Method for removing iron sediments of organic cultural relics in ocean effluent

Abstract

The invention discloses a method for removing iron sediments of organic matter cultural relics in ocean effluent. The method is characterized in that amidoxime modified cellulose reacts with the iron sediments of the organic matter cultural relics in the ocean effluent to remove iron from the iron sediments of the organic matter cultural relics in the ocean effluent. According to the position of the iron sediment to be removed in the cultural relic, the application form of the amidoxime-based modified cellulose can be one or more of amidoxime-based modified gauze application, amidoxime-based cellulose acetic acid solution soaking and amidoxime-based cellulose slurry coating. The method is easy to operate, economical, efficient and environmentally friendly, can be conveniently used for in-situ removal of the iron sediments of the ocean effluent organic matter cultural relics, and particularly can be conveniently used for large organic matter cultural relics such as ocean archaeological wooden sunken ships.

Description

Technical Field

[0001] This invention belongs to the field of cultural relic protection, and specifically relates to a method for removing iron deposits from organic cultural relics from marine outflow. Background Technology

[0002] In marine archaeology, organic artifacts, such as wooden shipwreck hulls or other wooden objects, undergo various types of iron-containing sediments during burial due to the marine environment. These sediments include iron-sulfur compounds such as FeS and FeS2, iron oxide compounds such as Fe2O3, Fe3O4, and FeOOH, and iron salts such as FeCO3. After being retrieved from the water, these iron-sulfur compounds readily oxidize in the presence of moisture and oxygen, producing sulfuric acid. This promotes the degradation of cellulose in the material and simultaneously generates iron oxides such as Fe2O3 and FeOOH, as well as iron salts such as FeNa2(SO4)2•12H2O. 2+ / Fe 3+ The redox reactions between iron and iron ions catalyze the Fenton reaction, leading to the degradation of organic components in the material and a decrease in its strength. When environmental temperature and relative humidity change, iron compounds continuously dissolve / precipitate, causing damage to the material's microstructure. The presence of iron deposits severely affects the appearance, dehydration, reinforcement, and long-term stable preservation of organic artifacts such as wooden ship hulls. Therefore, after excavating marine organic artifacts, the first step is to remove iron deposits from the material structure as much as possible to reduce their adverse effects and provide a foundation for the long-term stable preservation of the artifact.

[0003] However, iron compounds have extremely low solubility in water, making it difficult to dissolve iron deposits in the material structure. In recent years, studies have used complexing reagents, mixtures of complexing reagents and reducing agents, and mixed solutions of complexing reagents and oxidizing agents to remove iron deposits from marine organic artifacts. This involves using Fe... 3+ or Fe 2+ It forms stable, water-soluble metal complexes, removes iron deposits, and prevents Fe... 3+ or Fe 2+Iron deposits can redeposit or adhere to the surface of artifact materials. Commonly used complexing agents include disodium ethylenediaminetetraacetate (EDTA-2Na), diethylenetriaminepentaacetic acid (DTPA), and ethylenediamine-di(2-hydroxy-4-tolyl)acetic acid (EDDHMA). The reducing agent used in conjunction with the complexing agent is primarily sodium dithionite (Na2S2O4), and the oxidizing agent is primarily hydrogen peroxide (H2O2). These materials must first be dissolved in water to form an aqueous solution. Through spraying or soaking, they react with the insoluble iron deposits to form soluble and stable complexes, thereby removing the iron deposits from the organic artifact structure. However, these compounds must be dissolved to form a solution to be effective. For large marine artifacts recovered from the sea, such as wooden shipwrecks used in marine archaeology, removing iron deposits from the entire ship through soaking is practically impossible.

[0004] Organic artifacts unearthed in marine archaeological excavations undergo significant porosity due to microbial degradation during long-term burial. Their capillary structures become filled with water from the environment, forming saturated materials. Compared to conventional materials, saturated materials exhibit greatly increased shrinkage and severe anisotropy during drying. Uncontrolled drying can cause severe deformation or even damage to these artifacts. Therefore, during preservation, they are often immersed in water or sprayed with large amounts of water to maintain their shape stability. Furthermore, during the dehydration and drying process, which can last for several years or even decades, a high-humidity environment must be maintained to ensure a gradual and slow decrease in moisture content. Consequently, hydrogel application methods, commonly used in artifact preservation for pollutant removal and salt removal, cannot form an effective, peelable gel on the surface of marine-excavated organic artifacts exposed to long-term water spraying, high humidity, and high iron content. This results in gel residue remaining on the surface of marine-excavated wooden artifacts, causing contamination and even damage. Currently, there is no effective solution for removing iron deposits from large marine-excavated wooden shipwrecks, whether the Vasa and Mary Rose wrecks abroad or domestically.

[0005] Therefore, for the protection of marine organic artifacts, especially large wooden shipwrecks, a safe and effective method is needed to remove iron deposits in situ. This method should form a soluble complex with the insoluble iron deposits in the artifact materials to effectively remove the iron, and should not have any adverse effects on the artifact materials themselves during the process of removing iron deposits. The selected materials should be inexpensive, readily available, and economical.

[0006] To address the aforementioned problems, this invention provides a method for removing iron deposits from marine organic artifacts. This method involves reacting cellulose modified with a methylamine oxime group with the iron deposits, effectively removing them. This method is convenient, economical, efficient, and environmentally friendly. It can be readily used for the in-situ removal of iron deposits from marine organic artifacts, and is particularly suitable for large marine wooden artifacts, such as shipwrecks recovered from marine archaeological sites, where conventional methods are inconvenient. Summary of the Invention

[0007] This invention provides a method for removing iron deposits from marine organic artifacts. The method involves reacting cellulose modified with a methylamine oxime group with the iron deposits. This method is particularly suitable for removing iron deposits from the material structure of marine organic artifacts, especially for large marine wooden artifacts, such as marine wooden shipwrecks, and can be easily carried out.

[0008] A method for removing iron deposits from marine organic artifacts is characterized by reacting the iron deposits with a methylamine oxime-modified cellulose solution to remove iron.

[0009] Depending on the location of the iron deposits to be removed in the marine outflow organic artifacts, the application of the metallo-oxime modified cellulose may be one or more of the following: metallo-oxime modified gauze application, metallo-oxime cellulose acetic acid solution soaking, and metallo-oxime cellulose slurry coating.

[0010] The amylopyrime-modified gauze is a amylopyrime-functionalized gauze (Ami-gauze) prepared by a finishing process.

[0011] The method of this invention can be effectively used to remove iron deposits from marine-derived organic artifacts, such as marine-derived wooden artifacts, marine-derived bamboo artifacts, marine-derived leather artifacts, marine-derived lacquerware, and marine-derived plant fiber woven artifacts. Examples of marine-derived wooden artifacts include salvaged wooden shipwrecks, wooden hull components, and small wooden artifacts.

[0012] For large marine artifacts containing organic matter, a metallo-amine oxime-modified gauze is applied to remove iron. The specific steps of this method are as follows: 1) Clean the surface of the organic artifacts after they have been exposed to water to remove contaminants, for example, by mechanical methods; 2) Apply a methylamine oxime-modified gauze to the areas of iron deposits on cleaned marine artifacts containing organic matter. The gauze can be properly secured as needed to prevent it from slipping off during application; 3) Keep the gauze on for a period of time, during which the surface of the artifact needs to be kept moist, or spray a small amount of water onto the gauze; you can gently press or roll the gauze on the artifact as needed to make it adhere tightly to the surface of the artifact. 4) Observe that the gauze turns yellow until it becomes dark brown; then, remove the amylopyridine-modified gauze to regenerate it for recycling; The regeneration process involves immersing the removed gauze in an EDTA-2Na solution to wash away the adsorbed iron; the washing is repeated until the color of the gauze is basically restored; the concentration of the EDTA-2Na solution used is 9-15 mmol / L. During the soaking process, ultrasonic vibrations are used to accelerate the elution of iron. 5) The gauze is then applied again to the artifact to remove iron deposits; 6) Repeat steps 2)-5) until the gauze color no longer turns yellow, then stop applying the gauze and complete the removal of iron deposits.

[0013] In one embodiment of the method according to the present invention, for relatively small marine organic artifacts, such as small wooden artifacts or wooden ship hull components, iron deposits can be removed by immersing them in a methylamine oxime-modified cellulose solution; the specific steps are as follows: 1) Clean the surface of the water-extracted organic artifacts to remove contaminants, for example, through mechanical methods; 2) Add the cellulose oxime powder to the acetic acid solution to prepare a cellulose oxime solution; The concentration of the acetic acid solution is 0.05 mol / L, and the mass-to-volume ratio of the acetic acid solution to the methylamine oxime cellulose is 1:1000 g / ml.

[0014] 3) Immerse the marine-derived organic artifact materials in the solution, sealing the container to prevent evaporation; 4) During the soaking process, monitor the iron concentration in the solution. When the iron concentration tends to stabilize, replace the ammonium oxime cellulose solution. 5) Repeat the soaking step in step 4) until the solution color no longer changes after soaking, then end the soaking and complete the removal of iron deposits.

[0015] In another embodiment of the method according to the present invention, for relatively small marine organic artifacts, or for larger marine organic artifacts where it is inconvenient to apply the paste, such as in crevices, iron deposits can be removed by applying a metallo-oxime cellulose slurry. The specific steps are as follows: 1) Prepare a slurry from metallo-oxime cellulose with water and apply it to the areas of the marine organic artifact material where iron deposits are present; 2) After the metallo-oxime cellulose slurry adsorbs iron, wash with water to remove the iron deposits.

[0016] The methylamine oxime cellulose used in this invention was prepared according to CN104492486A, and the steps are as follows: Under alkaline conditions, cellulose undergoes a Michael addition reaction with acrylonitrile monomer to obtain cyanoethyl cellulose; subsequently, under alkaline conditions, cyanoethyl cellulose reacts with hydroxylamine hydrochloride to obtain amylopyroxime cellulose.

[0017] For more detailed information on the preparation of methylamine oxime cellulose, please refer to CN104492486A.

[0018] The methylamine oxime-modified gauze used in this invention is prepared by crosslinking methylamine oxime cellulose onto gauze using a polyurethane-based crosslinking agent: methylamine oxime cellulose is dissolved in an acidic solvent, the pH of the solution is adjusted to 3.0-5.0, and a polyurethane-based crosslinking agent is added and mixed to prepare a finishing solution; the desized gauze is immersed in the finishing solution for a certain period of time, excess finishing solution is squeezed out, and the gauze is dried to obtain the final product. For detailed information, please refer to CN114687211A.

[0019] In the method according to the present invention, the adsorption of iron by metallo-oxime cellulose is mainly chemical adsorption, resulting in good removal efficiency. It can effectively remove iron deposits on the surface and inside the wood of wooden artifacts. Metallo-oxime modified gauze has a large specific surface area, good adsorption selectivity, high adsorption capacity, high removal efficiency, and fast adsorption-desorption rate. It is reusable and does not cause pollution or damage to artifacts, making it a very promising green material. Furthermore, it provides in-situ removal, is easy to operate, and can be readily used to remove iron deposits from the structure of any marine-exposed organic artifact, especially large artifacts where iron deposit removal by immersion is not feasible, such as marine shipwrecks. Immersion in metallo-oxime cellulose solution or application of slurry can be conveniently used for removing iron deposits from small organic artifacts or in areas where application is inconvenient, such as crevices. Therefore, the present invention provides a new and highly effective solution for the removal of iron deposits from marine-exposed organic artifacts. Attached Figure Description

[0020] Figure 1 This is a scanning electron microscope image of iron deposits adsorbed on gauze A1 with a methylamine oxime group modified in Example 3 of the present invention.

[0021] Figure 2 This is a scanning electron microscope image of iron deposits adsorbed on gauze A1 modified with a methylamine oxime group in Example 3 of the present invention.

[0022] Figure 3 This is a scanning electron microscope image of iron deposits eluted from gauze A1 modified with amine oxime in Example 3 of the present invention.

[0023] Figure 4The energy dispersive spectroscopy (EDS) test points are located at the locations indicated by the black cross on the amylopyrime-modified gauze A1 that adsorbed iron deposits in Example 3 of this invention. Specific implementation plan: The present invention will be explained in further detail below with reference to specific embodiments, but the present invention is not limited thereto. All chemicals used are of analytical grade; the gauze is conventional gauze. Unless otherwise specified, all reagents and materials used are commercially available. The experimental wood block samples used in Examples 1 and 2 and the comparative examples were taken from loose timber used to secure cargo on the Song Dynasty shipwreck Nanhai I. The experimental location in Example 3 was the main body of the ship's timbers from the Nanhai I Song Dynasty shipwreck.

[0024] Preparation Example 1: Preparation of cellulose functionalized with amine oxime groups

[0025] (1) Preparation of cyanoethyl bacterial cellulose: 800 mL of milled nano-bacterial cellulose (solid content 0.9%, particle size approximately 30 nm, bacterial cellulose mass 7.3 g) was soaked in 800 mL of 1 mol / L NaOH for 7 hours, and then directly added to a 2000 mL round-bottom flask. While stirring at room temperature and a stirring speed of 900 rpm / min, 400 mL of acrylonitrile monomer (322 g) was added dropwise to the round-bottom flask. The reaction was stopped after 12 hours. The product in the round-bottom flask was washed three times with ultrapure water, and the supernatant was removed by centrifugation to obtain 10.5 g of cyanoethyl cellulose. (2) Preparation of gem-amino oxime cellulose: Weigh 200g of hydroxylamine hydrochloride (NH2OHxHCl) solid and 116g of NaOH solid, respectively, and add them to a 2000mL round-bottom flask. Add 1000mL of ultrapure water and place the flask in a 50°C water bath with stirring to dissolve for 2 hours. Add 10.5g of cyanoethyl cellulose to the mixed solution and keep the temperature constant at 50°C. Stir and react for 8 hours. After the reaction, the solution is centrifuged and washed three times in ultrapure water. Remove the supernatant to obtain amylopyroxime cellulose.

[0026] Preparation Example 2: Preparation of Gauze Modified with Aminooxime

[0027] Prepare a 1-liter acetic acid solution with pH 3.5, add 10 g of amyl oxime cellulose (AOC), and dissolve it in a 60°C water bath with stirring. Then add 30 g of toluene diisocyanate crosslinking agent to prepare a finishing solution. Immerse 50 g of desized gauze in the finishing solution (1.0 liter) for 1.0 hour, then squeeze out excess finishing solution and dry at 120°C for 5 minutes to obtain Ami-gauze. The AOC content was determined to be 1.2% (weight percentage) by measuring the mass increase of the Ami-gauze. Example 1

[0028] At room temperature, timber samples taken from the Song Dynasty shipwreck "Nanhai I" were placed in a container filled with deionized water, with the water level not exceeding the surface of the timber. Seven pieces of ammonia-oxime modified gauze (approximately 0.05g each, approximately 3cm x 3cm in size) were taken and numbered 1#, 2#, 3#, 4#, 5#, 6#, and 7#. The gauze was applied to areas of the sample surface with iron deposits, and a small amount of water was sprayed to ensure close contact with the timber surface. The application times were 10h, 20h, 30h, 40h, 50h, 100h, and 150h, respectively. After the specified time, the ammonia-oxime modified gauze was removed and placed in 100ml of 10mmol / L EDTA-2Na solution for 50h to elute the iron adsorbed by the ammonia-oxime modified gauze. The iron content data in the elution solution are shown in Table 1.

[0029] Table 1. Changes in iron concentration in the wash solution after the first application of the patch over time. Sample number 1# 2# 3# 4# 5# 6# 7# Application time (h) 9 20 30 40 50 100 150 [Fe] mg / L 0.06174 0.09093 0.07879 0.08586 0.23423 0.10614 0.13308 After the first application and elution, the amylopectin-modified gauze was removed, rinsed three times with 200 ml of deionized water, and then applied again to the surface of the wood sample for a second application to remove iron deposits. The application times were 10 h, 20 h, 30 h, 40 h, 50 h, 100 h, and 150 h. Within the specified time, the amylopectin-modified gauze was removed and placed in 100 ml of 10 mmol / L EDTA-2Na solution for 50 h to elute the iron adsorbed by the amylopectin-modified gauze. The iron content data in the elution solution are shown in Table 2.

[0030] Table 2. Changes in iron concentration in the wash-off solution after the second dressing application over time. Sample number 1# 2# 3# 4# 5# 6# 7# Application time (h) 9h 20h 30h 40h 50h 100h 150h [Fe] mg / L 0.07289 0.07566 0.08127 0.07761 0.11154 0.14175 0.14308 After the second application and elution, the amylopectin-modified gauze was removed, rinsed three times with 200 ml of deionized water, and then applied to the surface of the wood sample for a third application to remove iron deposits. The application times were 10 h, 20 h, 30 h, 40 h, 50 h, 100 h, and 150 h. The amylopectin-modified gauze was removed within the specified time and placed in 100 ml of 10 mmol / L EDTA-2Na solution for 50 h to elute the iron adsorbed by the amylopectin-modified gauze. The iron content data in the elution solution are shown in Table 3.

[0031] Table 3. Changes in iron concentration in the elution solution over time in step 3) (third application) Sample number 1# 2# 3# 4# 5# 6# 7# Application time (h) 9 20 30 40 50 100 150 [Fe] mg / L 0.11866 0.09067 0.09206 0.12644 0.09207 0.12047 0.17773 After the third application and elution, the amylopectin-modified gauze was removed, rinsed three times with 200 ml of deionized water, and then applied to the surface of the wood sample for a fourth application to remove iron deposits. The application times were 10 h, 20 h, 30 h, 40 h, 50 h, 100 h, and 150 h. The amylopectin-modified gauze was removed within the specified time and placed in 100 ml of 10 mmol / L EDTA-2Na solution for 50 h to elute the iron adsorbed by the amylopectin-modified gauze. The iron content data in the elution solution are shown in Table 4.

[0032] Table 4. Changes in iron concentration over time in the wash solution after the fourth application of the dressing. Sample number 1# 2# 3# 4# 5# 6# 7# Application time (h) 9 20 30 40 50 100 150 [Fe] mg / L 0.11057 0.0912 0.09803 0.10677 0.11552 0.13524 0.14419 After the fourth application and elution, the amylopectin-modified gauze was removed, rinsed three times with 200 ml of deionized water, and then applied to the surface of the wood sample for a fifth application to remove iron deposits. The application times were 10 h, 20 h, 30 h, 40 h, 50 h, 100 h, and 150 h. The amylopectin-modified gauze was removed within the specified time and placed in 100 ml of 10 mmol / L EDTA-2Na solution for 50 h to elute the iron adsorbed by the amylopectin-modified gauze. The iron content data in the elution solution are shown in Table 5.

[0033] Table 5. Changes in iron concentration over time in the wash solution after the fifth dressing application. Sample number 1# 2# 3# 4# 5# 6# 7# Application time (h) 9 20 30 40 50 100 150 [Fe] mg / L 0.11556 0.09653 0.13652 0.11484 0.13366 0.15088 0.16921 After the fifth application and elution, the amylopectin-modified gauze was removed, rinsed three times with 200 ml of deionized water, and then applied to the wood surface for a sixth application to remove iron deposits. The application times were 10 h, 20 h, 30 h, 40 h, 50 h, 100 h, and 150 h. The amylopectin-modified gauze was removed within the specified time and placed in 100 ml of 10 mmol / L EDTA-2Na solution for 50 h to elute the iron adsorbed by the amylopectin-modified gauze. The iron content data in the eluent is shown in Table 6.

[0034] Table 6. Changes in iron concentration over time in the wash solution after the sixth dressing application. Sample number 1# 2# 3# 4# 5# 6# 7# Application time (h) 9 20 30 40 50 100 150 [Fe] mg / L 0.11777 0.11304 0.12158 0.11873 0.14381 0.14526 0.15781 After the sixth application and elution, the amylopectin-modified gauze was removed, rinsed three times with 200 ml of deionized water, and then applied to the wood surface again for a seventh application to remove iron deposits from the wood. The application times were 10 h, 20 h, 30 h, 40 h, 50 h, 100 h, and 150 h. The amylopectin-modified gauze was removed within the specified time and then placed in 100 ml of 10 mmol / L EDTA-2Na solution for 50 h to elute the iron adsorbed by the amylopectin-modified gauze. The iron content data in the elution solution are shown in Table 7.

[0035] Table 7. Changes in iron concentration over time in the wash solution after the seventh dressing application. Sample number 1# 2# 3# 4# 5# 6# 7# Application time (h) 9 20 30 40 50 100 150 [Fe] mg / L 0.11553 0.11542 0.14686 0.16045 0.13438 0.13851 0.18415 After the seventh application and elution, the amylopectin-modified gauze was removed, rinsed three times with 200 ml of deionized water, and then applied to the wood surface for an eighth application to remove iron deposits. The application times were 10 h, 20 h, 30 h, 40 h, 50 h, 100 h, and 150 h. The amylopectin-modified gauze was removed within the specified time and placed in 100 ml of 10 mmol / L EDTA-2Na solution for 50 h to elute the iron adsorbed by the amylopectin-modified gauze. The iron content data in the elution solution are shown in Table 8.

[0036] Table 8. Changes in iron concentration over time in the wash solution after the eighth application. Sample number 1# 2# 3# 4# 5# 6# 7# Application time (h) 9 20 30 40 50 100 150 [Fe] μg / mL 0.12285 0.14117 0.12589 0.14902 0.16438 0.14627 0.17393 The results of multiple application and washing tests show that the oxime-modified gauze of the present invention can effectively remove iron from wooden artifacts recovered from the ocean, and has good reusability. It can be recycled multiple times and still maintain good iron removal ability. It is green, environmentally friendly, efficient and economical. Example 2

[0037] 0.1 g of methylamine oxime cellulose was dissolved in 100 ml of 0.05 mol / L acetic acid solution to prepare a methylamine oxime cellulose solution. A sample of approximately 1 cm × 1 cm × 1 cm, taken from a piece of driftwood recovered from the Nanhai No. 1 shipwreck, was placed in the solution, and the container was sealed to prevent evaporation. Samples of the solution were taken periodically at 15, 30, 71, 120, 173, 200, 270, 300, and 365 days to test the iron content.

[0038] Table 9. Changes in iron concentration in the elution solution over time in Example 2 Removal time (days) 15 30 71 120 173 200 270 300 365 [Fe] (mg / L) 36.9 43.0 57.7 77.8 90.4 107.0 141.0 164.0 218.12 Example 3

[0039] Take 4 pieces of amine oxime-modified gauze (each piece of amine oxime-modified gauze weighs approximately 10g and has an area of ​​approximately 1184cm²). 2 The gauze was numbered A1, A2, A3, and A4 respectively. It was applied to areas of the Nanhai No. 1 ship's hull with obvious and relatively uniform iron deposits. For uneven hull surfaces, after applying the metallo-oxime modified gauze, it was gently pressed to ensure a tight fit. Bamboo nails were then used to secure the gauze to the hull surface to prevent slippage during application. Specific information on the metallo-oxime modified gauze and its application location on the hull surface is shown in Table 10.

[0040] Four days after application, the amylopyridine-modified gauze was removed and soaked in 100 ml of 10 mmol / L EDTA-2Na solution for 50 h to elute the iron adsorbed by the amylopyridine-modified gauze. The iron content data in the elution solution are shown in Table 11.

[0041] Table 10. Information on amine oxime-modified gauze and its application location on the hull surface. Gauze number gauze weight / g <![CDATA[Gauze size / cm 2 > Application site A1 10.0520 1184 No. 4 cabin at the bow, bulkhead 1 A2 10.8485 1184 No. 4 compartment at the bow, bulkhead 2 A3 9.3099 1184 No. 4 cabin at the bow, bulkhead 1 A4 10.8523 1184 No. 4 compartment at the bow, bulkhead 2 Table 11. Iron concentration in the wash-off solution after 4 days of application in Example 3 Gauze number A1 A2 A3 A4 [Fe] (mg / L) 37.22 62.86 28.56 40.44 After the elution process following the 4-day application, the amylopectin-modified gauze was reapplied to the same location on the surface of the timber of the Nanhai I shipwreck to remove iron deposits. 48 days later, the amylopectin-modified gauze was removed and immersed in 100 ml of 10 mmol / L EDTA-2Na solution for 50 hours to elute the iron adsorbed by the gauze. The iron content data in the elution solution are shown in Table 12.

[0042] Table 12. Iron concentration in the wash-off solution after 48 days of application in Example 3 Gauze number A1 A2 A3 A4 [Fe] (mg / L) 3676.00 5915.00 3277.00 2088.00 The iron adsorption content of the amine oxime-modified gauze varied significantly with different application times. The iron adsorption content of the amine oxime-modified gauze applied for 48 days was much higher than that of the amine oxime-modified gauze applied for 4 days.

[0043] The iron adsorption content per unit area of ​​amine oxime-modified gauze and ordinary gauze was calculated, and the results are shown in Table 13.

[0044] Table 13. Iron adsorption content per unit area of ​​amine oxime-modified gauze and ordinary gauze (mg·cm³) 2 ) serial number 4-day adsorption capacity 48-day adsorption capacity A1 0.0314 3.1047 A2 0.0531 4.9958 A3 0.0241 2.7677 A4 0.0342 1.7635 Scanning electron microscopy observation of iron deposits adsorbed on a amine oxime-modified gauze (before) Figure 1 After adsorbing iron deposits ( Figure 2) and after elution of iron deposits ( Figure 3 The microstructure of the gauze was examined. Scanning electron microscopy (SEM) images showed that the fiber surface of the amylopectin-modified gauze was relatively smooth before and after adsorbing iron deposits. The surface of the amylopectin-modified gauze with adsorbed iron deposits was enriched with a large number of deposit particles, with most fibers completely encapsulated by the deposits. The composition of the adsorbed deposit particles was analyzed using energy dispersive spectroscopy (EDS). The analytical sites of the amylopectin-modified gauze A1 are shown in the image. Figure 4 The results of scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) analysis are shown in Table 14. The SEM-EDS results indicate that the main component of the deposited particles adsorbed on the amylopyridine-modified gauze is iron.

[0045] Table 14. Scanning electron microscopy (SEM) energy dispersive spectroscopy (EDS) analysis results of sediment particles adsorbed on gauze A1 modified with amine oxime (At%). Na Mg Al P S K Ca Fe 1.89 1.67 2.01 0.91 3.60 0.23 0.61 89.09 In the process of removing iron deposits from timber recovered from the Nanhai No. 1 shipwreck using the oxime-modified gauze application method, the effectiveness of removing iron deposits from the timber structure did not decrease over time, demonstrating good removal efficiency. Furthermore, with increasing cycles of use, the iron content extracted from the same oxime-modified gauze did not significantly decrease, indicating that the oxime-modified gauze can be reused.

[0046] Comparative Example 1: Example 2 was repeated, except that 100 ml of a 0.01 mol / L EDTA-2Na solution was used for soaking. Samples of the solution were taken periodically at 15, 30, 71, 120, 173, 200, 270, 300, and 365 days to test the iron content. The iron content in the solution is shown in Table 15.

[0047] Table 15. Changes in iron concentration over time in EDTA-2Na solution in Comparative Example 1 Removal time (days) 15 30 71 120 173 200 270 300 365 [Fe] (mg / L) 27.3 35.8 42.9 47.6 50.1 51.6 54.5 55.5 62.92 Compared with the results of iron removal by methylamine oxime cellulose in Example 2, it can be seen that under the same conditions of solution volume and removal time, the amount of iron removed by methylamine oxime cellulose solution is much higher than that of EDTA-2Na solution, indicating that the effect of methylamine oxime cellulose solution in removing iron from wood is much better than that of EDTA-2Na solution.

[0048] Comparative Example 2:

[0049] Example 2 was repeated, except that 100 ml of a 0.01 mol / L triamine citrate solution was used for immersion. Samples of the immersion solution were taken periodically at 15, 30, 71, 120, 173, 200, 270, 300, and 365 days to test the iron content. The iron content in the solution is shown in Table 16. Table 16. Changes in iron concentration over time in the triamine citrate solution of Comparative Example 2 Removal time (days) 15 30 71 120 173 200 270 300 365 [Fe] (mg / L) 19.2 22.1 20.6 20.7 8.2 7.92 8.89 9.86 8.5 Compared with the results of iron removal by methylamine oxime cellulose in Example 2, it can be seen that under the same conditions of solution volume and removal time, the amount of iron removed by methylamine oxime cellulose solution is much higher than that of triamine citrate solution, indicating that the effect of methylamine oxime cellulose solution in removing iron from wood is much better than that of triamine citrate solution.

[0050] Comparative Example 3:

[0051] Example 2 was repeated, except that 100 ml of a 0.01 mol / L sodium oxalate solution was used for soaking. Samples of the solution were taken periodically at 15, 30, 71, 120, 173, 200, 270, 300, and 365 days to test the iron content. The iron content in the solution is shown in Table 17. Table 17. Changes in iron concentration over time in sodium oxalate solution in Comparative Example 3 Removal time (days) 15 30 71 120 173 200 270 300 365 [Fe] (mg / L) 9.19 8.83 7.44 6.90 5.37 6.29 7.07 7.05 4.42 Compared with the results of iron removal by methylamine oxime cellulose in Example 2, it can be seen that under the same conditions of solution volume and removal time, the amount of iron removed by methylamine oxime cellulose solution is much higher than that of sodium oxalate solution, indicating that the effect of methylamine oxime cellulose solution in removing iron from wood is much better than that of sodium oxalate solution.

[0052] Comparative Example 4:

[0053] Example 2 was repeated, except that 100 ml of a mixed solution of 0.01 mol / L EDTA-2Na and 0.1 mol / L H2O2 was used for soaking. Samples of the solution were taken periodically at 15, 30, 71, 120, 173, 200, 270, 300, and 365 days to test the iron content. The iron content in the solution is shown in Table 17.

[0054] Table 17. Changes in iron concentration over time in the EDTA-2Na+H2O2 solution of Comparative Example 4. Removal time (days) 15 30 71 120 173 200 270 300 365 [Fe] (mg / L) 12.10 12.90 12.10 10.30 8.83 9.86 10.30 10.40 11.36 Compared with the results of iron removal by methylamine oxime cellulose in Example 2, it can be seen that under the same conditions of solution volume and removal time, the amount of iron removed by methylamine oxime cellulose solution is much higher than that of EDTA-2Na+H2O2 solution, indicating that the effect of methylamine oxime cellulose solution in removing iron from wood is much better than that of EDTA-2Na+H2O2 solution.

[0055] Comparative Example 5:

[0056] Repeat Example 3, except that an area of ​​800 cm² is used. 2 Ordinary gauze was applied. Specific information about the gauze and its application location on the hull surface is shown in Table 18.

[0057] Table 18. Information on ordinary gauze in Comparative Example 5 Four days after application, the amylopyridine-modified gauze was removed and soaked in 100 ml of 10 mmol / L EDTA-2Na solution for 50 h to elute the iron adsorbed by the amylopyridine-modified gauze. The iron content data in the elution solution are shown in Table 19. Table 19. Iron content in EDTA-2Na solution of gauze soaked with amine oxime-modified gauze (unit: mg / L) Experiment number Apply for 4 days Apply for 48 days C1 18.49 1012.00 The iron adsorption content per unit area of ​​the amine oxime-modified gauze and ordinary gauze was calculated, and the results are shown in Table 20. After 48 days of application, the iron adsorption content per square centimeter of the amine oxime-modified gauze was higher than that of the ordinary gauze (C1).

[0058] Table 20. Iron adsorption content per unit area of ​​amine oxime-modified gauze and ordinary gauze (mg / cm³) 2 ) serial number 4-day adsorption capacity 48-day adsorption capacity C1 0.0231 1.2650 .

[0059] Comparative Example 6:

[0060] Gellan gum hydrosols with concentrations of 1 wt%, 2 wt%, and 3 wt% were prepared and loaded with EDTA-2Na complexing agent at concentrations of 0 mmol / L, 10 mmol / L, and 30 mmol / L, respectively. The gellan gum was then applied to the surface of wooden marine archaeological artifacts.

[0061] Experimental results show that after application, gellan gum did not undergo significant cross-linking and could not form a peelable gel. Gellan gum failed to form a completely peelable gel on the surface of marine wooden artifacts containing deposited iron, adhering to the surface and causing contamination.

[0062] Comparative Example 7:

[0063] Carbomer hydrosols with concentrations of 4 wt% and 10 wt% were prepared and loaded with complexing reagent EDTA-2Na at concentrations of 5 mmol / L and 10 mmol / L, respectively. The carbomer hydrosols were then applied to the surface of wooden artifacts used in marine archaeology.

[0064] Experimental results show that after application, the carbomer hydrosol formed a viscous paste and did not form a peelable gel. Carbomer could not form a completely peelable gel on the surface of marine wooden artifacts with deposited iron, and instead adhered to the surface of the wooden artifacts, causing surface contamination.

[0065] Comparative Example 8:

[0066] Aqueous sols with concentrations of 6 wt% polyvinyl alcohol + 3 wt% chitosan and 9 wt% polyvinyl alcohol + 3 wt% chitosan were prepared and loaded with complexing reagent EDTA-2Na at concentrations of 10 mmol / L, 20 mmol / L and 30 mmol / L, respectively. An appropriate amount of sodium borate solution was added for cross-linking and the sols were then applied to the surface of wooden artifacts used in marine archaeology.

[0067] Experimental results showed that after 3 days of application, the gel could not be completely peeled off, leaving residue on the surface of the artifact. Furthermore, the gel's color change was not significant, indicating that its iron removal effect was not obvious. After 7 days of application, the gel softened and flowed, contaminating the surface of the wooden artifact. The polyvinyl alcohol + chitosan gel failed to form a completely peelable gel on the surface of marine-exposed wooden artifacts with deposited iron, adhering to the surface and causing contamination; moreover, the iron removal effect was not significant.

Claims

1. A method for removing iron-containing sediments from organic artifacts recovered from marine waters, characterized in that: Iron was removed from marine organic artifacts by reacting cellulose modified with amine oxime to the iron-containing sediments.

2. The method according to claim 1, characterized in that: The marine-derived organic artifacts include marine-derived wooden artifacts, marine-derived bamboo artifacts, marine-derived leather artifacts, marine-derived lacquerware, and marine-derived plant fiber woven artifacts.

3. The method according to claim 2, characterized in that: The marine-derived wooden artifacts include salvaged marine archaeological wooden shipwrecks, wooden hull components, and small wooden artifacts.

4. The method according to claim 1, characterized in that: The application of the metallo-oxime modified cellulose is one or more of the following methods: metallo-oxime modified gauze application, metallo-oxime cellulose acetic acid solution soaking, and metallo-oxime cellulose slurry coating.

5. The method according to any one of claims 1-4, characterized in that: For large marine organic artifacts recovered from the sea, the removal of iron-containing sediments is carried out as follows: 1) Clean the surface of the artifacts containing organic matter from the water to remove contaminants; 2) Apply a methylamine oxime-modified gauze to the areas of iron deposits on cleaned marine artifacts containing organic matter. 3) Keep the dressing on for a period of time, during which time the surface of the organic artifact must be kept moist, or spray a small amount of water onto the gauze; 4) Observe the color of the gauze as it turns yellow until it becomes dark brown; then, remove the amylopyridine-modified gauze and allow it to regenerate. 5) The gauze is then applied again to the artifact to remove iron deposits; 6) Repeat steps 2)-5) until the gauze no longer turns yellow, then stop applying the gauze and complete the removal of iron deposits.

6. The method according to claim 5, characterized in that: In step 4), the regeneration involves immersing the removed gauze in an EDTA-2Na solution to wash away the iron adsorbed on it; the washing is repeated until the color of the gauze is basically restored.

7. The method according to claim 6, characterized in that: The concentration of the EDTA-2Na solution used was 9-15 mmol / L; during the soaking process, ultrasonic oscillation was applied to accelerate the elution of iron.

8. The method according to any one of claims 1-4, characterized in that: For relatively small organic artifacts, the removal of iron deposits is carried out as follows: 1) Clean the surface of the artifacts containing organic matter from the water to remove contaminants; 2) Add the cellulose oxime powder to the acetic acid solution to prepare a cellulose oxime solution; 3) Immerse the marine-derived organic artifacts in the solution, sealing the container to prevent evaporation; 4) During the soaking process, monitor the iron concentration in the solution. When the iron concentration tends to stabilize, replace the ammonium oxime cellulose solution. 5) Repeat the soaking step in step 4) until the solution color no longer changes after soaking, then end the soaking and complete the removal of iron deposits.

9. The method according to claim 8, characterized in that: In step 2), the concentration of the acetic acid solution is 0.05 mol / L, and the mass-to-volume ratio of the acetic acid solution to the methylamine oxime cellulose is 1:1000 g / ml.

10. The method according to any one of claims 1-4, characterized in that: For relatively small marine organic artifacts, or for larger marine organic artifacts where it is inconvenient to apply plaster, the removal of iron deposits is carried out as follows: 1) Prepare a slurry of cellulose oxime with water and apply it to the areas of the marine organic artifact containing iron deposits; 2) After the cellulose oxime slurry adsorbs iron, wash with water to remove the iron deposits.

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