Composite ammonia-nitrogen removal agent for treating ammonia-nitrogen-containing wastewater as well as preparation method and application of composite ammonia-nitrogen removal agent

Abstract

The invention discloses a composite ammonia nitrogen removal agent for treating wastewater containing ammonia nitrogen as well as a preparation method and application of the composite ammonia nitrogen removal agent. The composite ammonia nitrogen removal agent is prepared from the following raw material components: polymerized ferrous sulfate, lanthanum sulfate, cerous sulfate, samarium sulfate, yttrium sulfate, calcium sulfate, silicon sulfate, sodium hypochlorite, potassium citrate and lauryl sodium sulfate. The composite ammonia nitrogen removal agent can quickly convert ammonia nitrogen in wastewater into an ammonia nitrogen compound precipitate under the synergistic effect of the components, has the advantages of high ammonia nitrogen reaction speed, good precipitation effect and the like, is a novel agent with excellent ammonia nitrogen removal performance, and has the advantages of low cost and high efficiency when being used for treating ammonia nitrogen-containing wastewater. According to the present invention, the ammonia nitrogen in the wastewater can be reduced to less than 5 mg / L under the synergistic effect of the flocculant, the advanced treatment and the large-scale treatment of the ammonia-nitrogen-containing wastewater can be achieved, and the method has advantages of simple process, simple operation, low treatment cost, high treatment efficiency, good removal effect and the like, and has important significance on the harmlessness and the reduction of the ammonia-nitrogen wastewater.

Description

Technical Field

[0001] The invention belongs to the technical field of environmental engineering, and relates to a composite ammonia nitrogen removal agent for treating ammonia nitrogen-containing wastewater, and a preparation method and application thereof. Background Art

[0002] The sources of ammonia nitrogen pollution include domestic sewage, industrial sewage, livestock and poultry sewage and landfill leachate. Among them, high-concentration ammonia nitrogen wastewater generally comes from landfill leachate, hydrometallurgy, large-scale breeding, flue gas desulfurization and denitrification wastewater, synthetic ammonia industry, coke, oil refining fertilizer, artificial fiber and other production processes. The harm of ammonia nitrogen wastewater to the environment has attracted the attention of the environmental protection field worldwide.

[0003] The main problems caused by the increase of ammonia nitrogen levels in water sources are: (1) Excessive ammonia nitrogen concentration will accelerate the process of eutrophication of water bodies, causing toxic algae to reproduce in large numbers, resulting in a decline in water quality, discoloration and taste change of water bodies, and the release of toxins that harm aquatic organisms and livestock; (2) The process of oxidizing ammonia nitrogen consumes a large amount of dissolved oxygen in the water environment, causing rivers, lakes and other water bodies to be hypoxic and fish to die; (3) Ammonia nitrogen can be converted into nitrates and nitrites in aqueous solution, causing diseases such as methemoglobinemia in humans, which seriously endangers human health. In addition, a large amount of ammonia gas may be produced during the treatment of ammonia nitrogen wastewater. Ammonia gas, as a relatively strong alkaline and corrosive pollutant, can cause severe burns to the eyes, skin and respiratory system. It can also react with SO x or NO x It reacts with other air pollutants to form ammonium salts, leading to an increase in the concentration of PM 2.5 in the atmospheric environment.

[0004] Technologies for removing ammonia nitrogen from wastewater include physical methods, chemical methods, biological methods, and a combination of multiple methods. Physical methods include air stripping, ion exchange, and membrane separation technology; biological methods include activated sludge, nitrification and denitrification, new methods based on activated sludge, microalgae treatment, and photosynthetic bacteria; chemical methods include breakpoint chlorination, wet catalytic oxidation, and magnesium ammonium phosphate precipitation. These technical methods for removing ammonia nitrogen have their own advantages and disadvantages. Although the physical method has a simple process and stable effect, it has problems such as high treatment cost and easy to cause secondary environmental pollution; although the biological method has the advantages of mild reaction conditions and no secondary pollution, it also has disadvantages such as large area and difficult maintenance; although the chemical method has the advantage of good treatment effect, the breakpoint chlorination method and magnesium ammonium phosphate method are prone to secondary pollution, and the wet catalytic oxidation method is too expensive. The above problems limit the widespread use of these methods.

[0005] For ammonia nitrogen wastewater generated by different industries, a single treatment method is difficult to meet the treatment requirements, and the main ammonia nitrogen wastewater treatment methods currently have their own limitations. For example, the precipitation method cannot meet the treatment standards in theory, and the adsorption method, membrane method and biological method have different requirements for the salinity and biodegradability of the influent water quality. In addition, some researchers have proposed a process for treating ammonia nitrogen wastewater using ammonium ferrous sulfite precipitation method, using soluble ferrous salts and soluble sulfite salts as precipitants to precipitate ammonia nitrogen wastewater and convert ammonia nitrogen in the wastewater into ammonium ferrous sulfite precipitate. However, this method still has defects such as poor precipitation effect and poor removal effect of ammonia nitrogen in wastewater, especially it is difficult to reduce the concentration of ammonia nitrogen (in terms of N) in wastewater to below 5 mg / L, which cannot meet the relevant emission standards. At the same time, the precipitant used in the above process also has shortcomings such as slow precipitation rate, which also leads to low treatment efficiency of the process, and thus it is difficult to increase the treatment capacity of ammonia nitrogen wastewater and difficult to treat ammonia nitrogen wastewater on a large scale. Therefore, obtaining a composite ammonia nitrogen removal agent with fast ammonia nitrogen precipitation speed and good removal effect is of great significance for achieving deep purification of ammonia nitrogen wastewater. Summary of the invention

[0006] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a composite ammonia nitrogen removal agent for treating ammonia nitrogen-containing wastewater with fast ammonia nitrogen precipitation speed and good removal effect, as well as a preparation method and application thereof.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions.

[0008] A composite ammonia nitrogen removal agent for treating ammonia nitrogen-containing wastewater, the composite ammonia nitrogen removal agent comprises the following raw material components: polyferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate, silicon sulfate, sodium hypochlorite, potassium citrate, and sodium dodecyl sulfate; the mass ratio of the polyferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate, and silicon sulfate is 6-8:3-4:2-3:2-3:1-2:1-2:1-2, and the mass ratio of the total mass of the polyferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate, and silicon sulfate to the mass ratio of the sodium hypochlorite, potassium citrate, and sodium dodecyl sulfate is 2-5:2-5:2-5:1-2.

[0009] The above-mentioned composite ammonia nitrogen removal agent is further improved, wherein the mass ratio of the polymerized ferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate and silicon sulfate is 35:17:13:11:9:8:7, and the mass ratio of the total mass of the polymerized ferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate and silicon sulfate to the mass ratio of the sodium hypochlorite, potassium citrate and sodium dodecyl sulfate is 3:3:3:1.

[0010] As a general technical concept, the present invention also provides a method for preparing the above-mentioned composite ammonia nitrogen removal agent for treating ammonia nitrogen-containing wastewater, comprising the following steps: S1, mixing polymerized ferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate and silicon sulfate to obtain a mixture; the mass ratio of the polymerized ferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate and silicon sulfate is 6-8:3-4:2-3:2-3:1-2:1-2:1-2; S2. Mix the mixture obtained in step S1, sodium hypochlorite, potassium citrate and sodium dodecyl sulfate, and obtain a composite ammonia nitrogen removal agent by drying, grinding and sieving; the mass ratio of the mixture, sodium hypochlorite, potassium citrate and sodium dodecyl sulfate is 2-5:2-5:2-5:1-2.

[0011] The above preparation method is further improved in that the particle size of the composite ammonia nitrogen removal agent is 80 mesh to 120 mesh, the drying temperature is 25° C. to 35° C., and the drying pressure is 0.1 MPa to 0.12 MPa.

[0012] As a general technical concept, the present invention also provides an application of the above-mentioned composite ammonia nitrogen removal agent in treating ammonia nitrogen-containing wastewater.

[0013] The above application, further improved, comprises the following steps: (1) Mixing the composite ammonia nitrogen removal agent and ammonia nitrogen-containing wastewater to perform precipitation reaction to obtain a mixed solution; (2) Add a flocculant to the mixed solution obtained in step (1) for flocculation treatment, and filter to complete the treatment of the ammonia nitrogen-containing wastewater.

[0014] The above application is further improved, in step (1), the composite ammonia nitrogen removal agent is implemented in the form of a composite ammonia nitrogen removal agent solution, and the preparation process of the composite ammonia nitrogen removal agent solution is: mixing the composite ammonia nitrogen removal agent and water to obtain a composite ammonia nitrogen removal agent solution; the volume ratio of the composite ammonia nitrogen removal agent solution to the ammonia nitrogen-containing wastewater is 1 to 2:20, and the mass percentage concentration of the composite ammonia nitrogen removal agent solution is 1%; In step (2), the volume ratio of the flocculant to the ammonia nitrogen-containing wastewater is 1-3:200, the flocculant is a polyacrylamide solution, and the mass percentage concentration of the polyacrylamide solution is 0.1%.

[0015] The above application is further improved in that the volume ratio of the composite ammonia nitrogen removal agent solution to the ammonia nitrogen-containing wastewater is 3-4:40, and the volume ratio of the flocculant to the ammonia nitrogen-containing wastewater is 1:200.

[0016] The above application is further improved in that the initial concentration of ammonia nitrogen in the ammonia nitrogen-containing wastewater is ≤100 mg / L.

[0017] The above application is further improved, in step (1), the precipitation reaction time is 15min to 30min, and the precipitation reaction is carried out under stirring conditions; In step (2), the flocculation treatment time is 60 min to 120 min.

[0018] Compared with the prior art, the advantages of the present invention are: (1) The present invention provides a composite ammonia nitrogen removal agent for treating ammonia nitrogen-containing wastewater, which uses polyferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate, silicon sulfate, sodium hypochlorite, potassium citrate and sodium dodecyl sulfate as raw materials, and according to the mass ratio of polyferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate and silicon sulfate of 6-8:3-4:2-3:2-3:1-2:1-2:1-2, and the mass ratio of their total mass to sodium hypochlorite, potassium citrate and sodium dodecyl sulfate of 2-5:2-5:2-5:1-2, they are compounded into a composite ammonia nitrogen removal agent. When the composite ammonia nitrogen removal agent is used to treat ammonia nitrogen-containing wastewater, under the synergistic effect of each component, ammonia nitrogen in the wastewater can be quickly converted into ammonia nitrogen complex precipitation to form dispersed large particle precipitation, so that the ammonia nitrogen precipitation in the wastewater is more thorough, and finally the effect of deep removal of ammonia nitrogen in the wastewater is achieved. The composite ammonia nitrogen removal agent of the present invention has the advantages of fast ammonia nitrogen reaction speed and good precipitation effect. It is a new type of agent with excellent ammonia nitrogen removal performance, can be widely used in treating ammonia nitrogen wastewater, and can achieve deep purification of ammonia nitrogen wastewater. It has high use value and good application prospects.

[0019] (2) The present invention also provides a method for preparing a composite ammonia nitrogen removal agent for treating ammonia nitrogen-containing wastewater, wherein the raw materials are polyferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate, silicon sulfate, sodium hypochlorite, potassium citrate and sodium dodecyl sulfate, and the mass ratio of polyferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate and silicon sulfate is 6-8:3-4:2-3:2-3:1-2:1-2:1-2, and the mass ratio of their total mass to sodium hypochlorite, potassium citrate and sodium dodecyl sulfate is 2-5:2-5:2-5:1-2. The composite ammonia nitrogen removal agent with fast reaction rate and good precipitation effect is prepared. At the same time, the preparation method also has the advantages of simple process and convenient operation, and is suitable for large-scale industrial production and convenient for industrial application.

[0020] (3) The present invention also provides an application of a composite ammonia nitrogen removal agent in treating ammonia nitrogen-containing wastewater. The composite ammonia nitrogen removal agent and ammonia nitrogen-containing wastewater are first mixed for precipitation reaction, so that the ammonia nitrogen in the wastewater can be quickly converted into dispersed large-particle ammonia nitrogen complex precipitation, and then a flocculant is added for flocculation treatment to promote the agglomeration of large-particle ammonia nitrogen complex precipitation and improve the sedimentation effect. After filtration, the filtrate and the ammonia nitrogen complex precipitation are effectively separated, and finally the ammonia nitrogen in the wastewater is completely removed. In the present invention, through the combined action of the "composite ammonia nitrogen removal agent + flocculant" multi-process, the ammonia nitrogen (in terms of N) in the wastewater can be reduced to less than 5 mg / L, and the deep treatment of ammonia nitrogen-containing wastewater of different water qualities can be achieved. It has the advantages of simple process, simple operation, low treatment cost, high treatment efficiency and good removal effect, which is conducive to the large-scale treatment of ammonia nitrogen wastewater and has important significance for achieving the harmlessness and reduction of ammonia nitrogen wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the process flow for treating ammonia nitrogen-containing wastewater using a composite ammonia nitrogen removal agent in Example 1 of the present invention. DETAILED DESCRIPTION

[0022] The present invention is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present invention is not limited thereby. The materials and instruments used in the following embodiments are all commercially available.

[0023] Embodiment 1: A composite ammonia nitrogen removal agent for treating ammonia nitrogen-containing wastewater of the present invention is composed of the following raw material components: polyferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate, silicon sulfate, sodium hypochlorite, potassium citrate and sodium dodecyl sulfate; wherein the mass ratio of polyferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate and silicon sulfate is 35:17:13:11:9:8:7, and the mass ratio of the total mass of polyferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate and silicon sulfate to the mass ratio of sodium hypochlorite, potassium citrate and sodium dodecyl sulfate is 3:3:3:1.

[0024] A method for preparing a composite ammonia nitrogen removal agent for treating ammonia nitrogen-containing wastewater according to the present embodiment comprises the following steps: (1) according to the mass ratio of polyferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate and silicon sulfate being 35:17:13:11:9:8:7, polyferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate and silicon sulfate are uniformly mixed to obtain a mixture A; (2) Mixing the mixture A obtained in step (1), sodium hypochlorite, potassium citrate and sodium dodecyl sulfate in a mass ratio of 3:3:3:1 to obtain a mixture B; (3) The mixture B obtained in step (2) is dried at a temperature of 28° C. and a pressure of 0.11 MPa, and then ground and sieved to control the particle size to 80 mesh to 120 mesh to obtain a composite ammonia nitrogen removal agent.

[0025] An application of the composite ammonia nitrogen removal agent prepared in the above embodiment in treating ammonia nitrogen-containing wastewater is to use a combined process of "composite ammonia nitrogen removal agent + flocculant" to treat ammonia nitrogen-containing wastewater. The treatment process is as follows: Figure 1 As shown, the following steps are included: (1) The prepared composite ammonia nitrogen removal agent is dissolved in water to obtain a composite ammonia nitrogen removal agent solution, wherein the mass percentage concentration of the composite ammonia nitrogen removal agent in the composite ammonia nitrogen removal agent solution is 1%.

[0026] (2) Take 200 mL of ammonia nitrogen-containing wastewater, the concentration of ammonia nitrogen (in terms of N) in the ammonia nitrogen-containing wastewater is 20.71 mg / L, add 15 mL of the composite ammonia nitrogen removal agent solution prepared in step (1) under stirring conditions for precipitation reaction, stir for 15 minutes, add 1 mL of polyacrylamide solution (the mass percentage concentration of the solution is 0.1%) for flocculation treatment, stir for 5 minutes, let stand for 1 hour, filter, and complete the treatment of the ammonia nitrogen-containing wastewater.

[0027] The filtrate obtained after filtration was tested to obtain the concentration of residual ammonia nitrogen in the filtrate, and the removal effect of the composite ammonia nitrogen removal agent on ammonia nitrogen in wastewater was calculated. The results are shown in Table 1.

[0028] Embodiment 2: A composite ammonia nitrogen removal agent for treating ammonia nitrogen-containing wastewater of the present invention is composed of the following raw material components: polyferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate, silicon sulfate, sodium hypochlorite, potassium citrate and sodium dodecyl sulfate; wherein the mass ratio of polyferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate and silicon sulfate is 35:15:13:11:9:8:7, and the mass ratio of the total mass of polyferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate and silicon sulfate to the mass ratio of sodium hypochlorite, potassium citrate and sodium dodecyl sulfate is 3:3:3:1.

[0029] A method for preparing a composite ammonia nitrogen removal agent for treating ammonia nitrogen-containing wastewater in this embodiment is basically the same as the method for preparing the composite ammonia nitrogen removal agent in Example 1, with the only difference being that the amount of raw materials used in the composite ammonia nitrogen removal agent is different.

[0030] The application of the composite ammonia nitrogen removal agent prepared in the above-mentioned embodiment in treating ammonia nitrogen-containing wastewater is basically the same as the application method in Example 1, with the only difference being that the composite ammonia nitrogen removal agent prepared in Example 2 replaces the composite ammonia nitrogen removal agent prepared in Example 1.

[0031] The filtrate obtained after filtration was tested to obtain the concentration of residual ammonia nitrogen in the filtrate, and the removal effect of the composite ammonia nitrogen removal agent on ammonia nitrogen in wastewater was calculated. The results are shown in Table 1.

[0032] Embodiment 3: A composite ammonia nitrogen removal agent for treating ammonia nitrogen-containing wastewater of the present invention is composed of the following raw material components: polyferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate, silicon sulfate, sodium hypochlorite, potassium citrate and sodium dodecyl sulfate; wherein the mass ratio of polyferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate and silicon sulfate is 35:20:13:11:9:8:7, and the mass ratio of the total mass of polyferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate and silicon sulfate to the mass ratio of sodium hypochlorite, potassium citrate and sodium dodecyl sulfate is 3:3:3:1.

[0033] A method for preparing a composite ammonia nitrogen removal agent for treating ammonia nitrogen-containing wastewater in this embodiment is basically the same as the method for preparing the composite ammonia nitrogen removal agent in Example 1, with the only difference being that the amount of raw materials used in the composite ammonia nitrogen removal agent is different.

[0034] The application of the composite ammonia nitrogen removal agent prepared in the above-mentioned embodiment in treating ammonia nitrogen-containing wastewater is basically the same as the application method in Example 1, with the only difference being that the composite ammonia nitrogen removal agent prepared in Example 3 replaces the composite ammonia nitrogen removal agent prepared in Example 1.

[0035] The filtrate obtained after filtration was tested to obtain the concentration of residual ammonia nitrogen in the filtrate, and the removal effect of the composite ammonia nitrogen removal agent on ammonia nitrogen in wastewater was calculated. The results are shown in Table 1.

[0036] Comparative Example 1: A composite ammonia nitrogen removal agent is basically the same as Example 1, except that in Comparative Example 1, lanthanum sulfate, cerium sulfate, samarium sulfate, and yttrium sulfate are not added.

[0037] The application of the composite ammonia nitrogen removal agent prepared in the above comparative example in treating ammonia nitrogen-containing wastewater is basically the same as the application method in Example 1, with the only difference being that the composite ammonia nitrogen removal agent prepared in Comparative Example 1 replaces the composite ammonia nitrogen removal agent prepared in Example 1.

[0038] The filtrate obtained after filtration was tested to obtain the concentration of residual ammonia nitrogen in the filtrate, and the removal effect of the composite ammonia nitrogen removal agent on ammonia nitrogen in wastewater was calculated. The results are shown in Table 1.

[0039] Comparative Example 2: A method for treating ammonia nitrogen-containing wastewater is basically the same as Example 1, with the only difference being that in Comparative Example 2, ferrous sulfate and sodium sulfite are used as ammonia nitrogen precipitants instead of the composite ammonia nitrogen removal agent prepared in Example 1.

[0040] Table 1 Comparison of the effects of different composite ammonia nitrogen removal agents on ammonia nitrogen-containing wastewater

[0041] It can be seen from the experimental results in Table 1 that the composite ammonia nitrogen removal agent prepared in Examples 1 to 3 has a very good ammonia nitrogen removal effect, and can reduce the ammonia nitrogen (in terms of N) in the wastewater to less than 5 mg / L. However, the composite ammonia nitrogen removal agent prepared in Comparative Example 1 has a poor ammonia nitrogen removal effect because lanthanum sulfate, cerium sulfate, samarium sulfate, and yttrium sulfate are not added. The ammonia nitrogen (in terms of N) content in the filtrate after treatment is still 7.97 mg / L, which cannot meet the relevant emission standards; in Comparative Example 2, ferrous sulfate and sodium sulfite are used as ammonia nitrogen precipitants instead of the composite ammonia nitrogen removal agent prepared in Example 1, and the ammonia nitrogen removal effect is the worst, and the ammonia nitrogen (in terms of N) content in the filtrate after treatment is still 15.35 mg / L. The ammonia nitrogen (in terms of N) content of the filtrate after treatment in Comparative Examples 1 and 2 exceeds 5 mg / L, which cannot meet the relevant emission standards.

[0042] Embodiment 4: An application of the composite ammonia nitrogen removal agent for treating ammonia nitrogen-containing wastewater of the present invention in treating ammonia nitrogen-containing wastewater comprises the following steps: The composite ammonia nitrogen removal agent prepared in Example 1 was dissolved in water to obtain a composite ammonia nitrogen removal agent solution (the mass percentage concentration of the solution was 1%); 200 mL of production wastewater from a new energy material plant was taken, the concentration of ammonia nitrogen (in terms of N) in the ammonia nitrogen-containing wastewater was 19.68 mg / L, 15 mL of the above composite ammonia nitrogen removal agent solution was added under stirring for precipitation reaction, and stirred for 15 minutes; then 1 mL of polyacrylamide solution (the mass percentage concentration of the solution was 0.1%) was added for flocculation treatment, stirred for 5 minutes, allowed to stand for 1 hour, and filtered to complete the treatment of the ammonia nitrogen-containing wastewater.

[0043] The filtrate obtained after filtration was tested to obtain the concentration of residual ammonia nitrogen in the filtrate, and the removal effect of the composite ammonia nitrogen removal agent on ammonia nitrogen in wastewater was calculated. The results are shown in Table 2.

[0044] In this embodiment, the effects of different amounts of composite ammonia nitrogen removal agent solutions on the removal of ammonia nitrogen from ammonia nitrogen-containing wastewater are also investigated, as shown in Table 2. Except for the different amounts of composite ammonia nitrogen removal agent, other conditions are the same as those in Example 4.

[0045] Table 2 Comparison of ammonia nitrogen removal effects on ammonia nitrogen-containing wastewater under different dosage conditions of composite ammonia nitrogen removal agent solution

[0046] It can be seen from the experimental results in Table 2 that when the dosage of the composite ammonia nitrogen removal agent solution is less than 10mL, the ammonia nitrogen removal effect is poor, and the ammonia nitrogen (in terms of N) content in the filtrate after wastewater purification is greater than 5mg / L; when the dosage of the composite ammonia nitrogen removal agent solution is 10mL~20mL, the ammonia nitrogen removal effect is good, and the ammonia nitrogen (in terms of N) content in the filtrate after wastewater purification is less than 5mg / L; when the dosage of the composite ammonia nitrogen removal agent solution is greater than 20mL, increasing the dosage of the composite ammonia nitrogen removal agent has little effect on the ammonia nitrogen removal effect. Therefore, the dosage of the composite ammonia nitrogen removal agent solution is more appropriate at 10mL~20mL.

[0047] It can be seen from the above results that the composite ammonia nitrogen removal agent of the present invention, under the synergistic effect of each component, can quickly convert ammonia nitrogen in wastewater into ammonia nitrogen complex precipitation to form large particle precipitation, which is conducive to the deep treatment of ammonia nitrogen wastewater, has the advantages of fast ammonia nitrogen reaction speed and good precipitation effect, is a novel agent with excellent ammonia nitrogen removal performance, can be widely used to treat ammonia nitrogen wastewater, and can achieve deep purification of ammonia nitrogen wastewater, has high use value and good application prospects. At the same time, the composite ammonia nitrogen removal agent of the present invention, under the synergistic effect of flocculants, can reduce ammonia nitrogen (in terms of N) in wastewater to less than 5mg / L, and can achieve deep treatment and large-scale treatment of ammonia nitrogen-containing wastewater of different water qualities, has the advantages of simple process, simple operation, low treatment cost, high treatment efficiency and good removal effect, and is of great significance for achieving harmlessness and reduction of ammonia nitrogen wastewater.

[0048] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as above in the preferred embodiment, it is not used to limit the present invention. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention, still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A composite ammonia nitrogen removal agent for treating ammonia nitrogen-containing wastewater, characterized in that: The composite ammonia nitrogen removal agent includes the following raw material components: polyferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate, silicon sulfate, sodium hypochlorite, potassium citrate, and sodium dodecyl sulfate; the mass ratio of the polyferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate, and silicon sulfate is 6-8:3-4:2-3:2-3:1-2:1-2:1-2, and the mass ratio of the total mass of the polyferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate, and silicon sulfate to the mass ratio of the sodium hypochlorite, potassium citrate, and sodium dodecyl sulfate is 2-5:2-5:2-5:1-2.

2. The composite ammonia nitrogen removal agent for treating ammonia nitrogen-containing wastewater according to claim 1, characterized in that: The mass ratio of the polymerized ferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate and silicon sulfate is 35:17:13:11:9:8:7, and the mass ratio of the total mass of the polymerized ferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate and silicon sulfate to the mass ratio of the sodium hypochlorite, potassium citrate and sodium dodecyl sulfate is 3:3:3:

1.

3. A method for preparing a composite ammonia nitrogen removal agent for treating ammonia nitrogen-containing wastewater, characterized in that: The following steps are involved: S1, mixing polymerized ferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate and silicon sulfate to obtain a mixture; the mass ratio of the polymerized ferrous sulfate, lanthanum sulfate, cerium sulfate, samarium sulfate, yttrium sulfate, calcium sulfate and silicon sulfate is 6-8:3-4:2-3:2-3:1-2:1-2:1-2; S2. Mix the mixture obtained in step S1, sodium hypochlorite, potassium citrate and sodium dodecyl sulfate, and obtain a composite ammonia nitrogen removal agent by drying, grinding and sieving; the mass ratio of the mixture, sodium hypochlorite, potassium citrate and sodium dodecyl sulfate is 2-5:2-5:2-5:1-2.

4. The method for preparing a composite ammonia nitrogen removal agent for treating ammonia nitrogen-containing wastewater according to claim 3, characterized in that: The particle size of the composite ammonia nitrogen removal agent is 80 mesh to 120 mesh, the drying temperature is 25° C. to 35° C., and the drying pressure is 0.1 MPa to 0.12 MPa.

5. Use of the composite ammonia nitrogen removal agent as claimed in claim 1 or 2 or the composite ammonia nitrogen removal agent prepared by the preparation method as claimed in claim 3 or 4 in treating ammonia nitrogen-containing wastewater.

6. The use according to claim 5, characterized in that: The following steps are involved: (1) Mixing the composite ammonia nitrogen removal agent and ammonia nitrogen-containing wastewater to perform precipitation reaction to obtain a mixed solution; (2) Add a flocculant to the mixed solution obtained in step (1) for flocculation treatment, and filter to complete the treatment of the ammonia nitrogen-containing wastewater.

7. The use according to claim 6, characterized in that: In step (1), the composite ammonia nitrogen removal agent is implemented in the form of a composite ammonia nitrogen removal agent solution, and the preparation process of the composite ammonia nitrogen removal agent solution is: mixing the composite ammonia nitrogen removal agent and water to obtain a composite ammonia nitrogen removal agent solution; the volume ratio of the composite ammonia nitrogen removal agent solution to the ammonia nitrogen-containing wastewater is 1 to 2:20, and the mass percentage concentration of the composite ammonia nitrogen removal agent solution is 1%; In step (2), the volume ratio of the flocculant to the ammonia nitrogen-containing wastewater is 1-3:200, the flocculant is a polyacrylamide solution, and the mass percentage concentration of the polyacrylamide solution is 0.1%.

8. The use according to claim 7, characterized in that: The volume ratio of the composite ammonia nitrogen removal agent solution to the ammonia nitrogen-containing wastewater is 3-4:40, and the volume ratio of the flocculant to the ammonia nitrogen-containing wastewater is 1:

200.

9. The use according to claim 8, characterized in that: The initial concentration of ammonia nitrogen in the ammonia nitrogen-containing wastewater is ≤100 mg / L.

10. The use according to any one of claims 6 to 9, characterized in that: In step (1), the precipitation reaction time is 15 min to 30 min, and the precipitation reaction is carried out under stirring conditions; In step (2), the flocculation treatment time is 60 min to 120 min.

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