Low-cost metal composite oxide anti-corrosion additive as well as preparation method and application thereof

Abstract

The invention relates to a low-cost metal composite oxide anti-corrosion auxiliary agent and a preparation method and application thereof, and belongs to the field of metal surface anti-corrosion treatment.The preparation method comprises the steps that 1, residual sludge of an urban domestic sewage plant is taken, dried at low temperature and then subjected to ball milling to form dry sludge (DAS); (2) carrying out adsorption treatment on Zn < 2 + > in the electroplating zinc-containing wastewater by using DAS to form DAS-Zn; (3) dissolving citric acid and cerous nitrate in deionized water, performing water bath gel forming, and adding DAS-Zn to form a mixed colloid; and (4) aging and drying the mixed colloid, and roasting in an inert gas atmosphere to obtain the BC-Zn-Ce composite material.

Description

Technical Field

[0001] The present invention relates to the field of metal surface anti-corrosion treatment, and in particular to a low-cost metal composite oxide anti-corrosion additive, a preparation method and application thereof. Background Art

[0002] Marine engineering equipment faces severe corrosion challenges in high-salinity, high-humidity, and multi-phase coupled corrosion environments. The continuous release of broad-spectrum biocides in traditional anti-corrosion coatings not only easily leads to microbial resistance but also poses potential health, safety, and ecological challenges. Therefore, the development of environmentally friendly and sustainable "green biofilm inhibitors" has become a key research direction in the field of microbial corrosion prevention technology.

[0003] Quorum sensing is a key mechanism by which bacteria regulate biofilm development through signaling molecules. Quenching signaling molecules effectively inhibits biofilm formation. Lactonases with the ability to quench signaling molecules are expensive and unstable, especially in marine environments, where high salt levels can inhibit their activity. Therefore, a biomimetic lactonase active center domain could help stabilize the quenching of signaling molecules, improving the reliability and service life of metal materials in marine environments.

[0004] High salt levels in marine environments accelerate electrochemical corrosion by destroying metal oxide films, while corrosive microorganisms such as sulfate-reducing bacteria (SRB) secrete acidic metabolites, causing a sudden drop in local pH. Therefore, the coexistence of high salt levels and microorganisms further exacerbates the corrosion process. Therefore, developing dual-functional composite materials that are both resistant to high salt levels and biofilm formation has important application value. Summary of the Invention

[0005] Technical Problems Solved: The present invention provides a low-cost metal composite oxide anti-corrosion additive and its preparation method and application, which solves the problem that the passivation film of traditional anti-corrosion materials is easily affected by Cl in a high-salt environment. - Erosion damage, biofilm inhibition failure due to drug resistance of broad-spectrum fungicides, and accelerated corrosion due to the coupling of acid metabolism of corrosive microorganisms such as SRB and salt penetration, the development of a Cl-resistant - A dual-functional composite material that can penetrate and efficiently quench quorum sensing signal molecules to achieve multi-level blocking of microbial-salt spray synergistic corrosion.

[0006] Technical solution: A method for preparing a low-cost metal composite oxide anti-corrosion additive material, comprising the following steps:

[0007] (1) The residual sludge from the municipal sewage treatment plant was dried at low temperature and then ball-milled to form dry sludge (DAS); (2) DAS was used to adsorb Zn in the zinc-containing electroplating wastewater. 2+, forming DAS-Zn; (3) dissolving citric acid and cerium nitrate in deionized water, and adding DAS-Zn to form a mixed colloid after forming a gel in a water bath; (4) aging and drying the mixed colloid, and then calcining it under an inert gas atmosphere to obtain a BC-Zn-Ce composite material.

[0008] The low-temperature drying temperature in step (1) is 60-80° C., and the particle size of the dry sludge is 5-20 μm.

[0009] The Zn2+ concentration of the zinc-containing electroplating wastewater in step (2) is 50-200 mg / L, the pH is 4-10, and the mass ratio of DAS to electroplating wastewater is 1:50-500.

[0010] The mass ratio of cerium nitrate to citric acid in step (3) is 1-10:1-15.

[0011] The mass ratio of DAS-Zn to cerium nitrate in step (3) is 0.5-1:1-2.

[0012] The aging time in step (4) is 8-12 hours, the roasting temperature is 550-950° C., and the roasting time is 2-6 hours.

[0013] The low-cost metal composite oxide anticorrosive additive material prepared by the above method has lactonase activity and high electrical resistance, can convert quorum sensing signal molecules and inhibit electrochemical corrosion.

[0014] The above-mentioned low-cost metal composite oxide anti-corrosion additive material is used in the field of corrosion prevention and control, and the corrosion prevention and control includes electrochemical corrosion and microbial corrosion.

[0015] The above-mentioned microbial corrosion is biofilm corrosion caused by corrosive microorganisms such as sulfate-reducing bacteria (SRB).

[0016] The application of the above-mentioned low-cost metal composite oxide anti-corrosion additive material in the anti-corrosion of marine engineering equipment, the composite material blocks microbial-salt spray synergistic corrosion by inhibiting Cl- penetration and quenching quorum sensing signal molecules.

[0017] Beneficial effects: The present invention prepares a low-cost metal composite oxide anti-corrosion additive with the following beneficial effects: the low-cost metal composite oxide anti-corrosion additive material (BC-Zn-Ce composite material) has lactonase activity, can convert signal molecules, and inhibit the formation of biofilms on metal surfaces; the high electrical resistivity of the Ce element in BC-Zn-Ce can effectively inhibit electrochemical corrosion caused by high salt, and significantly slow down the corrosion rate in a complex environment of microorganisms and high salt. In addition, the present invention uses solid waste residual sludge and electroplating zinc-containing wastewater as raw materials to prepare BC-Zn-Ce catalytic materials, realizing the gradient utilization of solid waste resources and establishing a green preparation paradigm for anti-corrosion composite materials of "waste-based anti-corrosion". BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is the preparation flow chart of BC-Zn-Ce composite material.

[0019] Figure 2 This is the BC-Zn-Ce element distribution diagram.

[0020] Figure 3 Schematic diagram of the conversion effect of composite materials on γ-heptanolactone under different preparation conditions.

[0021] Figure 4 is the corrosion area of carbon steel under the action of composite material coating under different preparation conditions. DETAILED DESCRIPTION

[0022] Embodiment 1:

[0023] The preparation steps of BC-Zn-Ce composite material are as follows:

[0024] (1) Take an appropriate amount of excess sludge from a municipal sewage treatment plant, dry it at 60°C, and then ball-mill it to 20 μm to form DAS;

[0025] (2) Using DAS as adsorbent, adsorption treatment of 50 mg / L Zn 2+ of electroplating wastewater to form DAS-Zn;

[0026] (3) Weigh cerium nitrate and citric acid in a mass ratio of 1:1, dissolve in deionized water, and gel in a 60°C water bath. Then, add DAS-Zn powder to the gel in a mass ratio of DAS-Zn to cerium nitrate of 0.5:1.

[0027] (4) The mixed colloid was aged for 8 h, dried at 80 °C, and then calcined at 550 °C for 6 h in a nitrogen atmosphere to form a BC-Zn-Ce composite material.

[0028] The prepared BC-Zn-Ce was used to degrade γ-heptanolactone at a concentration of 0.02 mL / mL, with a conversion rate of 63.4%; taking the epoxy resin coating as the control (the corrosion area was 100%), in an environment of 3.5% NaCl and mixed microorganisms, the corrosion area of the coating formed by the mixture of BC-Zn-Ce composite material and epoxy resin was 27.3%.

[0029] Example 2:

[0030] The preparation steps of BC-Zn-Ce composite material are as follows:

[0031] (1) Take an appropriate amount of excess sludge from a municipal sewage treatment plant, dry it at 80°C, and then ball-mill it to 5 μm to form DAS;

[0032] (2) Using DAS as adsorbent, adsorption treatment of 150 mg / L Zn 2+ of electroplating wastewater to form DAS-Zn;

[0033] (3) Weigh cerium nitrate and citric acid in a mass ratio of 1:10, dissolve in deionized water, and gel at 60°C in a water bath. Then, add DAS-Zn powder to the gel in a mass ratio of DAS-Zn to cerium nitrate of 0.5:2.

[0034] (4) The mixed colloid was aged for 10 h, dried at 80 °C, and then calcined at 750 °C for 5 h in a nitrogen atmosphere to form a BC-Zn-Ce composite material.

[0035] The prepared BC-Zn-Ce was used to degrade γ-heptanolactone at a concentration of 0.02 mL / mL, with a conversion rate of 95.8%; taking the epoxy resin coating as the control (the corrosion area was 100%), in an environment of 3.5% NaCl and mixed microorganisms, the corrosion area of the coating formed by the mixture of BC-Zn-Ce composite material and epoxy resin was 11.7%.

[0036] Example 3:

[0037] The preparation steps of BC-Zn-Ce composite material are as follows:

[0038] (1) Take an appropriate amount of excess sludge from a municipal sewage treatment plant, dry it at 70°C, and then ball-mill it to 10 μm to form DAS;

[0039] (2) Using DAS as adsorbent, adsorption treatment of 100 mg / L Zn 2+ of electroplating wastewater to form DAS-Zn;

[0040] (3) Weigh cerium nitrate and citric acid in a mass ratio of 5:15, dissolve in deionized water, and gel in a 60°C water bath. Then, add DAS-Zn powder to the gel in a mass ratio of DAS-Zn to cerium nitrate of 1:1.

[0041] (4) The mixed colloid was aged for 12 h, dried at 80 °C, and then calcined at 850 °C for 3 h in a N2 atmosphere to form a BC-Zn-Ce composite material.

[0042] The prepared BC-Zn-Ce was used to degrade γ-heptanolactone at a concentration of 0.02 mL / mL, with a conversion rate of 84.7%; taking the epoxy resin coating as the control (the corrosion area was 100%), in an environment of 3.5% NaCl and mixed microorganisms, the corrosion area of the coating formed by the mixture of BC-Zn-Ce composite material and epoxy resin was 16.5%.

[0043] Example 4:

[0044] The preparation steps of BC-Zn-Ce composite material are as follows:

[0045] (1) Take an appropriate amount of excess sludge from a municipal sewage treatment plant, dry it at 60°C, and then ball-mill it to 15 μm to form DAS;

[0046] (2) Using DAS as adsorbent, adsorption treatment of 200 mg / L Zn 2+ of electroplating wastewater to form DAS-Zn;

[0047] (3) Weigh cerium nitrate and citric acid in a mass ratio of 10:7, dissolve in deionized water, and gel in a 60°C water bath. Then, add DAS-Zn powder to the gel in a mass ratio of DAS-Zn to cerium nitrate of 1:2.

[0048] (4) The mixed colloid was aged for 10 h, dried at 80 °C, and then calcined at 950 °C for 2 h in a nitrogen atmosphere to form a BC-Zn-Ce composite material.

[0049] The prepared BC-Zn-Ce was used to degrade γ-heptanolactone at a concentration of 0.02 mL / mL, with a conversion rate of 75.1%; taking the epoxy resin coating as the control (the corrosion area was 100%), in an environment of 3.5% NaCl and mixed microorganisms, the corrosion area of the coating formed by the mixture of BC-Zn-Ce composite material and epoxy resin was 20.1%.

[0050] Control experiment 1:

[0051] The preparation steps of BC material are as follows:

[0052] (1) Take an appropriate amount of excess sludge from a municipal sewage treatment plant, dry it at 80°C, and then ball-mill it to 5 μm to form DAS;

[0053] (2) Calcination of DAS at 750°C for 5 h in N2 atmosphere to form BC material

[0054] The prepared BC material was used to degrade γ-heptanolactone at a concentration of 0.02 mL / mL, with a conversion rate of 41.1%; taking the epoxy resin coating as the control (the corrosion area was 100%), in an environment of 3.5% NaCl and mixed microorganisms, the corrosion area of the coating formed by the mixture of BC material and epoxy resin was 66.5%.

[0055] Control experiment 2:

[0056] The preparation steps of BC-Zn composite material are as follows:

[0057] (1) Take an appropriate amount of excess sludge from a municipal sewage treatment plant, dry it at 80°C, and then ball-mill it to 5 μm to form DAS;

[0058] (2) Using DAS as adsorbent, adsorption treatment of 150 mg / L Zn 2+of electroplating wastewater to form DAS-Zn;

[0059] (3) DAS-Zn was calcined at 750℃ for 5h in N2 atmosphere to form BC-Zn composite material

[0060] The prepared BC-Zn composite material was used to degrade γ-heptanolactone at a concentration of 0.02 mL / mL, with a conversion rate of 42.8%; taking the epoxy resin coating as the control (the corrosion area was 100%), in an environment of 3.5% NaCl and mixed microorganisms, the corrosion area of the coating formed by the mixture of BC-Zn composite material and epoxy resin was 51.4%.

[0061] The conversion effect of composite materials on γ-heptalactone under different preparation conditions is as follows Figure 2 As shown, the composite material prepared in Example 2 has the best conversion effect of 95.8% and the lowest corrosion area of 11.7%.

[0062] The above describes the embodiments of the present invention in detail with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. After knowing the contents described in the present invention, ordinary technicians in this technical field can make several equivalent changes and substitutions without departing from the principles of the present invention. These equivalent changes and substitutions should also be regarded as falling within the scope of protection of the present invention.

Claims

1. A method for preparing a low-cost metal composite oxide anticorrosive additive, characterized in that The following steps are involved: (1) The residual sludge from the municipal sewage treatment plant was dried at low temperature and then ball-milled to form dry sewage sludge (DAS); (2) Treatment of Zn in electroplating zinc-containing wastewater by DAS adsorption 2 +, forming DAS-Zn; (3) Dissolving citric acid and cerium nitrate in deionized water, forming a gel in a water bath, and then adding DAS-Zn to form a mixed colloid; (4) After aging and drying the mixed colloid, it is calcined under an inert gas atmosphere to obtain a BC-Zn-Ce composite material.

2. The preparation method according to claim 1, wherein: The low-temperature drying temperature in step (1) is 60-80° C., and the particle size of the dry sludge is 5-20 μm.

3. The preparation method according to claim 1, wherein: The Zn2+ concentration of the zinc-containing electroplating wastewater in step (2) is 50-200 mg / L, the pH is 4-10, and the mass ratio of DAS to electroplating wastewater is 1:50-500.

4. The preparation method according to claim 1, wherein: The mass ratio of cerium nitrate to citric acid in step (3) is 1-10:1-15.

5. The preparation method according to claim 1, wherein: The mass ratio of DAS-Zn to cerium nitrate in step (3) is 0.5-1:1-2.

6. The preparation method according to claim 1, wherein: The aging time in step (4) is 8-12 hours, the roasting temperature is 550-950° C., and the roasting time is 2-6 hours.

7. A low-cost metal composite oxide anticorrosive agent prepared by the method according to any one of claims 1 to 6, wherein the composite material has lactonase activity and high electrical resistivity, can convert quorum sensing signal molecules and inhibit electrochemical corrosion.

8. Use of the low-cost metal composite oxide anti-corrosion additive according to claim 7 in the field of corrosion prevention and control, wherein the corrosion prevention and control includes electrochemical corrosion and microbial corrosion.

9. The use according to claim 8, characterized in that: The microbial corrosion is biofilm corrosion caused by corrosive microorganisms.

10. Use of the low-cost metal composite oxide anticorrosive additive according to claim 7 in anti-corrosion of marine engineering equipment, wherein the composite material blocks microbial-salt spray synergistic corrosion by inhibiting Cl- permeation and quenching quorum sensing signal molecules.

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