A treatment process for refinery wastewater

Abstract

This application relates to the technical field of wastewater treatment, and specifically discloses a treatment process for refinery wastewater. A treatment process for refinery wastewater includes the following steps: I. Cooling, flocculation and air flotation; II. Ammonia nitrogen removal: Adjust the pH value of the refinery wastewater obtained after air flotation treatment to 6.7 - 7.5, then add an ammonia nitrogen adsorbent into the system, with an addition amount of 2 - 2.5 g / L. After stirring for 4 - 5 h, refinery wastewater with an ammonia nitrogen concentration of 50.3 - 50.7 mg / L is obtained. The ammonia nitrogen adsorbent includes a composite adsorbent and a modified zeolite adsorbent with a weight ratio of (1 - 1.2):1; III. Reverse osmosis and activated carbon degradation. The treatment process of this application can be used to treat refinery wastewater with a high ammonia nitrogen concentration (680 - 700 mg / L), has the advantage of a high ammonia nitrogen removal rate, and the final ammonia nitrogen removal rate can reach over 98.06%.

Description

Technical Field

[0001] The present application relates to the technical field of wastewater treatment, and particularly to a treatment process for refinery wastewater. Background Art

[0002] During the process of petroleum refining, acidic wastewater is generated. This acidic refinery wastewater comes from the process of deep processing of oil products, such as catalytic cracking, hydrocracking, delayed coking and other processing units. The refinery wastewater produced by different processing units contains pollutants such as ammonia nitrogen, metal ions and organic matter respectively, which cause great harm to the environment. In particular, ammonia nitrogen can lead to eutrophication of water bodies, making the water ecological environment deteriorate continuously.

[0003] The existing treatment processes for industrial wastewater usually include steps such as cooling, flocculation, air flotation, reverse osmosis and activated carbon degradation to remove pollutants in the water and make the produced water meet the discharge requirements. However, since refinery wastewater is treated after mixing the water qualities of different units such as catalytic cracking, hydrocracking, and delayed coking, and there are significant differences in the water qualities of the produced water from different units, the water quality components after mixing become complex, and the contents of ammonia nitrogen, metal ions and organic matter are all at relatively high levels. Therefore, when refinery wastewater passes through the reverse osmosis membrane, the pollutants on the membrane surface increase, and the filtration efficiency of the reverse osmosis membrane decreases significantly. This not only reduces the service life of the reverse osmosis membrane and increases the process energy consumption, but more seriously, at this time, the removal rate of ammonia nitrogen by the reverse osmosis membrane is only 50 - 55%, far lower than the expected removal rate of 72 - 76%, which will directly affect the water quality of the produced water and cannot achieve the expected treatment effect of refinery wastewater.

[0004] Some researchers have proposed that a certain amount of potassium dihydrogen phosphate and magnesium chloride can be added to the water before filtering the refinery wastewater through the reverse osmosis membrane to remove part of the ammonia nitrogen, so as to reduce the ammonia nitrogen content before reverse osmosis and ensure the filtration efficiency of the reverse osmosis membrane. However, this method can only reduce the ammonia nitrogen content of refinery wastewater with a low ammonia nitrogen concentration (150 - 200 mg / L) to below the national standard (<25 mg / L). For refinery wastewater with a high ammonia nitrogen concentration (680 - 700 mg / L), the ammonia nitrogen removal effect of potassium dihydrogen phosphate and magnesium chloride can no longer meet the actual requirements, the filtration efficiency of the reverse osmosis membrane is low, and the ammonia nitrogen content in the finally obtained refinery wastewater is still 60 - 96 mg / L, which does not meet the national standard. Summary of the Invention

[0005] In order to solve the above technical problems, the present application provides a treatment process for refinery wastewater.

[0006] A treatment process for refinery wastewater provided by the present application adopts the following technical solutions:

[0007] A treatment process for refinery wastewater includes the following steps:

[0008] I, Cooling, flocculation and air flotation;

[0009] II, Ammonia nitrogen removal: Adjust the pH value of the refinery wastewater obtained after air flotation treatment to 6.7 - 7.5, then add an ammonia nitrogen adsorbent into the system, with the addition amount being 2 - 2.5 g / L. After stirring for 4 - 5 h, refinery wastewater with an ammonia nitrogen concentration of 50.3 - 50.7 mg / L is obtained. The ammonia nitrogen adsorbent includes a composite adsorbent and a modified zeolite adsorbent with a weight ratio of (1 - 1.2):1;

[0010] III, Reverse osmosis and activated carbon degradation.

[0011] Preferably, the weight ratio of the composite adsorbent to the modified zeolite adsorbent is 1.09:1.

[0012] By adopting the above technical solutions, after the refinery wastewater with a high ammonia nitrogen concentration is cooled in this application, through the steps of air flotation and filtration, the insoluble organic matters in the water are removed. Then, the pH value of the refinery wastewater is adjusted, and a certain amount of ammonia nitrogen adsorbent is added to the water to remove ammonia nitrogen. Finally, through reverse osmosis and activated carbon degradation, refinery wastewater reclaimed water meeting the national standards is obtained. Specifically speaking, in this application, a composite adsorbent and a modified zeolite adsorbent with a certain weight ratio are mixed to obtain an ammonia nitrogen adsorbent, giving full play to the synergistic effect of the two. The ammonia nitrogen concentration of the refinery wastewater is reduced from 630 - 650 mg / L after air flotation to 50.3 - 50.7 mg / L, and the removal rate reaches 91.82 - 92.26%; while using potassium dihydrogen phosphate and magnesium chloride can only reduce the ammonia nitrogen concentration of the refinery wastewater from 550 - 620 mg / L after air flotation to 148 - 192 mg / L, and the removal rate is only 70.36 - 77.16%. The test data shows that the ammonia nitrogen removal rate of the ammonia nitrogen remover in this application is much higher than that of potassium dihydrogen phosphate and magnesium chloride for ammonia nitrogen, and the removal effect on ammonia nitrogen is more significant. It not only reduces the content of pollutants in the refinery wastewater, but also reduces the number of pollutants on the surface of the reverse osmosis membrane, thereby improving the filtration efficiency of the reverse osmosis membrane, enabling the ammonia nitrogen removal rate in reverse osmosis to be increased to about 75.3%, and finally being able to reduce the ammonia nitrogen concentration of the refinery wastewater reclaimed water to below 13.58 mg / L. Therefore, by replacing potassium dihydrogen phosphate and magnesium chloride with a composite adsorbent and a modified zeolite adsorbent in this application, the ammonia nitrogen removal rate in the ammonia nitrogen removal step is significantly improved, and further the ammonia nitrogen removal rate in the reverse osmosis step is improved, making both of the above two steps have a high ammonia nitrogen removal rate.

[0013] Moreover, through detection and calculation, when using the modified zeolite adsorbent alone, the removal rate of ammonia nitrogen is 89.91%. When using the composite material adsorbent alone, the removal rate of ammonia nitrogen is 91.32%. After treating the refinery wastewater with each of them separately and then mixing the refinery wastewater, the removal rate of ammonia nitrogen is 90.61%. However, when using them in combination, the removal rate of ammonia nitrogen can exceed 92.26%. The test data show that this application fully utilizes the synergistic effect of the composite material adsorbent and the modified zeolite adsorbent, controls their weight ratio, and overall optimizes the adsorption effect of the ammonia nitrogen adsorbent. Further, when the weight ratio of the composite material adsorbent to the modified zeolite adsorbent is 1.09:1, the ammonia nitrogen removal rate of the ammonia nitrogen remover is the highest, reaching 94.35%.

[0014] Optionally, the composite material adsorbent is prepared by the following method:

[0015] S1. Surface-treat carbon fiber;

[0016] S2. Calcinate the mixed sludge at 500 - 520 °C for 0.8 - 1 h. After cooling, put it into a hydrochloric acid solution with a concentration of 35 - 40 wt% according to a bath ratio of 1:(15 - 18), stir for 1 - 1.5 h, centrifuge, take the supernatant after filtration, mix it with carbon fiber according to a weight ratio of (25 - 28):1, stir for 1.5 - 1.8 h and then filter to obtain composite carbon fiber. Then add an alkali solution with an alkali concentration of 1 - 1.2 mol / L and let it stand for 1 - 1.5 h, filter, wash the composite carbon fiber, and dry it to a constant mass to obtain a crude product;

[0017] S3. Deposit conductive diamond on the surface of the crude product until the layer thickness of the conductive diamond reaches 45 - 50 μm to obtain the composite material adsorbent.

[0018] By adopting the above technical solution, the present application calcines the mixed sludge containing alumina and iron oxide at a certain temperature, and then obtains a supernatant rich in aluminum ions and ferric ions after acid extraction with hydrochloric acid solution, and soaks the surface-treated carbon fiber under the above conditions. Since the surface of the surface-treated carbon fiber has high chemical activity, the present application obtains a composite carbon fiber with alumina crystals and iron oxide crystals loaded on the surface. After drying to a constant mass, a conductive diamond layer with a certain thickness is deposited on the surface of the crude product by means of direct current spraying, and a composite material adsorbent is obtained. The composite material adsorbent prepared in the present application realizes the removal of ammonia nitrogen through the adsorption of ammonia nitrogen by oxide crystals, and has a higher ammonia nitrogen removal rate compared with potassium dihydrogen phosphate and magnesium chloride. At the same time, the conductive diamond has good physical and chemical stability, thermal stability and high applicability to high-concentration organic wastewater. During the stirring operation in step II, the conductive diamond film can not only cooperate with the carbon fiber preliminarily modified by alumina and iron oxide to improve the thermal stability of the modified carbon fiber and promote it to more stably exert the effect of removing ammonia nitrogen, but also can remove the organic matter in the refinery wastewater and reduce the COD content in the reclaimed water.

[0019] Preferably, in the step S1, the surface treatment of the carbon fiber is specifically:

[0020] Place the carbon fiber in a sulfuric acid-aqueous solution with a concentration of 0.7-0.8 wt%, and perform electrolysis for 15-20 s under the condition of a current of 0.2-0.6 A to obtain the surface-treated carbon fiber.

[0021] Preferably, the current is 0.48 A.

[0022] By adopting the above technical solution, the present application realizes the surface treatment of the carbon fiber by electrolyzing the carbon fiber in an acidic aqueous solution environment, improves the carbon-oxygen element ratio on the surface of the carbon fiber (up to 38.9-41.8%), and compared with surface treatment methods such as low-temperature plasma bombardment treatment and chemical grafting modification, the electrochemical treatment method adopted in the present application hardly affects the mechanical structure stability of the carbon fiber after surface treatment (the tensile strength can reach 3.5-3.8 GPa), which also makes the composite material adsorbent have a relatively stable mechanical structure. During the stirring operation in step II, the ammonia nitrogen adsorbent of the present application can more stably and efficiently exert the effect of removing ammonia nitrogen.

[0023] The present application also controls the magnitude of the current in the surface treatment of carbon fibers. On the premise of ensuring that the tensile strength of the carbon fibers is at a relatively high level, the oxygen-to-carbon element ratio on the surface of the carbon fibers is increased as much as possible, thereby enhancing the chemical activity on the surface of the carbon fibers, and further enhancing the loading rate of alumina crystals and iron oxide crystals on the surface of the carbon fibers. If the current is too large, the tensile strength of the carbon fibers will decrease; if the current is too small, the oxygen-to-carbon element ratio on the surface of the carbon fibers will be too low. Experimental data shows that when the current is 0.48 A, the tensile strength of the carbon fibers and the oxygen-to-carbon element ratio on the surface are in an optimal balance, the tensile strength is 3.75 GPa, and the surface carbon-to-oxygen element ratio can reach 41.6%. At this time, the ammonia nitrogen removal rate of the composite adsorbent is the highest.

[0024] Preferably, the modified zeolite adsorbent is prepared by the following method:

[0025] According to a bath ratio of 1:(90 - 105), the zeolite is immersed in a sodium chloride - aqueous solution, stirred and oscillated for 10 - 12 h, then the zeolite is taken out, washed, and dried to obtain the modified zeolite adsorbent, where the sodium chloride concentration in the sodium chloride - aqueous solution is 3 - 5 wt%.

[0026] By adopting the above technical solution, the present application utilizes zeolite which inherently has certain ion exchange capacity and pore structure function to remove ammonia nitrogen by ion exchange and adsorption removal. On this basis, the present application further modifies it with sodium chloride, which can broaden the internal pores and pore diameters, thereby further enhancing the adsorption capacity of the zeolite. And the sodium ions in sodium chloride will undergo ion exchange reactions with metal cations such as aluminum ions, magnesium ions, and calcium ions in the zeolite, increasing the ion exchange capacity of the zeolite. Therefore, the ammonia nitrogen removal rate of the modified zeolite adsorbent is further improved.

[0027] More importantly, due to the ion exchange reactions of sodium ions with metal cations such as aluminum ions, magnesium ions, and calcium ions in the zeolite, the number of aluminum ions, magnesium ions, and calcium ions released when the modified zeolite adsorbent is put into refinery wastewater for ion exchange to remove ammonia nitrogen is greatly reduced, and the number of aluminum ions, magnesium ions, and calcium ions in the refinery wastewater is correspondingly reduced. Since these metal cations will compete with ammonia nitrogen for the adsorption sites on the surface of the composite adsorbent and affect the adsorption effect of the composite adsorbent, the present application modifies the zeolite with sodium chloride, which not only improves its own ammonia nitrogen removal rate, but also optimizes the adsorption effect of the composite adsorbent.

[0028] Preferably, in the step III, the specific operation is as follows:

[0029] The refinery wastewater obtained in Step II is subjected to reverse osmosis treatment, and then activated carbon is introduced under the conditions of a treatment load of 10 - 15 kg / m3·d and an introduction speed of 4 - 5 L / h. After activated carbon degradation, the regenerated water of the refinery wastewater is obtained.

[0030] Preferably, the operating pressure for the reverse osmosis treatment of the refinery wastewater obtained in Step III is 3 - 3.4 Mpa.

[0031] By adopting the above technical solution, in this application, the refinery wastewater after reverse osmosis treatment is introduced into activated carbon under a certain treatment load and introduction speed, and activated carbon degradation is carried out to remove the organic matter in the refinery wastewater. Finally, the COD of the regenerated water of the refinery wastewater obtained is less than 50 mg / L, and the COD removal rate can reach more than 96.77%. Moreover, compared with other treatment processes, in this application, the ammonia nitrogen removal rate in Step II is higher, and the number of pollutants on the surface of the reverse osmosis membrane is less. Even when the operating pressure of the reverse osmosis membrane is greater, that is, in the case of a shorter treatment time, the ammonia nitrogen removal rate and COD removal rate of the finally treated regenerated water of the refinery wastewater can still remain at a very high level. Therefore, there is a cooperative effect between the steps of the treatment process in this application, which can still have a very high ammonia nitrogen removal rate and COD removal rate under the conditions of reducing the operating time (saving about 10 - 12 minutes for every 50 kg of refinery wastewater treated) and operating costs, and the treatment effect of the refinery wastewater is relatively good.

[0032] In summary, this application has the following beneficial technical effects:

[0033] 1. By replacing potassium dihydrogen phosphate and magnesium chloride with a composite adsorbent and a modified zeolite adsorbent in this application, the ammonia nitrogen removal rate in the ammonia nitrogen removal step is significantly improved, thereby improving the filtration efficiency of reverse osmosis, so that the ammonia nitrogen content of high-concentration refinery wastewater can be reduced to below the national standard;

[0034] 2. This application gives full play to the cooperative effect of the composite adsorbent and the modified zeolite adsorbent, effectively improving the ammonia nitrogen removal rate of the ammonia nitrogen remover;

[0035] 3. There is a cooperative effect between the steps of the treatment process in this application, which can still have a very high COD removal rate under the conditions of reducing the operating time and operating costs, and the treatment effect of the refinery wastewater is relatively good. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is the process flow chart of the treatment process of this application. DETAILED DESCRIPTION

[0037] SOURCE OF MATERIALS

[0038] Unless otherwise specified, the raw materials used in this application are all commercially available products, specifically:

[0039] The refinery wastewater used in this application is selected from the mixed wastewater of catalytic cracking acidic water, hydrocracking acidic water, and delayed coking acidic water provided by Sinopec Corporation. The mixed wastewater is passed through an acidic stripping unit to obtain refinery wastewater. The COD content of this refinery wastewater is 1650 mg / L, and the ammonia nitrogen content is 680 - 700 mg / L.

[0040] The carbon fiber is purchased from Zhongke Leiming Technology Co., Ltd., and the fiber diameter is 150 - 200 nm.

[0041] The mixed sludge components include Fe2O3, Al2O3, and other oxides, and the mass fractions are 45.12%, 31.59%, and 23.29% in sequence.

[0042] Nitric acid and sulfuric acid are purchased from Shanghai Aladdin Reagent Co., Ltd., and the concentrations are 16 mol / L and 18.4 mol / L respectively.

[0043] The conductive diamond is purchased from Lingshou County Kuna Mineral Products Processing Factory, and the particle size is 10 - 12 nm.

[0044] The amino-functionalized graphene oxide is purchased from Suzhou Kaifa New Materials Technology Co., Ltd.

[0045] The zeolite is purchased from Gongyi Sifeng Water Purification Materials Co., Ltd. After being crushed and sieved, the particle size is 10 - 20 mesh.

[0046] The polyaluminum chloride is purchased from Gongyi Shengquan Water Purification Materials Factory, and the CAS number is 1327 - 41 - 9.

[0047] The polysulfone membrane is purchased from Jiangsu Jiayixinchen Membrane Technology Co., Ltd., and the pore size is 0.1 um.

[0048] The aromatic polyamide composite membrane is purchased from Ningxia Jingtang Environmental Protection Equipment Co., Ltd., and the pore size is 0.1 um.

[0049] The potassium dihydrogen phosphate is purchased from Weifang Chenyang Chemical Industry Co., Ltd.

[0050] The magnesium chloride is purchased from Shandong Dengyi Chemical Industry Group Co., Ltd.

[0051] In the treatment process of the refinery wastewater in this application, after the treatment in step II, after the reverse osmosis membrane treatment, and for the finally obtained refinery wastewater reclaimed water, the ammonia nitrogen content and the COD content of the refinery wastewater reclaimed water are detected with reference to the Comprehensive Wastewater Discharge Standard of GB 8978 - 2002.

[0052] The following further illustrates this application with preparation examples, examples, and comparative examples.

[0053] Preparation Example 1.1

[0054] Preparation method of composite adsorbent, comprising the following steps:

[0055] S1. Surface treatment of carbon fiber: In an environment with a pressure of 101.325 kPa, air is used as the carbon fiber surface treatment medium to generate atmospheric low-temperature plasma, and the surface of the moving carbon fiber (3 kg in total) is bombarded with low-temperature plasma. The running speed of the carbon fiber tow is 80 m / h, the working environment temperature for carbon fiber treatment is 15 °C, the gap between the carbon fiber and the plasma emission device is 8 mm, the humidity of the carbon fiber surface treatment environment is 60%, the power range for carbon fiber surface treatment is 500 W / tow, and the temperature of the low-temperature plasma carbon fiber surface treatment is 80 °C, obtaining surface-treated carbon fiber with a tensile strength of 2.8 GPa and a carbon-oxygen element ratio of 39.2%.

[0056] S2. Calcine 50 kg of mixed sludge at 500 °C for 0.8 h. After cooling, put it into a hydrochloric acid solution with a concentration of 40 wt% according to a bath ratio of 1:15, stir for 1.5 h, centrifuge, take the supernatant, filter, take 56 kg of the supernatant and mix it with 2 kg of surface-treated carbon fiber, stir for 1.8 h and then filter. After obtaining the composite carbon fiber, add it to a sodium hydroxide-aqueous solution with a sodium hydroxide concentration of 1 mol / L and let it stand for 1.5 h, filter, and then wash and dry the composite carbon fiber to a constant mass to obtain a crude product.

[0057] S3. Under the condition of introducing gas and methane, deposit boron-doped conductive diamond on the surface of the crude product by means of DC spraying until the layer thickness of the conductive diamond reaches 50 μm and the boron doping amount is greater than 1×1000 atoms·cm⁻³ to obtain a composite adsorbent, where the deposition temperature is 850 °C, the chamber pressure is 3 kPa, the gas flow rate is 8 SLM, and the methane flow rate is 130 sccm.

[0058] Preparation Example 1.2

[0059] Preparation method of composite adsorbent, comprising the following steps:

[0060] S1. Surface-treated carbon fiber: Wind 3 kg of carbon fiber around a square glass frame, then immerse the square glass frame in a beaker containing 4 kg of nitric acid and 1.2 kg of sulfuric acid. Then place the beaker on a magnetic stirrer and react at room temperature for 8 h. Wash with deionized water until the washing liquid is neutral, and then dry in a vacuum at 100 °C for 24 h to obtain acid-oxidized carbon fiber. Then dissolve 2 kg of amino-functionalized graphene oxide in 4.2 kg of dimethylformamide, and add all of the acyl chloride-functionalized carbon fiber to the system. Heat in a constant temperature water bath at 70 °C for 48 h, wash with acetone until the filtrate is neutral to obtain grafted carbon fiber. Reflux the grafted carbon fiber with 150 ml of acetone for 24 h, and then dry in a vacuum at 60 °C for 24 h to obtain surface-treated carbon fiber with a tensile strength of 2.6 GPa and a carbon-oxygen element ratio of 41.1%.

[0061] S2. Calcinate 50 kg of mixed sludge at 520 °C for 1 h. After cooling, put it into a hydrochloric acid solution with a concentration of 35 wt% according to a bath ratio of 1:18, stir for 1 h, centrifuge, take the supernatant, filter, take 50 kg of the supernatant and mix it with 2 kg of surface-treated carbon fiber, stir for 1.5 h and then filter. After obtaining the composite carbon fiber, add it to a sodium hydroxide-aqueous solution with a sodium hydroxide concentration of 1.2 mol / L and let it stand for 1 h, filter, and then wash and dry the composite carbon fiber to a constant mass to obtain the crude product.

[0062] S3. Deposit boron-doped conductive diamond on the surface of the crude product by the same DC spraying method as in Preparation Example 1.1. Different from Preparation Example 1.1, the layer thickness of the conductive diamond reaches 45 μm.

[0063] Preparation Example 1.3

[0064] The preparation method of the composite adsorbent is different from Preparation Example 1.1 in that: the surface treatment of the carbon fiber in step S1 adopts the following steps:

[0065] Place 3 kg of carbon fiber in 10 kg of sulfuric acid-aqueous solution with a concentration of 0.8 wt%, and perform electrolysis for 15 s under the condition of a current of 0.2 A to obtain surface-treated carbon fiber with a tensile strength of 3.8 GPa and a carbon-oxygen element ratio of 38.9%.

[0066] Preparation Example 1.4

[0067] The preparation method of the composite adsorbent is different from Preparation Example 1.1 in that: the surface treatment of the carbon fiber in step S1 adopts the following steps:

[0068] Place 3 kg of carbon fiber in 10 kg of sulfuric acid-aqueous solution with a concentration of 0.7 wt%, and perform electrolysis for 20 s under the condition of a current of 0.6 A to obtain surface-treated carbon fiber with a tensile strength of 3.5 GPa and a carbon-oxygen element ratio of 41.8%.

[0069] Preparation Example 2.1

[0070] The preparation method of the composite adsorbent is different from that of Preparation Example 1.1 in that: the surface treatment of the carbon fiber in Step S1 adopts the following steps:

[0071] Put 3 kg of carbon fiber into 10 kg of sulfuric acid-aqueous solution with a concentration of 0.8 wt%, and perform electrolysis for 15 s under the condition of a current of 0.15 A to obtain the surface-treated carbon fiber with a tensile strength of 4.0 GPa and a carbon-oxygen element ratio of 34.9%.

[0072] Preparation Example 2.2

[0073] The preparation method of the composite adsorbent is different from that of Preparation Example 1.1 in that: the surface treatment of the carbon fiber in Step S1 adopts the following steps:

[0074] Put 3 kg of carbon fiber into 10 kg of sulfuric acid-aqueous solution with a concentration of 0.8 wt%, and perform electrolysis for 15 s under the condition of a current of 0.65 A to obtain the surface-treated carbon fiber with a tensile strength of 3.1 GPa and a carbon-oxygen element ratio of 42.3%.

[0075] Preparation Example 2.3

[0076] The preparation method of the composite adsorbent is different from that of Preparation Example 1.3 in that: the current in the surface treatment of the carbon fiber in Step S1 is 0.48 A, and the rest are the same as Preparation Example 1.3, and the surface-treated carbon fiber with a tensile strength of 3.75 GPa and a carbon-oxygen element ratio of 41.6% is obtained.

[0077] Preparation Example 3

[0078] The preparation method of the composite adsorbent is different from that of Preparation Example 1.1 in that: Step S3 is removed, and the rest are the same as Preparation Example 1.1.

[0079] Preparation Example 4.1

[0080] The preparation method of the modified zeolite adsorbent includes the following steps:

[0081] According to a bath ratio of 1:90, immerse 3 kg of zeolite in a sodium chloride-aqueous solution with a sodium chloride concentration of 3 wt%, stir and oscillate for 12 h, then take out the zeolite, wash it, and obtain the modified zeolite adsorbent after drying.

[0082] Preparation Example 4.2

[0083] The preparation method of the modified zeolite adsorbent includes the following steps:

[0084] According to a bath ratio of 1:105, 3 kg of zeolite was immersed in a sodium chloride - aqueous solution with a sodium chloride concentration of 5 wt%, stirred and oscillated for 10 h, then the zeolite was taken out, washed, and dried to obtain a modified zeolite adsorbent.

[0085] Example 1.1.1

[0086] A treatment process for refinery wastewater includes the following steps:

[0087] 1. Cooling, flocculation and air flotation: 50 kg of refinery wastewater with an ammonia nitrogen content of 700 mg / L was naturally cooled to 25 °C, then 2.5 g of polyaluminum chloride was added for flocculation to make the suspended particles in the liquid aggregate, followed by air flotation treatment. After that, the refinery wastewater after air flotation was ultrafiltered to remove insoluble organic matters and solid particles in the refinery wastewater, obtaining refinery wastewater after air flotation with an ammonia nitrogen content of 650 mg / L;

[0088] II. Ammonia nitrogen removal: Adjust the pH value of the refinery wastewater after air flotation obtained in step I to 7.5, then add 2 g / L of ammonia nitrogen adsorbent (the composite adsorbent prepared in Preparation Example 1.1, with an addition amount of 1 g / L, and the modified zeolite adsorbent prepared in Preparation Example 4.1, with an addition amount of 1 g / L) into the system, and stir for 5 h to obtain refinery wastewater with an ammonia nitrogen concentration of 50.31 mg / L; III. Reverse osmosis and activated carbon degradation: The refinery wastewater obtained in step II was subjected to reverse osmosis treatment using a polysulfone membrane at an operating pressure of 3 MPa to obtain refinery wastewater with an ammonia nitrogen concentration of 13.67 mg / L, and then activated carbon was introduced under the conditions of a treatment load of 10 kg / m 3 ·d and an inlet speed of 5 L / h, and after activated carbon degradation, refinery wastewater reclaimed water with an ammonia nitrogen concentration of 13.23 mg / L and a COD concentration of 50.00 mg / L was obtained.

[0089] Example 1.1.2

[0090] A treatment process for refinery wastewater includes the following steps:

[0091] 2. Cooling, flocculation and air flotation: 50 kg of refinery wastewater with an ammonia nitrogen content of 700 mg / L was naturally cooled to 40 °C, then 2.5 g of polyaluminum chloride was added for flocculation to make the suspended particles in the liquid aggregate, followed by air flotation treatment. After that, the refinery wastewater after air flotation was ultrafiltered to remove insoluble organic matters and solid particles in the refinery wastewater, obtaining refinery wastewater after air flotation with an ammonia nitrogen content of 650 mg / L;

[0092] II. Ammonia nitrogen removal: Adjust the pH value of the oil-refining wastewater after air flotation treatment obtained in Step I to 7.5, and then add 2 g / L of ammonia nitrogen adsorbent to the system (the composite adsorbent prepared in Preparation Example 1.1, with an addition amount of 1 g / L, and the modified zeolite adsorbent prepared in Preparation Example 4.1, with an addition amount of 1 g / L). After stirring for 5 h, the oil-refining wastewater with an ammonia nitrogen concentration of 50.3 mg / L is obtained; III. Reverse osmosis and activated carbon degradation: Use a polysulfone membrane to perform reverse osmosis treatment on the oil-refining wastewater obtained in Step II, with an operating pressure of 3 MPa, to obtain oil-refining wastewater with an ammonia nitrogen concentration of 13.68 mg / L. Then, under the conditions of a treatment load of 10 kg / m 3 ·d and an inlet gas velocity of 5 L / h, introduce activated carbon. After activated carbon degradation, the regenerated water of the oil-refining wastewater with an ammonia nitrogen concentration of 13.30 mg / L and a COD concentration of 50.00 mg / L is obtained.

[0093] Example 1.2.1

[0094] A treatment process for oil-refining wastewater, comprising the following steps:

[0095] 1. Cooling, flocculation, and air flotation: Naturally cool 50 kg of oil-refining wastewater with an ammonia nitrogen content of 680 mg / L to 25°C, then add 2.5 g of polyaluminum chloride for flocculation to make the suspended particles in the liquid aggregate, and then perform air flotation treatment. After that, ultrafilter the oil-refining wastewater after air flotation to remove insoluble organic matters and solid particles in the oil-refining wastewater, and obtain the oil-refining wastewater after air flotation treatment with an ammonia nitrogen content of 630 mg / L;

[0096] II. Ammonia nitrogen removal: Adjust the pH value of the oil-refining wastewater after air flotation treatment obtained in Step I to 6.7, and then add 2.5 g / L of ammonia nitrogen adsorbent to the system (the composite adsorbent prepared in Preparation Example 1.2, with an addition amount of 1.36 g / L, and the modified zeolite adsorbent prepared in Preparation Example 4.2, with an addition amount of 1.14 g / L). After stirring for 4 h, the oil-refining wastewater with an ammonia nitrogen concentration of 50.7 mg / L is obtained; III. Reverse osmosis and activated carbon degradation: Use an aromatic polyamide composite membrane to perform reverse osmosis treatment on the oil-refining wastewater obtained in Step II, with an operating pressure of 3.4 MPa, to obtain oil-refining wastewater with an ammonia nitrogen concentration of 13.4 mg / L. Then, under the conditions of a treatment load of 15 kg / m 3 ·d and an inlet gas velocity of 4 L / h, introduce activated carbon. After activated carbon degradation, the regenerated water of the oil-refining wastewater with an ammonia nitrogen concentration of 13.19 mg / L and a COD concentration of 53.13 mg / L is obtained.

[0097] Example 1.2.2

[0098] A treatment process for oil-refining wastewater, comprising the following steps:

[0099] 1. Cooling, flocculation and air flotation: 50 kg of refinery wastewater with an ammonia nitrogen content of 680 mg / L is naturally cooled to 40 °C, and then 2.5 g of polyaluminum chloride is added for flocculation to cause the suspended particles in the liquid to aggregate. Then, air flotation treatment is carried out. After that, the refinery wastewater that has undergone air flotation is ultrafiltered to remove insoluble organic matter and solid particles in the refinery wastewater, obtaining refinery wastewater after air flotation treatment with an ammonia nitrogen content of 630 mg / L;

[0100] II. Ammonia nitrogen removal: Adjust the pH value of the refinery wastewater after air flotation treatment obtained in step I to 6.7, and then add 2.5 g / L of ammonia nitrogen adsorbent to the system (the composite adsorbent prepared in Preparation Example 1.2, with an addition amount of 1.36 g / L, and the modified zeolite adsorbent prepared in Preparation Example 4.2, with an addition amount of 1.14 g / L). After stirring for 4 h, refinery wastewater with an ammonia nitrogen concentration of 50.7 mg / L is obtained; III. Reverse osmosis and activated carbon degradation: The refinery wastewater obtained in step II is subjected to reverse osmosis treatment using an aromatic amide composite membrane at an operating pressure of 3.4 MPa, obtaining refinery wastewater with an ammonia nitrogen concentration of 13.4 mg / L. Then, under the conditions of a treatment load of 15 kg / m 3 ·d and an inlet rate of 4 L / h, activated carbon is introduced, and after activated carbon degradation, refinery wastewater reclaimed water with an ammonia nitrogen concentration of 13.19 mg / L and a COD concentration of 53.30 mg / L is obtained.

[0101] Example 1.3

[0102] A treatment process for refinery wastewater, which is different from Example 1.1.1 in that: in step II, the addition amount of the composite adsorbent in Preparation Example 1.1 is 1.04 g / L, and the addition amount of the modified zeolite adsorbent prepared in Preparation Example 4.1 is 0.96 g / L, obtaining refinery wastewater with an ammonia nitrogen concentration of 36.73 mg / L. The rest are the same as Example 1.1.1. After passing through the reverse osmosis membrane, refinery wastewater with an ammonia nitrogen concentration of 8.65 mg / L is obtained, and finally refinery wastewater reclaimed water with an ammonia nitrogen concentration of 8.12 mg / L and a COD concentration of 45.21 mg / L is obtained.

[0103] Example 2.1

[0104] A treatment process for refinery wastewater, which is different from Example 1.1.1 in that: the composite adsorbent prepared in Preparation Example 1.1 in step II is replaced with the composite adsorbent prepared in Preparation Example 1.3, obtaining refinery wastewater with an ammonia nitrogen concentration of 45.83 mg / L. The rest are the same as Example 1.1.1. After passing through the reverse osmosis membrane, refinery wastewater with an ammonia nitrogen concentration of 12.07 mg / L is obtained, and finally refinery wastewater reclaimed water with an ammonia nitrogen concentration of 11.69 mg / L and a COD concentration of 47.02 mg / L is obtained.

[0105] Example 2.2

[0106] A treatment process for refinery wastewater, which is different from Example 1.1.1 in that: the composite adsorbent prepared in Preparation Example 1.1 in Step II is replaced with the composite adsorbent prepared in Preparation Example 1.4, obtaining refinery wastewater with an ammonia nitrogen concentration of 45.89 mg / L. The rest are the same as those in Example 1.1.1. After passing through the reverse osmosis membrane, refinery wastewater with an ammonia nitrogen concentration of 12.59 mg / L is obtained, and finally, refinery wastewater reclaimed water with an ammonia nitrogen concentration of 11.62 mg / L and a COD concentration of 47.19 mg / L is obtained.

[0107] Example 2.3

[0108] A treatment process for refinery wastewater, which is different from Example 1.1.1 in that: the composite adsorbent prepared in Preparation Example 1.1 in Step II is replaced with the composite adsorbent prepared in Preparation Example 2.1, obtaining refinery wastewater with an ammonia nitrogen concentration of 47.13 mg / L. The rest are the same as those in Example 1.1.1. After passing through the reverse osmosis membrane, refinery wastewater with an ammonia nitrogen concentration of 12.68 mg / L is obtained, and finally, refinery wastewater reclaimed water with an ammonia nitrogen concentration of 12.25 mg / L and a COD concentration of 47.52 mg / L is obtained.

[0109] Example 2.4

[0110] A treatment process for refinery wastewater, which is different from Example 1.1.1 in that: the composite adsorbent prepared in Preparation Example 1.1 in Step II is replaced with the composite adsorbent prepared in Preparation Example 2.2, obtaining refinery wastewater with an ammonia nitrogen concentration of 47.00 mg / L. The rest are the same as those in Example 1.1.1. After passing through the reverse osmosis membrane, refinery wastewater with an ammonia nitrogen concentration of 12.61 mg / L is obtained, and finally, refinery wastewater reclaimed water with an ammonia nitrogen concentration of 12.18 mg / L and a COD concentration of 47.52 mg / L is obtained.

[0111] Example 2.5

[0112] A treatment process for refinery wastewater, which is different from Example 2.1 in that: the composite adsorbent prepared in Preparation Example 1.3 in Step II is replaced with the composite adsorbent prepared in Preparation Example 2.3, obtaining refinery wastewater with an ammonia nitrogen concentration of 45.37 mg / L. The rest are the same as those in Example 2.1. After passing through the reverse osmosis membrane, refinery wastewater with an ammonia nitrogen concentration of 12.12 mg / L is obtained, and finally, refinery wastewater reclaimed water with an ammonia nitrogen concentration of 11.69 mg / L and a COD concentration of 46.53 mg / L is obtained.

[0113] Example 2.6.1

[0114] A treatment process for refinery wastewater, which is different from Example 1.1.1 in that: the composite adsorbent prepared in Preparation Example 1.1 in Step II is replaced with the composite adsorbent prepared in Preparation Example 3, obtaining refinery wastewater with an ammonia nitrogen concentration of 55.12 mg / L. The rest are the same as in Example 1.1.1. After passing through the reverse osmosis membrane, refinery wastewater with an ammonia nitrogen concentration of 15.04 mg / L is obtained, and finally refinery wastewater reclaimed water with an ammonia nitrogen concentration of 14.49 mg / L and a COD concentration of 70.62 mg / L is obtained.

[0115] Example 2.6.2

[0116] A treatment process for refinery wastewater, which is different from Example 1.1.2 in that: in Step II, the composite adsorbent prepared in Preparation Example 1.1 is replaced with the composite adsorbent prepared in Preparation Example 3, obtaining refinery wastewater with an ammonia nitrogen concentration of 81.06 mg / L. The rest are the same as in Example 1.1.2. After passing through the reverse osmosis membrane, refinery wastewater with an ammonia nitrogen concentration of 30.24 mg / L is obtained, and finally refinery wastewater reclaimed water with an ammonia nitrogen concentration of 28.70 mg / L and a COD concentration of 102.30 mg / L is obtained.

[0117] Comparative Example 1.1

[0118] It is different from Example 1.1.1 in that: the ammonia nitrogen adsorbent in Step II is replaced with potassium dihydrogen phosphate and magnesium chloride, with the addition amount of potassium dihydrogen phosphate being 1 g / L and the addition amount of magnesium chloride being 1 g / L, obtaining refinery wastewater with an ammonia nitrogen concentration of 192.66 mg / L. The rest are the same as in Example 1.1.1. After passing through the reverse osmosis membrane, refinery wastewater with an ammonia nitrogen concentration of 98.06 mg / L is obtained, and finally refinery wastewater reclaimed water with an ammonia nitrogen concentration of 96.53 mg / L and a COD concentration of 60.39 mg / L is obtained.

[0119] Comparative Example 1.2

[0120] It is different from Example 1.1.1 in that: the ammonia nitrogen adsorbent in Step II is replaced with potassium dihydrogen phosphate and magnesium chloride, with the addition amount of potassium dihydrogen phosphate being 1 g / L and the addition amount of magnesium chloride being 1 g / L, and the operating pressure of reverse osmosis treatment in Step III is 2.5 MPa, obtaining refinery wastewater with an ammonia nitrogen concentration of 148.46 mg / L. The rest are the same as in Example 1.1.1. After passing through the reverse osmosis membrane, refinery wastewater with an ammonia nitrogen concentration of 66.47 mg / L is obtained, and finally refinery wastewater reclaimed water with an ammonia nitrogen concentration of 52.37 mg / L and a COD concentration of 60.39 mg / L is obtained.

[0121] Comparative Example 2.1

[0122] The difference from Example 1.1.1 is as follows: In Step II, the dosage of the composite adsorbent prepared in Preparation Example 1.1 is 1.5 g / L, and the dosage of the modified zeolite adsorbent prepared in Preparation Example 4.1 is 0.5 g / L, obtaining refinery wastewater with an ammonia nitrogen concentration of 54.86 mg / L. The rest is the same as in Example 1.1.1. After passing through the reverse osmosis membrane, refinery wastewater with an ammonia nitrogen concentration of 21.55 mg / L is obtained, and finally, refinery wastewater reclaimed water with an ammonia nitrogen concentration of 21.00 mg / L and a COD concentration of 78.21 mg / L is obtained.

[0123] Comparative Example 2.2

[0124] The difference from Example 1.1.1 is as follows: In Step II, the dosage of the composite adsorbent prepared in Preparation Example 1.1 is 0.5 g / L, and the dosage of the modified zeolite adsorbent prepared in Preparation Example 4.1 is 1.5 g / L, obtaining refinery wastewater with an ammonia nitrogen concentration of 54.67 mg / L. The rest is the same as in Example 1.1.1. After passing through the reverse osmosis membrane, refinery wastewater with an ammonia nitrogen concentration of 21.48 mg / L is obtained, and finally, refinery wastewater reclaimed water with an ammonia nitrogen concentration of 20.93 mg / L and a COD concentration of 77.88 mg / L is obtained.

[0125] Comparative Example 2.3

[0126] The difference from Example 1.1.1 is as follows: Remove the modified zeolite adsorbent in Step II, and the dosage of the composite adsorbent is 2 g / L, obtaining refinery wastewater with an ammonia nitrogen concentration of 53.8 mg / L and refinery wastewater with an ammonia nitrogen concentration of 56.42 mg / L. The rest is the same as in Example 1.1.1. After passing through the reverse osmosis membrane, refinery wastewater with an ammonia nitrogen concentration of 24.81 mg / L is obtained, and finally, refinery wastewater reclaimed water with an ammonia nitrogen concentration of 25.06 mg / L and a COD concentration of 94.71 mg / L is obtained.

[0127] Comparative Example 2.4

[0128] The difference from Example 1.1.1 is as follows: Remove the composite adsorbent in Step II, and the dosage of the modified zeolite adsorbent is 2 g / L, obtaining refinery wastewater with an ammonia nitrogen concentration of 62.6 mg / L and refinery wastewater with an ammonia nitrogen concentration of 65.59 mg / L. The rest is the same as in Example 1.1.1. After passing through the reverse osmosis membrane, refinery wastewater with an ammonia nitrogen concentration of 27.57 mg / L is obtained, and finally, refinery wastewater reclaimed water with an ammonia nitrogen concentration of 27.09 mg / L and a COD concentration of 93.89 mg / L is obtained.

[0129] Comparative Example 3

[0130] It is different from Example 1.1.1 in that the specific operation in Step II is as follows: adjust the pH value of the refinery wastewater after air flotation treatment in Step I to 7.5, divide the refinery wastewater into two equal parts, add the composite adsorbent prepared in Preparation Example 1.1 to one part, with an addition amount of 1.0 g / L, and add the modified zeolite adsorbent prepared in Preparation Example 4.1 to the other part, with an addition amount of 1.0 g / L. After stirring for 5 h, mix the two parts together to obtain refinery wastewater with an ammonia nitrogen concentration of 61.04 mg / L. After passing through the reverse osmosis membrane, refinery wastewater with an ammonia nitrogen concentration of 25.32 mg / L is obtained. Finally, refinery wastewater reclaimed water with an ammonia nitrogen concentration of 25.27 mg / L and a COD concentration of 79.53 mg / L is obtained.

[0131] Comparative Example 4

[0132] It is different from Example 1.1.1 in that the modified zeolite adsorbent prepared in Preparation Example 4.1 in Step II is replaced with zeolite, obtaining refinery wastewater with an ammonia nitrogen concentration of 84.63 mg / L. The rest is the same as Example 1.1.1. After passing through the reverse osmosis membrane, refinery wastewater with an ammonia nitrogen concentration of 35.00 mg / L is obtained. Finally, refinery wastewater reclaimed water with an ammonia nitrogen concentration of 32.48 mg / L and a COD concentration of 115.17 mg / L is obtained.

[0133] Performance detection

[0134] According to the measured ammonia nitrogen content of the refinery wastewater reclaimed water after the treatment in Step II, after the reverse osmosis membrane treatment, and finally obtained, as well as the COD content of the refinery wastewater reclaimed water, calculate respectively in Examples 1 - 3 and Comparative Examples 1 - 4:

[0135] 1. Ammonia nitrogen removal rate in Step II;

[0136] 2. Ammonia nitrogen removal rate in Step III;

[0137] 3. COD removal rate of the finally obtained refinery wastewater reclaimed water;

[0138] 4. Ammonia nitrogen removal rate of the finally obtained refinery wastewater reclaimed water; Record the results in Table 1.

[0139] Table 1

[0140]

[0141]

[0142] Data analysis:

[0143] As can be seen from Table 1, in Step II of Examples 1.1.1 - 1.2.2, the ammonia nitrogen removal rate can reach 91.82 - 94.35%, in Step III the ammonia nitrogen removal rate can reach 72.81 - 73.54%, and the ammonia nitrogen removal rate of the finally obtained refinery wastewater reclaimed water can reach 98.06 - 98.11%, and the COD removal rate can reach 96.77 - 96.97%. This proves that replacing potassium dihydrogen phosphate and magnesium chloride with a composite adsorbent and a modified zeolite adsorbent in this application not only improves the ammonia nitrogen removal rate in the ammonia nitrogen removal step but also improves the ammonia nitrogen removal rate in the reverse osmosis step. Both of the above two steps have a high ammonia nitrogen removal rate, and a synergistic effect is exerted between the two steps, reducing the ammonia nitrogen content of the refinery wastewater reclaimed water to 13.23 - 13.58 mg / L, showing a good ammonia nitrogen removal effect;

[0144] In Step II of Example 1.3, the ammonia nitrogen removal rate, in Step III the ammonia nitrogen removal rate, the ammonia nitrogen removal rate of the finally obtained refinery wastewater reclaimed water, and the COD removal rate are all higher than those of Example 1.1.1. This proves that by controlling the weight ratio of the composite adsorbent and the modified zeolite adsorbent in this application, the ammonia nitrogen removal effect of the ammonia nitrogen remover is optimized, and the ammonia nitrogen removal rate in Step II is increased to 94.35%;

[0145] In Step II of Examples 2.1 - 2.2, the ammonia nitrogen removal rate, in Step III the ammonia nitrogen removal rate, the ammonia nitrogen removal rate of the finally obtained refinery wastewater reclaimed water, and the COD removal rate are all higher than those of Example 1.1.1. This proves that using the electrochemical treatment method to treat the surface of carbon fiber in this application can make the composite adsorbent have a relatively stable mechanical structure. During the stirring operation in Step II, the ammonia nitrogen adsorbent of this application can more stably and efficiently exert the effect of removing ammonia nitrogen;

[0146] In Step II of Examples 2.3 - 2.4, the ammonia nitrogen removal rate, in Step III the ammonia nitrogen removal rate, the ammonia nitrogen removal rate of the finally obtained refinery wastewater reclaimed water, and the COD removal rate are all lower than those of Example 2.1. In Step II of Example 2.5, the ammonia nitrogen removal rate, in Step III the ammonia nitrogen removal rate, the ammonia nitrogen removal rate of the finally obtained refinery wastewater reclaimed water, and the COD removal rate are all higher than those of Example 2.1. This proves that by controlling the current magnitude in the surface treatment of carbon fiber in this application, the tensile strength of carbon fiber and the oxygen - carbon element ratio on the surface are in an optimal balance, which also makes the ammonia nitrogen removal rate of the composite adsorbent at the highest level;

[0147] In Example 2.6.1, the ammonia nitrogen removal rate in Step II, the ammonia nitrogen removal rate in Step III, the ammonia nitrogen removal rate of the finally obtained refinery wastewater reclaimed water, and the COD removal rate are all lower than those in Example 1.1.1. In Example 2.6.2, the ammonia nitrogen removal rate in Step II, the ammonia nitrogen removal rate in Step III, the ammonia nitrogen removal rate of the finally obtained refinery wastewater reclaimed water, and the COD removal rate are even much lower than those in Example 1.1.2. This proves that depositing a conductive diamond layer with a certain thickness on the surface of the crude product in this application can enable the composite adsorbent to cooperate with the carbon fiber preliminarily modified by alumina and iron oxide, promoting it to more stably exert the effect of ammonia nitrogen removal. It can also remove the organic matter in the refinery wastewater and reduce the COD content in the reclaimed water. Moreover, it further proves that the conductive diamond layer in this application can effectively improve the thermal stability of the carbon fiber after preliminary modification, enabling it to still have good ammonia nitrogen and COD removal capabilities under the condition that the treatment temperature is 15°C higher than the conventional temperature, proving that the composite adsorbent provided in this application has a wide temperature application range, strong applicability, and stable ammonia nitrogen and COD removal capabilities;

[0148] In Comparative Example 1.1, the ammonia nitrogen removal rate in Step II, the ammonia nitrogen removal rate in Step III, and the ammonia nitrogen removal rate of the finally obtained refinery wastewater reclaimed water are all lower than those in Example 1.1.1. This proves that replacing potassium dihydrogen phosphate and magnesium chloride with the composite adsorbent and the modified zeolite adsorbent in this application not only improves the ammonia nitrogen removal rate in the ammonia nitrogen removal step but also improves the ammonia nitrogen removal rate in the reverse osmosis step, and both steps have a high ammonia nitrogen removal rate;

[0149] In Comparative Example 1.2, the ammonia nitrogen removal rate in Step II, the ammonia nitrogen removal rate in Step III, and the ammonia nitrogen removal rate of the finally obtained refinery wastewater reclaimed water are all significantly higher than those in Comparative Example 1.1. This proves that there is a coordination effect among the steps of the treatment process in this application, and it can still have a very high ammonia nitrogen removal rate and COD removal rate under the condition of reducing the operation time and operation cost, and the treatment effect of the refinery wastewater is relatively good;

[0150] In Comparative Examples 2.1 - 2.2, the ammonia nitrogen removal rate in Step II, the ammonia nitrogen removal rate in Step III, the ammonia nitrogen removal rate of the finally obtained refinery wastewater reclaimed water, and the COD removal rate are all lower than those in Example 1.1.1. This proves that by controlling the weight ratio of the composite adsorbent and the modified zeolite adsorbent in this application, the ammonia nitrogen removal effect of the ammonia nitrogen remover is further optimized;

[0151] In Comparative Examples 2.3 - 2.4, the ammonia nitrogen removal rate in Step II, the ammonia nitrogen removal rate in Step III, the ammonia nitrogen removal rate of the finally obtained refinery wastewater reclaimed water, and the COD removal rate are all lower than those in Example 1.1.1. This proves that the synergistic effect of the composite adsorbent and the modified zeolite adsorbent is fully exerted in this application, improving the ammonia nitrogen removal rate of the ammonia nitrogen remover;

[0152] Comparative Example 3 uses a composite adsorbent and a modified zeolite adsorbent to treat refinery wastewater respectively, and it is found that the ammonia nitrogen removal rate in Step II is much lower than that in Example 1.1.1, which proves that there is a synergistic effect between the composite adsorbent and the modified zeolite adsorbent of the present application. The effect of using them simultaneously is much higher than the superposition effect after using them separately. Therefore, the two cooperate to significantly improve the ammonia nitrogen removal effect of the ammonia nitrogen remover;

[0153] The ammonia nitrogen removal rate in Step II, the ammonia nitrogen removal rate in Step III, the ammonia nitrogen removal rate of the finally obtained regenerated water of refinery wastewater and the COD removal rate in Comparative Example 4 are all lower than those in Example 1.1.1, which proves that the present application uses sodium chloride to modify zeolite, which can broaden the internal pores and pore diameters, thereby further improving the adsorption capacity of zeolite. Moreover, the sodium ions in sodium chloride will undergo ion exchange reactions with metal cations such as aluminum ions, magnesium ions and calcium ions in zeolite, increasing the ion exchange capacity of zeolite. Therefore, the ammonia nitrogen removal rate of the modified zeolite adsorbent is further improved.

[0154] The examples of this specific embodiment are all preferred embodiments of the present application, and do not limit the protection scope of the present application accordingly. Therefore, all equivalent changes made according to the structure, shape and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A treatment process for refinery wastewater, characterized in that: It includes the following steps: Step I, cooling, flocculation and air flotation; Step II, ammonia nitrogen removal: adjust the pH value of the refinery wastewater obtained after air flotation treatment to 7.5, then add 1.04 g / L of composite adsorbent and 0.96 g / L of modified zeolite adsorbent into the system, and stir for 5 h to obtain refinery wastewater with an ammonia nitrogen concentration of 36.73 mg / L; Step III, reverse osmosis and activated carbon degradation: Under the condition that the operating pressure is 3 - 3.4 Mpa, the refinery wastewater obtained in Step II is subjected to reverse osmosis treatment, and then activated carbon is introduced under the conditions that the treatment load is 10 - 15 kg / m 3 ·d and the feeding rate is 4 - 5 L / h for activated carbon degradation to obtain the regenerated water of refinery wastewater; The composite adsorbent is prepared by the following method: S1. Surface treatment of carbon fiber: In an environment with a pressure of 101.325 kPa, use air as the carbon fiber surface treatment medium to generate atmospheric low-temperature plasma, and perform low-temperature plasma bombardment on the surface of the moving carbon fiber. The running speed of the carbon fiber tow is 80 m / h, the working environment temperature of carbon fiber treatment is 15 °C, the gap between the carbon fiber and the plasma emission device is 8 mm, the humidity of the carbon fiber surface treatment environment is 60%, the power range of carbon fiber surface treatment is 500 W / tow, and the low-temperature plasma carbon fiber surface treatment temperature is 80 °C to obtain surface-treated carbon fiber with a tensile strength of 2.8 GPa and a carbon-oxygen element ratio of 39.2%; S2. Calcinate 50 kg of the mixed sludge containing alumina and iron oxide at 500 °C for 0.8 h. After cooling, put it into a hydrochloric acid solution with a concentration of 40 wt% according to a bath ratio of 1:15, stir for 1.5 h, centrifuge, take the supernatant, filter, take 56 kg of the supernatant and mix it with 2 kg of surface-treated carbon fiber, stir for 1.8 h and then filter. After obtaining the composite carbon fiber, add it to a sodium hydroxide-aqueous solution with a sodium hydroxide concentration of 1 mol / L and let it stand for 1.5 h, filter, then wash the composite carbon fiber and dry it to a constant mass to obtain the crude product; S3. Under the conditions of introducing gas and methane, deposit conductive diamond doped with boron element on the surface of the crude product by means of DC injection until the layer thickness of the conductive diamond reaches 50 μm and the boron doping amount is greater than 1×1000 atoms·cm -3 , to obtain a composite adsorbent, wherein the deposition temperature is 850 °C, the chamber pressure is 3 KPa, the gas flow rate is 8 SLM, and the methane flow rate is 130 sccm; The modified zeolite adsorbent is prepared by the following method: Immerse 3 kg of zeolite in a sodium chloride-aqueous solution with a sodium chloride concentration of 3 wt% according to a bath ratio of 1:90, stir and oscillate for 12 h, then take out the zeolite, wash it, and dry it to obtain the modified zeolite adsorbent.

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