A method of wastewater treatment

Abstract

The present application relates to a kind of wastewater treatment methods, comprising the following steps: S1, the impurity insoluble in water in wastewater is filtered;S2, the wastewater after impurity removal obtained in step S1 is carried out primary reverse osmosis treatment in primary reverse osmosis membrane module, and water and first concentrated water are obtained;S3, water is carried out secondary reverse osmosis treatment in secondary reverse osmosis membrane module, and second concentrated water and reuse water are obtained;S4, first concentrated water, second concentrated water and new filtered wastewater are combined into primary reverse osmosis membrane module and carried out osmosis treatment, and third concentrated water and water are obtained;S5, step S3 and S4 are recycled multiple times, and the final concentrated water after being treated by primary reverse osmosis membrane module is obtained.The present application filters the impurity insoluble in water in wastewater by microfiltration machine, primary reverse osmosis membrane module is repeatedly treated multiple times, secondary reverse osmosis membrane module is processed again to the fresh water obtained by disc tube reverse osmosis membrane, to obtain reuse water, and the processing technology method is simple, and processing efficiency is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wastewater treatment, in particular to a wastewater treatment method. BACKGROUND

[0002] Electroplating is a basic industry in industrial production and manufacturing process, and is widely used in industries such as electronics, hardware, machinery and other industries that require surface treatment of products, in order to achieve basic needs such as corrosion resistance, wear resistance, electrical conductivity, decoration, etc. It is an indispensable part of the process of industrial upgrading and structural adjustment. Due to the diversity of products and the difference in performance requirements, the wastewater generated in the electroplating production process generally has characteristics such as a large number of pollutant types, high pollutant concentration, and large water quality fluctuations.

[0003] The wastewater treatment process in the prior art usually includes multiple steps such as sedimentation, filtration, dosing treatment, membrane treatment, etc., and the treatment process is complex and the treatment efficiency is low. SUMMARY

[0004] (I) Technical problems to be solved

[0005] In view of the above shortcomings and deficiencies of the prior art, the present application provides a wastewater treatment method which solves the technical problem of low treatment efficiency due to the complexity of the treatment process in the prior art.

[0006] (II) Technical solutions

[0007] In order to achieve the above purpose, the main technical solution adopted by the present application comprises:

[0008] A wastewater treatment method comprising the following steps:

[0009] S1, filtering impurities in the wastewater that are insoluble in water;

[0010] S2, the wastewater after removing impurities obtained in step S1 enters a first reverse osmosis membrane assembly for first reverse osmosis treatment to obtain product water and first concentrated water;

[0011] S3, the product water enters a second reverse osmosis membrane assembly for second reverse osmosis treatment to obtain second concentrated water and recycled water;

[0012] S4, all concentrated water and new filtered wastewater are combined and enter the first reverse osmosis membrane assembly for osmosis treatment to obtain third concentrated water and product water;

[0013] S5, steps S3 and S4 are repeated multiple times to obtain final concentrated water treated by the first reverse osmosis membrane assembly and recycled water treated by the second reverse osmosis membrane assembly.

[0014] Preferably, in step S1, the wastewater is filtered by a microfiltration machine, and the pore size of the filter core of the microfiltration machine is 10-20 μm.

[0015] Preferably, the primary reverse osmosis membrane assembly in step S2 is a disc tube reverse osmosis membrane assembly, and the secondary reverse osmosis membrane assembly is a brackish water reverse osmosis membrane assembly.

[0016] Preferably, in step S2, 2-20 primary reverse osmosis membrane assemblies are arranged in series, and the membrane pore size of the primary reverse osmosis membrane assembly is 0.0001-0.01 μm, and the pressure of the wastewater entering the primary reverse osmosis membrane assembly is 30-60 bar.

[0017] Preferably, in step S3, the membrane pore size of the secondary reverse osmosis membrane assembly is 0.0001-0.001 μm.

[0018] Preferably, in step S4, the conductivity of the final concentrated water after the primary reverse osmosis membrane assembly is treated for multiple times is 5800-12000 μs / Ω, and the conductivity of the produced water after the primary reverse osmosis membrane assembly is treated is 300-1000 μs / Ω.

[0019] Preferably, in step S5, steps S3 and S4 are repeated for 10-30 times.

[0020] Preferably, the conductivity of the recycled water obtained in steps S3 and S4 is 5-100 μs / Ω.

[0021] Preferably, the recycling rate of the wastewater is 90-99%.

[0022] Preferably, the wastewater treatment method is applied to electroplating wastewater treatment.

[0023] (Three) beneficial effects

[0024] The beneficial effects of the present application are:

[0025] The present application removes most of the impurities in the wastewater through multiple repeated treatments by the primary reverse osmosis membrane assembly, and the produced water obtained by the disc tube reverse osmosis membrane treatment is subjected to desalination treatment again by the secondary reverse osmosis membrane assembly, so that the desalination rate is high, and within the allowable water quality range, recycled water can be continuously produced. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The flow chart of the wastewater treatment method in the present application is shown in the figure;

[0027] Figure 2 The structure schematic diagram of the wastewater treatment system used in the wastewater treatment method in the present application is shown in the figure.

[0028]

Explanation of reference signs

[0029] 4: primary reverse osmosis membrane assembly; 5: secondary reverse osmosis membrane assembly; 12: microfiltration machine. DETAILED DESCRIPTION

[0030] In order to better explain the present application, so as to be understood, the present application is described in detail below by specific embodiments in combination with the drawings.

[0031] The wastewater treatment method can be used for electroplating wastewater treatment, and can also be used for wastewater treatment in the industries of metallurgy, electronics, chemical industry, leather making, printing, power generation, and garbage incineration, etc. In the embodiment, the electroplating wastewater treatment is taken as an example.

[0032] A wastewater treatment method, comprising the following steps:

[0033] S1, filtering water-insoluble impurities in wastewater;

[0034] S2, the wastewater after impurities removal obtained in step S1 enters a primary reverse osmosis membrane assembly 4 for primary reverse osmosis treatment, to obtain product water and first concentrated water;

[0035] S3, the product water enters a secondary reverse osmosis membrane assembly 5 for secondary reverse osmosis treatment, to obtain second concentrated water and reused water;

[0036] S4, all the concentrated water and new filtered wastewater are combined to enter the primary reverse osmosis membrane assembly 4 for osmosis treatment, to obtain third concentrated water and product water. The all the concentrated water refers to the concentrated water obtained after the treatment of the primary reverse osmosis assembly 4 and the secondary reverse osmosis assembly 5, including the first concentrated water, the second concentrated water and the third concentrated water.

[0037] S5, steps S3 and S4 are repeated for multiple times, and the final concentrated water treated by the primary reverse osmosis membrane assembly 4 and the reused water treated by the secondary reverse osmosis membrane assembly 5 are obtained.

[0038] In step S1, the wastewater is filtered by a microfiltration machine 12, and the pore size of the filter core of the microfiltration machine 12 is 10-20 μm.

[0039] Further, in step S2, the primary reverse osmosis membrane assembly 4 is a disc tube reverse osmosis membrane assembly, and the secondary reverse osmosis membrane assembly 5 is a brackish water reverse osmosis membrane assembly.

[0040] Further, in step S2, 2-20 primary reverse osmosis membrane assemblies 4 are arranged in series, the membrane pore size of the primary reverse osmosis membrane assembly 4 is 0.0001-0.01 μm, and the pressure of the wastewater entering the primary reverse osmosis membrane assembly 4 is 30-60 bar.

[0041] In step S3, the membrane pore size of the secondary reverse osmosis membrane assembly 5 is 0.0001-0.001 μm.

[0042] In step S4, the conductivity of the final concentrated water after multiple treatments of the primary reverse osmosis membrane assembly 4 is 5800 μs / Ω-12000 μs / Ω, and the conductivity of the product water after treatment of the primary reverse osmosis membrane assembly 4 is 300 μs / Ω-1000 μs / Ω.

[0043] Further, in step S5, steps S3 and S4 are repeated for 10-30 times.

[0044] Further, the conductivity of the reused water obtained in steps S3 and S4 is 5 μs / Ω-100 μs / Ω.

[0045] Preferably, the reuse rate of the wastewater is 90%-99%, and the reuse rate of the wastewater refers to the ratio of the amount of the wastewater for reuse after treatment to the total amount of the wastewater treated.

[0046] The present application removes most of the impurities in the wastewater through multiple treatments of the primary reverse osmosis membrane assembly, and the secondary reverse osmosis membrane assembly further desalts the product water obtained by the treatment of the disk tube reverse osmosis membrane, so that the desalination rate is high, and the reused water can be continuously produced within the allowable water quality range. In addition, no other reagents are added during the wastewater treatment process, and the amount of impurities in the outlet of the replenished fresh water is small, which does not affect the subsequent use.

[0047] Example 1

[0048] This example is a cyanide silver plating production line in the production of printed circuit boards in the electronic industry, wherein the conductivity of the discharged rinsing water is 30 μs / Ω-40 μs / Ω, the drainage amount is 8 tons per day, and the quality requirement of the reused water is that the conductivity is less than 10 μs / Ω.

[0049] A wastewater treatment method, comprising the following steps:

[0050] S1, filtering the insoluble impurities in the wastewater. The wastewater is filtered by a microfiltration machine, and the pore size of the filter core of the microfiltration machine is 18 μm.

[0051] S2, the wastewater after removal of impurities obtained in step S1 is subjected to primary reverse osmosis treatment by a primary reverse osmosis membrane assembly 4 to obtain product water and first concentrated water.

[0052] The primary reverse osmosis membrane assembly 4 is a disk tube reverse osmosis membrane assembly, the number of the primary reverse osmosis membrane assembly 4 is 4, the membrane pore size of the primary reverse osmosis membrane assembly is 0.005 μm, and the pressure of the wastewater entering the primary reverse osmosis membrane assembly 4 is 43 bar. The secondary reverse osmosis membrane assembly 5 is a brackish water reverse osmosis membrane assembly, and the number of the secondary reverse osmosis membrane assembly 5 is 3. The membrane pore size of the secondary reverse osmosis membrane assembly 5 is 0.007 μm.

[0053] S3, the water production enters the secondary reverse osmosis membrane assembly 5 for secondary reverse osmosis treatment, and second concentrated water and reuse water are obtained, and the conductivity of the reuse water is 5-100 μs / Ω.

[0054] S4, all the concentrated water and the new filtered waste water are combined to enter the primary reverse osmosis membrane assembly 4 for osmosis treatment, and third concentrated water and water production are obtained.

[0055] S5, the steps S3 and S4 are repeated for 25 times, and the final concentrated water treated by the primary reverse osmosis membrane assembly 4 and the reuse water treated by the secondary reverse osmosis membrane assembly 5 are obtained. The conductivity of the reuse water is 5-100 μs / Ω. The conductivity of the final concentrated water treated by the primary reverse osmosis membrane assembly 4 is 5800-12000 μs / Ω, and the conductivity of the water production obtained after the treatment of the primary reverse osmosis membrane assembly 4 is 300-1000 μs / Ω.

[0056] After the treatment of the above steps, the output of the reuse water is 0.6-0.8 tons / hour, the amount of the reuse water obtained per day is 7.9 tons, the amount of the final concentrated water discharged from the waste water treatment device is 0.1 tons, and the reuse rate of the waste water is 98.75%. The reuse rate of the waste water refers to the ratio of the amount of the waste water treated by the waste water treatment method for repeated use to the total amount of the treated waste water. The waste water reuse rate in the embodiment is the ratio of the total amount of the reuse water to the total amount of the treated waste water.

[0057] Embodiment 2

[0058] The embodiment is the production of diamond wire for cutting photovoltaic glass, the diamond sand is adhered to the sand and the flushing wire runs at a high speed, and the liquid concentration amount is large and the concentration is high. The water quality requirement is that the conductivity is below 100 μs / Ω.

[0059] A waste water treatment method, comprising the following steps:

[0060] S1, filtering the insoluble impurities in the waste water. The waste water is filtered by a microfiltration machine 12, and the pore size of the filter core of the microfiltration machine 12 is 18 μm.

[0061] S2, the waste water after the impurities are removed in the step S1 enters the primary reverse osmosis membrane assembly 4 for primary reverse osmosis treatment, and water production and first concentrated water are obtained.

[0062] The primary reverse osmosis membrane assembly 4 is a disc tube reverse osmosis membrane assembly, the number of the primary reverse osmosis membrane assembly 4 is one, the membrane pore size of the primary reverse osmosis membrane assembly 4 is 0.005 μm, and the pressure of the waste water entering the primary reverse osmosis membrane assembly is 43 bar. The secondary reverse osmosis membrane assembly 5 is a brackish water reverse osmosis membrane assembly, the number of the secondary reverse osmosis membrane assembly 5 is two in series, and the membrane pore size of the secondary reverse osmosis membrane assembly 5 is 0.007 μm.

[0063] S3, the water production enters the secondary reverse osmosis membrane assembly 5 to carry out secondary reverse osmosis treatment, and second concentrated water and reuse water are obtained, and the conductivity of the reuse water is 5 μs / Ω~100 μs / Ω.

[0064] S4, all concentrated water and new filtered wastewater are combined to enter the primary reverse osmosis membrane assembly 4 to carry out osmosis treatment, and third concentrated water and water production are obtained.

[0065] S5, 25 times of steps S3 and S4 are carried out, and the final concentrated water treated by the primary reverse osmosis membrane assembly 4 and the reuse water treated by the secondary reverse osmosis membrane assembly 5 are obtained. The conductivity of the reuse water is 5 μs / Ω~100 μs / Ω. The conductivity of the final concentrated water treated by the primary reverse osmosis membrane assembly 4 is 5800 μs / Ω~12000 μs / Ω, and the conductivity of the water production obtained after the treatment of the primary reverse osmosis membrane assembly 4 is 300 μs / Ω~1000 μs / Ω.

[0066] After the treatment of the above steps, the amount of reuse water obtained by a single line per day is 1.9 tons, and the amount of final concentrated water discharged from the wastewater treatment device is 0.1 tons, and the reuse rate of the wastewater is 95%. The wastewater reuse rate in the embodiment is the ratio of the total amount of reuse water to the total amount of treated wastewater.

[0067] Example 3

[0068] In this embodiment, the rinse after passivation of building material aluminum alloy production is carried out, and the chromium content in the drainage is 100 mg / L.

[0069] A wastewater treatment method, comprising the following steps:

[0070] S1, filtering the water-insoluble impurities in the wastewater. The wastewater is filtered by a microfiltration machine 12, and the pore size of the filter core of the microfiltration machine is 18 μm.

[0071] S2, the wastewater obtained after the impurities are removed in step S1 enters the primary reverse osmosis membrane assembly 4 to carry out primary reverse osmosis treatment, and water production and first concentrated water are obtained.

[0072] The primary reverse osmosis membrane assembly 4 is a disc tube reverse osmosis membrane assembly, the number of the primary reverse osmosis membrane assembly 4 is 1, the membrane pore size of the primary reverse osmosis membrane assembly is 0.005 μm, and the pressure of the wastewater entering the primary reverse osmosis membrane assembly 4 is 43 bar. The secondary reverse osmosis membrane assembly 5 is a brackish water reverse osmosis membrane assembly, the secondary reverse osmosis membrane assembly 5 is arranged in series in two, and the membrane pore size of the secondary reverse osmosis membrane assembly 5 is 0.007 μm.

[0073] S4, all concentrated water and new filtered wastewater are combined to enter the primary reverse osmosis membrane assembly 4 to carry out osmosis treatment, and third concentrated water and water production are obtained.

[0074] S5, 25 cycles of steps S3 and S4 are performed, and the final concentrated water treated by the first reverse osmosis membrane assembly 4 and the reclaimed water treated by the second reverse osmosis membrane assembly 5 are obtained. The conductivity of the reclaimed water is 5 μs / Ω-100 μs / Ω. The conductivity of the final concentrated water treated by the first reverse osmosis membrane assembly 4 after 25 times of treatment is 5800 μs / Ω-12000 μs / Ω, and the conductivity of the water produced after treatment by the first reverse osmosis membrane assembly 4 is 300 μs / Ω-1000 μs / Ω.

[0075] After the above treatment, the chromium content in the reclaimed water is less than 1 mg / L, and the chromium content in the final concentrated water is 2000 mg / L. The final concentrated water is directly supplemented to the passivation tank as the supplement of the effluent, so that the "water balance" is achieved, and the final concentrated water can also be reclaimed. The reclamation rate of the waste water is 99%. In this embodiment, the reclaimed water is used to supplement the rinsing tank, and the final concentrated water is used to supplement the passivation tank, and the treated waste water can be recycled, so the reclamation rate of the waste water is 99%.

[0076] Comparative Example 1

[0077] This comparative example is a nickel electroplating production line. The rinsing water drainage contains nickel chloride, and the content of nickel ions is 20-30 mg / L, and the conductivity is 600-750 μs / Ω. The tank-side reclamation equipment only filters the rinsing water by the brackish water reverse osmosis membrane assembly to obtain the reclaimed water. The conductivity of the obtained reclaimed water is 50-80 μs / Ω, and the reclamation rate of the waste water is 40-55%.

[0078] Comparative Example 2

[0079] Different from the embodiment 1, in this comparative example, the pressure of the waste water entering the first reverse osmosis membrane assembly 4 is 25 bar. After treatment, the output of the reclaimed water is 0.3 tons / hour, the amount of the reclaimed water obtained per day is 3.4 tons, and the amount of the final concentrated water discharged from the waste water treatment device is 0.6 tons, and the reclamation rate of the waste water is 85%.

[0080] In the description of the present application, it should be understood that the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can be explicitly or implicitly included one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0081] In the present application, unless specifically defined otherwise, the terms "mounting", "connected", "connection", "fixed", "unfixed", and the like should be construed broadly, for example, can be fixed connection, can be detachable connection, or integral; can be mechanical connection, can be electrical connection; can be direct connection, can be indirect connection through an intermediate medium; can be internal communication of two elements or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0082] In the present application, unless specifically defined otherwise, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Moreover, the first feature is "above", "over" and "on" the second feature, which can be directly above or obliquely above the first feature, or only indicates that the first feature is higher than the second feature in horizontal height. The first feature is "below", "under" and "under" the second feature, which can be directly below or obliquely below the first feature, or only indicates that the first feature is lower than the second feature in horizontal height.

[0083] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or examples described in the present application and the features of the different embodiments or examples without contradiction.

[0084] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can modify, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A wastewater treatment method applied to electroplating wastewater treatment, characterized in that, Includes the following steps: S1. Filter impurities in the wastewater that are insoluble in water by filtering the wastewater through a microfilter (12), wherein the filter element of the microfilter (12) has a pore size of 10μm~20μm; S2. The wastewater obtained after removing impurities in step S1 enters the first-stage reverse osmosis membrane module (4) for first-stage reverse osmosis treatment to obtain permeate and first concentrate; 2 to 20 first-stage reverse osmosis membrane modules (4) are arranged in series, and the membrane pore size of the first-stage reverse osmosis membrane module (4) is 0.0001μm to 0.01μm. S3. The permeate enters the secondary reverse osmosis membrane module (5) for secondary reverse osmosis treatment to obtain the second concentrate and reclaimed water. The membrane pore size of the secondary reverse osmosis membrane module (5) is 0.0001μm~0.001μm. S4. All concentrated water and newly filtered wastewater are combined and fed into the first-stage reverse osmosis membrane module (4) for permeation treatment to obtain third concentrated water and permeate. S5, repeat steps S3 and S4 multiple times to obtain the final concentrate after treatment by the primary reverse osmosis membrane module (4) and the recycled water after treatment by the secondary reverse osmosis membrane module (5); In step S2, the primary reverse osmosis membrane module (4) is a disc tube reverse osmosis membrane module, and the secondary reverse osmosis membrane module (5) is a brackish water reverse osmosis membrane module. The pressure of wastewater entering the first-stage reverse osmosis membrane module (4) is 30 bar to 60 bar.

2. The wastewater treatment method as described in claim 1, characterized in that, In step S4, the conductivity of the final concentrate after multiple treatments by the first-stage reverse osmosis membrane module (4) is 5800μs / Ω~12000μs / Ω, and the conductivity of the permeate obtained after treatment by the first-stage reverse osmosis membrane module (4) is 300μs / Ω~1000μs / Ω.

3. The wastewater treatment method as described in claim 1, characterized in that, In step S5, steps S3 and S4 are repeated 10 to 30 times.

4. The wastewater treatment method as described in claim 1, characterized in that, The conductivity of the recycled water obtained in steps S3 and S4 is 5 μs / Ω to 100 μs / Ω.

5. The wastewater treatment method as described in claim 1, characterized in that, The wastewater reuse rate is 90%~99%.

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