A method for treating industrial organic wastewater

Abstract

The application provides a treatment method of industrial organic wastewater, comprising the following steps: adjusting the pH of the industrial organic wastewater to 3.8-5.5, and performing a stirring reaction to obtain wastewater A; adding reagent B into the wastewater A, and performing a stirring reaction; and after standing, obtaining treated industrial organic wastewater; the reagent B is one or more of sodium dimethyl dithiocarbamate, sodium diethyl dithiocarbamate, trisodium trithiocyanate and sodium piperazine dithiocarbamate. The treatment method has the advantages of simple operation, simple process equipment, low investment cost, easy engineering promotion, cheap and easily available reagent, and can be used for treating heavy metal-containing organic wastewater in different industrial fields, and has good heavy metal removal effect and good industrial application value.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of wastewater treatment, and particularly relates to a treatment method for industrial organic wastewater containing heavy metals. BACKGROUND

[0002] Industrial wastewater containing heavy metals is mostly from smelting, chemical industry, electroplating, chlor-alkali and papermaking industries. The heavy metals in wastewater from different industries exist in various forms, including complex state, ionic state and metal complexes. Common methods for treating heavy metal wastewater include chemical precipitation, resin adsorption, membrane technology and ion exchange. Among them, the chemical precipitation method is the most commonly used heavy metal removal process, which makes the ionic heavy metals generate insoluble substances by adding hydroxide or sulfide; resin adsorption, ion exchange and membrane technology are not suitable for high difficulty industrial wastewater, and there are problems of frequent cleaning and waste of a large amount of clean water.

[0003] The wastewater from fine chemical industry contains organic matters such as alkanes, benzene rings and aldehydes, and has high COD and high alkalinity, and contains stable molybdenum ammonia salt complexes. Molybdenum is stable in nature and is not easy to remove, which not only leads to heavy metal exceeding the standard, but also leads to total nitrogen exceeding the standard. Patent CN111892138A uses sulfide and iron salt flocculants to cooperatively remove molybdenum in molybdenum-containing wastewater from smelting; by first adding sulfide to remove other heavy metals in the wastewater, MoS4 2- is generated at the same time, which exists in the aqueous solution, and then adsorbs and bridges with the iron salt flocculant to form a precipitate and is removed. CN117003348A discloses a molybdenum removal composite agent for micro-polluted water, which mainly uses polymeric ferric sulfate, polymeric aluminum sulfate and other polymer coagulants to remove molybdenum. The molybdenum removal composite agent has good removal effect on water-soluble molybdate in micro-polluted water. In an organic wastewater system, heavy metals mostly exist in the form of metal complexes, and the charge is weak, so the effect of simple hydroxide precipitation and sulfide precipitation is very small.

[0004] In addition, there is currently no effective heavy metal removal process for high-salt organic wastewater generated by the emerging sodium battery industry, especially for the removal of iron citrate and manganese citrate complexes.

[0005] Therefore, due to the complexity of the components, high salt, high COD and high alkalinity in the organic wastewater system, the effect of one-step or multi-step chemical precipitation treatment is limited, and a new treatment method needs to be developed. SUMMARY

[0006] In view of the above technical problems, the application provides a treatment method for industrial organic wastewater, which can effectively treat industrial organic wastewater containing high salt, high COD and high alkalinity.

[0007] To achieve the above purpose, the application provides the following technical scheme:

[0008] A treatment method for industrial organic wastewater, comprising:

[0009] (1) adjusting pH of the industrial organic wastewater to 3.8-5.5, and stirring to obtain wastewater A;

[0010] (2) adding reagent B to wastewater A, stirring, and standing to obtain treated industrial organic wastewater; the reagent B is one or more of sodium dimethyl dithiocarbamate, sodium diethyl dithiocarbamate, trisodium trithiocyanate, and sodium piperazine dithiocarbamate.

[0011] Further, step (1) comprises: adding release and buffering acid-regulating granules to the industrial organic wastewater, and stirring until the pH of the wastewater is adjusted to 3.8-5.5 to obtain wastewater A.

[0012] Further, in step (1), the temperature of the stirring is 20-50°C.

[0013] Further, in step (1), the release and buffering acid-regulating granules are prepared from an acid-regulating agent, an adsorbent, a binder, and a forming agent; and the mass ratio of the acid-regulating agent to the adsorbent, the diluent, the binder, the forming agent is (0.63-0.83):(0.1-0.2):(0.05-0.1):(0.01-0.02):(0.01-0.05).

[0014] Further, in step (1), the particle size of the release and buffering acid-regulating granules is 2-10 mm.

[0015] Further, the acid-regulating agent is one or more of acetic acid, phosphoric acid, glycolic acid, nitrilotriacetic acid, and citric acid.

[0016] Further, the adsorbent is one or more of bentonite, diatomite, chitosan, and activated carbon.

[0017] Further, the binder is one or more of starch, gelatin, and cellulose.

[0018] Further, the diluent is one or more of glycerol, water, and ethanol.

[0019] Further, the forming agent is talc.

[0020] Further, in step (1), the preparation method of the release and buffering acid-regulating granules comprises: mixing the acid-regulating agent, the adsorbent, and the diluent into slurry according to the proportion, adding the forming agent and the binder, stirring again, and granulating.

[0021] Further, in step (1), the release and buffering acid-regulating granules are added to the industrial organic wastewater at an amount of 20-50 g / L.

[0022] Further, in step (1), the industrial organic wastewater is one or more of molybdenum-containing chemical wastewater, high-salt wastewater containing ferric citrate and / or manganese citrate.

[0023] Further, in step (2), the reagent B is added in an amount of 5-20 times the mass of the heavy metal in the wastewater.

[0024] Further, in step (2), the reagent B is prepared into a solution with a mass concentration of 10-20% and added to the wastewater A.

[0025] Further, in step (2), the stirring reaction is performed for 20-40 min, the standing time is 10-60 min, and the stirring reaction temperature is 20-50℃.

[0026] Further, the COD concentration of the industrial organic wastewater is 20000-100000 mg / L.

[0027] Further, the molybdenum content in the molybdenum-containing chemical wastewater is 100-400 mg / L.

[0028] Further, the alkalinity of the molybdenum-containing chemical wastewater is 10000-35000 mg / L.

[0029] Further, the total content of iron and manganese in the high-salt wastewater containing ferric citrate and / or manganese citrate is 50-450 mg / L.

[0030] Further, the total salt content in the high-salt wastewater containing ferric citrate and / or manganese citrate accounts for 10-35% of the total mass of the wastewater.

[0031] Compared with the prior art, one or more of the above technical solutions can achieve at least one of the following beneficial effects:

[0032] 1. The above industrial organic wastewater treatment method is simple to operate, requires simple process equipment, has low investment cost, is easy to promote, uses inexpensive and readily available reagents, and can be used to remove heavy metals from organic wastewater containing heavy metals in different industrial fields, such as efficiently treating molybdenum-containing catalyst chemical wastewater, breaking the complex of ferric citrate, removing iron, etc., and removing heavy metals from high-salt wastewater, which can solve the problem of floe floating during the chemical precipitation process of removing heavy metals from high-salt wastewater.

[0033] 2. The coupling process of release and slow-release acid particles and solvent B can achieve better heavy metal removal and decolorization effects.

[0034] 3. The method for treating industrial organic wastewater has simple dosing mode of slow-release and acid adjusting particles, less environmental protection equipment, simple application, and can omit traditional liquid acid preparation, coagulant dosing, and adsorption and decoloring processes and related structures.

[0035] 4. The method for treating industrial organic wastewater can achieve 99.8% removal rate of molybdenum in chemical wastewater, and 99.9% removal rate of complex iron, and has good heavy metal removal effect. DETAILED DESCRIPTION

[0036] The applicant found that COD in wastewater is easy to remove, but the molybdenum-containing catalyst is stable in nature and is not easy to be decomposed and removed, which not only causes molybdenum to exceed the standard, but also causes total nitrogen to exceed the standard, seriously affecting wastewater discharge and recycling. The production wastewater of fine chemical industry is alkaline, and although flocculation and precipitation are formed after adding polymeric ferric sulfate after acid adjusting, the removal effect of molybdenum is limited. In addition, the organic matter content in wastewater is high, and it is difficult to use membrane method for treatment, and the membrane is quickly blocked. Although the resin adsorption has effect, the cleaning water enriched with molybdenum generated in the resin desorption process has no disposal method, and as a hazardous waste, the cost is high.

[0037] Based on the above phenomenon, it is found that the reason why molybdenum in the above fine chemical wastewater is difficult to remove is that organic matter in wastewater forms a complex with metal, promotes its dissolution in water, and is not easy to be flocculated and removed. For this reason, the applicant found that under acidic conditions, these reagents such as dimethyl dithiocarbamic acid sodium, diethyl dithiocarbamic acid sodium, trisodium thiocyanate, and sodium piperazine dithiocarbamate can chelate with metals in wastewater to form water-insoluble metal precipitates, and good molybdenum removal can be achieved. Based on this, the present application is completed.

[0038] The present application provides a method for treating industrial organic wastewater, comprising:

[0039] (1) adjusting the pH of the industrial organic wastewater to 3.8-5.5, and stirring to obtain wastewater A;

[0040] (2) adding reagent B to the wastewater A, stirring, and standing to obtain treated industrial organic wastewater; the reagent B is one or more of dimethyl dithiocarbamic acid sodium, diethyl dithiocarbamic acid sodium, trisodium thiocyanate, and sodium piperazine dithiocarbamate.

[0041] In some preferred embodiments, step (1) comprises: adding the slow-release acid-adjusting granules into the industrial organic wastewater, and stirring until the pH of the wastewater is adjusted to 3.8-5.5, to obtain wastewater A. The slow-release acid-adjusting granules and reagent B are coupled to remove heavy metals from the industrial organic wastewater, which integrates the effects of acid adjustment, decarburization, complex breaking, adsorption, decolorization and coagulation, and maximizes the effects. The analysis shows that the mechanism may be as follows: when the slow-release acid-adjusting granules are added into the industrial organic wastewater, the acid is dissolved in water first, the pH is continuously reduced, the carbon dioxide in the wastewater is gradually dissolved and released, and the alkalinity of the wastewater is reduced. Second, the stirring of the acid-adjusting granules in water can intensify the disturbance, promote the overflow of carbon dioxide out of the water, and reduce the heating step. Third, after the industrial organic wastewater is adjusted to the set pH, reagent B is added, which has a stronger binding force with heavy metals than the oxygen-containing organic molybdenum, to generate stable organic sulfur and heavy metal chelate precipitates, thereby removing the heavy metals. Fourth, during the process of adding reagent B to break the complex and remove the heavy metals, the acid in the acid-adjusting granules continuously releases to maintain the pH of the wastewater stable, the binder in the acid-adjusting granules continuously releases into the water to play a role of sweeping and supplementing, promote the flocculation and agglomeration of the flocculation, and strengthen the precipitation effect; at the same time, the adsorbent in the acid-adjusting granules continuously releases into the water to adsorb the ion state metals and organic matter that are broken from the complex, thereby playing a role of decolorization and heavy metal removal.

[0042] In some preferred embodiments, in step (1), the slow-release acid-adjusting granules are prepared from an acid-adjusting agent, an adsorbent, a binder and a forming agent; and the mass ratio of the acid-adjusting agent to the adsorbent, the diluent, the binder and the forming agent is (0.63-0.83):(0.1-0.2):(0.05-0.1):(0.01-0.02):(0.01-0.05).

[0043] In some preferred embodiments, in step (1), the particle size of the slow-release acid-adjusting granules is 2-10 mm.

[0044] In some preferred embodiments, in step (1), the acid-adjusting agent is one or more of acetic acid, phosphoric acid, hydroxyacetic acid, nitrilotriacetic acid and citric acid.

[0045] In some preferred embodiments, in step (1), the adsorbent is one or more of bentonite, diatomite, chitosan and activated carbon.

[0046] In some preferred embodiments, in step (1), the binder is one or more of starch, gelatin and cellulose.

[0047] In some preferred embodiments, in step (1), the diluent is one or more of glycerol, water and ethanol.

[0048] In some preferred embodiments, in step (1), the molding agent is talcum powder.

[0049] In some preferred embodiments, in step (1), the preparation method of the slow-release and buffering acid-regulating granules comprises: mixing the acid-regulating agent, the adsorbent, and the diluent into a slurry according to a certain proportion, adding the molding agent and the binder, and stirring again to obtain a uniform mixture, and then granulating.

[0050] In some preferred embodiments, in step (1), the slow-release and buffering acid-regulating granules are added to the industrial organic wastewater in an amount of 20-50 g / L.

[0051] In some preferred embodiments, in step (1), the industrial organic wastewater is one or more of molybdenum-containing chemical wastewater, and high-salt wastewater containing ferric citrate and / or manganese citrate.

[0052] In step (1), the stirring reaction time is determined according to the pH regulation effect of the reaction system; in some embodiments, the stirring reaction time is 30-60 min.

[0053] In step (1), the stirring reaction speed can be any speed that can keep the reaction system in a relatively uniform state; in some embodiments, the stirring reaction speed can be 40-100 rpm.

[0054] In step (1), the stirring reaction can be carried out at room temperature without heating or cooling, which is the most cost-effective. In fact, the stirring reaction can also be carried out at a temperature range of 20-50°C.

[0055] In some preferred embodiments, in step (2), the reagent B is added in an amount of 5-20 times the mass of the heavy metal in the wastewater.

[0056] In some preferred embodiments, in step (2), the reagent B is prepared into a solution with a concentration of 10-20% and then added to the wastewater A.

[0057] In some preferred embodiments, in step (2), the stirring reaction time is 20-40 min, and the standing time is 10-60 min.

[0058] In step (2), the stirring reaction can be carried out at room temperature without heating or cooling, which is the most cost-effective. In fact, the stirring reaction can also be carried out at a temperature range of 20-50°C.

[0059] Specifically, in step (1), the high-salt wastewater containing ferric citrate and / or manganese citrate is high-salt wastewater produced by battery production.

[0060] In some embodiments, the COD concentration of the industrial organic wastewater is 20,000-100,000 mg / L.

[0061] In some embodiments, the molybdenum-containing chemical wastewater has a molybdenum content of 100-400 mg / L.

[0062] In some embodiments, the molybdenum-containing chemical wastewater has an alkalinity of 10000-35000 mg / L, where the alkalinity mainly refers to the total concentration of carbonate and bicarbonate.

[0063] In some embodiments, the high-salt wastewater containing iron citrate and / or manganese citrate has a total content of iron and manganese of 50-450 mg / L.

[0064] In some embodiments, the high-salt wastewater containing iron citrate and / or manganese citrate has a total salt content of 10-35% of the total mass of the wastewater.

[0065] In order to facilitate the understanding of the present application, the following will make a more comprehensive and detailed description of the present application in combination with preferred embodiments, but the protection scope of the present application is not limited to the following specific embodiments.

[0066] Example 1

[0067] 830 g of phosphoric acid, 100 g of diatomite and 50 g of glycerol were mixed and stirred into a slurry, and then 10 g of talc powder and 10 g of gelatin were added. The mixture was heated to 60-70℃ and stirred for 1-3 h, and then cooled to room temperature. Granulation was performed to obtain acid-regulating granules with a particle size of 3 mm.

[0068] The COD concentration of the fine chemical production wastewater was 48190 mg / L, the alkalinity was 31543 mg / L, the pH was 8.5, and the molybdenum content was 400 mg / L. 1 L of the water sample was taken, the pH was adjusted to 3.8, 40 g of the acid-regulating granules was added, and the mixture was stirred at room temperature for 30 min, and the alkalinity was reduced to 20 mg / L. According to the mass ratio of sodium diethyldithiocarbamate to the molybdenum content in the wastewater of 7:1, 28 g of a 10% sodium diethyldithiocarbamate solution was added, and the mixture was stirred for 30 min, and then was allowed to stand for 10 min. The supernatant was tested, and the molybdenum content was reduced to 0.8 mg / L, and the molybdenum removal rate was 99.8%.

[0069] Example 2

[0070] The COD concentration of the fine chemical production wastewater was 48190 mg / L, the alkalinity was 31543 mg / L, the pH was 8.5, and the molybdenum content was 400 mg / L. 1 L of the water sample was taken, the pH was adjusted to 3.8, 40 g of the acid-regulating granules was added, and the mixture was stirred at room temperature for 30 min, and the alkalinity was reduced to 20 mg / L. According to the mass ratio of sodium diethyldithiocarbamate to the molybdenum content in the wastewater of 7:1, 28 g of a 10% sodium diethyldithiocarbamate solution was added, and the mixture was stirred for 30 min, and then was allowed to stand for 10 min. The supernatant was tested, and the molybdenum content was reduced to 0.8 mg / L, and the molybdenum removal rate was 99.8%.

[0071] Example 3

[0072] The COD concentration of the fine chemical production wastewater is 48190 mg / L, the alkalinity is 31543 mg / L, the pH is 8.5, and the molybdenum content is 400 mg / L. 1 L of water sample is taken, dilute sulfuric acid is added, stirring at room temperature for 30 min, the pH is adjusted to 3.8, and the alkalinity is reduced to 45 mg / L. According to the mass ratio of sodium piperazine dithiocarbamate to the molybdenum content in the wastewater of 5:1, 20 g of 10% sodium piperazine dithiocarbamate is added, stirring for 30 min, and standing for 10 min. The supernatant is tested, and the molybdenum content is reduced to 20.5 mg / L, and the molybdenum removal rate reaches 94.87%.

[0073] Comparative Example 1

[0074] The COD concentration of the fine chemical production wastewater is 48190 mg / L, the alkalinity is 31543 mg / L, the pH is 8.5, and the molybdenum content is 400 mg / L. 1 L of water sample is taken, dilute sulfuric acid is added, stirring at room temperature for 30 min, the pH is adjusted to 3.8, and the alkalinity is reduced to 45 mg / L. According to the mass ratio of sodium piperazine dithiocarbamate to the molybdenum content in the wastewater of 5:1, 20 g of 10% sodium piperazine dithiocarbamate is added, stirring for 30 min, and standing for 10 min. The supernatant is tested, and the molybdenum content is reduced to 20.5 mg / L, and the molybdenum removal rate reaches 94.87%.

[0075] Comparing Examples 1-3 with Comparative Example 1 can see that the treatment method of the present application has good heavy metal removal effect on fine chemical production wastewater; and comparing the heavy metal removal effects of Comparative Example 1 and Example 2 can see that the heavy metal removal effect of the treatment method of using the acid-releasing granular acid regulator is better than that of the treatment method of directly adjusting the acid, and after analysis, this may be because the pH gradually decreases by adding the acid-releasing granular acid regulator to the wastewater, the carbon dioxide in the wastewater is gradually dissolved and released, and the alkalinity in the wastewater is reduced, and after the pH is adjusted to the set pH, the reagent B is added, which has stronger combination with heavy metals in the wastewater than the oxygen-containing organic molybdenum, to generate stable organic sulfur and heavy metal chelate precipitates, thereby removing heavy metals; in the process of removing heavy metals by adding the reagent B, the acid in the acid-releasing granular acid regulator continuously releases to maintain the pH of the wastewater stable, the binder in the acid-releasing granular acid regulator is continuously released into the water to play the role of sweeping and supplementing, promote the flocculation of the flocculation body, and strengthen the precipitation effect, and the adsorbent in the acid-releasing granular acid regulator is also continuously released into the water to adsorb the ion state metals and organic matter released in the process of breaking the complex, thereby playing the role of decolorization and heavy metal removal, so the use of the acid-releasing granular acid regulator is conducive to further improving the heavy metal removal effect.

[0076] Example 4

[0077] The acid-releasing granular acid regulator has the same proportion as that of Example 1.

[0078] The fine chemical production wastewater contains COD 38780 mg / L, alkalinity 10000 mg / L; pH 7.8, molybdenum content 40 mg / L. Take 1L water sample, add 20g acid-adjusting granules, stir at room temperature for 30 min, pH adjustment 4.1, alkalinity reduced to 50 mg / L. According to the mass ratio of dimethyl dithiocarbamic acid sodium to the molybdenum content in the wastewater 10:1, add 2g of 20% dimethyl dithiocarbamic acid sodium solution, stir for 30 min, stand for 10 min, the supernatant test molybdenum content reduced to 0.08 mg / L, molybdenum removal rate reached 99.98%.

[0079] Example 5

[0080] The acid-adjusting granules are the same as in Example 1.

[0081] The fine chemical production wastewater contains COD 38780 mg / L, alkalinity 10000 mg / L; pH 7.8, molybdenum content 40 mg / L. Take 1L water sample, add 30g acid-adjusting granules, stir at room temperature for 30 min, pH adjustment 4.1, alkalinity reduced to 50 mg / L. According to the mass ratio of piperazine dithiocarbamic acid sodium to the molybdenum content in the wastewater 5:1, add 2g of 10% piperazine dithiocarbamic acid sodium solution, stir for 30 min, stand for 10 min, the supernatant test molybdenum content reduced to 0.09 mg / L, molybdenum removal rate reached 99.78%.

[0082] Example 6

[0083] The acid-adjusting granules are the same as in Example 1.

[0084] The fine chemical production wastewater contains COD 38780 mg / L, alkalinity 10000 mg / L; pH 7.8, molybdenum content 40 mg / L. Take 1L water sample, add 30g acid-adjusting granules, stir at room temperature for 30 min, pH adjustment 4.1, alkalinity reduced to 50 mg / L. According to the mass ratio of trisodium trithiocyanate to the molybdenum content in the wastewater 5:1, add 2g of 10% trisodium trithiocyanate solution, stir for 30 min, stand for 10 min, the supernatant test molybdenum content reduced to 0.08 mg / L, molybdenum removal rate reached 99.98%.

[0085] Example 7

[0086] 630g of citric acid, 200g of diatomite and 100g of water are stirred into a slurry, then 50g of talc powder and 20g of gelatin are added, heated to 60-70℃, stirred for 1-3h, cooled to room temperature, granulated to obtain 10mm particle size acid-adjusting granules.

[0087] The battery production high-salt wastewater contains 223 g / L of sodium sulfate, 255 g / L of sodium citrate, high-concentration ferric citrate (300 mg / L of iron), 200 pcU of color, and pH 6.1. The total salt content in the high-salt wastewater is about 30%, and the COD content is about 970,000 mg / L. 1 L of water sample is taken, 20 g of acid-adjusting granules is added, stirring at room temperature for 30 min, the pH is reduced to 4.8, 30 g of 20% dimethyl dithiocarbamic acid sodium solution is added according to the mass ratio of dimethyl dithiocarbamic acid sodium to iron content in the wastewater 20:1, stirring for 30 min, and precipitating for 30 min. The flocculent is settled at the bottom, and the supernatant is tested for iron content of 3 mg / L and color of 5 PCU.

[0088] Example 8

[0089] The acid-adjusting granules have the same proportion as in Example 7.

[0090] The battery production high-salt wastewater contains 223 g / L of sodium sulfate, 255 g / L of sodium citrate, high-concentration ferric citrate (300 mg / L of iron), 200 pcU of color, and pH 6.1. The total salt content in the high-salt wastewater is about 30%, and the COD content is about 970,000 mg / L. 1 L of water sample is taken, 30 g of acid-adjusting granules is added, stirring at room temperature for 30 min, the pH is reduced to 4.3, 60 g of 10% piperazine dithiocarbamic acid sodium solution is added according to the mass ratio of piperazine dithiocarbamic acid sodium to iron content in the wastewater 20:1, stirring for 30 min, and precipitating for 30 min. The flocculent is settled at the bottom, and the supernatant is tested for iron content of 2 mg / L and color of 5 PCU.

[0091] Example 9

[0092] The acid-adjusting granules have the same proportion as in Example 7.

[0093] The battery production high-salt wastewater contains 223 g / L of sodium sulfate, 255 g / L of sodium citrate, high-concentration ferric citrate (300 mg / L of iron), 200 pcU of color, and pH 6.1. The total salt content in the high-salt wastewater is about 30%, and the COD content is about 970,000 mg / L. 1 L of water sample is taken, 50 g of acid-adjusting granules is added, stirring at room temperature for 30 min, the pH is reduced to 3.8, 15 g of 10% piperazine dithiocarbamic acid sodium solution is added according to the mass ratio of piperazine dithiocarbamic acid sodium to iron content in the wastewater 5:1, stirring for 30 min, and precipitating for 30 min. The flocculent is settled at the bottom, and the supernatant is tested for iron content of 1 mg / L and color of 5 PCU.

[0094] Example 10

[0095] The battery production high-salt wastewater contains 223 g / L of sodium sulfate, 255 g / L of sodium citrate, high-concentration ferric citrate (300 mg / L of iron), 200 pcU of color, and pH 6.1. The total salt content of the high-salt wastewater is about 30%, and the COD content is about 970,000 mg / L. 1 L of water sample is taken, liquid is added with acid to reduce the pH to 4.8, 28 g of 10% sodium diethyldithiocarbamate solution is added, stirring is performed for 30 min, and standing is performed for 30 min. The supernatant is tested, and the iron content is 50 mg / L, and the color is 45 PCU.

[0096] Comparative Example 2

[0097] The battery production high-salt wastewater contains 223 g / L of sodium sulfate, 255 g / L of sodium citrate, high-concentration ferric citrate (300 mg / L of iron), 200 pcU of color, and pH 6.1. The total salt content of the high-salt wastewater is about 30%, and the COD content is about 970,000 mg / L. 1 L of water sample is taken, liquid is added with acid to reduce the pH to 4.8, 28 g of 10% sodium diethyldithiocarbamate solution is added, stirring is performed for 30 min, and standing is performed for 30 min. The supernatant is tested, and the iron content is 50 mg / L, and the color is 45 PCU.

[0098] Comparing Example 7-10 with Comparative Example 2 can see that the treatment method of the application has good effect on removing heavy metals and color from the battery production high-salt wastewater. Comparing the heavy metal removal effect of Comparative Example 7 with Example 10 can see that when the acid adjusting granules are used to adjust the acid, the heavy metal removal effect is also better than that of directly adjusting the acid.

[0099] Example 11

[0100] The difference between this example and Example 1 is that under the same working condition, when the molybdenum is reduced from 335 mg / L to 0.8 mg / L by directly adding the medicament sodium diethyldithiocarbamate, 6.3 g of sodium diethyldithiocarbamate needs to be added.

[0101] Comparing Comparative Example 1 with Example 11 can find that the solution adding method needs to add about 2.5 g of medicament, while the direct adding method needs to add 6.3 g of medicament to achieve similar technical effect. It can be seen that the preferred method is to add the medicament in the form of solution.

[0102] The above only describes the preferred embodiments of the application. It should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the application, and these improvements and refinements should also be considered within the protection scope of the application.

Claims

1. A method for treating industrial organic wastewater, characterized by, The application relates to a method for treating industrial organic wastewater. The method comprises the following steps: (1) adding release and buffering acid-regulating particles into industrial organic wastewater, adjusting the pH of the industrial organic wastewater to 3.8-5.5, and stirring to obtain wastewater A; the industrial organic wastewater is one or more of molybdenum-containing chemical wastewater, high-salt wastewater containing iron citrate and / or manganese citrate; the release and buffering acid-regulating particles are prepared from an acid-regulating agent, an adsorbent, a diluent, a binder and a forming agent; (2) adding reagent B into the wastewater A, stirring, and standing to obtain treated industrial organic wastewater; the reagent B is one or more of sodium dimethyl dithiocarbamate, sodium diethyl dithiocarbamate, trisodium trithiocyanate and sodium piperazine dithiocarbamate; the acid-regulating agent is one or more of acetic acid, phosphoric acid, hydroxyacetic acid, nitrilotriacetic acid and citric acid; the adsorbent is one or more of bentonite, diatomite, chitosan and activated carbon; the binder is one or more of starch, gelatin and cellulose; the diluent is one or more of glycerol, water and ethanol; the forming agent is talc; 2. The method of treating industrial organic wastewater according to claim 1, wherein the preparation method of the release and buffering acid-regulating particles comprises the following steps: mixing the acid-regulating agent, the adsorbent and the diluent into slurry according to a proportion, adding the binder and the forming agent, stirring again, and granulating.

3. The method of treating industrial organic wastewater according to claim 2, wherein In step (1), the stirring temperature is 20-50 DEG C.

4. The method for treating industrial organic wastewater according to claim 3, characterized by, In step (1), the mass ratio of the acid-regulating agent to the adsorbent, the diluent, the binder and the forming agent is (0.63-0.83):(0.1-0.2):(0.05-0.1):(0.01-0.02):(0.01-0.05).

5. The method for treating industrial organic wastewater according to claim 2, wherein In step (1), the particle size of the release and buffering acid-regulating particles is 2-10 mm.

6. The method for treating industrial organic wastewater according to claim 1 or 2, characterized by, In step (1), the release and buffering acid-regulating particles are added into the industrial organic wastewater at an amount of 20-50 g / L.

7. The method for treating industrial organic wastewater according to claim 1 or 2, characterized by, In step (2), the reagent B is added into the wastewater A at a mass concentration of 10-20%.

8. The method for treating industrial organic wastewater according to claim 1 or 2, characterized by, In step (2), the stirring time is 20-40 min, the standing time is 10-60 min, and the stirring temperature is 20-50 DEG C.

9. The industrial organic wastewater treatment method according to any one of claims 1 to 5, characterized by, The COD concentration of the industrial organic wastewater is 20000-100000 mg / L; the molybdenum content in the molybdenum-containing chemical wastewater is 100-400 mg / L, and the alkalinity of the molybdenum-containing chemical wastewater is 10000-35000 mg / L; the total content of iron and manganese in the high-salt wastewater containing iron citrate and / or manganese citrate is 50-450 mg / L, and the total salt content in the high-salt wastewater containing iron citrate and / or manganese citrate accounts for 10-35% of the total mass of the wastewater.