Solid cleaning agent

Abstract

The invention discloses a solid cleaning agent, and belongs to the technical field of cleaning agents. The solid cleaning agent comprises the following components in parts by mass: 1-5 parts of a biological enzyme preparation, 3-10 parts of a surfactant, 50-75 parts of a chelating agent, 1-5 parts of a cleaning aid and 20-30 parts of an inorganic compound, the surface active agent comprises an anionic surface active agent and a nonionic surface active agent; the anionic surfactant is sodium alpha-olefin sulfonate or acylamino carboxylic acid sodium salt, and the acylamino carboxylic acid sodium salt has a benzene ring and an amide group; and the nonionic surfactant is cocoanut fatty acid diethanolamide. The invention discloses a solid cleaning agent with good cleaning performance, and the solid cleaning agent not only can clean organic pollutants in a membrane separation element, but also has high removal efficiency on composite pollutants formed by combining calcium ions, aluminum ions and organic matters.

Description

Technical Field

[0001] The invention relates to the technical field of cleaning agents, and in particular to a solid cleaning agent. Background Art

[0002] With the development of industry, the scarcity of water resources and the increase in demand for water resources, membrane separation elements such as ultrafiltration membranes, reverse osmosis membranes and nanofiltration membranes are widely used in water purification. However, after the membrane separation element has been used for a period of time, various pollutants will gradually adhere to the membrane. The accumulation of these pollutants not only affects the permeability of the membrane, but also leads to a significant decrease in the operating efficiency of the system. In order to solve this problem, the system will regularly use water to physically flush the membrane during operation, trying to remove some of the pollutants on the membrane surface. However, it is often difficult to completely remove the pollutants inside the membrane by water flushing alone, resulting in a continuous decline in its performance. Therefore, it is particularly important to use a special cleaning agent to clean the membrane separation element to ensure that the pollutants attached to the inside of the membrane can be effectively removed and the cleaning efficiency of the membrane can be restored. The cleaning agents commonly used on the market are generally compound liquid cleaning agents. The use of such liquid cleaning agents increases storage and transportation costs, and there are relatively few solid cleaning agents on the market. Therefore, the development of a solid cleaning agent has practical significance and market prospects. Summary of the invention

[0003] The object of the present invention is to provide a solid cleaning agent to improve the removal efficiency of organic pollutants on polluted membrane separation elements and composite pollutants formed by the combination of calcium ions and aluminum ions with organic matter.

[0004] The technical solution adopted by the present invention to achieve the above-mentioned purpose is: A solid cleaning agent comprises the following components in parts by mass: 1-5 parts of a biological enzyme preparation, 3-10 parts of a surfactant, 50-75 parts of a chelating agent, 1-5 parts of a cleaning aid and 20-30 parts of an inorganic compound; the surfactant comprises an anionic surfactant and a nonionic surfactant; the anionic surfactant is sodium α-olefin sulfonate or sodium amide carboxylate, and the sodium amide carboxylate has a benzene ring and an amide group; the nonionic surfactant is coconut oil fatty acid diethanolamide.

[0005] The solid cleaning agent of the present invention has excellent cleaning performance, can effectively remove organic pollutants inside the membrane separation element, and complex pollutants formed by the combination of calcium ions and aluminum ions with organic matter, thereby restoring the normal separation performance of the membrane separation element; the solid cleaning agent uses amide carboxylic acid sodium salt instead of α-olefin sulfonate sodium as an anionic surfactant, the amide carboxylic acid sodium salt has a benzene ring and an amide group, can form micelles in the solution, so that the solubilized substance is dissolved inside the micelle, which helps to indirectly improve the solubility of organic pollutants inside the membrane separation element and complex pollutants formed by the combination of calcium ions and aluminum ions with organic matter, thereby achieving effective removal of these pollutants.

[0006] Preferably, the mass ratio of the anionic surfactant to the nonionic surfactant is 1:0.1-0.5.

[0007] Preferably, in the preparation of the amidocarboxylic acid sodium salt, octadecylamine, methyl 4-vinylbenzoate and 1,4-cyclohexanediyl chloride are reacted in the presence of an acid binding agent, and then saponified with sodium hydroxide to obtain the amidocarboxylic acid sodium salt; the acid binding agent is triethylamine.

[0008] More preferably, the molar ratio of octadecylamine to methyl 4-vinylbenzoate is 1:1-2, and the molar ratio of octadecylamine to 1,4-cyclohexanediyl chloride is 1:0.2-1.

[0009] Preferably, the preparation of the sodium salt of amidocarboxylic acid is specifically as follows: Add methanol to octadecylamine, add methyl 4-vinylbenzoate dropwise, stir at room temperature for 12-36 hours, rotary evaporate, add triethylamine and 1,4-cyclohexanediyl chloride, stir at 30-50°C for 6-18 hours, wash with deionized water after the reaction solution is cooled, rotary evaporate, add sodium hydroxide solution, wash with detergent, and dry to obtain amidocarboxylic acid sodium salt.

[0010] More preferably, the usage ratio of octadecylamine to methanol is 1 mol: 300-500 mL.

[0011] More preferably, the molar ratio of octadecylamine to methyl 4-vinylbenzoate is 1:1-2.

[0012] More preferably, the usage ratio of octadecylamine to triethylamine is 1 mol: 1-2 mL.

[0013] More preferably, the molar ratio of octadecylamine to 1,4-cyclohexanediyl chloride is 1:0.2-1.

[0014] More preferably, the usage ratio of octadecylamine to sodium hydroxide is 1 mol:50-150 mL, and the concentration of sodium hydroxide is 0.2-1 mol / L.

[0015] More preferably, the detergent comprises ethanol and cyclohexane, and the volume ratio of ethanol to cyclohexane is 1:5-15.

[0016] Preferably, the bioenzyme preparation comprises alkaline protease, lipase and α-amylase, the mass ratio of alkaline protease to lipase is 1:1-2, and the mass ratio of alkaline protease to α-amylase is 1:1-2.

[0017] Preferably, the chelating agent comprises tetrasodium ethylenediaminetetraacetate, sodium tripolyphosphate and sodium citrate, the mass ratio of tetrasodium ethylenediaminetetraacetate to sodium tripolyphosphate is 1:1-2, and the mass ratio of tetrasodium ethylenediaminetetraacetate to sodium citrate is 1:0.2-1.

[0018] Preferably, the cleaning aid is sodium polymethacrylate, which has a sodium carboxylate group.

[0019] Preferably, the cleaning aid is also modified sodium polymethacrylate, which has a benzene ring. The present invention uses modified sodium polymethacrylate as a cleaning aid in a solid cleaning agent, which can further improve the cleaning performance of the solid cleaning agent and improve the removal efficiency of organic pollutants inside the contaminated membrane separation element and complex pollutants formed by the combination of calcium ions and aluminum ions with organic matter.

[0020] More preferably, the preparation of modified sodium polymethacrylate is specifically as follows: Mix methacrylic acid and 4-vinylbenzoic acid, add toluene, stir evenly, introduce nitrogen for 20-60 minutes, add azobisisobutyronitrile, stir and react at 60-100°C for 2-6 hours, slowly drop sodium hydroxide solution, wait for the reaction liquid to cool to room temperature, wash with acetone for 2-5 times, vacuum filter, and vacuum dry at 55-75°C for 6-18 hours to obtain modified sodium polymethacrylate.

[0021] More preferably, the mass ratio of methacrylic acid to 4-vinylbenzoic acid is 1:2-5.

[0022] More preferably, the usage ratio of methacrylic acid to toluene is 1 g:10-30 mL.

[0023] More preferably, the mass ratio of methacrylic acid to azobisisobutyronitrile is 1:0.02-0.1.

[0024] More preferably, the usage ratio of methacrylic acid to sodium hydroxide is 1 g:10-30 mL, and the concentration of sodium hydroxide is 0.2-1 mol / L.

[0025] Preferably, the inorganic compound comprises sodium hydroxide and sodium sulfate, and the mass ratio of sodium hydroxide to sodium sulfate is 1:0.2-1.

[0026] The present invention also discloses a method for preparing a solid cleaning agent, comprising: first mixing 1-5 parts of a biological enzyme preparation, 50-75 parts of a chelating agent, 1-5 parts of a cleaning aid and 20-30 parts of an inorganic compound, crushing and sieving, adding 3-10 parts of a surfactant, drying, and sieving to obtain a solid cleaning agent; the solid cleaning agent is particles with a diameter of 1.5-3.5 mm.

[0027] Preferably, a method for preparing a solid cleaning agent comprises: Weigh 1-5 parts of biological enzyme preparation, 50-75 parts of chelating agent, 1-5 parts of cleaning aid and 20-30 parts of inorganic compound, crush and sieve them with a pulverizer, mix them evenly to make a powdery mixture, transport the mixture to a disc granulator or a drum granulator, spray 3-10 parts of surfactant onto the surface of the mixture by high-pressure spray, perform rolling granulation, and then transport the granules to a drying drum for drying, sieve and screen particles with a diameter of 1.5-3.5 mm to obtain a solid cleaning agent.

[0028] More preferably, the biological enzyme preparation includes alkaline protease, lipase and α-amylase.

[0029] More preferably, the mass ratio of alkaline protease to lipase is 1:1-2.

[0030] More preferably, the mass ratio of alkaline protease to α-amylase is 1:1-2.

[0031] More preferably, the chelating agent includes tetrasodium EDTA, sodium tripolyphosphate and sodium citrate.

[0032] More preferably, the mass ratio of tetrasodium EDTA to sodium tripolyphosphate is 1:1-2.

[0033] More preferably, the mass ratio of tetrasodium EDTA to sodium citrate is 1:0.2-1.

[0034] More preferably, the cleaning aid is sodium polymethacrylate or modified sodium polymethacrylate.

[0035] More preferably, the inorganic compound includes sodium hydroxide and sodium sulfate.

[0036] More preferably, the mass ratio of sodium hydroxide to sodium sulfate is 1:0.2-1.

[0037] More preferably, the surfactant includes anionic surfactants and nonionic surfactants.

[0038] More preferably, the anionic surfactant is sodium α-olefin sulfonate or sodium amide carboxylate.

[0039] More preferably, the nonionic surfactant is coconut oil fatty acid diethanolamide.

[0040] More preferably, the mass ratio of the anionic surfactant to the nonionic surfactant is 1:0.1-0.5.

[0041] The invention also discloses the use of the solid cleaning agent in cleaning the filter membrane separation element.

[0042] The present invention adopts amidocarboxylic acid sodium salt and modified sodium polymethacrylate to prepare the solid cleaning agent, so it has the following beneficial effects: the solid cleaning agent of the present invention has a good removal effect on organic pollutants inside the membrane separation element, and composite pollutants formed by the combination of calcium ions and aluminum ions with organic matter, and the solid cleaning agent of the present invention has a removal efficiency of 90-99% for calcium ions inside the membrane separation element, and a removal efficiency of 83-98% for aluminum ions. Therefore, the present invention provides a solid cleaning agent with high removal efficiency for organic pollutants and composite pollutants formed by the combination of calcium ions and aluminum ions with organic matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is the infrared spectrum of the amidocarboxylic acid sodium salt obtained in Example 4 of the present invention. DETAILED DESCRIPTION

[0044] The present invention is further described in detail below in conjunction with specific embodiments, and the examples provided are only for illustrating the present invention, rather than for limiting the scope of the present invention. The examples provided below can be used as a guide for further improvements by those of ordinary skill in the art, and do not constitute a limitation of the present invention in any way.

[0045] The experimental methods in the following examples are conventional methods unless otherwise specified. The materials, reagents, etc. used in the following examples are commercially available unless otherwise specified.

[0046] Embodiment 1: S1. Preparation of solid cleaning agent, comprising: The solid cleaning agent comprises the following raw materials in parts by weight: 0.5 parts of alkaline protease, 0.5 parts of lipase, 0.5 parts of α-amylase, 5 parts of sodium α-olefin sulfonate, 1 part of coconut oil fatty acid diethanolamide, 25 parts of tetrasodium ethylenediaminetetraacetic acid, 30 parts of sodium tripolyphosphate, 10 parts of sodium citrate, 2 parts of sodium polymethacrylate, 15.5 parts of sodium hydroxide and 10 parts of sodium sulfate. Alkaline protease, lipase, α-amylase, tetrasodium ethylenediaminetetraacetic acid, sodium tripolyphosphate, sodium citrate, sodium polymethacrylate, sodium hydroxide and sodium sulfate are weighed according to the proportion, crushed and sieved by a pulverizer, mixed evenly to form a powdery mixture, transported the mixture to a disc granulator or a rotary drum granulator, sprayed sodium α-olefin sulfonate and coconut oil fatty acid diethanolamide onto the surface of the mixture by high-pressure spraying, rolling granulation is performed, and the produced particles are transported to a drying drum for drying, and sieved to screen particles with a diameter of 2.5 mm to obtain a solid cleaning agent.

[0047] Embodiment 2: S1. Preparation of sodium salt of amidocarboxylic acid, comprising: Methanol was added to octadecylamine, methyl 4-vinylbenzoate was added dropwise, stirred at room temperature for 24 hours, rotary evaporated, triethylamine and 1,4-cyclohexanediyl chloride were added, stirred at 40°C for 12 hours, the reaction solution was cooled and washed with deionized water, rotary evaporated, sodium hydroxide solution was added, washed with detergent, and dried to obtain amidocarboxylic acid sodium salt. The molar ratio of octadecylamine to methanol was 1 mol: 400 mL; the molar ratio of octadecylamine to methyl 4-vinylbenzoate was 1: 1.5; the molar ratio of octadecylamine to triethylamine was 1 mol: 1.5 mL; the molar ratio of octadecylamine to 1,4-cyclohexanediyl chloride was 1: 0.4; the molar ratio of octadecylamine to sodium hydroxide was 1 mol: 100 mL, and the concentration of sodium hydroxide was 1 mol / L; the detergent included ethanol and cyclohexane, and the volume ratio of ethanol to cyclohexane was 1: 9.

[0048] S2. Preparation of a solid cleaning agent, except that sodium α-olefin sulfonate is replaced by sodium amide carboxylate prepared in step S1 of this embodiment, other conditions are the same as those of Example 1.

[0049] Embodiment 3: In the preparation of the solid detergent, the other conditions were the same as those in Example 2, except that the amount of amidocarboxylic acid sodium salt used was changed to 3 parts by mass.

[0050] Embodiment 4: S1. Preparation of sodium salt of amidocarboxylic acid is the same as in Example 2.

[0051] S2. Preparation of modified sodium polymethacrylate, comprising: Mix methacrylic acid and 4-vinylbenzoic acid, add toluene, stir evenly, introduce nitrogen for 30 minutes, add azobisisobutyronitrile, stir and react at 80°C for 4 hours, slowly drop sodium hydroxide solution, wait for the reaction liquid to cool to room temperature, wash with acetone for 3 times, vacuum filter, and vacuum dry at 60°C for 12 hours to obtain modified sodium polymethacrylate. The mass ratio of methacrylic acid to 4-vinylbenzoic acid is 1:3; the dosage ratio of methacrylic acid to toluene is 1g:20mL; the mass ratio of methacrylic acid to azobisisobutyronitrile is 1:0.1; the dosage ratio of methacrylic acid to sodium hydroxide is 1g:20mL, and the concentration of sodium hydroxide is 1mol / L.

[0052] S3, preparation of a solid cleaning agent, except that sodium α-olefin sulfonate is replaced by sodium amide carboxylate prepared in step S1 of this embodiment, and sodium polymethacrylate is replaced by sodium polymethacrylate prepared in step S2 of this embodiment to obtain modified sodium polymethacrylate, other conditions are the same as those in Example 1.

[0053] Embodiment 5: Except that the amount of modified sodium polymethacrylate used in the preparation of the solid cleaning agent was changed to 1 part by mass, other conditions were the same as those in Example 4.

[0054] Comparative Example 1: S1. Preparation of modified sodium polymethacrylate, same as Example 4.

[0055] S2. Preparation of a solid cleaning agent, except that sodium polymethacrylate is replaced by the modified sodium polymethacrylate prepared in step S1 of this comparative example, other conditions are the same as those in Example 1.

[0056] Experimental example 1. Material Characterization The infrared spectrum of the amidocarboxylic acid sodium salt prepared in Example 4 was measured by Fourier transform infrared spectrometer using KBr tablet method at a wave number of 400-4000 cm -1 Measurement within the range, resolution 0.06cm -1 , scanned 32 times.

[0057] Figure 1 The infrared spectrum of the amidocarboxylic acid sodium salt prepared in Example 4 of the present invention is shown at 2920 cm -1 、2850cm -1 The absorption peaks of saturated alkanes -CH3 and -CH2 appear near 1660cm -1 There is a C=O absorption peak near 1650cm -1 and 1490cm -1 The absorption peak of benzene ring appears near 1565cm -1 The absorption peak of -COONa group appears near 1360cm-1 An absorption peak of CN appears nearby.

[0058] 2. Determination of the flux of membrane separation elements after cleaning The solid cleaning agents obtained in Examples 1-5 and Comparative Example 1 were taken, and pure water with a total dissolved solid content of less than 100 mg / L was added at 25°C to a final concentration of 2%, and the pH was adjusted to 12. A pre-contaminated membrane separation element was selected and loaded into a membrane cleaning device. The solid cleaning agents obtained in Examples 1-5 and Comparative Example 1 of the present invention were respectively sent into the membrane through a cleaning pump, and circulated or soaked for 12 hours, so that the solid cleaning agents obtained in Examples 1-5 and Comparative Example 1 of the present invention were fully in contact with the membrane separation element for cleaning, and the flux (m 3 / m 2 / d), membrane separation element flux = fluid volume m 3 / (Effective membrane area m 2 × time d), the measurement results are shown in Table 1.

[0059] Table 1 Flux of membrane separation element after cleaning (m 3 / m 2 / d)

[0060] As can be seen from Table 1, the flux of the membrane separation element after cleaning in Example 2-3 is higher than that in Example 1, because in the preparation of the solid cleaning agent, Example 1 uses sodium α-olefin sulfonate as an anionic surfactant, while Example 2-3 uses sodium amide carboxylate to replace sodium α-olefin sulfonate; the flux of the membrane separation element after cleaning in Example 2 is higher than that in Example 3, because in the preparation of the solid cleaning agent, Example 3 reduces the amount of sodium amide carboxylate used. This shows that using sodium amide carboxylate as an anionic surfactant to prepare the solid cleaning agent can effectively improve the cleaning performance of the solid cleaning agent, thereby improving the flux of the membrane separation element after cleaning.

[0061] The flux of the membrane separation element after cleaning in Example 4-5 is higher than that in Example 2 and Comparative Example 1 because in the preparation of the solid cleaning agent, Examples 4-5 not only use amidocarboxylic acid sodium salt to replace sodium α-olefin sulfonate as an anionic surfactant, but also use modified sodium polymethacrylate to replace sodium polymethacrylate as a cleaning aid; Example 2 only uses amidocarboxylic acid sodium salt to replace sodium α-olefin sulfonate, and Comparative Example 1 only uses modified sodium polymethacrylate to replace sodium polymethacrylate. The flux of the membrane separation element after cleaning in Example 4 is higher than that in Example 5 because in the preparation of the solid cleaning agent, Example 5 reduces the amount of modified sodium polymethacrylate used. This shows that in the preparation of the solid cleaning agent using amidocarboxylic acid sodium salt as an anionic surfactant, further using modified sodium polymethacrylate as a cleaning aid can further increase the flux of the membrane separation element after cleaning.

[0062] 3. Determination of pressure difference after cleaning The solid cleaning agents obtained in Examples 1-5 and Comparative Example 1 were taken, and pure water with a total dissolved solid content of less than 100 mg / L was added at 25°C to a final concentration of 2%, and the pH was adjusted to 12. A pre-contaminated membrane separation element was selected and loaded into a membrane cleaning device, and the solid cleaning agents obtained in Examples 1-5 of the present invention and Comparative Example 1 of the present invention were respectively sent into the membrane through a cleaning pump, and circulated or soaked for 12 hours, so that the solid cleaning agents obtained in Examples 1-5 of the present invention and Comparative Example 1 of the present invention were fully in contact with the membrane separation element for cleaning, and the pressure difference (MPa) on both sides of the membrane separation element after cleaning was measured. The measurement results are shown in Table 2.

[0063] Table 2 Pressure difference after cleaning (MPa)

[0064] As shown in Table 2, the pressure difference between the two sides of the membrane after cleaning in Example 2-3 is lower than that in Example 1, because in the preparation of the solid cleaning agent, Example 1 uses sodium α-olefin sulfonate as an anionic surfactant, while Example 2-3 uses sodium amide carboxylate to replace sodium α-olefin sulfonate; the pressure difference between the two sides of the membrane after cleaning in Example 2 is lower than that in Example 3, because in the preparation of the solid cleaning agent, Example 3 reduces the amount of sodium amide carboxylate used. This shows that the use of sodium amide carboxylate as an anionic surfactant to prepare the solid cleaning agent can effectively improve the cleaning performance of the solid cleaning agent, thereby reducing the pressure difference between the two sides of the membrane after cleaning.

[0065] The pressure difference on both sides of the membrane after cleaning in Example 4-5 is lower than that in Example 2 and Comparative Example 1, because in the preparation of the solid cleaning agent, Examples 4-5 not only use amidocarboxylic acid sodium salt to replace α-olefin sulfonate sodium as an anionic surfactant, but also use modified sodium polymethacrylate to replace sodium polymethacrylate as a cleaning aid; Example 2 only uses amidocarboxylic acid sodium salt to replace α-olefin sulfonate sodium, and Comparative Example 1 only uses modified sodium polymethacrylate to replace sodium polymethacrylate. The pressure difference on both sides of the membrane after cleaning in Example 4 is lower than that in Example 5, because in the preparation of the solid cleaning agent, Example 5 reduces the amount of modified sodium polymethacrylate used. This shows that in the preparation of the solid cleaning agent using amidocarboxylic acid sodium salt as an anionic surfactant, further using modified sodium polymethacrylate as a cleaning aid can further reduce the pressure difference on both sides of the membrane after cleaning.

[0066] 4. Calcium ion removal efficiency When using membrane separation elements for water purification, the calcium ion components coexisting in the water body combine with organic matter to form a composite pollution layer on the membrane surface, affecting the normal use of the membrane separation element. Take the solid cleaning agent obtained in Examples 1-5 and Comparative Example 1, add pure water with a total dissolved solid content of less than 100 mg / L to a final concentration of 2% at 25°C, and adjust the pH to 12. Select a pre-contaminated membrane separation element, use EDTA titration to determine the calcium ion content of the membrane separation element before cleaning, then install the membrane separation element into a membrane cleaning device, and use a cleaning pump to send the solid cleaning agents obtained in Examples 1-5 and Comparative Example 1 of the present invention into the membrane, circulate or soak for 12 hours, so that the solid cleaning agents obtained in Examples 1-5 and Comparative Example 1 of the present invention are fully in contact with the membrane separation element for cleaning. After cleaning, the residual calcium ion content on the membrane separation element is determined by EDTA titration. The calcium ion removal efficiency (%) = (calcium ion content before cleaning-calcium ion content after cleaning) / calcium ion content before cleaning × 100%, and the results of the determination of calcium ion removal efficiency are shown in Table 3.

[0067] Table 3 Calcium ion removal efficiency (%)

[0068] As shown in Table 3, the calcium ion removal efficiency of Example 2-3 is higher than that of Example 1 because, in the preparation of the solid cleaning agent, Example 1 uses sodium α-olefin sulfonate as an anionic surfactant, while Example 2-3 uses sodium amide carboxylate to replace sodium α-olefin sulfonate; the calcium ion removal efficiency of Example 2 is higher than that of Example 3 because, in the preparation of the solid cleaning agent, Example 3 reduces the amount of sodium amide carboxylate used. This shows that the use of sodium amide carboxylate as an anionic surfactant to prepare the solid cleaning agent can effectively improve the removal efficiency of calcium ions inside the membrane separation element.

[0069] The calcium ion removal efficiency of Examples 4-5 is higher than that of Examples 2 and Comparative Example 1 because, in the preparation of the solid cleaning agent, Examples 4-5 not only use amidocarboxylic acid sodium salt to replace sodium α-olefin sulfonate as an anionic surfactant, but also use modified sodium polymethacrylate to replace sodium polymethacrylate as a cleaning aid; Example 2 only uses amidocarboxylic acid sodium salt to replace sodium α-olefin sulfonate, and Comparative Example 1 only uses modified sodium polymethacrylate to replace sodium polymethacrylate. The calcium ion removal efficiency of Example 4 is higher than that of Example 5 because, in the preparation of the solid cleaning agent, Example 5 reduces the amount of modified sodium polymethacrylate used. This shows that in the preparation of the solid cleaning agent using amidocarboxylic acid sodium salt as an anionic surfactant, further using modified sodium polymethacrylate as a cleaning aid can further improve the calcium ion removal efficiency inside the membrane separation element.

[0070] 5. Aluminum ion removal efficiency When using membrane separation elements for water purification, aluminum ion components coexisting in the water body combine with organic matter to form a composite pollution layer on the membrane surface, affecting the normal use of the membrane separation element. Take the solid cleaning agent obtained in Examples 1-5 and Comparative Example 1, add pure water with a total dissolved solid content of less than 100 mg / L at 25°C to a final concentration of 2%, and adjust the pH to 12. A pre-contaminated membrane separation element was selected, and the aluminum ion content of the membrane separation element before cleaning was determined by the chrome azuro blue s ultraviolet spectrophotometer method. The membrane separation element was then installed in a membrane cleaning device, and the solid cleaning agents obtained in Examples 1-5 of the present invention and Comparative Example 1 were respectively sent into the membrane through a cleaning pump, and circulated or soaked for 12 hours, so that the solid cleaning agents obtained in Examples 1-5 of the present invention and Comparative Example 1 were fully in contact with the membrane separation element for cleaning. After cleaning, the residual aluminum ion content on the membrane separation element was determined by the chrome azuro blue s ultraviolet spectrophotometer method, and the aluminum ion removal efficiency (%) = (aluminum ion content before cleaning - aluminum ion content after cleaning) / aluminum ion content before cleaning × 100%. The measurement results of the aluminum ion removal efficiency are shown in Table 4.

[0071] Table 4 Aluminum ion removal efficiency (%)

[0072] As shown in Table 4, the aluminum ion removal efficiency of Example 2-3 is higher than that of Example 1 because, in the preparation of the solid cleaning agent, Example 1 uses sodium α-olefin sulfonate as an anionic surfactant, while Example 2-3 uses sodium amide carboxylate to replace sodium α-olefin sulfonate; the aluminum ion removal efficiency of Example 2 is higher than that of Example 3 because, in the preparation of the solid cleaning agent, Example 3 reduces the amount of sodium amide carboxylate used. This shows that the use of sodium amide carboxylate as an anionic surfactant to prepare the solid cleaning agent can effectively improve the solid cleaning agent's removal efficiency of aluminum ions inside the membrane separation element.

[0073] The aluminum ion removal efficiency of Examples 4-5 is higher than that of Examples 2 and Comparative Example 1 because, in the preparation of the solid cleaning agent, Examples 4-5 not only use amidocarboxylic acid sodium salt to replace sodium α-olefin sulfonate as an anionic surfactant, but also use modified sodium polymethacrylate to replace sodium polymethacrylate as a cleaning aid; Example 2 only uses amidocarboxylic acid sodium salt to replace sodium α-olefin sulfonate, and Comparative Example 1 only uses modified sodium polymethacrylate to replace sodium polymethacrylate. The aluminum ion removal efficiency of Example 4 is higher than that of Example 5 because, in the preparation of the solid cleaning agent, Example 5 reduces the amount of modified sodium polymethacrylate used. This shows that in the preparation of the solid cleaning agent using amidocarboxylic acid sodium salt as an anionic surfactant, further using modified sodium polymethacrylate as a cleaning aid can further improve the aluminum ion removal efficiency inside the membrane separation element.

[0074] The conventional operations in the operating steps of the present invention are well known to those skilled in the art and will not be described in detail here.

[0075] The embodiments described above provide a detailed description of the technical solutions of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, supplements or similar substitutions made within the scope of the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A solid cleaning agent, comprising the following components in parts by weight: 1-5 parts of a biological enzyme preparation, 3-10 parts of a surfactant, 50-75 parts of a chelating agent, 1-5 parts of a cleaning aid and 20-30 parts of an inorganic compound; the surfactant comprises an anionic surfactant and a nonionic surfactant; the anionic surfactant is sodium α-olefin sulfonate or sodium amide carboxylate, and the sodium amide carboxylate has a benzene ring and an amide group; the nonionic surfactant is coconut oil fatty acid diethanolamide.

2. A solid cleaning agent according to claim 1, characterized in that: The mass ratio of the anionic surfactant to the nonionic surfactant is 1:0.1-0.

5.

3. A solid cleaning agent according to claim 1, characterized in that: In the preparation of the amidocarboxylic acid sodium salt, octadecylamine, methyl 4-vinylbenzoate and 1,4-cyclohexanediyl chloride are reacted under the action of an acid binding agent, and then saponified with sodium hydroxide to obtain the amidocarboxylic acid sodium salt; the acid binding agent is triethylamine.

4. A solid cleaning agent according to claim 3, characterized in that: The molar ratio of octadecylamine to methyl 4-vinylbenzoate is 1:1-2, and the molar ratio of octadecylamine to 1,4-cyclohexanediyl chloride is 1:0.2-1.

5. A solid cleaning agent according to claim 1, characterized in that: The biological enzyme preparation comprises alkaline protease, lipase and alpha-amylase, the mass ratio of the alkaline protease to the lipase is 1:1-2, and the mass ratio of the alkaline protease to the alpha-amylase is 1:1-2.

6. A solid cleaning agent according to claim 1, characterized in that: The chelating agent comprises tetrasodium ethylenediaminetetraacetate, sodium tripolyphosphate and sodium citrate, the mass ratio of the tetrasodium ethylenediaminetetraacetate to sodium tripolyphosphate is 1:1-2, and the mass ratio of the tetrasodium ethylenediaminetetraacetate to sodium citrate is 1:0.2-1.

7. A solid cleaning agent according to claim 1, characterized in that: The cleaning aid is sodium polymethacrylate, and the sodium polymethacrylate has a sodium carboxylate group.

8. A solid cleaning agent according to claim 1, characterized in that: The inorganic compound includes sodium hydroxide and sodium sulfate, and the mass ratio of the sodium hydroxide to the sodium sulfate is 1:0.2-1.

9. A method for preparing a solid cleaning agent, comprising: first mixing 1-5 parts of a biological enzyme preparation, 50-75 parts of a chelating agent, 1-5 parts of a cleaning aid and 20-30 parts of an inorganic compound, crushing and sieving, adding 3-10 parts of a surfactant, drying, and sieving to obtain a solid cleaning agent; the solid cleaning agent is particles with a diameter of 1.5-3.5 mm.

10. Use of the solid cleaning agent according to claim 1 in cleaning membrane separation elements.

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