Composite reagent for removing hydrogen sulfide in pipe network and preparation method and application thereof

Abstract

The present application relates to municipal engineering pipe network maintenance technical field, specifically to a kind of composite reagent for removing hydrogen sulfide in pipe network and its preparation method and application.The present application provides a kind of composite reagent for removing hydrogen sulfide in pipe network, by weight parts, including 90-95 parts of ferric salt, 3-7 parts of dispersing agent, 2-3 parts of 2-amino benzothiazole.Three components form "dispersion-adsorption-synergistic" integrated mechanism: dispersing agent guarantees that reagent is fully contacted with hydrogen sulfide, ferric salt provides precipitation reaction basis, synergist further strengthens adsorption and reaction kinetics, improves the removal rate of hydrogen sulfide with the advantages of low cost, no secondary pollution, realizes efficient, economic, environmental hydrogen sulfide management.

Description

Technical Field

[0001] This invention relates to the field of municipal engineering pipeline maintenance technology, specifically to a composite agent for removing hydrogen sulfide from pipelines, its preparation method, and its application. Background Technology

[0002] The generation of hydrogen sulfide in urban underground pipe networks is a serious problem. It not only causes foul odor pollution and health threats, but is also a key factor leading to pipe network corrosion and damage. The causes of corrosion mainly include: chemical corrosion (hydrogen sulfide dissolves in water to form an acidic solution, triggering hydrogen evolution corrosion in metal pipes) and microbial corrosion (such as sulfate-reducing bacteria metabolizing to produce hydrogen sulfide and forming a biofilm that accelerates localized corrosion). This corrosion brings enormous harm: long-term corrosion leads to thinning of pipe walls, decreased strength, and even perforation and leakage, causing structural safety hazards (such as ground subsidence); maintenance costs are high, consuming a large amount of resources and affecting pipe network operation; corrosion leaks can also pollute soil and groundwater, threatening the environment and drinking water safety.

[0003] Current conventional methods for treating hydrogen sulfide in pipeline networks (biological deodorization, chemical absorption, and physical ventilation) all have significant limitations. Biological methods require large equipment footprints, have slow start-up times, and the microorganisms involved are subject to stringent environmental requirements; chemical methods, while fast-acting, consume large amounts of reagents, are costly, and are prone to secondary pollution; physical ventilation has limited effectiveness in complex underground pipeline networks. More importantly, these methods generally fail to adequately consider the effective dispersion of reagents in the complex environment of pipeline networks and the synergistic effects between different components, resulting in unsatisfactory overall treatment outcomes. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defects of low hydrogen sulfide removal rate in pipeline networks, difficulty in agent dispersion, and insufficient utilization of synergistic effect in the prior art, thereby providing a composite agent for removing hydrogen sulfide from pipeline networks, its preparation method and application.

[0005] In a first aspect, the present invention provides a composite agent for removing hydrogen sulfide from pipeline networks, comprising, by weight, 90-95 parts of ferric salt, 3-7 parts of dispersant, and 2-3 parts of 2-aminobenzothiazole.

[0006] And / or, the compound agent, by weight, further comprises 1900-2100 parts of water.

[0007] The ferric salts include at least one of ferric sulfate, ferric chloride, and ferric nitrate.

[0008] The dispersant includes at least one of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, fatty alcohol polyoxyethylene ether, and sodium polyacrylate.

[0009] Preferably, the trivalent iron salt is selected from ferric sulfate;

[0010] It should be noted that ferric sulfate hydrolyzes in aqueous solution to produce ferric hydroxide colloid. This colloid has a large specific surface area and adsorption capacity, which can adsorb sulfur ions from the ionization of hydrogen sulfide and form ferric sulfide precipitate, thereby removing hydrogen sulfide. Ferric sulfate is widely available and relatively inexpensive, providing a fundamental guarantee for the removal of hydrogen sulfide.

[0011] Preferably, the dispersant is selected from sodium dodecyl sulfate.

[0012] It is important to note that the dispersant acts as a micelle template: its addition during the preparation process plays a crucial role. In ferric sulfate solution, the dispersant forms micelles. When subsequent components (especially water) are removed (drying process), these micelles act as "sacrificial templates"; the micelles collapse and are encapsulated / replaced by ferric sulfate or its precursors, forming a richly porous and wrinkled structure. Sodium dodecyl sulfate (SDS) is preferably used as the dispersant because it has an amphiphilic structure. Its long-chain dodecyl group acts as a lipophilic group, encapsulating solid or oil-soluble components in the drug, while the sulfate ion acts as a hydrophilic group, interacting with water molecules outwards. This ensures that the drug particles are uniformly dispersed in the wastewater, preventing aggregation and ensuring that components such as ferric sulfate can fully react with hydrogen sulfide, thus improving reaction efficiency.

[0013] Furthermore, the amino group and benzothiazole ring in the 2-aminobenzothiazole molecule endow it with a unique electronic cloud structure. The amino group can form a coordinate bond with iron ions in the ferric hydroxide colloid, a product of ferric sulfate hydrolysis, thereby altering the electron cloud density around the iron ions and enhancing the adsorption capacity of the ferric hydroxide colloid for sulfur ions. Simultaneously, it can lower the activation energy of the reaction between hydrogen sulfide and ferric hydroxide through electron transfer, promoting a faster and more complete reaction and significantly improving the efficiency of the composite agent in removing hydrogen sulfide.

[0014] Secondly, the present invention provides a method for preparing the above-mentioned composite agent, comprising the following steps:

[0015] S1, first dissolve the ferric salt in water, then add the dispersant and mix to form a mixed solution;

[0016] S2, 2-aminobenzothiazole is added to the mixed solution and stirred continuously to obtain a composite agent.

[0017] In step S1, the dissolution temperature is 20-30℃ and the time is 15-25 min;

[0018] In step S1, the mixing temperature is 20-30℃ and the mixing time is 35-45 minutes.

[0019] In step S2, the stirring temperature is 20-30℃, the stirring time is 50-70 min, and the stirring speed is 90-110 rpm.

[0020] It should be noted that in the preparation process of the composite agent for removing hydrogen sulfide from the pipeline network provided by the present invention, the thorough mixing in the last 50-70 minutes ensures that all components are uniformly combined in the hydrated precursor. The subsequent drying process leads to the removal of water and volume shrinkage, which further exacerbates the formation of wrinkles and pores.

[0021] And / or, the preparation method of the present invention further includes a step of drying the obtained composite agent.

[0022] Thirdly, the present invention provides an application of the above-mentioned composite agent or the preparation method of the above-mentioned composite agent in the removal of hydrogen sulfide from pipeline networks.

[0023] And / or, the dosage of the compound agent is 1-3 mg / m³. 3 .

[0024] The present invention also provides an addition strategy for the above-mentioned composite agent or the composite agent prepared by the above-mentioned preparation method, comprising the following steps:

[0025] (1) Pipeline network assessment: Before using the compound agent, a comprehensive assessment of the target pipeline network is required. Parameters such as pipe diameter, hydrogen sulfide concentration, and water flow velocity at different locations within the pipeline network are measured using detection equipment. For example, for long straight sections of the pipeline network, a detection point can be set every 5 km; for complex sections such as bends and branches, the number of detection points should be increased. The obtained data is then processed and analyzed to create a hydrogen sulfide concentration distribution map and a water flow characteristic map of the pipeline network.

[0026] (2) Dosage Determination: Based on the assessment of the pipeline network, determine the dosage of the compound agent. Generally, the dosage is 1~3 mg / m³. 3 .

[0027] (3) Selection of Dosing Method: Choose a suitable dosing method based on the specific structure and layout of the pipeline network. For pipelines with larger diameters and slower water flow, a fixed-point dosing method can be used, where the compound agent is directly dosed to a specific location in the network using dedicated dosing equipment, such as setting a dosing point every 5 km. For pipelines with smaller diameters or rapid water flow, a multi-point decentralized dosing method is preferable, utilizing the water flow dynamics of the pipeline itself to disperse the agent. For example, small dosing devices can be installed at pipeline branches, diameter changes, etc., allowing the agent to be rapidly dispersed throughout the entire network with the water flow.

[0028] (4) Real-time monitoring and adjustment: After the compound agent is administered, the concentration change of hydrogen sulfide in the pipeline network is monitored in real time using online hydrogen sulfide monitoring equipment. The monitoring equipment should be evenly distributed at all key locations in the pipeline network to ensure comprehensive and accurate acquisition of hydrogen sulfide concentration information. Based on the monitoring results, the dosage and frequency of the compound agent are adjusted in a timely manner. If the hydrogen sulfide concentration in a certain area decreases slowly or rebounds, the dosage of the agent in that area can be appropriately increased or the dosage interval shortened; if the hydrogen sulfide concentration in a certain area decreases rapidly and falls below the set safety threshold, the dosage of the agent can be reduced or the dosage interval extended accordingly.

[0029] In addition, the present invention also includes the following for the detection and verification of the effects of the above-mentioned compound agents:

[0030] (1) Regular sampling and testing: Water samples from the pipeline network should be regularly sampled and tested at different time points after the compound reagent is applied. Sampling points should cover different locations in the pipeline network, including straight sections, bends, and branches. The main test items include hydrogen sulfide concentration, sulfide content, and pH value. By testing these indicators, the removal effect of the compound reagent on hydrogen sulfide and its impact on the water quality of the pipeline network can be evaluated.

[0031] (2) Long-term effect tracking: Establish a long-term pipeline maintenance effect tracking mechanism to record the effects of the composite agent on hydrogen sulfide removal and corrosion protection of the pipeline over a relatively long period (e.g., several months to several years). The corrosion status of the pipeline materials will be regularly monitored, such as by measuring changes in pipe wall thickness and observing signs of corrosion on the pipe surface, to assess the mitigating effect of the composite agent on pipeline corrosion. Simultaneously, relevant data during pipeline operation, such as drainage flow and blockage status, will be collected to comprehensively evaluate the improvement effect of the composite agent on the overall operation of the pipeline network.

[0032] Through the above specific implementation methods, it can be ensured that the composite agent effectively removes hydrogen sulfide in the pipeline network. At the same time, it can be flexibly adjusted according to the actual situation of the pipeline network to achieve efficient and precise treatment of hydrogen sulfide problems in the pipeline network.

[0033] The technical solution of this invention has the following advantages:

[0034] 1. This invention provides a composite agent for removing hydrogen sulfide from pipeline networks. The agent's main component is a ferric salt (which hydrolyzes to produce ferric hydroxide colloid, which adsorbs sulfur ions to form ferric sulfide precipitate), achieving basic removal of hydrogen sulfide. A synergist is added to enhance the colloid's adsorption capacity for sulfur ions and lower the reaction activation energy, significantly improving the reaction rate and thoroughness. The added dispersant, with its amphiphilic structure, ensures uniform dispersion of the agent in the pipeline network, preventing agglomeration and failure. The three components synergistically form an integrated "dispersion-adsorption-synergism" mechanism: the dispersant ensures sufficient contact between the agent and hydrogen sulfide, the ferric salt provides the basis for the precipitation reaction, and the synergist further enhances adsorption and reaction kinetics, improving the removal rate of hydrogen sulfide. With the advantages of low cost and no secondary pollution, this method achieves efficient, economical, and environmentally friendly hydrogen sulfide treatment.

[0035] 2. The present invention provides a composite agent for removing hydrogen sulfide from pipelines. Ferric sulfate is the main component, which is widely available and relatively inexpensive. Moreover, the entire composite agent does not generate difficult-to-treat secondary pollutants during the removal of hydrogen sulfide, thus meeting environmental protection requirements. The preferred 2-aminobenzothiazole can significantly enhance the adsorption capacity of ferric hydroxide colloid for sulfur ions and reduce the reaction activation energy, promoting a faster and more complete reaction between hydrogen sulfide and ferric hydroxide, thereby greatly improving the hydrogen sulfide removal efficiency.

[0036] 3. The present invention provides a method for preparing a composite agent for removing hydrogen sulfide from a pipeline network. Through specific mixing steps, stirring speed and temperature control, the method ensures that the components are fully mixed and no adverse reactions occur, thus guaranteeing the stable performance of the composite agent.

[0037] 4. The present invention provides an application of the above-mentioned composite agent in the removal of hydrogen sulfide from pipeline networks. Since the composite agent provided by the present invention is used, it has the same advantages as the above-mentioned composite agent, which will not be repeated here. Attached Figure Description

[0038] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0039] Figure 1 This is a physical image of the composite agent for removing hydrogen sulfide from the pipeline network provided in Embodiment 1 of the present invention. The left image shows the liquid state, and the right image shows the solid state after drying.

[0040] Figure 2 This is a SEM image of the composite agent for removing hydrogen sulfide from the pipeline network provided in Example 1 of the present invention after drying, with a scale bar of 1 μm;

[0041] Figure 3 This is the XRD pattern of the composite agent for removing hydrogen sulfide from the pipeline network provided in Example 1 of the present invention after drying. Detailed Implementation

[0042] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0043] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0044] Example 1

[0045] This embodiment provides a method for preparing an oxygen-containing compound removal agent, comprising the following steps:

[0046] S1. First, place 90g of ferric sulfate in 2000g of water and stir at 25℃ for 20min until completely dissolved. Then add 7g of sodium dodecyl sulfate and mix and stir at 25℃ for 40min to make SDS uniformly dispersed in the ferric sulfate solution to form a mixed solution.

[0047] S2, add 3g of 2-aminobenzothiazole to the mixed solution, and stir continuously at 25°C for 60min at a stirring rate of 100rpm to ensure that the three components are fully mixed and homogeneous, thereby obtaining a composite agent.

[0048] Example 2

[0049] This embodiment provides a method for preparing an oxygen-containing compound removal agent, comprising the following steps:

[0050] S1. First, place 95g of ferric sulfate in 2000g of water and stir at 25℃ for 20 minutes until completely dissolved. Then add 3g of sodium dodecyl sulfate and mix and stir at 25℃ for 40 minutes to make SDS uniformly dispersed in the ferric sulfate solution to form a mixed solution.

[0051] S2, add 3g of 2-aminobenzothiazole to the mixed solution, and stir continuously at 25°C for 60min at a stirring rate of 100rpm to ensure that the three components are fully mixed and homogeneous, thereby obtaining a composite agent.

[0052] Example 3

[0053] This embodiment provides a method for preparing an oxygen-containing compound removal agent, comprising the following steps:

[0054] S1. First, place 92g of ferric sulfate in 2000g of water and stir at 25℃ for 20 minutes until completely dissolved. Then add 5g of sodium dodecyl sulfate and mix and stir at 25℃ for 40 minutes to make SDS evenly dispersed in the ferric sulfate solution to form a mixed solution.

[0055] S2, add 2.5g of 2-aminobenzothiazole to the mixed solution, and stir continuously at 25℃ for 60min at a stirring speed of 100rpm to ensure that the three components are fully mixed and homogeneous, thereby obtaining a composite agent.

[0056] Example 4

[0057] This embodiment provides a method for preparing an oxygen-containing compound removal agent, comprising the following steps:

[0058] S1. First, place 90g of ferric chloride in 2000g of water and stir at 25℃ for 20min until completely dissolved. Then add 7g of sodium dodecyl sulfate and mix and stir at 25℃ for 40min to make SDS uniformly dispersed in the ferric sulfate solution to form a mixed solution.

[0059] S2, add 3g of 2-aminobenzothiazole to the mixed solution, and stir continuously at 25°C for 60min at a stirring rate of 100rpm to ensure that the three components are fully mixed and homogeneous, thereby obtaining a composite agent.

[0060] Example 5

[0061] This embodiment provides a method for preparing an oxygen-containing compound removal agent, comprising the following steps:

[0062] S1. First, place 90g of ferric nitrate in 2000g of water and stir at 25℃ for 20min until completely dissolved. Then add 7g of sodium dodecyl sulfate and mix and stir at 25℃ for 40min to make SDS uniformly dispersed in the ferric sulfate solution to form a mixed solution.

[0063] S2, add 3g of 2-aminobenzothiazole to the mixed solution, and stir continuously at 25°C for 60min at a stirring rate of 100rpm to ensure that the three components are fully mixed and homogeneous, thereby obtaining a composite agent.

[0064] Example 6

[0065] This embodiment provides a method for preparing an oxygen-containing compound removal agent, comprising the following steps:

[0066] S1. First, place 90g of ferric sulfate in 2000g of water and stir at 25℃ for 20min until completely dissolved. Then add 7g of fatty alcohol polyoxyethylene ether and mix and stir at 25℃ for 40min to make SDS uniformly dispersed in the ferric sulfate solution to form a mixed solution.

[0067] S2, add 3g of 2-aminobenzothiazole to the mixed solution, and stir continuously at 25°C for 60min at a stirring rate of 100rpm to ensure that the three components are fully mixed and homogeneous, thereby obtaining a composite agent.

[0068] Example 7

[0069] This embodiment provides a method for preparing an oxygen-containing compound removal agent, comprising the following steps:

[0070] S1. First, place 90g of ferric sulfate in 2000g of water and stir at 25℃ for 20min until completely dissolved. Then add 7g of sodium polyacrylate and mix and stir at 25℃ for 40min to make SDS uniformly dispersed in the ferric sulfate solution to form a mixed solution.

[0071] S2, add 3g of 2-aminobenzothiazole to the mixed solution, and stir continuously at 25°C for 60min at a stirring rate of 100rpm to ensure that the three components are fully mixed and homogeneous, thereby obtaining a composite agent.

[0072] Comparative Example 1

[0073] This comparative example provides a composite agent for removing hydrogen sulfide from a pipeline network. The difference between this agent and Example 1 is that it contains ferric sulfate (93g) and sodium dodecyl sulfate (7g), but does not contain 2-aminobenzothiazole.

[0074] Comparative Example 2

[0075] This comparative example provides a composite agent for removing hydrogen sulfide from a pipeline network. The difference between this agent and Example 1 is that it contains ferric sulfate (97g) and 2-aminobenzothiazole (3g), but does not contain sodium dodecyl sulfate.

[0076] Comparative Example 3

[0077] This comparative example provides a composite agent for removing hydrogen sulfide from a pipeline network. The difference between this agent and Example 1 is that ferric sulfate (100g) is used, and sodium dodecyl sulfate and 2-aminobenzothiazole are not added.

[0078] Experimental Example

[0079] The composite agents prepared in each embodiment and comparative example were dried to remove moisture, and the concentration of hydrogen sulfide in the same pipeline network was detected. The removal rate of hydrogen sulfide was calculated. When no agent was added, the concentration of hydrogen sulfide in the pipeline network was 3 mg / L.

[0080] The concentration of hydrogen sulfide was detected in accordance with HJ 1388—2024 "Determination of Hydrogen Sulfide in Exhaust Gas from Stationary Sources by Methylene Blue Spectrophotometric Method".

[0081] The specific formula for calculating the removal rate is as follows:

[0082]

[0083] Where X0 is the target pollutant concentration before treatment, in mg / L;

[0084] X represents the concentration of the target pollutant after treatment, in mg / L.

[0085] Table 1 Test results of experimental samples

[0086]

[0087] As can be seen from the examples and comparative examples, the presence and synergistic effect of ferric salts, dispersants, and 2-aminobenzothiazole in the composite agent are of great significance for achieving efficient removal of hydrogen sulfide from the pipeline network. Compared with Example 1, the composite agents prepared in Comparative Examples 1-3 without the addition of 2-aminobenzothiazole, sodium dodecyl sulfate, and without both sodium dodecyl sulfate and 2-aminobenzothiazole showed a significant decrease in hydrogen sulfide removal capacity.

[0088] Figure 1 This is a physical image of the composite agent for removing hydrogen sulfide from the pipeline network provided in Embodiment 1 of the present invention. The left image shows the liquid composite agent, and the right image shows the solid state of the composite agent after drying.

[0089] Figure 2 The image provided in Example 1 of this invention is a SEM image of a composite agent for removing hydrogen sulfide from a pipeline network after drying. The image clearly shows the extremely complex wrinkled structure and abundant pores on the drug surface. This uneven, porous structure is a typical characteristic of materials with high specific surface area; this high specific surface area and abundant pores are crucial for hydrogen sulfide (H2S) removal, providing a large contact area and channels for the adsorption and diffusion of H2S gas molecules. The addition of SDS during the preparation process plays a key role. In ferric sulfate solution, SDS forms micelles. When subsequent components (especially water) are removed (drying process), these micelles act as "sacrificial templates." The micelles collapse and are encapsulated / replaced by ferric sulfate or its precursors, forming the abundant porous and wrinkled structure seen in the image.

[0090] Figure 3The XRD pattern of a composite agent for removing hydrogen sulfide from a pipeline network provided in Example 1 of the present invention after drying shows that the broadened and relatively significant peak at 25°2θ, rather than a sharp multiple peak, indicates that the main structural component of the composite agent (i.e., ferric sulfate accounting for 90-95%) exists in an amorphous (non-crystalline) or highly defective microcrystalline form. SDS (sodium dodecyl sulfate) acts as a dispersant. After being added to the ferric sulfate solution and stirred, its molecules adsorb onto the surface of the tiny ferric sulfate particles / aggregates, thus playing a dispersing role. The micelles or adsorption layers formed by SDS also hinder the orderly arrangement and crystal growth of ferric sulfate particles. There are basically no other obvious sharp diffraction peaks in the spectrum, indicating that the content of SDS and 2-aminobenzothiazole in this composite is too low to form a detectable crystalline phase, or that they have been highly dispersed / embedded in the ferric sulfate matrix and cannot exhibit the bulk crystalline characteristics.

[0091] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A composite agent for removing hydrogen sulfide from pipeline networks, characterized in that, By weight, it includes 90-95 parts of ferric salt, 3-7 parts of dispersant, and 2-3 parts of 2-aminobenzothiazole; The dispersant includes at least one of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, fatty alcohol polyoxyethylene ether, and sodium polyacrylate.

2. The composite agent according to claim 1, characterized in that, The ferric salts include at least one of ferric sulfate, ferric chloride, and ferric nitrate.

3. The composite agent according to claim 2, characterized in that, The trivalent iron salt is selected from ferric sulfate; And / or, the dispersant is selected from sodium dodecyl sulfate.

4. The compound agent according to any one of claims 1-3, characterized in that, It also includes 1900-2100 parts by weight of water.

5. A method for preparing the composite agent according to any one of claims 1-4, characterized in that, Includes the following steps: S1, first dissolve the ferric salt in water, then add the dispersant and mix to form a mixed solution; S2, 2-aminobenzothiazole is added to the mixed solution and stirred continuously to obtain a composite agent.

6. The preparation method according to claim 5, characterized in that, In S1, the dissolution temperature is 20-30℃ and the time is 15-25 min; And / or, the mixing temperature is 20-30°C and the time is 35-45 min.

7. The preparation method according to claim 5, characterized in that, In S2, the stirring temperature is 20-30℃, the stirring time is 50-70min, and the stirring speed is 90-110rpm.

8. The preparation method according to claim 5, characterized in that, It also includes a step of drying the obtained compound agent.

9. The application of a composite agent according to any one of claims 1-4 or a composite agent prepared by any one of claims 5-8 in the removal of hydrogen sulfide from pipeline networks.

10. The application according to claim 9, characterized in that, The dosage of the compound agent is 1-3 mg / m³. 3 .

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