A method for resourceful treatment of water-based cutting waste liquid and products and applications thereof

Abstract

The present application relates to a kind of water-based cutting waste liquid resource processing method and its product and application.The resource processing method in the present application includes the following steps: (1) water-based cutting waste liquid is treated by acid separation and then stands still;(2) the lower layer treatment liquid obtained by standing still in (1) is reacted under the action of Fenton reagent, stands still, filters;(3) after the filtrate obtained by filtering in (2) is mixed with nitrogen source and phosphorus source to obtain a mixed solution, hydrolytic acidification treatment is carried out, and a composite carbon source is obtained.The resource processing method in the present application makes the harmful water-based cutting waste liquid with high toxicity, high COD Cr , poor biodegradability into a composite carbon source, with high COD removal efficiency, which can be used as a carbon source for denitrification treatment of nitrate wastewater while effectively treating waste, reducing environmental pollution and achieving resource recycling.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of wastewater treatment, and particularly relates to a resourceful treatment method of water-based cutting waste liquid and a product and application thereof. BACKGROUND

[0002] Cutting fluid is used for lubrication, cooling, cleaning of processing tools and parts in the machining process, and improves product quality and reduces tool wear. Cutting fluid is a lubricant mixed with various additives, and is divided into oil-based cutting fluid focusing on lubrication and water-based cutting fluid focusing on cooling according to processing requirements. The properties of water-based cutting fluid vary with different formulations, and the water-based cutting fluid contains a large amount of mineral oil and difficult-to-degrade high molecular organic matter, and has stable chemical properties. However, the oil-water separation of water-based cutting fluid waste liquid is difficult, the toxicity is high, the COD content is high, can reach more than 10000 mg / L, the biodegradability is poor, the treatment is difficult, the water ecological environment is seriously damaged, and long-term accumulation can easily cause cancer and other diseases, which seriously threatens human life safety. Cr

[0003] At present, the treatment methods of cutting fluid waste liquid can be divided into physical method, chemical method and biological method. The physical method such as adsorption method uses the porous and large specific surface area characteristics of adsorbent to physically and chemically adsorb the oil and organic matter in the cutting fluid, but the adsorption capacity is limited, and the recovery cost of used adsorbent is high, which forms secondary pollution. The chemical method such as electrochemical method can purify pollutants in cutting fluid waste liquid by applying current to the cutting fluid waste liquid to produce physical and chemical reactions, but the power consumption is too large, the cost is high, and there is a certain risk. The biological method such as activated sludge method uses the process of metabolizing organic matter into inorganic salts by microorganisms, but the cutting fluid waste liquid is highly toxic and has high COD content, which seriously threatens the survival of microorganisms and affects the treatment efficiency. Cr SUMMARY

[0004] Based on the problems existing in the prior art, an object of the present application is to provide a resourceful treatment method of water-based cutting waste liquid. The resourceful treatment method successfully harmless treats the water-based cutting waste liquid, obtains a resource product of composite carbon source, and reduces the COD in the composite carbon source, which can be further used in a denitrification system to cooperatively treat nitrate wastewater.

[0005] To achieve the above object, the technical scheme adopted by the present application is as follows:

[0006] A resourceful treatment method of water-based cutting waste liquid, comprising the following steps:

[0007] (1) allowing the water-based cutting waste liquid to be subjected to acid precipitation treatment and then standing;

[0008] ​​(2) reacting the lower treatment liquid obtained by standing in (1) under the action of Fenton reagent, standing, filtering;

[0009] (3) after mixing the filtrate obtained by filtering in (2) with nitrogen source and phosphorus source, hydrolytic acidification treatment is performed to obtain a resource product.

[0010] In step (1)

[0011] Preferably, the acid precipitation treatment comprises a step of controlling the water-based cutting waste liquid to be acidic by using one or more of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and oxalic acid.

[0012] Preferably, the acid precipitation treatment is performed when the pH of the water-based cutting waste liquid is controlled to be 1.0-6.0; preferably 1.0-3.0; further preferably 1.5-2.5.

[0013] According to a specific and preferred embodiment, the standing is performed in a separatory funnel, which facilitates the collection of the lower treatment liquid and the next step of treatment.

[0014] Further, the standing time is 6h or more, which can be 6h, 10h, 14h, 18h, 24h, 28h, 32h, 36h, 40h, 44h, 48h, 72h, or can be further prolonged according to the layering situation.

[0015] Further, the mixture after the acid precipitation treatment can be left to stand overnight.

[0016] In step (2)

[0017] Preferably, the specific operation of step (2) is as follows: after controlling the pH of the lower treatment liquid obtained by standing in (1) to be 2.5-4.0, Fenton reagent is added for stirring and reaction, and then the pH of the system is controlled to be 4.0-8.0, and after standing and precipitation, filtering is performed.

[0018] Preferably, the Fenton reagent comprises hydrogen peroxide and an iron salt containing Fe 2+ .

[0019] Further, the iron salt containing Fe 2+ is one or more of ferrous sulfate heptahydrate (FeSO4·7H2O), ferrous sulfate (FeSO4), and ferrous chloride (FeCl2).

[0020] According to some embodiments, the volume of hydrogen peroxide added accounts for 0.5-3% of the volume of the water-based cutting waste liquid in (1); preferably 0.5-2%; further preferably 0.5-1%.

[0021] Preferably, the content of H2O2 in the hydrogen peroxide is 20-30wt%; preferably 25-30wt%.

[0022] According to some embodiments, the Fe in the iron salt is 2+ The molar ratio of the Fe in the iron salt to the H2O2 in the hydrogen peroxide is 1:(4-16).

[0023] Further, the Fe in the iron salt is 2+ The molar ratio of the Fe in the iron salt to the H2O2 in the hydrogen peroxide is 1:(4-12), for example 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12.

[0024] Still further, the Fe in the iron salt is 2+ The molar ratio of the Fe in the iron salt to the H2O2 in the hydrogen peroxide is 1:(4-8).

[0025] Preferably, the substance for controlling the pH of the obtained lower layer treatment liquid and the system is an inorganic alkali salt, which can be selected from sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, sodium acetate, etc.

[0026] Preferably, the reaction is carried out under stirring, which promotes the full progress of the Fenton reaction and improves the reaction efficiency.

[0027] According to some embodiments, the reaction is carried out under stirring on a magnetic stirrer.

[0028] Preferably, the stirring speed of the stirring is 200-350 rpm, and the reaction time is 30 min-90 min.

[0029] Further, the stirring speed of the stirring is 200-300 rpm, and the reaction time is 30 min-80 min.

[0030] Further, after the addition of the Fenton reagent and the reaction, the pH of the system needs to be controlled to be 6.0-8.0; further preferably 6.0-7.5.

[0031] In step (3)

[0032] Preferably, the COD in the obtained filtrate after the (2) filtration is Cr The mass ratio of the nitrogen source to the phosphorus source is (100-600):(4-6):1.

[0033] Further, the COD in the obtained filtrate after the (2) filtration is CrThe mass ratio of the nitrogen source to the phosphorus source is (150-550) : (4-5) : 1, for example, 150:4:1, 200:4:1, 250:4:1, 300:4:1, 350:4:1, 400:4:1, 450:4:1, 500:4:1, 550:4:1, 150:4.5:1, 200:4.5:1, 250:4.5:1, 300:4.5:1, 350:4.5:1, 400:4.5:1, 450:4.5:1, 500:4.5:1, 550:4.5:1, 150:5:1, 200:5:1, 250:5:1, 300:5:1, 350:5:1, 400:5:1, 450:5:1, 500:5:1, 550:5:1.

[0034] Further, the COD in the filtrate obtained by the filtration in (2) is controlled to be (0.5-1.5) g / L. Cr The mass ratio of the nitrogen source to the phosphorus source is (200-500) : (4.5-5) : 1.

[0035] It is to be noted that the COD in the filtrate obtained by the filtration in (2) is controlled to be (0.5-1.5) g / L. Cr The mass of the carbon source in the filtrate is equivalent to the mass of the carbon source in the filtrate, and thus the COD in the filtrate obtained by the filtration in (2) can be used to add the nitrogen source and the phosphorus source according to a certain feeding ratio. Cr The mass of the carbon source in the filtrate is equivalent to the mass of the carbon source in the filtrate, and thus the COD in the filtrate obtained by the filtration in (2) can be used to add the nitrogen source and the phosphorus source according to a certain feeding ratio.

[0036] Preferably, the nitrogen source is selected from one or more of ammonium chloride, urea, ammonium sulfate, ammonium nitrate, and ammonium carbonate; preferably one or both of ammonium chloride and ammonium sulfate.

[0037] Preferably, the phosphorus source is selected from one or more of potassium dihydrogen phosphate, sodium dihydrogen phosphate, ammonium monohydrogen phosphate, and potassium phosphate; preferably one or more of potassium dihydrogen phosphate and sodium dihydrogen phosphate.

[0038] Preferably, the pH of the mixed solution is controlled to be 6-8 before the hydrolytic acidification treatment; preferably 7-8; further preferably 7-7.5.

[0039] Further, after the pH of the mixed solution is controlled to be 6-8, an alkaline salt having a buffering effect is added to provide alkalinity, so that the mixed solution is maintained within a certain pH value range during the later hydrolytic acidification process.

[0040] Further, the alkaline salt having a buffering effect can be exemplified by sodium bicarbonate, potassium bicarbonate, sodium carbonate, potassium carbonate, sodium dihydrogen phosphate, sodium hydrogen phosphate, and sodium acetate.

[0041] According to some embodiments, the mass concentration of the auxiliary agent in the system is 0.5-1.5 g / L; preferably 0.8-1.2 g / L.

[0042] Preferably, the TDS of the mixed liquor is controlled to be less than 15 g / L before the hydrolysis-acidification treatment.

[0043] Further, the TDS of the mixed liquor is controlled to be less than 14 g / L, such as 13.5 g / L, 13 g / L, 12.5 g / L, 12 g / L, 11.5 g / L, 11 g / L, 10.5 g / L, 10 g / L, etc.

[0044] Preferably, the hydrolysis-acidification treatment is performed in an anaerobic hydrolysis-acidification system, which employs anaerobic granular sludge.

[0045] Further, in the anaerobic hydrolysis-acidification system, the reactor stirring speed is 25 rpm to 120 rpm, the hydraulic retention time HRT is 18 h to 4 d, and the reaction temperature is 25 to 55℃.

[0046] Still further, in the anaerobic hydrolysis-acidification system, the reactor stirring speed is 25 rpm to 105 rpm (such as 25 rpm, 35 rpm, 45 rpm, 55 rpm, 65 rpm, 75 rpm, 85 rpm, 95 rpm, 105 rpm), the hydraulic retention time HRT is 1 d to 3.5 d (such as 1 d, 1.5 d, 2 d, 2.5 d, 3 d, 3.5 d), and the reaction temperature is 25 to 40℃ (25℃, 30℃, 35℃, 40℃).

[0047] In further, in the anaerobic hydrolysis-acidification system, the reactor stirring speed is 29 rpm to 100 rpm, the hydraulic retention time HRT is 1.5 d to 3 d, and the reaction temperature is 25 to 35℃.

[0048] A second object of the present application is to provide a composite carbon source obtained after the above-mentioned resourceful treatment of water-based cutting waste liquid.

[0049] A third object of the present application is to provide a treatment method of nitrate-containing wastewater, in which the above-mentioned composite carbon source is mixed with the nitrate-containing wastewater to obtain a second mixed liquor, and a denitrification system is used for denitrification treatment.

[0050] Preferably, the COD:NO3- content in the second mixed liquor is controlled to be greater than or equal to 3 before entering the denitrification system; further preferably, the COD:NO3- content in the second mixed liquor is greater than or equal to 4; still further preferably, the COD:NO3- content in the second mixed liquor is greater than or equal to 5. Cr : NO3 - Cr : NO3 - Cr : NO3 - : NO3 Cr : NO3​​- content is ≤10, further preferably ≤8.

[0051] Preferably, the pH of the second mixed solution is adjusted to 4.5-8 before entering the denitrification system; further preferably, the pH of the second mixed solution is 5.5-8; more preferably, the pH of the second mixed solution is 6.5-7.5.

[0052] Preferably, the salinity of the second mixed solution is adjusted to 2.0-6.0% before entering the denitrification system; further preferably, the salinity of the second mixed solution is 2.5-5.5%; more preferably, the salinity of the second mixed solution is 3.0-5.0%.

[0053] According to some preferred embodiments, the second mixed solution further comprises a supplemental carbon source, and the replacement rate of the composite carbon source is 50-90%; preferably, 50-85%; further preferably, 50-80%.

[0054] The replacement rate of the composite carbon source in the present application refers to the replacement rate of COD Cr in the composite carbon source to the total COD Cr in the second mixed solution. For example, if the replacement rate of the composite carbon source is 50%, it means that 50% of the total COD Cr in the second mixed solution is derived from the composite carbon source, and the remaining 50% is supplemented by the COD Cr in the supplemental carbon source.

[0055] Further, the supplemental carbon source is a carbon-containing organic matter, which can be selected from acetic acid, formic acid, methanol, ethanol, sodium acetate, glucose, etc.

[0056] Preferably, the denitrification system is an upflow anaerobic reactor with internal circulation.

[0057] Further, the denitrification system uses anoxic sludge in the biochemical treatment stage of municipal wastewater.

[0058] Further, in the denitrification system, the hydraulic retention time HRT is 14-24 h, the internal circulation ratio is 100-300%, and the reaction temperature is 20-40℃.

[0059] More further, in the denitrification system, the hydraulic retention time HRT is 18-23 h, the internal circulation ratio is 150-250%, and the reaction temperature is 25-40℃.

[0060] Due to the use of the above technical solution, the present application has the following advantages compared with the prior art:

[0061] (1) The water-based cutting waste liquid in the application is acidified, and the lower treatment liquid obtained by standing is subjected to Fenton oxidation reaction, and finally hydrolytic acidification reaction is carried out with nitrogen source and phosphorus source, so that the harmful water-based cutting waste liquid with high toxicity, COD Cr high, and poor biodegradability is recycled as a composite carbon source, which can be used as a carbon source for nitrate treatment by denitrification, saves or even completely replaces the addition of carbon source, reduces the treatment cost of cutting waste liquid, and also saves the carbon source cost required for biological denitrification treatment of nitrate waste liquid.

[0062] (2) The resource recycling treatment method in the application has no secondary pollution, low cost, environmental friendliness, high removal efficiency, reduces environmental pollution, and realizes resource recycling, successfully implementing the new concept of "waste treatment with waste, turning waste into treasure". BRIEF DESCRIPTION OF DRAWINGS

[0063] Figure 1 The flow chart of the resource recycling treatment method of water-based cutting waste liquid and the treatment of nitrate wastewater DETAILED DESCRIPTION

[0064] All features disclosed in the present application, or steps in all disclosed methods or processes, can be combined in any manner, except for mutually exclusive features or steps.

[0065] In view of the deficiencies in the prior art, the present inventors have obtained the technical solution of the present application through long-term research and a large number of practices. The technical solution, its implementation process and principles will be further explained as follows.

[0066] With the rapid development of urbanization, industrial production activities have gradually increased, generating a large amount of wastewater containing nitrate, which seriously threatens the ecological environment and human health. The most economical and environmentally friendly treatment method for nitrate wastewater is biological denitrification treatment, which converts nitrate into nitrogen without secondary pollution, but often requires additional carbon source, resulting in increased treatment cost, and the treatment effect of different carbon sources also has a big difference.

[0067] The application can effectively reduce the COD value and toxicity of the water-based cutting waste liquid by acid precipitation treatment, Fenton oxidation treatment and hydrolysis acidification reaction treatment, realizes harmless treatment, and the obtained resource product is a composite carbon source, which can be used to save or even replace the addition of carbon source in the denitrification system. First, the acid precipitation treatment is carried out on the water-based cutting waste liquid, so as to separate the oil substances in the water-based cutting waste liquid from the water phase, then the lower layer of the obtained treatment liquid is subjected to oxidation treatment in the presence of Fenton reagent, so as to promote the rapid decomposition of a large number of free radicals with oxidation performance in the Fenton reagent to the organic matters in the treatment liquid, finally, the filtrate obtained after decomposition and filtration is mixed with a nitrogen source and a phosphorus source and subjected to hydrolysis acidification treatment, so as to further convert the existing macromolecular organic matters into small molecular carbon-containing substances, and form a composite carbon source rich in elements, which is helpful to use it in the denitrification system to cooperatively treat nitrate wastewater.

[0068] Further, in the application, the pH of the water-based cutting waste liquid is controlled to be 1.0-3.0 for acid precipitation treatment, so as to realize the demulsification treatment of the water-based cutting waste liquid, improve the removal rate of COD in the system, and easily realize the oil-water separation in the cutting waste liquid after standing, so that the upper layer obtains unusable oil, and the lower layer treatment liquid contains more macromolecular organic matters, and the upper layer treatment liquid will not enter the lower layer treatment liquid, so as to facilitate centralized collection and treatment.

[0069] Further, the pH of the lower layer treatment liquid obtained by standing is controlled to be 2.5-4.0, then the Fenton reagent is added and stirred for reaction, the Fe 2+ In an acidic environment, hydrogen peroxide generates ·OH free radicals, which can degrade organic matters, and then can remove most of the organic matters in the system. If the pH of the solution is too high, Fe 2+ will lose catalytic activity to form iron hydroxide precipitate, and if the pH of the solution is too low, the Fe 3+ oxidized will not be reduced to Fe 2+ smoothly.

[0070] Further, by controlling the mass ratio of the filtrate, the nitrogen source and the phosphorus source obtained in (2) to be (200-500):5:1, the reaction is carried out in an anaerobic hydrolysis acidification system, so as to obtain a composite carbon source rich in elements, meet the common reproduction of various microorganisms, and avoid the microbial domestication caused by a single carbon source, which in turn affects the decarburization reaction in the denitrification process, and using it as a carbon source can promote the denitrification reaction.

[0071] The composite carbon source obtained in this invention has high treatment efficiency, good denitrification effect, and no nitrite accumulation effect when used for synergistic treatment of nitrate wastewater. It realizes the development of a new technology of "treating waste with waste and turning waste into treasure", reduces treatment costs, has strong practicality, and can be used as a treatment method for high-salt and high-concentration nitrate wastewater.

[0072] The present invention will be further described below with reference to embodiments. However, the present invention is not limited to the following embodiments. The implementation conditions used in the embodiments can be further adjusted according to different requirements of specific applications, and the implementation conditions not specified are conventional conditions in the industry. The technical features involved in the various embodiments of the present invention can be combined with each other as long as they do not conflict with each other.

[0073] Unless otherwise specified, the experimental methods used in the following examples are conventional methods; and the experimental materials used, unless otherwise specified, were purchased from conventional biochemical reagent manufacturers.

[0074] The experimental methods in the following examples use water-based cutting waste fluid generated after using 10% water-based cutting fluid TM-3.

[0075] Example 1

[0076] This embodiment provides an application of the resource-based product prepared by a method for the resource recovery of water-based cutting waste fluid in the treatment of nitrate wastewater. Water-based cutting waste fluid (waste fluid generated after using 10% water-based cutting fluid TM-3) and high-concentration nitrate wastewater from electroless nickel plating are used as research objects. Figure 1 As shown: Includes the following steps:

[0077] (1) Adjust the pH of the water-based cutting waste liquid to about 2.0 with sulfuric acid, perform acid precipitation treatment, let it stand overnight in a separatory funnel, and take the lower layer of treated liquid.

[0078] (2) Take the waste liquid after treatment in step (1), adjust the pH to about 3.0 with 1M sodium hydroxide, add Fenton's reagent, and the dosage of Fenton's reagent is 0.5% of the volume ratio of hydrogen peroxide (H2O2) to waste liquid, Fe 2+ The mixture was stirred with H2O2 at a molar ratio of 1:4 for 60 minutes on a magnetic stirrer (220 rpm), then the pH was adjusted to 6.0, and the mixture was allowed to settle and then filtered.

[0079] (3) The filtrate prepared in step (2) is mixed with ammonium chloride and dipotassium hydrogen phosphate in a ratio of 200:5:1, and the pH of the mixture is adjusted to 7.0 with 1M sodium hydroxide. Sodium bicarbonate is added to provide alkalinity at a content of 1g / L, and the salinity TDS is 13g / L. The mixture is put into an anaerobic hydrolysis acidification system (anaerobic granular sludge is used) for hydrolysis acidification treatment, wherein the stirring reactor speed is 100rpm, the hydraulic retention time is 3d, and the reaction temperature is 30°C;

[0080] (4) The composite carbon source obtained by resource utilization in step (3) is mixed with the nitrate waste liquid, and the COD Cr : NO3 - of the mixture is 6, the pH is 7.0, and the salinity is 3.0%. The composite carbon source has a replacement rate of 50%, and the remaining part is supplemented with acetic acid as a carbon source. The mixture is put into a denitrification treatment system, and the denitrification system uses anoxic sludge in the biochemical treatment stage of municipal wastewater. The hydraulic retention time is 23h, the internal circulation ratio is 200%, and the temperature is 35°C. Denitrification treatment is performed.

[0081] Water samples are taken at each stage for detection and analysis, and the detection results are shown in Table 1.

[0082] The COD Cr is determined according to the national standard GB11914-89 "Determination of Chemical Oxygen Demand - Dichromate Method";

[0083] The NO3-N (NO3 - ) content is detected according to the national standard SL 84-1994 "Determination of Nitrate Nitrogen (UV Spectrophotometry)".

[0084] Table 1 shows the water quality detection results at each stage in Example 1

[0085] COD Cr (mg / L) NO3-N (mg / L) pH TM-3 10% water-based cutting waste liquid 150000 -- 11 Acid precipitation water 25000 -- 2.0 Fenton effluent water 23200 -- 6.0 Hydrolytic acidification influent water 18000 -- 7.0 Hydrolytic acidification effluent water 17250 -- 6.2 Denitrification system influent water 11000 1800 7.0 Denitrification system effluent water 3960 5.48 9.3

[0086] The results in Table 1 show that the composite carbon source prepared by acid precipitation-Fenton-hydrolysis acidification resource utilization of the water-based cutting waste liquid effectively replaces the use of conventional carbon sources, and the nitrate removal rate is high, which can reach 99.7%.

[0087] Example 2

[0088] Example 2 is basically the same as Example 1, except that:

[0089] In step (2), the Fenton reagent is added in a volume ratio of 0.5% of hydrogen peroxide (H2O2) to the waste liquid, and the molar ratio of Fe 2+ to H2O2 is 1:8. After stirring on a magnetic stirrer, the pH is adjusted to 7.5, and the precipitate is filtered after standing;

[0090] Step (3) The ammonium chloride and dipotassium hydrogen phosphate were mixed according to the C:N:P ratio of 500:5:1, and the pH of the mixed solution was adjusted to 7.5, and the salinity TDS was 11 g / L. The hydrolysis acidification treatment was carried out in an anaerobic hydrolysis acidification system, and the composite carbon source was prepared, wherein the stirring reactor speed was 29 rpm, and the hydraulic retention time was 2 d.

[0091] Step (4) The COD of the mixed solution Cr : NO3 - was 5, the pH was 6.7, the salinity was 5.0%, and the composite carbon source replacement rate was 80%.

[0092] The water samples at each stage were taken for detection and analysis, and the detection results are shown in Table 2.

[0093] Table 2 Water quality detection results at each stage in Example 2

[0094]

[0095]

[0096] Compared with Example 1, the amount of reagents used in Example 2 was reduced, but the nitrate load of the denitrification system and the salinity increased significantly, and the composite carbon source replacement rate was further improved. The nitrate nitrogen removal rate of the denitrification system effluent can still be 99.7%, which further illustrates that the method can be used as a treatment method for high-salinity and high-concentration nitrate wastewater.

[0097] Example 3

[0098] The same as Example 1, except that:

[0099] Step (2) The Fenton reagent dosing amount was as follows: the volume ratio of hydrogen peroxide (H2O2) to waste liquid was 2%, and the molar ratio of Fe 2+ to H2O2 was 1:2.

[0100] The water samples at each stage were taken for detection and analysis, and the detection results are shown in Table 3.

[0101] Table 3 Water quality detection results at each stage in Example 3

[0102] COD Cr (mg / L) NO3-N (mg / L) pH TM-3 10% water-based cutting waste liquid 150000 -- 11 Acid precipitation water 24560 -- 2.0 Fenton effluent water 22510 -- 6.5 Hydrolytic acidification influent water 20920 -- 7.2 Hydrolytic acidification effluent water 20500 -- 7.6 Denitrification system influent water 6000 1000 7.0 Denitrification system effluent water 5200 890 7.8

[0103] Compared with Examples 1 and 2, the amount of reagents used in Example 3 was high, but the removal rate of nitrate nitrogen was not high, only 11%, under the condition of reducing the nitrate load, which indicates that the resource product prepared under this operating condition cannot be used as a substitute carbon source.

Claims

1. A method for the resource-based treatment of water-based cutting waste fluid, characterized in that: Includes the following steps: (1) Allow the water-based cutting waste fluid to stand after acid precipitation treatment; (2) Allow the lower layer of the treatment liquid obtained by (1) to stand to react under the action of Fenton's reagent, stand, and filter; (3) After mixing the filtrate obtained from (2) with nitrogen and phosphorus sources to obtain a mixed solution, perform hydrolysis and acidification treatment to obtain a composite carbon source. In step (3), the COD in the filtrate obtained from filtration in step (2) is... Cr The mass ratio of nitrogen source to phosphorus source is (100-600):(4-6):1; the nitrogen source is selected from one or more of ammonium chloride, urea, ammonium sulfate, ammonium nitrate, and ammonium carbonate; the phosphorus source is selected from one or more of potassium dihydrogen phosphate, sodium dihydrogen phosphate, and potassium phosphate. The total dissolved solids (TDS) of the mixture is controlled to be below 15 g / L, and the pH of the mixture is controlled to be 6-8 before hydrolysis and acidification treatment is carried out in an anaerobic hydrolysis and acidification system. The anaerobic hydrolysis and acidification system uses anaerobic granular sludge, the reactor stirring speed is 25 rpm-120 rpm, the hydraulic retention time (HRT) is 18 h-4 d, and the reaction temperature is 25-55 °C.

2. The method for resource-based treatment of water-based cutting waste fluid according to claim 1, characterized in that: In step (2), the Fenton reagent includes hydrogen peroxide and a solution containing Fe. 2+ Iron salts; The volume of hydrogen peroxide added accounts for 0.5 to 3% of the volume of water-based cutting waste liquid in (1); Fe in the iron salt 2+ The molar ratio of H2O2 in hydrogen peroxide to H2O2 in hydrogen peroxide is 1:(4~16); The hydrogen peroxide contains 20-30 wt% H2O2; The containing Fe 2+ The iron salt is selected from one or more of ferrous sulfate heptahydrate, ferrous sulfate, and ferrous chloride.

3. The method for resource-based treatment of water-based cutting waste fluid according to claim 1, characterized in that: The specific operation of step (2) is as follows: control the pH of the lower layer of the treatment liquid obtained by standing (1) to 2.5 to 4.0, add Fenton's reagent and stir to react, then control the pH of the system to 4.0 to 8.0, let it stand to precipitate and then filter.

4. The method for resource recovery treatment of water-based cutting waste fluid according to claim 3, characterized in that: In step (2), the reaction is carried out under stirring, and the stirring speed is 200-350 rpm; and / or, the reaction time is 30 min-90 min.

5. The method for resource recovery treatment of water-based cutting waste fluid according to claim 1, characterized in that: In step (1), the acid precipitation treatment includes a step of controlling the water-based cutting waste fluid to be acidic by using one or more of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and oxalic acid. And / or, the pH of the water-based cutting waste fluid undergoing acid precipitation treatment is controlled to be 1.0 to 6.0; and / or, the settling time is 6 hours or more.

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