An application of a phenolic soil pollution remediation material involves adding a prepared phenolic soil pollution remediation material, SFB400, to phenol-contaminated soil to enhance the bioremediation of phenol-contaminated soil. After completion, the residual phenol concentration and microbial community in the soil are tested to evaluate the pollution remediation effect.

[0044] Example 4: A phenolic soil pollution remediation material SFB450, the raw materials of which include willow branch fragments and iron-containing sludge particles in a mass ratio of 1.5:1; The iron-containing sludge was taken from the wastewater Fenton treatment unit of a paper mill and stored in a sealed low temperature after collection. Before preparing biochar, the iron-containing sludge was naturally settled, centrifuged and dehydrated, dried overnight, and after the moisture was fully removed, it was ground into 1-2 mm particles. After drying, the iron-containing sludge particles had an ash content of 68.8%, a carbon content of 6.8%, and an Fe content of 42.6%. The sand willow branch fragments were collected from the desertified area of ​​Yulin, air-dried after collection and stored at room temperature; before preparing biochar, they were dried overnight and then ground into 1-2 mm fragments. After drying, the ash content of the sand willow debris was 12.5%, the carbon content was 75.5%, and the Fe content was 0.00%.

[0045] A method for preparing a phenolic soil pollution remediation material SFB300 includes the following steps: S1. The dried sand willow branch fragments and iron-containing sludge particles are uniformly mixed at a mass ratio of 2:1 to obtain the mixed raw materials. S2. Place the mixed raw materials obtained in step S1 into a tube furnace for anaerobic pyrolysis under the following conditions: initial temperature set at 40℃, and pyrolysis rate at 10℃·min. -1 The temperature was raised to 450℃, held for 1.5 h, and then naturally cooled to room temperature to prepare a phenolic soil pollution remediation material, SFB450.

[0046] The prepared phenolic soil remediation material SFB450 had a yield of 53.71%, an ash content of 59.84%, a pH of 8.23, and a specific surface area of ​​86.41 m². 2 ·g -1 It has a pore size of 4.77 nm and is magnetic.

[0047] The prepared phenolic soil pollution remediation material SFB450 has an H / C ratio of 0.03 (<0.4) and an O / C ratio of 0.29 (<0.4), which meets the standards for biochar materials as soil conditioners proposed by the European Biochar Foundation (EBC) (i.e., H / C<0.4 and O / C<0.4), and has good aromaticity and stability.

[0048] The prepared phenolic soil pollution remediation material SFB450 has an Fe content of 57.26% and a Ca content of 7.38%, and exhibits the characteristic Fe=O peak (580 cm⁻¹) in infrared spectroscopy. - ¹Near metal-ligand vibration peaks) and characteristic structural peaks of aromatic compounds (850 cm⁻¹) - ¹Out-of-plane bending peak of the nearby monosubstituted benzene ring =CH, 2900 cm⁻¹ - ¹Near CH2-asymmetric stretching vibration peak and 3100 cm⁻¹ - ¹Near the stretching vibration peak of the benzene ring -CH=CH2.

[0049] The prepared phenolic soil pollution remediation material SFB450 exhibits rapid adsorption of phenol, with an adsorption equilibrium time of 90 min and a maximum adsorption capacity of 8.05 mg·g⁻¹. -1 .

[0050] An application of a phenolic soil pollution remediation material involves adding a prepared phenolic soil pollution remediation material, SFB450, to phenol-contaminated soil to enhance the bioremediation of phenol-contaminated soil. After completion, the residual phenol concentration and microbial community in the soil are tested to evaluate the pollution remediation effect.

[0051] Example 5: A phenolic soil pollution remediation material SFB550, the raw materials of which include willow branch fragments and iron-containing sludge particles in a mass ratio of 1:2. The iron-containing sludge was taken from the wastewater Fenton treatment unit of a paper mill and stored in a sealed low temperature after collection. Before preparing biochar, the iron-containing sludge was naturally settled, centrifuged and dehydrated, dried overnight, and after the moisture was fully removed, it was ground into 1-2 mm particles. After drying, the iron-containing sludge particles had an ash content of 76.0%, a carbon content of 8.4%, and an Fe content of 47.6%. The sand willow branch fragments were collected from the desertified area of ​​Yulin, air-dried after collection and stored at room temperature; before preparing biochar, they were dried overnight and then ground into 1-2 mm fragments. After drying, the ash content of the sand willow debris was 17.5%, the carbon content was 82.5%, and the Fe content was 0.02%.

[0052] A method for preparing a phenolic soil pollution remediation material SFB550 includes the following steps: S1. The dried sand willow branch fragments and iron-containing sludge particles are uniformly mixed at a mass ratio of 2:1 to obtain the mixed raw materials. S2. Place the mixed raw materials obtained in step S1 into a tube furnace for anaerobic pyrolysis under the following conditions: initial temperature set at 40℃, and pyrolysis rate at 10℃·min. -1 The temperature was raised to 550℃, held for 1.5 h, and then naturally cooled to room temperature to prepare a phenolic soil pollution remediation material, SFB550.

[0053] The prepared phenolic soil remediation material SFB550 had a yield of 65.48%, an ash content of 70.52%, a pH of 9.04, and a specific surface area of ​​84.26 m². 2 ·g -1 It has a pore size of 4.93 nm and is magnetic.

[0054] The prepared phenolic soil pollution remediation material SFB200 has an H / C ratio of 0.05 (<0.4) and an O / C ratio of 0.35 (<0.4), which meets the standards for biochar materials as soil conditioners proposed by the European Biochar Foundation (EBC) (i.e., H / C<0.4 and O / C<0.4), and has good aromaticity and stability.

[0055] The prepared phenolic soil pollution remediation material SFB550 has an Fe content of 60.04% and a Ca content of 8.27%, and possesses the characteristic Fe=O peak (580 cm⁻¹) in infrared spectroscopy. - ¹Near metal-ligand vibration peaks) and characteristic structural peaks of aromatic compounds (850 cm⁻¹) - ¹Out-of-plane bending peak of the nearby monosubstituted benzene ring =CH, 2900 cm⁻¹ - ¹Near CH2-asymmetric stretching vibration peak and 3100 cm⁻¹ - ¹Near the stretching vibration peak of the benzene ring -CH=CH2.

[0056] The prepared phenolic soil pollution remediation material SFB550 exhibits rapid adsorption of phenol, with an adsorption equilibrium time of 45 min and a maximum adsorption capacity of 8.12 mg·g⁻¹. -1 .

[0057] An application of a phenolic soil pollution remediation material involves adding a prepared phenolic soil pollution remediation material, SFB200, to phenol-contaminated soil to enhance the bioremediation of phenol-contaminated soil. After completion, the residual phenol concentration and microbial community in the soil are tested to evaluate the pollution remediation effect.

[0058] Comparative Example 1: FB500, a phenolic soil pollution remediation material, whose raw material is iron-containing sludge particles; The iron-containing sludge was taken from the wastewater Fenton treatment unit of a paper mill and stored in a sealed low temperature after collection. Before preparing biochar, the iron-containing sludge was naturally settled, centrifuged and dehydrated, dried overnight, and after the moisture was fully removed, it was ground into 1-2 mm particles. After drying, the iron-containing sludge particles had an ash content of 72.4%, a carbon content of 7.6%, and an Fe content of 45.1%.

[0059] A method for preparing a phenolic soil pollution remediation material FB500 includes the following steps: S1. Take dried iron-containing sludge particles as raw materials; S2. Place the raw materials described in step S1 into a tube furnace for anaerobic pyrolysis under the following conditions: initial temperature set at 40℃, and pyrolysis rate at 10℃·min. -1 The temperature was raised to 500℃, held for 1 hour, and then naturally cooled to room temperature to obtain a pyrolytic biochar material FB500.

[0060] The prepared pyrolytic biochar material FB500 had a yield of 81.12%, an ash content of 96.35%, a pH of 8.11, and a specific surface area of ​​27.73 m². 2 ·g -1 It has a pore size of 15.24 nm and is magnetic.

[0061] The prepared pyrolytic biochar material FB500 has H / C (0.43) > 0.4 and O / C (0.28) < 0.4, which does not meet the standards for biochar materials as soil conditioners proposed by the European Biochar Foundation (EBC) (i.e., H / C < 0.4 and O / C < 0.4).

[0062] The prepared pyrolytic biochar material FB500 has an Fe content of 89.85% and a Ca content of 4.13%, and possesses the characteristic Fe=O peak (580 cm⁻¹) in infrared spectroscopy. - ¹Near metal-ligand vibrational peaks.

[0063] The prepared pyrolytic biochar material FB500 had an adsorption equilibrium time of 10 min for phenol, and the maximum adsorption capacity was only 2.53 mg·g. -1 .

[0064] Comparative Example 2: SLB500, a phenolic soil pollution remediation material, whose raw materials include willow branch fragments. The sand willow branch fragments were collected from the desertified area of ​​Yulin, air-dried after collection and stored at room temperature; before preparing biochar, they were dried overnight and then ground into 1-2 mm fragments. After drying, the ash content of the sand willow debris was 15.0%, the carbon content was 80.5%, and the Fe content was 0.02%.

[0065] A method for preparing a phenolic soil pollution remediation material SLB500 includes the following steps: S1. Take dried sand willow fragments as raw materials; S2. Place the raw materials described in step S1 into a tube furnace for anaerobic pyrolysis under the following conditions: initial temperature set at 40℃, and pyrolysis rate at 10℃·min. -1 The temperature was raised to 500℃, held for 1 h, and then naturally cooled to room temperature to obtain a pyrolytic biochar material SLB500.

[0066] The prepared pyrolytic biochar material SLB500 had a yield of 32.65%, an ash content of 9.14%, a pH of 7.89, and a specific surface area of ​​3.85 m². 2 ·g -1 It has an aperture of 8.62 nm and is non-magnetic.

[0067] The prepared phenolic soil pollution remediation material SLB500 has an H / C ratio of 0.14 (<0.4) and an O / C ratio of 0.87 (>0.4), which does not meet the standards for biochar materials as soil conditioners proposed by the European Biochar Foundation (EBC) (i.e., H / C<0.4 and O / C<0.4).

[0068] The prepared phenolic soil pollution remediation material SLB500 has an Fe content of 0.59% and a Ca content of 20.09%, and possesses the structural characteristic peak of aromatic compounds (850 cm⁻¹). - ¹Out-of-plane bending peak of the nearby monosubstituted benzene ring =CH, 2900 cm⁻¹ - ¹Near CH2-asymmetric stretching vibration peak and 3100 cm⁻¹ - ¹Near the stretching vibration peak of the benzene ring -CH=CH2.

[0069] The prepared phenolic soil remediation material SLB500 exhibits phenol adsorption capabilities, but the adsorption rate is slow, with an adsorption equilibrium time of 250 min and a maximum adsorption capacity of 9.46 mg·g⁻¹. -1 .

[0070] The basic characteristics of the materials prepared in Examples 1, 2, 3, 4, 5 and Comparative Examples 1 and 2 are shown in Table 1. In comparison, the materials prepared in these examples possess the structural characteristics of both raw materials, are magnetic, and can achieve rapid adsorption of large quantities of phenol.

[0071] Table 1 Material Naming SFB500 SFB600 SFB400 SFB450 SFB550 FB500 SLB500 Yield / % 58.26 78.38 50.22 53.71 65.48 81.12 32.65 Ash content / % 69.90 72.36 41.57 59.84 70.52 96.35 9.14 pH 8.81 9.21 7.89 8.23 9.04 8.11 7.89 SSA / m2·g-1 90.05 80.90 85.57 86.41 84.26 27.73 3.85 APS / nm 4.63 5.17 4.81 4.77 4.93 15.24 8.62 magnetic + + + + + + - H / C 0.03 0.09 0.02 0.03 0.05 0.43 0.14 O / C 0.26 0.32 0.37 0.29 0.35 0.28 0.87 Fe / % 59.67 60.18 54.82 57.26 60.04 89.85 0.59 Ca / % 7.70 8.31 7.14 7.38 8.27 4.13 20.90 Fe=O characteristic peak (FTIR wavenumber 580 cm⁻¹) + + + + + + - Characteristic peaks of aromatic structure (FTIR wavenumbers 850 cm⁻¹, 2900 cm⁻¹, 3100 cm⁻¹) + + + + + - + Adsorption equilibrium time / min 50 30 120 90 45 10 250 Maximum adsorption capacity / mg·g⁻¹ 8.71 7.82 7.93 8.05 8.12 2.53 9.46 SSA: Specific Surface Area; APS: Average Pore Size; +: Yes; -: No The application of SFB500, a phenolic soil pollution remediation material prepared in Example 1, is described in detail below.

[0072] An application method for SFB500, a phenolic soil pollution remediation material, includes the following steps: Step 1: Add 5% (w / w) of the phenolic soil pollution remediation material SFB500 prepared in Example 1 to 100 mg·kg⁻¹. -1 Phenol-contaminated soil was thoroughly mixed; at the same time, a control group (CK) with added biological inhibitors and a natural decay group (NA) without any additives were set up. Step 2: Samples were taken on days 1, 2, and 3 to test the concentration of residual phenol in the soil and assess the phenol remediation effect; samples were also taken on days 1, 2, and 3 to analyze the changes in soil functional bacteria using 16S rDNA high-throughput sequencing technology and identify the functional bacteria driving phenol degradation.

[0073] Final repair results as follows Figure 1 As shown, the residual phenol rates in the control group (CK) with added bioinhibitor were 95.67±5.88%, 83.94±2.46%, and 67.39±0.20% on days 1, 2, and 3, respectively. The residual phenol rate in the naturally decaying group (NA) without any additives was 78.62±6.96% on day 2, while the residual phenol rate in the experimental group with the material prepared in Example 1 was only 1.25±0.23% on day 2, achieving rapid and enhanced phenol degradation.

[0074] Changes in soil functional microorganisms, such as Figure 2 As shown in the figure: Initial (initial soil sample); NA (no additives); SFB500 (with added SFB500 composite material from Example 1). The microbial community structure underwent significant changes during phenol degradation. The phenolic soil remediation material SFB500 prepared in Example 1 significantly stimulated the microbial community with phenol degradation properties. Exiguobacterium and Variovorax Fungal proliferation (of which) Exiguobacterium (These are magnetite-loving microorganisms); in the initial soil sample, Exiguobacterium and Variovorax The abundance percentages were 0.61% and 0.03%, respectively; in the naturally decaying group (NA) without any additives, the abundance on day 1 was... Exiguobacterium and Variovorax The abundance percentages were 0.32% and 0.02% respectively, on the 3rd day. Exiguobacterium and Variovorax The abundance percentages were 0.03% and 0.00%, respectively. The experimental group containing SFB500, a phenolic soil pollution remediation material prepared in Example 1, showed degradation on day 1. Exiguobacterium and Variovorax The abundance percentages were 17.50% and 0.96%, respectively, and the degradation occurred on day 3. Exiguobacterium and Variovorax The abundance percentages were 8.06% and 12.03%, respectively.

[0075] The application effects of Embodiments 2, 3, 4 and 5 of the present invention are similar to those of Embodiment 1.

Claims

1. A phenolic soil pollution remediation material, characterized in that: Its raw materials include willow branch fragments and iron-containing sludge particles in a mass ratio of 1:4 to 2:1; The iron-containing sludge was taken from the Fenton wastewater treatment unit of a paper mill and stored in a sealed, low-temperature environment after collection. Before preparing biochar, the iron-containing sludge was naturally settled, centrifuged to remove water, dried overnight, and then ground into 1-2 mm particles after thorough water removal. The dried iron-containing sludge particles had an ash content of 68.8-76%, a carbon content of 6.8-8.4%, and an Fe content of 42.6-47.6%. The sand willow branch fragments were collected from desertified areas, air-dried after collection, and stored at room temperature. Before preparing biochar, they were dried overnight and then ground into 1-2 mm fragments. After drying, the sand willow fragments had an ash content of 12.5-17.5%, a carbon content of 75.5-82.5%, and an Fe content of 0-0.02%. The preparation method of the phenolic soil pollution remediation material includes the following steps: S1. The dried sand willow branch fragments and iron-containing sludge particles are uniformly mixed at a mass ratio of 1:4 to 2:1 to obtain the mixed raw materials; S2. Place the mixed raw materials obtained in step S1 into a tube furnace for anaerobic pyrolysis under the following conditions: initial temperature set at 35~45℃, and temperature at 9~11℃·min. -1 The temperature was raised to 400~550℃, held for 1~1.5 h, and then naturally cooled to room temperature to obtain a phenolic soil pollution remediation material. The prepared phenolic soil pollution remediation material had a yield of 50.22%–78.38%, an ash content of 41.57%–72.36%, a pH of 7.89–9.21, and a specific surface area of ​​80.90–90.05 m². 2 ·g -1 It has a pore size of 4.63~5.17nm and is magnetic; A phenolic soil pollution remediation material was prepared with H / C < 0.4 and O / C < 0.4, which meets the standards for biochar materials as soil conditioners proposed by the European Biochar Foundation (EBC) and has good aromaticity and stability. The prepared phenolic soil pollution remediation material has an Fe content of 54.82-60.18% and a Ca content of 7.14-8.31%, and exhibits the characteristic Fe=O peak in infrared spectroscopy, i.e., at 580 cm⁻¹. - ¹Near metal-ligand vibrational peaks; also possesses characteristic peaks of aromatic compounds, namely 850 cm⁻¹. - ¹Out-of-plane bending peak of the nearby monosubstituted benzene ring =CH, 2900 cm⁻¹ - ¹Near CH2-asymmetric stretching vibration peak and 3100 cm⁻¹ - ¹Near the stretching vibration peak of the benzene ring -CH=CH2; A phenolic soil pollution remediation material was prepared, exhibiting rapid adsorption of phenol, with an adsorption equilibrium time of 50–180 min and a maximum adsorption capacity of 7.82–8.71 mg·g⁻¹. -1 .

2. The application of the phenolic soil pollution remediation material according to claim 1, characterized in that: A phenolic soil pollution remediation material was prepared and added to phenol-contaminated soil to enhance the bioremediation of phenol-contaminated soil. After completion, the residual phenol concentration and microbial community in the soil were tested to evaluate the pollution remediation effect.

3. The application method of the phenolic soil pollution remediation material as described in claim 2, characterized in that, Includes the following steps: Step 1: Add 4-6% (w / w) of a phenolic soil pollution remediation material to 100 mg·kg⁻¹ -1 Phenol-contaminated soil, mix thoroughly; Step 2: Samples were taken on days 1, 2, and 3 to test the concentration of residual phenol in the soil and assess the phenol remediation effect; Samples were taken on days 1, 2, and 3, and changes in soil functional microbial genera were analyzed using 16S rDNA high-throughput sequencing technology.

4. The application method according to claim 3, characterized in that: The final remediation effect was that 98.75% of phenol was removed within 2 days. The prepared phenolic soil pollution remediation material significantly stimulated the degradation of phenol. Exiguobacterium and Variovorax Fungal proliferation, among which Exiguobacterium These are magnetite-loving microorganisms; on days 1 and 3 of the remediation process, Exiguobacterium and Variovorax The abundance percentage increased from the initial 0.64% to 18.46% and 18.05%.

5. A phenolic soil pollution remediation material SFB500, characterized in that: Its raw materials include willow branch fragments and iron-containing sludge particles in a mass ratio of 1:1; The iron-containing sludge was taken from the wastewater Fenton treatment unit of a paper mill and stored in a sealed low temperature after collection. Before preparing biochar, the iron-containing sludge was naturally settled, centrifuged and dehydrated, dried overnight, and after the moisture was fully removed, it was ground into 1-2 mm particles. After drying, the iron-containing sludge particles had an ash content of 72.4%, a carbon content of 7.6%, and an Fe content of 45.1%. The sand willow branch fragments were collected from the desertified area of ​​Yulin, air-dried after collection and stored at room temperature; before preparing biochar, they were dried overnight and then ground into 1-2 mm fragments. After drying, the ash content of the sand willow debris was 15.0%, the carbon content was 80.5%, and the Fe content was 0.02%.

6. The preparation method of SFB500, a phenolic soil pollution remediation material according to claim 5, is characterized in that, Includes the following steps: S1. The dried sand willow branch fragments and iron-containing sludge particles are uniformly mixed in a mass ratio of 1:1 to obtain the mixed raw materials. S2. Place the mixed raw materials obtained in step S1 into a tube furnace for anaerobic pyrolysis under the following conditions: initial temperature set at 40℃, and pyrolysis rate at 10℃·min. -1 The temperature was raised to 500℃ and held for 1 hour, then naturally cooled to room temperature to obtain a phenolic soil pollution remediation material SFB500. The prepared phenolic soil remediation material SFB500 had a yield of 58.26%, an ash content of 69.90%, a pH of 8.81, and a specific surface area of ​​90.05 m². 2 ·g -1 It has a pore size of 4.63 nm and is magnetic; The prepared phenolic soil pollution remediation material SFB500 has an H / C ratio of 0.03 and an O / C ratio of 0.26, which meets the standards for biochar materials as soil conditioners proposed by the European Biochar Foundation (EBC), namely H / C < 0.4 and O / C < 0.

4. It also has good aromaticity and stability. The prepared phenolic soil pollution remediation material SFB500 has an Fe content of 59.67% and a Ca content of 7.70%, and possesses the characteristic Fe=O peak in infrared spectroscopy, i.e., at 580 cm⁻¹. - ¹Near metal-ligand vibrational peaks; also possesses characteristic peaks of aromatic compounds, namely 850 cm⁻¹. - ¹Out-of-plane bending peak of the nearby monosubstituted benzene ring =CH, 2900 cm⁻¹ - ¹Near CH2-asymmetric stretching vibration peak and 3100 cm⁻¹ - ¹Near the stretching vibration peak of the benzene ring -CH=CH2; The prepared phenolic soil pollution remediation material SFB500 exhibits rapid adsorption of phenol, with an adsorption equilibrium time of 50 min and a maximum adsorption capacity of 8.71 mg·g⁻¹. -1 .

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