Thioacetamide modified electrolytic manganese residue catalyst as well as preparation method and application thereof

Abstract

The invention discloses a thioacetamide modified electrolytic manganese residue catalyst as well as a preparation method and application thereof, and belongs to the technical field of organic wastewater treatment. Electrolytic manganese residues are subjected to water washing pretreatment and then mixed with thioacetamide and water for a hydrothermal reaction, the thioacetamide modified electrolytic manganese residue catalyst is obtained, the catalyst has high catalytic activity on persulfate, the degradation efficiency of the persulfate on organic matter can be improved, and the catalytic activity of the thioacetamide modified electrolytic manganese residue catalyst is improved. And the preparation method takes the electrolytic waste residues generated in manganese metal production as the raw material, the cost is low, the steps are simple, only one-step washing and hydro-thermal treatment are needed, and large-scale production is facilitated.

Description

Technical Field

[0001] The invention relates to a catalytic material, in particular to a thioacetamide modified electrolytic manganese slag catalyst, a method for preparing the thioacetamide modified electrolytic manganese slag catalyst by utilizing the electrolytic manganese slag, and application of the thioacetamide modified electrolytic manganese slag catalyst in activating persulfate oxidation and degradation of organic wastewater, belonging to the technical field of catalytic materials and organic wastewater treatment. Background Art

[0002] Transition metal oxides, such as Fe2O3, Co3O4 and CuFeO2, provide a wide range of applications for catalysts of advanced oxidation processes (AOPs), and they have shown high efficiency in wastewater treatment. These catalysts have the ability to activate oxidants, including hydrogen peroxide (H2O2), peroxymonosulfate (PMS) and peroxydisulfate (K2S2O8), thereby producing a large number of reactive oxygen species (ROS) components, which in turn degrade organic pollutants in wastewater. However, the preparation process of these catalysts is difficult and the cost is high. In addition, the metal ions in the catalysts are easily dissolved and leached, which affects the long-term stability of the catalyst. For the use of hydrogen peroxide as an oxidant, the catalyst is only effective under acidic conditions with a pH of less than 3.0, and under this pH condition, the metal ions in the catalyst are very easy to leach.

[0003] The electrolytic manganese industry is facing a serious problem, that is, a large amount of electrolytic manganese slag is produced, and it is urgent to solve the problem of handling and disposing of electrolytic manganese slag. In order to effectively reduce the harm of manganese slag, one method is to prepare it into a material with catalytic performance and high added value. However, due to the large amount of calcium and magnesium compounds wrapped on the surface of electrolytic manganese slag, it needs to be treated to have better utilization performance. At present, there are many studies on the preparation and application of modified electrolytic manganese slag-based catalysts, but there are still some technical problems. For example, a Chinese patent (CN110586176A) discloses a catalyst for catalyzing oil fume VOCs pollutants, which is a mixture of electrolytic manganese slag after calcination with sodium hydroxide, and then hydrothermally synthesized with tetrapropylammonium hydroxide (TPAOH), cerium nitrate and polydimethylammonium chloride (PDADMAC) solution. Although the catalyst has good activity and stability, toxic TPAOH and cerium nitrate are added therein, which increases the risk of poisoning in use and production. The Chinese patent (CN102614830A) uses electrolytic manganese slag as raw material to prepare manganese magnetic activated carbon, and the process has many steps and is complicated, which is not conducive to industrialization. Summary of the invention

[0004] In view of the above technical problems existing in the prior art, the first object of the present invention is to provide a thioacetamide modified electrolytic manganese slag catalyst, which has a high catalytic activity for persulfate and can improve the degradation efficiency of persulfate for organic matter. The electrolytic manganese slag is hydrothermally modified by thioacetamide, which not only fully exposes the iron and manganese metal sites and can fully contact with PMS (permonosulfate), thereby activating PMS, but also introduces sulfur species to produce metal sulfides with transition metals. The metal sulfides show good electrical conductivity, low redox potential, electron-rich properties and chemical stability to oxidants, and the reduced sulfur species can ensure the low-valent Fe 2+ , Mn 3+ / Mn 2+ Regeneration can more effectively activate persulfate to degrade pollutants.

[0005] The second object of the present invention is to provide a method for preparing a thioacetamide modified electrolytic manganese slag catalyst, which uses the electrolytic waste slag produced by the production of metallic manganese as a raw material, has low cost and simple steps, and only requires simple water washing and thioacetamide soaking modification treatment, which is conducive to large-scale production.

[0006] The third object of the present invention is to provide an application of a thioacetamide modified electrolytic manganese slag catalyst, which is applied to catalyze the persulfate oxidation degradation of organic pollutant wastewater, and can achieve rapid and efficient degradation of antibiotics, dyes and other difficult-to-degrade organic matter. The catalyst is adapted to a wide pH range and exhibits high catalytic activity at room temperature, which is conducive to large-scale promotion and application.

[0007] In order to achieve the above technical purpose, the present invention provides a method for preparing a thioacetamide modified electrolytic manganese slag catalyst, which comprises pre-treating the electrolytic manganese slag by water washing, mixing it with thioacetamide and water, and performing a hydrothermal reaction to obtain the catalyst.

[0008] The present invention uses electrolytic manganese slag as a raw material and thioacetamide as a modifier to obtain a thioacetamide-modified electrolytic manganese slag catalyst through a hydrothermal reaction. The electrolytic manganese slag is pre-treated by water washing, which is mainly used to remove soluble salts or soluble alkalis in the electrolytic manganese slag, which is beneficial to the subsequent modification process of the thioacetamide solution. The modification of thioacetamide can cause a qualitative change in the chemical composition and structure of the electrolytic manganese slag. On the one hand, through the hydrothermal modification treatment of the thioacetamide solution, the ammonia water generated by the decomposition of thioacetamide is used to increase the pH of the solution, react with the inert components in the manganese slag, expose the metal site, and thus fully contact with PMS to better activate PMS; on the other hand, the sulfur component generated by the decomposition of thioacetamide during the hydrothermal process can react with the transition metal in the electrolytic manganese slag to generate metal sulfide. The metal sulfide exhibits good electrical conductivity, low redox potential, electron-rich properties and chemical stability to oxidants, which can improve the catalytic activity and stability of the catalytic material. At the same time, the reduced sulfur generated can ensure Fe 2+ Regeneration can more effectively activate persulfate to degrade pollutants.

[0009] As a preferred scheme, the mass ratio of thioacetamide to electrolytic manganese slag is 0.4-1.6:1. The usage ratio of thioacetamide has a relatively large influence on the modification effect of electrolytic manganese slag. The mass ratio of thioacetamide to electrolytic manganese slag is within the selection range. As the mass ratio of thioacetamide increases, the ability of thioacetamide-modified electrolytic manganese slag to catalytically activate persulfate shows a trend of first increasing and then decreasing. When the mass ratio of thioacetamide to electrolytic manganese slag reaches 0.8:1, the catalytic activity of thioacetamide-modified electrolytic manganese slag catalyst reaches a peak value, but as the mass ratio of thioacetamide increases further, the catalytic activation of thioacetamide-modified electrolytic manganese slag shows an inhibitory effect. Thus, the results show that appropriate thioacetamide concentration has a positive effect on the reaction, and too high thioacetamide concentration has an inhibitory effect on the reaction. The preferred mass ratio of thioacetamide to electrolytic manganese slag is within the range of 0.4-1.2:1.

[0010] As a preferred solution, the conditions of the hydrothermal reaction are: solid-liquid ratio of 1g:40-80mL, temperature of 150-200°C, and time of 8-15h. If the reaction time is too short or the temperature is too low, the thioacetamide and the manganese slag will not react sufficiently and the complex reaction cannot be completed well (under high temperature hydrothermal conditions, thioacetamide decomposes in an alkaline solution to produce S 2- 、CH3COO - , NH3, among which S 2- It can react with Fe and Mn metal elements in manganese slag to form a complex reaction); if the reaction time is too long or the temperature is too high, the manganese slag will dissolve and a large amount of manganese ions will leach out, resulting in a decrease in catalyst activity.

[0011] The electrolytic manganese slag of the present invention is washed with water, dried, and then screened with a 150-200 mesh screen to obtain electrolytic manganese slag with appropriate particle size distribution.

[0012] The invention also provides a thioacetamide modified electrolytic manganese slag catalyst, which is obtained by the preparation method.

[0013] The invention also provides an application of a thioacetamide-modified electrolytic manganese slag catalyst, which is applied to catalyze the persulfate oxidation degradation of organic wastewater.

[0014] As a preferred solution, the organic wastewater includes at least one of antibiotic wastewater and dye wastewater.

[0015] As a preferred solution, the pH range of the organic wastewater is 3 to 9. The thioacetamide modified electrolytic manganese slag catalyst of the present invention still has good catalytic activity in a higher pH range, which solves the disadvantage that the existing catalyst needs to be activated under the condition of pH < 3.0 when catalyzing oxidants such as persulfate and H2O2, and can avoid the existing catalyst from dissolving transition metal ions under strong acidic conditions, thereby reducing the service life of the catalyst.

[0016] As a preferred solution, the concentration of the thioacetamide modified electrolytic manganese slag catalyst added to the organic wastewater is 0.3 to 1.8 g / L; more preferably 0.3 to 0.6 g / L.

[0017] As a preferred solution, the concentration of the persulfate added to the organic wastewater is 0.3-1.2 g / L. The persulfate is preferably potassium peroxymonosulfate and / or potassium peroxydisulfate.

[0018] As a preferred solution, the concentration of the antibiotic wastewater or dye wastewater in the organic wastewater is 5-40 mg / L.

[0019] The present invention is specifically described by taking antibiotic wastewater as an example. The antibiotic concentration in the antibiotic wastewater is 5-40 mg / L. For organic wastewater within the concentration range, the dosage of thioacetamide-modified electrolytic manganese slag catalyst is 0.6-1.8 g / L, and the added concentration of persulfate in the organic wastewater is 0.3-0.6 g / L. Within 30-60 minutes, the removal rate of antibiotics is 95%-100%.

[0020] The organic wastewater of the present invention is antibiotic wastewater or dye wastewater. Antibiotic wastewater includes wastewater of metronidazole, tinidazole, ornidazole, secnidazole, etc. Dye wastewater includes wastewater of azo dyes, onion quinone dyes, indigo dyes, chemical dyes, triarylmethane dyes, heterocyclic dyes, etc.

[0021] The preparation method of the thioacetamide modified electrolytic manganese slag catalyst provided by the present invention comprises the following steps:

[0022] Step 1) First, the electrolytic manganese dioxide waste residue is washed with water for 1 to 2 times, and then dried at 50 to 60° C. for 5 to 8 hours. The dried waste residue is screened with 150 to 200 mesh, and the waste residue under the screen is collected for later use;

[0023] Step 2) 1 g of the undersize waste residue obtained in step 1) was mixed with 0.8 g of thioacetamide and placed in a beaker containing 60 mL of deionized water for reaction for 90 min, and then placed in an autoclave with a set temperature of 180° C. and a reaction time of 12 hours;

[0024] Step 3) The product in step 2 is then washed multiple times and dried at 60° C. for 12 hours to obtain a thioacetamide-modified electrolytic manganese slag catalyst.

[0025] The thioacetamide modified electrolytic manganese slag catalyst of the present invention is used to remove nidazole pollutants in antibiotic wastewater. The modified electrolytic manganese waste slag catalyst is added to the wastewater at 0.6-1.8 g / L, and the dosage of the oxidant is 0.3-0.6 g / L. The pH value of the wastewater is controlled at 3-9, and the reaction is carried out at room temperature. The concentration of nidazole pollutants in the wastewater is 10 mg / L, the degradation reaction time is 30-60 min, and the removal rate of benznidazole pollutants is 95%-98%.

[0026] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0027] 1) The thioacetamide modified electrolytic manganese slag catalyst of the present invention uses electrolytic manganese slag as the main raw material, which is cheap and easily available, realizes efficient resource utilization of harmful solid waste, is helpful for environmental protection, and has simple steps, only needs one step of water washing and hydrothermal treatment, which is conducive to large-scale production. No other chemical substances with catalytic activity are needed, and good catalytic effect can be exerted by compounding with thioacetamide.

[0028] 2) The thioacetamide-modified electrolytic manganese slag catalyst of the present invention can be used as an advanced oxidation catalyst to efficiently activate persulfate to degrade organic wastewater, and has good application prospects.

[0029] 3) The thioacetamide modified electrolytic manganese slag catalyst of the present invention can efficiently and quickly degrade antibiotics, and exhibits high catalytic activity to persulfate in a wide pH range (3.0-9.0), which can extend the service life of the catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is the XRD spectrum of electrolytic manganese slag before and after modification. After modification, the characteristic peak of calcium sulfate is reduced, indicating that more metal sites are exposed.

[0031] Figure 2 The XPS spectra of electrolytic manganese slag before and after modification are shown in Figure 2 In a, the C1s fine spectrum shows a characteristic absorption peak of C=S, and Figure 2 Zhongb found that sulfur species were successfully introduced to form metal sulfides. Figure 2 In c, a large amount of trivalent iron is reduced to divalent iron, and tetrahedral and octahedral divalent iron are shown. Figure 2 Part of the manganese element in d is reduced from tetravalent to trivalent.

[0032] Figure 3 This is a comparison chart of the degradation of metronidazole by catalysts prepared at different hydrothermal reaction temperatures when using thioacetamide to modify electrolytic manganese slag. It can be seen from the figure that thioacetamide is partially hydrolyzed at a temperature of 140°C, and the reaction is not complete. The thioacetamide electrolytic manganese slag catalyst prepared at a temperature of 180°C has the best effect.

[0033] Figure 4 This is a comparison chart of the degradation of metronidazole by catalysts prepared at different reaction times in a high-pressure reactor when thioacetamide is used to modify electrolytic manganese slag. When the reaction time is short, thioacetamide and manganese slag do not react fully and the complex reaction cannot be completed well; when the reaction time is too long, the manganese slag dissolves and a large amount of manganese ions are leached, which is not conducive to the preparation of the catalyst.

[0034] Figure 5 This is a comparison chart of the degradation of metronidazole by catalysts prepared with different mass ratios of thioacetamide to electrolytic manganese slag when thioacetamide is used to modify electrolytic manganese slag. At different mass ratios of thioacetamide to electrolytic manganese slag, the best mass ratio is shown at 0.8:1.

[0035] Figure 6 This is a diagram showing the degradation effect of metronidazole using the TAA-manganese slag catalyst in Example 1 (manganese slag catalyst prepared using 0.8 g of thioacetamide) under different pH conditions.

[0036] Figure 7 This is a diagram showing the effect of using the TAA-manganese slag catalyst in Example 1 to degrade metronidazole under different persulfate addition conditions.

[0037] Figure 8 This is a diagram showing the degradation effect of metronidazole using the TAA-manganese slag catalyst in Example 1 at different TAA-manganese slag catalyst dosages.

[0038] Fig. 9 This is a diagram showing the effect of using the TAA-manganese slag catalyst in Example 1 to degrade metronidazole of different concentrations.

[0039] Fig.10 This is a diagram showing the effect of using the TAA-manganese slag catalyst in Example 1 to degrade different nitroazole pollutants.

[0040] Fig.11 This is a diagram showing the effect of using the TAA-manganese slag catalyst in Example 1 to degrade bisphenol A. DETAILED DESCRIPTION

[0041] The following examples are intended to further illustrate the present invention, rather than to limit the scope of protection of the claims of the present invention.

[0042] Example 1

[0043] Preparation of modified electrolytic manganese slag: After washing the manganese slag (taken from Songtao Sanhe Manganese Industry Group Co., Ltd. (Tongren, Guizhou), the main element composition is shown in Table 1) with water twice, it was dried at 60°C for 6h, and the dry manganese slag was passed through a 200-mesh sieve, and the manganese slag under the sieve was collected. Weigh 1g of manganese slag and soak it in 60mL deionized water, add 0.8g of thioacetamide, transfer it to a 100mL stainless steel autoclave with a PTFE liner, heat it at 180°C for 8, 10, 12, 14, and 16h, then wash it repeatedly with deionized water several times, and finally dry it at 60°C for 6h. The products obtained are named TAA-8 manganese slag, TAA-10 manganese slag, TAA-manganese slag, TAA-14 manganese slag, and TAA-16 manganese slag.

[0044] Take 50 mg of the modified manganese slag and 1 mL of 30 g / L potassium persulfate and add them to 50 mL of 10 mg / L metronidazole simulated wastewater with a pH of 6.5-7.5, and stir at room temperature for 60 minutes. After the catalytic reaction is completed, the products are named TAA-8 manganese slag, TAA-10 manganese slag, TAA-manganese slag, TAA-14 manganese slag, and TAA-16 manganese slag. The degradation rates of metronidazole in the water samples of the reaction system are 54%, 66.1%, 96.5%, 91%, and 86.6%, respectively. Figure 4 .

[0045] Table 1 Main element composition of electrolytic manganese slag

[0046]

[0047]

[0048] Example 2

[0049] Preparation of modified electrolytic manganese slag: After washing the manganese slag (taken from Songtao Sanhe Manganese Industry Group Co., Ltd. (Tongren, Guizhou), the main element composition is shown in Table 1) with water twice, it was dried at 60°C for 6h, and the dry manganese slag was passed through a 200-mesh sieve, and the manganese slag under the sieve was collected. Weigh 1g of manganese slag and soak it in 60mL deionized water, then add 0.4, 0.8, 1.2, and 1.6g of thioacetamide, respectively, transfer it to a 100mL stainless steel autoclave with a PTFE liner, heat it at 180°C for 12h, then wash it repeatedly with deionized water several times, and finally dry it at 60°C for 6h. The products obtained were named 0.4TAA-manganese slag, TAA-manganese slag, 1.2TAA-manganese slag, and 1.6TAA-manganese slag.

[0050] 50 mg of modified manganese slag and 1 mL of 30 g / L potassium persulfate were added to 50 mL of 10 mg / L metronidazole simulated wastewater with a pH of 6.5-7.5, and stirred at room temperature for 60 min. After the catalytic reaction was completed, the degradation rates of metronidazole in the water samples of the 0.4 TAA-manganese slag, TAA-manganese slag, 1.2 TAA-manganese slag, and 1.6 TAA-manganese slag reaction systems were 90%, 99%, 94%, and 91%, respectively. Figure 5 .

[0051] Example 3

[0052] Preparation of modified electrolytic manganese slag: After washing the manganese slag (taken from Songtao Sanhe Manganese Industry Group Co., Ltd. (Tongren, Guizhou), the main element composition is shown in Table 1) with water twice, it was dried at 60°C for 6h, and the dry manganese slag was passed through a 200-mesh sieve, and the manganese slag under the sieve was collected. Weigh 1g of manganese slag and soak it in 60mL deionized water, then add 0.8 thioacetamide, transfer it to a 100mL stainless steel autoclave with a PTFE liner, heat it at 140°C, 180°C, and 220°C for 12h, then wash it repeatedly with deionized water several times, and finally dry it at 60°C for 6h. The products obtained were named 140TAA-manganese slag, TAA-manganese slag, and 220TAA-manganese slag.

[0053] 50 mg of modified manganese slag and 1 mL of 30 g / L potassium persulfate were added to 50 mL of 10 mg / L metronidazole simulated wastewater with a pH of 6.5 to 7.5, and stirred at room temperature for 60 min. After the catalytic reaction was completed, the degradation rates of metronidazole in the water samples of the 140 TAA-manganese slag, TAA-manganese slag, and 220 TAA-manganese slag reaction systems were 82%, 100%, and 100%, respectively. Figure 3 .

[0054] Example 4

[0055] The TAA-manganese slag prepared in Example 1 was used as a catalyst. In the experiment, 50 mg of TAA-manganese slag and 1 mL of potassium persulfate (concentration of 30 g / L) were added to 50 mL of metronidazole wastewater at the same time, wherein the pH values ​​of the wastewater were 3, 5, 7.06, 9, and 11, respectively, and the concentration was 10 mg / L. After stirring and reacting at room temperature for 60 minutes, the degradation rate was measured. The results were 73%, 75.8%, 94.5%, 55.3%, and 5.2% at 20 minutes of reaction, respectively. Figure 6 .

[0056] Example 5

[0057] The TAA-manganese slag prepared in Example 1 was used as a catalyst. In the experiment, 50 mg of TAA-manganese slag and 0.2, 0.3, 0.4, 0.5, and 0.6 mL of potassium persulfate (concentration of 30 g / L) were added to 50 mL of metronidazole wastewater at the same time, and the concentration was 10 mg / L, Ph = 6.5-7.5. After stirring and reacting at room temperature for 60 minutes, the degradation rate was measured. The results were 38.2%, 70%, 96%, 100%, and 100% respectively at 20 minutes of reaction. Figure 7 .

[0058] Example 6

[0059] The TAA-manganese slag prepared in Example 1 was used as a catalyst. In the experiment, 10, 30, 50, 70, and 90 mg of TAA-manganese slag and 1 mL of potassium persulfate (concentration of 30 g / L) were added to 50 mL of metronidazole wastewater at the same time, and the concentration was 10 mg / L and the pH was 6.5-7.5. After stirring and reacting at room temperature for 60 minutes, the degradation rate was measured. The results were 85.5%, 100%, 100%, 100%, and 99.5% respectively at 20 minutes of reaction. Figure 8 .

[0060] Example 7

[0061] The TAA-manganese slag prepared in Example 1 was used as a catalyst. In the experiment, 50 mg of TAA-manganese slag and 1 mL of potassium persulfate (concentration of 30 g / L) were added to 50 mL of metronidazole wastewater at the same time, and the concentrations were 5, 10, 20, 30, 40 mg / L, pH = 6.5-7.5. After stirring and reacting at room temperature for 60 minutes, the degradation rate was measured. The results were 100%, 100%, 86%, 70%, 51% at 20 minutes of reaction, respectively. Fig. 9 .

[0062] Example 8

[0063] The TAA-manganese slag prepared in Example 1 was selected as a catalyst, and 50 mg of TAA-manganese slag and 1 mL of 30 g / L potassium permonosulfate were simultaneously added to 50 mL of wastewater containing 10 mg / L of metronidazole, tinidazole, ornidazole, and secnidazole at pH 6.5-7.5, respectively, and stirred at room temperature for 60 minutes. After the catalytic reaction was completed, the degradation rates of metronidazole, tinidazole, ornidazole, and secnidazole were measured to be 100%, 100%, 100%, and 100%, respectively. Fig.10 .

[0064] Example 9

[0065] The TAA-manganese slag prepared in Example 1 was used as a catalyst. 50 mg of TAA-manganese slag and 1 mL of 30 g / L potassium permonosulfate were added to 50 mL of 10 mg / L bisphenol A wastewater with a pH of 6.5 to 7.5, and stirred at room temperature for 60 minutes. After the catalytic reaction was completed, the degradation rates were 100%, 120%, 130%, 140%, 150%, 160%, 170%, 180%, 190%, 200%, 210%, 220%, 230%, 240%, 250%, 260%, 270%, 280%, 290%, 300%, 310%, 320%, 330%, 340%, 360%, 370%, 380%, 390%, 400%, Fig.11 .

Claims

1. A method for preparing a thioacetamide modified electrolytic manganese slag catalyst, characterized in that: The electrolytic manganese slag is pre-treated by water washing, and then mixed with thioacetamide and water for hydrothermal reaction to obtain the product.

2. The method for preparing a thioacetamide modified electrolytic manganese slag catalyst according to claim 1, characterized in that: The mass ratio of the thioacetamide to the electrolytic manganese slag is 0.4-1.6:

1.

3. The method for preparing a thioacetamide modified electrolytic manganese slag catalyst according to claim 1 or 2, characterized in that: The conditions of the hydrothermal reaction are: solid-liquid ratio of 1 g:40-80 mL, temperature of 150-200° C., and time of 8-15 h.

4. A thioacetamide modified electrolytic manganese slag catalyst, characterized in that: The method is obtained by any one of claims 1 to 3.

5. The use of a thioacetamide modified electrolytic manganese slag catalyst according to claim 4, characterized in that: Used to catalyze the persulfate oxidation and degradation of organic wastewater.

6. The use of a thioacetamide modified electrolytic manganese slag catalyst according to claim 5, characterized in that: The organic wastewater includes at least one of antibiotic wastewater and dye wastewater.

7. The use of a thioacetamide modified electrolytic manganese slag catalyst according to claim 5, characterized in that: The pH range of the organic wastewater is 3-9.

8. The use of a thioacetamide modified electrolytic manganese slag catalyst according to any one of claims 5 to 7, characterized in that: The concentration of the thioacetamide modified electrolytic manganese slag catalyst added to the organic wastewater is 0.3-1.8 g / L; The persulfate is added to the organic wastewater at a concentration of 0.3 to 1.2 g / L; The concentration of the antibiotic wastewater or dye wastewater in the organic wastewater is 5-40 mg / L.

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