Composite Nano Liquid Caustic and Its Preparation Method and Wastewater Treatment Method for Printed Circuit Board Production

Abstract

The present invention discloses a composite nano liquid caustic soda, its preparation method and a method for treating wastewater from printed circuit board production, which relates to the technical field of treating wastewater from printed circuit board production. The composite nano liquid caustic soda of the present invention includes inorganic substances, organic substances, nano materials, wetting agents, flocculants, accelerators and dispersants. This composite nano liquid caustic soda can effectively adsorb and decompose organic substances and heavy metal ions in water, achieving the purpose of rapidly removing heavy metals, organic substances, ammonia nitrogen and other substances in the wastewater.

Description

Technical Field

[0001] The present invention relates to the technical field of wastewater treatment for printed circuit board production, and particularly to a composite nano liquid caustic soda, a preparation method thereof, and a method for treating wastewater in printed circuit board production. Background Art

[0002] The wastewater discharged from printed circuit board (PCB) manufacturing enterprises contains heavy metals, acids, ammonia nitrogen, ink and other high-COD substances, which are difficult to treat. With the progress of PCB manufacturing technology and environmental protection treatment technology, treating PCB production wastewater with nano liquid caustic soda can reduce the difficulty of wastewater treatment, lower the cost of wastewater treatment, and can recycle the relatively clean rinsing water in the process by reverse osmosis, and the recycling rate can reach 60 - 80%.

[0003] Traditional liquid caustic soda has high corrosivity and / or volatility in wastewater treatment, which is likely to cause harm to the environment and human health. The composite nano liquid caustic soda combines nanotechnology with liquid caustic soda, has a high surface area and pore structure, which makes it have better activity and selectivity in the fields of adsorption and catalysis. At the same time, the relatively low basicity of the composite nano liquid caustic soda enables it to achieve milder conditions in catalytic reactions compared with traditional solid base catalysts, thus helping to improve reaction selectivity and reduce the occurrence of side reactions. In addition, the composite nano liquid caustic soda has good solubility and interfacial activity, which enables it to better interact with reactants or target substances in wastewater during catalytic and adsorption processes, improving reaction efficiency and material conversion rate. Moreover, the composite nano liquid caustic soda also has better stability and reusability, and can maintain high catalytic activity and adsorption capacity during multiple cycles of use, so that it has a wider application ability and lower environmental risk. Therefore, as a new type of nanomaterial, the composite nano liquid caustic soda has low environmental risk and broad application prospects. Summary of the Invention

[0004] The present invention provides a composite nano liquid caustic soda for treating wastewater generated in the process of printed circuit board production. Instead of traditional liquid caustic soda, it can quickly achieve acid-base neutralization, improve the efficiency of sewage treatment, activate and modify the nano particles to capture metals, has high controllability, low volatility and corrosivity. At the same time, it is environmentally friendly, does not contain harmful chemical substances, not only maintains the alkalinity and solubility of traditional liquid caustic soda, but also improves the stability of liquid caustic soda, can quickly remove heavy metals, organic substances, ammonia nitrogen and other substances in wastewater, while reducing costs by 20 - 40% and saving more than 40% of the wastewater treatment time, and is simple and convenient to operate. Specifically, it includes the following technical solutions.

[0005] On the one hand, a composite nano liquid caustic soda is provided, including the following components in mass concentration:

[0006] Inorganic substances: 3 - 20 g / L,

[0007] Organic substances: 0.5 - 3 g / L,

[0008] Nanomaterials: 0.2 - 3 g / L,

[0009] Wetting agents: 0.5 - 3 g / L,

[0010] Flocculants: 0.2 - 2 g / L,

[0011] Accelerators: 2 - 10 g / L,

[0012] Dispersants: 0.1 - 1 g / L,

[0013] The mass concentration ratio of the accelerator and the dispersant is 1:(0.02 - 0.3);

[0014] The inorganic substances are selected from at least one of sodium hydroxide, potassium hydroxide, cesium hydroxide, and rubidium hydroxide;

[0015] The organic substances are selected from at least one of butyllithium, lithium diisopropylamide, benzyllithium, and sodium tert - butoxide;

[0016] The nanomaterials are selected from at least one of nanoscale zinc chloride, silver chloride, and zinc oxide;

[0017] The wetting agents are selected from at least one of polyvinyl alcohol, sodium methylene bisnaphthalenesulfonate, and sodium cetylsulfonate;

[0018] The flocculants are selected from at least one of polyaluminum chloride, polyferric sulfate, polyacrylamide, and sodium metaaluminate;

[0019] The accelerators are selected from at least one of potassium manganate, sodium manganate, and sodium ammonium manganate;

[0020] The dispersants are selected from at least one of allylsulfonic acid sodium salt, propargylsulfonic acid sodium salt, and sodium dodecylbenzenesulfonate.

[0021] Preferably, the mass concentration ratio of the inorganic substances and the organic substances is 1:(0.02 - 0.2).

[0022] More preferably, the mass concentration of the inorganic substances is 8 - 12 g / L, the mass concentration of the organic substances is 1.2 - 1.8 g / L; the mass concentration of the nanomaterials is 1.2 - 1.8 g / L; the mass concentration of the wetting agents is 1.5 - 2.0 g / L; the mass concentration of the flocculants is 0.8 - 1.2 g / L; the mass concentration of the accelerators is 5 - 7 g / L; the mass concentration of the dispersants is 0.4 - 0.6 g / L.

[0023] More preferably, the composite nano-liquid caustic soda consists of the following components by mass concentration:

[0024] Inorganic substances: 3 - 20 g / L,

[0025] Organic substances: 0.5 - 3 g / L,

[0026] Nano materials: 0.2 - 3 g / L,

[0027] Wetting agents: 0.5 - 3 g / L,

[0028] Flocculants: 0.2 - 2 g / L,

[0029] Accelerators: 2 - 10 g / L,

[0030] Dispersants: 0.1 - 1 g / L,

[0031] The balance is water.

[0032] The preparation method of the above-mentioned composite nano-liquid caustic soda is to add inorganic substances, organic substances, nano materials, wetting agents, flocculants, accelerators, and dispersants into water and mix them evenly to obtain the composite nano-liquid caustic soda.

[0033] In some specific embodiments, inorganic substances, organic substances, nano materials, wetting agents, flocculants, accelerators, and dispersants can be added into water and stirred for 20 - 60 min to mix evenly to obtain the composite nano-liquid caustic soda.

[0034] On the other hand, a method for treating wastewater from printed circuit board (PCB) production is provided, including the following steps: adjusting the pH of the wastewater from PCB production to 7.0 - 8.5 using the above-mentioned composite nano-liquid caustic soda.

[0035] Preferably, the temperature of the wastewater from PCB production is 25 - 35 °C; the addition amount of the composite nano-liquid caustic soda in the wastewater from PCB production is 0.5 - 5 wt%.

[0036] Further, after adjusting the pH of the wastewater from PCB production to 7.0 - 8.5, it further includes circulating and filtering for 10 - 20 min.

[0037] Further, it also includes performing RO reverse osmosis treatment on the wastewater after circulating and filtering.

[0038] During the PCB production process, general cleaning wastewater is produced from processes such as water washing after PCB pickling and micro-etching, and water washing after electroplating copper. The pollutant components are relatively single, mainly inorganic salts. The comprehensive wastewater mainly contains Cu 2+ 、Ni 2+Wastewater containing complex metal ions, various surfactants, organic acids and alkalis, such as cleaning wastewater after processes like degreasing, neutralization and browning. Generally, the pH of the general washing wastewater is 2 - 4. The pH is adjusted to about 8.0 for coagulation precipitation. After removing heavy metal ions, it enters the RO reverse osmosis system. The produced water can be used as production line water, and the concentrated water flows into the organic wastewater collection tank for physico-chemical and biochemical treatment.

[0039] For the washing wastewater generated during the PCB production process, the present invention also provides a method for treating the washing wastewater (PCB wastewater) using the above-mentioned composite nano liquid caustic soda. The specific process flow is as Figure 1 shown.

[0040] After the PCB wastewater enters the pH adjustment tank, the composite nano liquid caustic soda is added to adjust the pH of the wastewater to 7.0 - 8.5. Then the wastewater enters the coagulation tank, and a coagulant (such as polyaluminum chloride, polyferric sulfate, etc.) is added to the coagulation tank. Through chemical bonding or physical adsorption and other effects, the coagulant molecules form a bridge between the colloidal particles and fine suspended solids in the wastewater, gradually forming larger flocculent alum flowers. Then the wastewater enters the flocculation tank, and appropriate turbulent conditions are formed in the flocculation tank to make the flocculent alum flowers in the wastewater continue to grow and thicken. This process requires an appropriate degree of turbulence and sufficient residence time until a large amount of alum flowers are finally observed to aggregate and slowly sink. After that, the wastewater enters the sedimentation tank. In the sedimentation tank, the thick alum flowers are preferentially deposited at the bottom of the tank, the upper layer of water becomes clarified water, and the remaining small particles continue to slowly sink and finally deposit at the bottom of the tank. The wastewater after sedimentation in the sedimentation tank enters the comprehensive intermediate tank. When the wastewater passes through the comprehensive intermediate tank, part of the sediment, suspended solids, etc. in the water will naturally settle down. Then the wastewater passes through multi-media (such as quartz sand, anthracite, manganese sand) filtration, activated carbon filtration, and two-stage ultrafiltration filtration and enters the ultrafiltration tank. After passing through the security filter (a precision filtration device mainly used in water treatment systems or other fluid treatment systems as a pre-treatment or terminal fine treatment link to protect subsequent more delicate or expensive equipment from pollutants such as particulate matter, colloids, and microorganisms), it is filtered through the RO membrane, and the produced water enters the recycled water tank and can be used as production line water.

[0041] Preferably, in the pH adjustment tank, the circulating filtration time is 10 - 20 min, the addition amount of nano liquid caustic soda is 0.5 - 5 wt%, and the temperature of the wastewater solution is 25 - 35 °C.

[0042] More preferably, in the pH adjustment tank, the circulating filtration time is 14 - 16 min, and the addition amount of nano liquid caustic soda is 2 - 3 wt%.

[0043] The beneficial effects of the present invention are as follows:

[0044] (1) The effective components such as inorganic substances, organic substances, nanomaterials, wetting agents, flocculants, accelerators, and dispersants in the composite nano liquid caustic soda of the present invention interact with each other, improving the practicality of the caustic soda solution. The nanoparticles in the nanomaterials have an extremely high specific surface area and activity, capable of effectively adsorbing and decomposing organic substances and heavy metal ions in water, achieving the purpose of rapidly removing heavy metals, organic substances, ammonia nitrogen, and other substances in wastewater, thereby reducing environmental pollution;

[0045] (2) The composite nano liquid caustic soda of the present invention replaces ordinary liquid caustic soda, with simple and efficient operation. It can better interact with reactants or target substances in wastewater during processes such as catalysis and adsorption, improving the reaction efficiency and material conversion rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0047] Figure 1 It is the process flow diagram of the PCB wastewater treatment of the present invention;

[0048] Figure 2 is the wastewater from printed circuit board production;

[0049] Figure 3 is the solution after the wastewater from printed circuit board production is treated with the composite nano liquid caustic soda of Example 1;

[0050] Figure 4 is the solution after the wastewater from printed circuit board production is treated with the composite nano liquid caustic soda of Example 2;

[0051] Figure 5 is the solution after the wastewater from printed circuit board production is treated with the composite nano liquid caustic soda of Comparative Example 1;

[0052] Figure 6 is the solution after the wastewater from printed circuit board production in Comparative Example 18 is treated;

[0053] Figure 7 is the solution after the wastewater from printed circuit board production in Comparative Example 19 is treated;

[0054] Figure 8 is the solution after the wastewater from printed circuit board production in Comparative Example 22 is treated;

[0055] Figure 9 is the solution after the wastewater from printed circuit board production in Comparative Example 23 is treated;

[0056] Figure 10The solution after treating the wastewater from the production of the printed circuit board for Comparative Example 24. Detailed implementation manners

[0057] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0058] It should be understood that when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations.

[0059] Example 1

[0060] The composite nano liquid alkali of this example includes the following components by mass concentration: 10 g / L of sodium hydroxide, 1.2 g / L of butyllithium, 1.2 g / L of zinc chloride, 1.5 g / L of polyvinyl alcohol, 0.8 g / L of polyaluminum chloride, 5 g / L of potassium manganate, 0.4 g / L of allylsulfonic acid sodium, and the balance is deionized water.

[0061] Example 2

[0062] The composite nano liquid alkali of this example includes the following components by mass concentration: 10 g / L of potassium hydroxide, 1.2 g / L of lithium diisopropylamide, 1.4 g / L of silver chloride, 1.6 g / L of methylene bisnaphthalenesulfonate, 1.0 g / L of polyferric sulfate, 5.5 g / L of sodium manganate, 0.5 g / L of propargylsulfonic acid sodium, and the balance is deionized water.

[0063] Example 3

[0064] The composite nano liquid alkali of this example includes the following components by mass concentration: 12 g / L of cesium hydroxide, 1.0 g / L of benzyllithium, 1.4 g / L of silver chloride, 1.5 g / L of polyvinyl alcohol, 0.8 g / L of polyaluminum chloride, 6 g / L of potassium manganate, 0.4 g / L of allylsulfonic acid sodium, and the balance is deionized water.

[0065] Example 4

[0066] The composite nano-liquid caustic soda of this embodiment comprises the following components by mass concentration: 12 g / L of potassium hydroxide, 1.2 g / L of sodium tert-butoxide, 1.4 g / L of silver chloride, 1.6 g / L of sodium methylene dinaphthalene sulfonate, 1.0 g / L of polymeric ferric sulfate, 5.5 g / L of sodium manganate, 0.5 g / L of sodium dodecylbenzenesulfonate, and the balance is deionized water.

[0067] Example 5

[0068] The composite nano-liquid caustic soda of this embodiment comprises the following components by mass concentration: 10 g / L of rubidium hydroxide, 1.0 g / L of benzyllithium, 1.2 g / L of silver chloride, 1.5 g / L of polyvinyl alcohol, 1.0 g / L of sodium metaaluminate, 7 g / L of potassium manganate, 0.5 g / L of allylsulfonic acid sodium salt, and the balance is deionized water.

[0069] Example 6

[0070] The composite nano-liquid caustic soda of this embodiment comprises the following components by mass concentration: 10 g / L of sodium hydroxide, 1.1 g / L of lithium diisopropylamide, 1.2 g / L of silver chloride, 1.8 g / L of sodium hexadecylsulfonate, 1.0 g / L of sodium metaaluminate, 7 g / L of potassium manganate, 0.4 g / L of allylsulfonic acid sodium salt, and the balance is deionized water.

[0071] Example 7

[0072] The composite nano-liquid caustic soda of this embodiment comprises the following components by mass concentration: 8 g / L of sodium hydroxide, 1.2 g / L of benzyllithium, 1.2 g / L of zinc chloride, 1.5 g / L of polyvinyl alcohol, 1.0 g / L of polymeric aluminum chloride, 6 g / L of sodium manganate, 0.5 g / L of allylsulfonic acid sodium salt, and the balance is deionized water.

[0073] Example 8

[0074] The composite nano-liquid caustic soda of this embodiment comprises the following components by mass concentration: 3 g / L of sodium hydroxide, 0.6 g / L of butyllithium, 0.2 g / L of zinc chloride, 0.5 g / L of polyvinyl alcohol, 0.2 g / L of polymeric aluminum chloride, 2 g / L of potassium manganate, 0.6 g / L of allylsulfonic acid sodium salt, and the balance is deionized water.

[0075] Example 9

[0076] The composite nano-liquid caustic soda of this embodiment comprises the following components by mass concentration: 20 g / L of sodium hydroxide, 3 g / L of butyllithium, 3 g / L of zinc chloride, 3 g / L of polyvinyl alcohol, 2 g / L of polymeric aluminum chloride, 10 g / L of potassium manganate, 1 g / L of allylsulfonic acid sodium salt, and the balance is deionized water.

[0077] The composite nano-liquid caustic soda of Examples 1-9 was used for the treatment of wastewater from printed circuit board production to verify the treatment effect.

[0078] The wastewater from printed circuit board production used in the following tests is as Figure 2 shown. The contents of various substances before the treatment of the wastewater from printed circuit board production are shown in Table 1 below:

[0079]

[0080] Treatment method: Take 500 ml of the above-mentioned wastewater from printed circuit board production, add the composite nano-liquid caustic soda of the example, stir and mix evenly, and adjust the pH of the solution in the beaker to 7.0 - 8.5 (the specific addition amount of the composite nano-liquid caustic soda and the pH of the solution are shown in Table 2), and continue to stir for 15 min.

[0081] After the treatment is completed, the following detections or analyses are carried out.

[0082] 1) Sedimentation rate detection: After stopping stirring, let it stand still, and record the sedimentation time when the sediment in the solution is completely sedimented.

[0083] 2) COD content analysis: Measure the absorbance of trivalent chromium (Cr³⁺) produced by the reduction of potassium dichromate at a wavelength of 600 ± 20 nm. The COD value in the sample is in direct proportion to the increase in the absorbance of trivalent chromium (Cr³⁺), and the absorbance of trivalent chromium (Cr³⁺) is converted into the COD value of the sample.

[0084] 3) Heavy metal content analysis: The heavy metal content is quantitatively analyzed by measuring the absorbance of the colored compound formed by the reaction of the heavy metal with the chromogenic agent through ultraviolet-visible spectrophotometry.

[0085] The test results of Examples 1-9 are shown in Table 2:

[0086]

[0087] It can be seen from the test results in Table 2 that using the composite nano-liquid caustic soda provided by the present invention for the treatment of wastewater from printed circuit board production has a rapid reaction and a fast sedimentation rate, and can quickly remove heavy metals, organic substances and ammonia nitrogen in the wastewater.

[0088] The solution after the wastewater from printed circuit board production is treated with the composite nano-liquid caustic soda of Example 1 is as Figure 3 shown; the solution after the wastewater from printed circuit board production is treated with the composite nano-liquid caustic soda of Example 2 is as Figure 4 shown.

[0089] In the research process of the present invention, the following explorations were also carried out based on Example 1.

[0090] I. Influence based on different mass concentrations of inorganic substances

[0091] The differences between the composite nano-liquid caustic of Comparative Examples 1-3 and that of Example 1 are as follows: the mass concentration of inorganic substances in the composite nano-liquid caustic is different, as shown in Table 3 specifically.

[0092] Treatment method: Take 500 ml of the above-mentioned printed circuit board production wastewater respectively, add the composite nano-liquid caustic of Comparative Examples 1-3 and stir to mix evenly (the specific addition amount of the composite nano-liquid caustic and the measured solution pH are shown in Table 3), and continue to stir for 15 min.

[0093] After the treatment, sedimentation rate detection, COD content analysis, and heavy metal content analysis are carried out, and the test results are shown in Table 3:

[0094]

[0095] It can be seen from the test results in Table 3 that when no inorganic substances are added to the composite nano-liquid caustic for treating printed circuit board production wastewater (Comparative Example 1), the test results are not ideal. When the mass concentration of inorganic substances is lower than 3 g / L (Comparative Example 2) or higher than 20 g / L (Comparative Example 3), the test results are also not ideal. Therefore, the mass concentration of inorganic substances in the composite nano-liquid caustic for treating printed circuit board production wastewater is preferably 3-20 g / L.

[0096] The solution after the printed circuit board production wastewater is treated with the composite nano-liquid caustic of Comparative Example 1 is as Figure 5 shown.

[0097] II. Influence based on different mass concentrations of organic substances

[0098] The differences between the composite nano-liquid caustic of Comparative Examples 4-6 and that of Example 1 are as follows: the mass concentration of organic substances in the composite nano-liquid caustic is different, as shown in Table 4 specifically.

[0099] Treatment method: Take 500 ml of the above-mentioned printed circuit board production wastewater respectively, add the composite nano-liquid caustic of Comparative Examples 4-6 and stir to mix evenly (the specific addition amount of the composite nano-liquid caustic and the measured solution pH are shown in Table 4), and continue to stir for 15 min.

[0100] After the treatment, sedimentation rate detection, COD content analysis, and heavy metal content analysis are carried out, and the test results are shown in Table 4:

[0101]

[0102] It can be seen from the test results in Table 4 that when no organic substances are added to the composite nano-liquid caustic for treating printed circuit board production wastewater (Comparative Example 4), when the mass concentration of organic substances is lower than 0.5 g / L (Comparative Example 5) or higher than 3 g / L (Comparative Example 6), the test results are all not ideal. Therefore, the mass concentration of organic substances in the composite nano-liquid caustic for treating printed circuit board production wastewater is preferably 0.5-3 g / L.

[0103] III. Influence of Different Mass Concentrations of Nanomaterials

[0104] The differences between the composite nano liquid caustics of Comparative Examples 7 - 9 and Example 1 lie in that the mass concentrations of the nanomaterials in the composite nano liquid caustics are different, as shown in Table 5 specifically.

[0105] Treatment method: Take 500 ml of the above - mentioned printed circuit board production wastewater respectively, add the composite nano liquid caustics of Comparative Examples 7 - 9 and stir to mix evenly (the specific addition amounts of the composite nano liquid caustics and the measured solution pH values are shown in Table 5), and continue stirring for 15 minutes.

[0106] After the treatment, sedimentation speed detection, COD content analysis, and heavy metal content analysis are carried out. The test results are shown in Table 5:

[0107]

[0108] It can be seen from the test results in Table 5 that when no nanomaterials are added (Comparative Example 7), the mass concentration of nanomaterials is lower than 0.2 g / L (Comparative Example 8), or higher than 3 g / L (Comparative Example 9) in the composite nano liquid caustic for printed circuit board production wastewater treatment, the test results are not ideal. Therefore, the mass concentration of the nanomaterials in the composite nano liquid caustic for printed circuit board production wastewater treatment is preferably 0.2 - 3 g / L.

[0109] IV. Influence of Different Mass Concentrations of Wetting Agents

[0110] The differences between the composite nano liquid caustics of Comparative Examples 10 - 12 and Example 1 lie in that the mass concentrations of the wetting agents in the composite nano liquid caustics are different, as shown in Table 6 specifically.

[0111] Treatment method: Take 500 ml of the above - mentioned printed circuit board production wastewater respectively, add the composite nano liquid caustics of Comparative Examples 10 - 12 and stir to mix evenly (the specific addition amounts of the composite nano liquid caustics and the measured solution pH values are shown in Table 6), and continue stirring for 15 minutes.

[0112] After the treatment, sedimentation speed detection, COD content analysis, and heavy metal content analysis are carried out. The test results are shown in Table 6:

[0113]

[0114] It can be seen from the test results in Table 6 that when no wetting agent is added (Comparative Example 10), the mass concentration of the wetting agent is lower than 0.5 g / L (Comparative Example 11), or higher than 3 g / L (Comparative Example 12) in the composite nano liquid caustic for printed circuit board production wastewater treatment, the test results are not ideal. Therefore, the mass concentration of the wetting agent in the composite nano liquid caustic for printed circuit board production wastewater treatment is preferably 0.5 - 3 g / L.

[0115] V. Influence of Different Mass Ratios of Accelerator and Dispersant

[0116] The composite nano-liquid caustic of Comparative Examples 13 and 14 is different from that of Example 1 in that the mass concentration of the accelerator in the composite nano-liquid caustic is different. See Table 7 for details.

[0117] Treatment method: Take 500 ml of the above printed circuit board production wastewater respectively, and add the composite nano-liquid caustic of Comparative Examples 13 and 14 and stir to mix evenly (the specific addition amount of the composite nano-liquid caustic and the measured solution pH are shown in Table 7), and continue to stir for 15 minutes.

[0118] After the treatment, sedimentation rate detection, COD content analysis, and heavy metal content analysis are carried out. The test results are shown in Table 7:

[0119]

[0120] It can be seen from the test results in Table 7 that when the proportion of the accelerator in the accelerator and the dispersant in the composite nano-liquid caustic used for treating printed circuit board production wastewater is too small (Comparative Example 13) or too large (Comparative Example 14), the test results are not ideal. Therefore, the mass ratio of the accelerator and the dispersant in the composite nano-liquid caustic used for treating printed circuit board production wastewater is preferably 1:(0.02 - 0.3).

[0121] VI. Influence of Different Mass Concentrations of Flocculant

[0122] The composite nano-liquid caustic of Comparative Examples 15 - 17 is different from that of Example 1 in that the mass concentration of the flocculant in the composite nano-liquid caustic is different. See Table 8 for details.

[0123] Treatment method: Take 500 ml of the above printed circuit board production wastewater respectively, and add the composite nano-liquid caustic of Comparative Examples 15 - 17 and stir to mix evenly (the specific addition amount of the composite nano-liquid caustic and the measured solution pH are shown in Table 8), and continue to stir for 15 minutes.

[0124] After the treatment, sedimentation rate detection, COD content analysis, and heavy metal content analysis are carried out. The test results are shown in Table 8:

[0125]

[0126] It can be seen from the test results in Table 8 that when no flocculant is added (Comparative Example 15), the mass concentration of the flocculant is lower than 0.2 g / L (Comparative Example 16) or higher than 2 g / L (Comparative Example 17) in the composite nano-liquid caustic used for treating printed circuit board production wastewater, the test results are not ideal. Therefore, the mass concentration of the flocculant in the composite nano-liquid caustic used for treating printed circuit board production wastewater is preferably 0.2 - 2 g / L.

[0127] VII. Influence of Adjusting Different pH Values of Wastewater Solution

[0128] The composite nano-liquid caustic used in Comparative Examples 18-23 is the same as that in Example 1.

[0129] The difference in the treatment methods between Comparative Examples 18-23 and Example 1 lies in the different addition amounts of the composite nano-liquid caustic. Specifically: 500 ml of the above-mentioned printed circuit board production wastewater was taken respectively, and the composite nano-liquid caustic with the addition amounts shown in Table 9 was added respectively and stirred and mixed evenly (the pH of the solution was measured as shown in Table 9), and stirring was continued for 15 min.

[0130] After the treatment, sedimentation rate detection, COD content analysis, and heavy metal content analysis were carried out, and the test results are shown in Table 9:

[0131]

[0132] It can be seen from the test results in Table 9 that when treating the printed circuit board production wastewater, when the pH of the printed circuit board production wastewater is adjusted by the composite nano-liquid caustic to be less than 7 or greater than 8.5, the ability to treat the wastewater is not obvious.

[0133] The solution after treating the printed circuit board production wastewater in Comparative Example 18 is as Figure 6 shown; the solution after treating the printed circuit board production wastewater in Comparative Example 19 is as Figure 7 shown; the solution after treating the printed circuit board production wastewater in Comparative Example 22 is as Figure 8 shown; the solution after treating the printed circuit board production wastewater in Comparative Example 23 is as Figure 9 shown.

[0134] VIII. Comparative experiment test based on the composite nano-liquid caustic and ordinary caustic solution

[0135] Ordinary caustic solution (1.5 wt% sodium hydroxide solution) was used in Comparative Example 24 for treating the printed circuit board production wastewater. Specifically: 500 ml of the above-mentioned printed circuit board production wastewater was taken respectively, and the ordinary caustic solution was added and stirred and mixed evenly to adjust the pH of the wastewater solution (specifically shown in Table 10), and stirring was continued for 15 min.

[0136] After the treatment, sedimentation rate detection, COD content analysis, and heavy metal content analysis were carried out, and the test results are shown in Table 10:

[0137]

[0138] The solution after treating the printed circuit board production wastewater in Comparative Example 24 is as Figure 10 shown.

[0139] In summary, the composite nano-liquid caustic soda provided by the present invention can replace traditional liquid caustic soda for the treatment of wastewater from printed circuit board production. It can quickly achieve acid-base neutralization, improve the efficiency of sewage treatment, activate the capture of metals by modified nano-particles, and has high controllability, low volatility and corrosiveness. At the same time, it is environmentally friendly, does not contain harmful chemical substances, not only maintains the alkalinity and solubility of traditional liquid caustic soda, but also improves the stability of liquid caustic soda. It can quickly remove heavy metals, organic substances and ammonia nitrogen in wastewater, while reducing costs by 20-40% and saving more than 40% of the time, and the operation is simple and convenient.

[0140] As described above, the above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A composite nano-liquid caustic soda, characterized in that, Composed of components with the following mass concentrations: Inorganic substances: 3 - 20 g / L, Organic substances: 0.5 - 3 g / L, Nanomaterials: 0.2 - 3 g / L, Wetting agents: 0.5 - 3 g / L, Flocculants: 0.2 - 2 g / L, Accelerators: 2 - 10 g / L, Dispersants: 0.1 - 1 g / L, The balance is water; The mass concentration ratio of the accelerator to the dispersant is 1:(0.02 - 0.3); The inorganic substances are selected from at least one of sodium hydroxide, potassium hydroxide, cesium hydroxide, and rubidium hydroxide; The organic substances are selected from at least one of butyllithium, lithium diisopropylamide, benzyllithium, and sodium tert-butoxide; The nanomaterials are selected from at least one of nanoscale zinc chloride, silver chloride, and zinc oxide; The wetting agents are selected from at least one of polyvinyl alcohol, sodium methylene bisnaphthalenesulfonate, and sodium cetylsulfonate; The flocculants are selected from at least one of polyaluminum chloride, polyferric sulfate, polyacrylamide, and sodium metaaluminate; The accelerators are selected from at least one of potassium manganate, sodium manganate, and sodium ammonium manganate; The dispersants are selected from at least one of sodium allylsulfonate, sodium propargylsulfonate, and sodium dodecylbenzenesulfonate.

2. The composite nano liquid caustic soda according to claim 1, characterized in that, The mass concentration ratio of the inorganic substances to the organic substances is 1:(0.02 - 0.2).

3. The composite nano-liquid caustic soda according to claim 1, wherein The mass concentration of the inorganic substances is 8 - 12 g / L, and the mass concentration of the organic substances is 1.2 - 1.8 g / L.

4. The preparation method of the composite nano liquid caustic soda according to any one of claims 1-3, characterized in that, Add inorganic substances, organic substances, nanomaterials, wetting agents, flocculants, accelerators, and dispersants into water and mix evenly to obtain a composite nano liquid caustic soda.

5. A method for treating wastewater from printed circuit board production, characterized in that, Including the following steps: adjusting the pH of the wastewater from printed circuit board production to 7.0 - 8.5 using the composite nano liquid caustic soda according to any one of claims 1 - 3.

6. The method for treating wastewater from printed circuit board production according to claim 5, wherein The temperature of the wastewater from printed circuit board production is 25 - 35 °C.

7. The wastewater treatment method for printed circuit board production according to claim 5, characterized in that, The addition amount of the composite nano liquid caustic soda in the wastewater from printed circuit board production is 0.5 - 5 wt%.

8. The wastewater treatment method for printed circuit board production according to claim 5, wherein, After adjusting the pH of the wastewater from printed circuit board production to 7.0 - 8.5, it further includes circulating and filtering for 10 - 20 min.

9. The method for treating wastewater from printed circuit board production according to claim 8, characterized in that, It also includes performing RO reverse osmosis treatment on the wastewater after circulating and filtering.

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