Flocculating agent for synchronously removing ammonia nitrogen and phosphorus as well as preparation method and application of flocculating agent

Abstract

The invention provides a flocculating agent for synchronously removing ammonia nitrogen and phosphorus as well as a preparation method and application thereof, and relates to the technical field of wastewater treatment. The flocculating agent for synchronously removing ammonia nitrogen and phosphorus comprises the following components in parts by weight: 40-50% of kaolin, 20-30% of bentonite, 5-8% of sodium carbonate, 70-100 parts of water, 10-15% of zirconium oxychloride and 5-10% of lanthanum cerium chloride, 20-26 parts of sodium hydroxide is added, and the mass ratio of zirconium oxychloride to lanthanum cerium chloride is 7: 9. The mass ratio of the sodium carbonate to the zirconium oxychloride is 5: 2. The inorganic flocculant is firstly added for primary treatment, and then the high-molecular-weight flocculant is added for fine treatment, so that the effect is better than that of single use of one flocculant, and the sewage treatment efficiency can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of wastewater treatment, and specifically to a flocculant for simultaneously removing ammonia nitrogen and phosphorus, a preparation method thereof, and an application thereof. Background Art

[0002] With the frequent occurrence of water bloom pollution events in surface water bodies, water eutrophication has become an important environmental problem. Nitrogen and phosphorus are the key factors causing water eutrophication. Reducing nitrogen and phosphorus emissions and strengthening the comprehensive treatment of wastewater containing ammonia nitrogen and phosphorus are important ways to reduce water eutrophication in inland rivers, lakes and other water bodies and ensure the safety of drinking water sources.

[0003] When the applicant applied for the present invention, after retrieval, it was found that a Chinese patent disclosed a "flocculant for simultaneously removing ammonia nitrogen and phosphorus, a preparation method thereof, and an application thereof", and its application number was "201710407512.3". This patent mainly uses [AlO4Al + loaded with Mg2 12 (OH) 24 (H2O) 12 7 + pillared zeolite, and uses it to prepare a flocculant for simultaneously removing ammonia nitrogen and phosphorus. When this flocculant is added to water, the adsorption of the pillared zeolite causes low-concentration ammonia nitrogen and phosphorus in the water to gather around the flocculant and gradually enter the pores of the pillared zeolite. When the adsorbed ammonia nitrogen and phosphorus reach a certain concentration, they will react with Mg2 + loaded on the pillared zeolite to generate magnesium ammonium phosphate (MgNH4PO4·6H2O) in the pores, thereby being fixed in the pillared zeolite. At the same time, [AlO4Al 12 (OH) 24 (H2O) 12 7 ++ of the pillared zeolite will gradually be released into the water, thereby enhancing the flocculation effect of the aluminum-based flocculant, removing solid particulate matter in the water through flocculation precipitation, and finally achieving the deep removal of low-concentration ammonia nitrogen and phosphorus. Although this patent can treat the impurities in sewage in the specification, however, the treatment effect of the impurities in sewage under extremely acidic conditions is poor. Therefore, according to the invention of the applicant, a flocculant capable of treating the impurities in sewage under extremely acidic conditions is invented, which solves the problem of poor treatment of impurities in sewage in extremely acidic conditions. Summary of the Invention

[0004] (1) Technical Problems to be Solved

[0005] Aiming at the deficiencies of the prior art, the present invention provides a flocculant for simultaneously removing ammonia nitrogen and phosphorus, a preparation method thereof, and an application thereof, which solves the problem of poor treatment of impurities in sewage in extremely acidic conditions.

[0006] (2) Technical Solutions

[0007] To achieve the above object, the present invention is realized by the following technical solutions: A flocculant for synchronous removal of ammonia nitrogen and phosphorus, its preparation method and application. The flocculant comprises the following components in proportion: 40-50% by weight of kaolin, 20-30% by weight of bentonite, 5-8% by weight of soda ash, 70-100 parts of water, 10-15% by weight of zirconium oxychloride, 5-10% by weight of lanthanum cerium chloride, and additionally 20-26 parts of sodium hydroxide are added;

[0008] The mass ratio of the zirconium oxychloride to the lanthanum cerium chloride is 7:9; the mass ratio of the soda ash to the zirconium oxychloride is 5:2.

[0009] Preferably, (1) The operation steps are as follows:

[0010] Step 1: Mix kaolin, bentonite, soda ash and water, stir, wash with water until neutral, and dry at 105 °C for standby;

[0011] Step 2: Mix zirconium oxychloride, lanthanum cerium chloride and water to form a solution, and slowly add it to Step (1), and stir;

[0012] Step 3: For the stirring in Step 2, use a heating rod to heat and stir the stirring tank, and after completion, filter press, dry and crush to obtain the finished product;

[0013] (2) Adjust the acidity and alkalinity of the flocculant;

[0014] Step 1: Use the flocculant in combination. First, add an inorganic flocculant for preliminary treatment, and then add a high molecular weight flocculant for fine treatment;

[0015] Step 2: First add the inorganic flocculant polyaluminum chloride to adjust the pH value to 6-8;

[0016] Step 3: Then add an organic high molecular weight flocculant to adjust the pH to 4-9.

[0017] Preferably, the stirring time is 24-28 hours, the stirring speed is 200-400 revolutions per minute, and the temperature rise in Step 3 is 230-280 °C.

[0018] Preferably, in Step 1, the kaolin and bentonite are pretreated, crushed by a crushing roller to 200 mesh, and soaked in 5% hydrochloric acid for 2 h to remove impurities, and the impurities are Fe2O3 and CaCO3.

[0019] Preferably, in Step 3, the drying temperature is 320-360 °C, and the crushing is 240 mesh.

[0020] Preferably, in Step 2, the zirconium oxychloride and lanthanum cerium chloride are dissolved in deionized water according to the ratio, and the concentration is 0.5-1.0 mol / L.

[0021] Preferably, it is used to treat wastewater containing ammonia nitrogen and phosphorus.

[0022] (III) Beneficial effects

[0023] The present invention provides a flocculant for simultaneously removing ammonia nitrogen and phosphorus, its preparation method and application. It has the following beneficial effects:

[0024] 1. After the flocculant is prepared, sodium hydroxide is added to the flocculant. The effect of the flocculant on treating extremely acidic sewage can be achieved. By adding sodium hydroxide, the pH value can be increased, the pH value can be adjusted, the flocculation environment can be optimized, the hydrolysis of metal ions can be promoted, the flocculation effect can be enhanced, the floc structure can be improved, the sedimentation can be accelerated, and the water quality of high-phosphorus wastewater and heavy metal-containing wastewater can be adapted.

[0025] 2. By using the flocculant in combination, the inorganic flocculant is added first for preliminary treatment, and then the high-molecular-weight flocculant is added for fine treatment. When using only one flocculant alone cannot achieve the expected effect, the effect can be improved by using different types of flocculants in combination, thereby ensuring the sewage treatment effect. Specific embodiments

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0027] Example 1:

[0028] The embodiment of the present invention provides a flocculant for simultaneously removing ammonia nitrogen and phosphorus, its preparation method and application. The flocculant is composed of the following in proportion: 40% kaolin, 20% bentonite, 5% soda ash, 70 parts of water, 10% zirconium oxychloride, 5% lanthanum cerium chloride, and additionally 20 parts of sodium hydroxide are added;

[0029] The mass ratio of the zirconium oxychloride to the lanthanum cerium chloride is 7:9; the mass ratio of the soda ash to the zirconium oxychloride is 5:2.

[0030] (1) The operation steps are as follows:

[0031] Step 1: Mix and stir kaolin, bentonite, soda ash, and water, wash until neutral, and dry at 105 °C for standby;

[0032] Step 2: Mix zirconium oxychloride, lanthanum cerium chloride, and water to form a solution, and slowly add it to step (1) and stir;

[0033] Step 3: For the stirring in Step 2, use a heating rod to raise the temperature of the stirring tank for stirring. After completion, perform pressure filtration, drying, and pulverization to obtain the finished product.

[0034] (2). Adjust the acidity and alkalinity in the flocculant.

[0035] Step 1: Use the flocculant in combination. First, add an inorganic flocculant for preliminary treatment, and then add a high-molecular-weight flocculant for fine treatment.

[0036] Step 2: First, add the inorganic flocculant polyaluminum chloride and adjust the pH value to 6 - 8.

[0037] Step 3: Then add the organic high-molecular-weight flocculant and adjust the pH to 4 - 9.

[0038] The stirring time is 24 - 28 hours, the stirring speed is 200 - 400 revolutions per minute. In Step 3, the temperature is raised to 230 - 280 °C. In Step 1, kaolin and bentonite are pretreated, pulverized using a pulverizing roller to 200 mesh, soaked in 5% hydrochloric acid for 2 h to remove impurities, and the impurities are Fe2O3 and CaCO3. In Step 3, the drying temperature is 320 - 360 °C, and the pulverization is to 240 mesh. In Step 2, zirconium oxychloride and lanthanum cerium chloride are dissolved in deionized water in proportion at a concentration of 0.5 - 1.0 mol / L for treating wastewater containing ammonia nitrogen and phosphorus.

[0039] Example 2:

[0040] The flocculant includes the following in proportion: 42% kaolin, 23% bentonite, 6% soda ash, 78 parts of water, 12% zirconium oxychloride, 6% lanthanum cerium chloride, and additionally 23 parts of sodium hydroxide are added.

[0041] The mass ratio of zirconium oxychloride to lanthanum cerium chloride is 7:9; the mass ratio of soda ash to zirconium oxychloride is 5:2.

[0042] (1). Its operation steps are as follows:

[0043] Step 1: Mix kaolin, bentonite, soda ash, and water, stir, wash until neutral, and dry at 105 °C for standby.

[0044] Step 2: Mix zirconium oxychloride, lanthanum cerium chloride, and water to form a solution, and slowly add it to Step (1) and stir.

[0045] Step 3: For the stirring in Step 2, use a heating rod to raise the temperature of the stirring tank for stirring. After completion, perform pressure filtration, drying, and pulverization to obtain the finished product.

[0046] (2). Adjust the acidity and alkalinity in the flocculant.

[0047] Step 1: Use flocculants in combination. First, add an inorganic flocculant for preliminary treatment, and then add a high-molecular-weight flocculant for fine treatment.

[0048] Step 2: First, add polyaluminum chloride inorganic flocculant and adjust the pH value to 6 - 8.

[0049] Step 3: Then, add an organic high-molecular-weight flocculant and adjust the pH to 4 - 9.

[0050] Example 3:

[0051] The flocculant consists of the following components in proportion: 45% kaolin, 25% bentonite, 6% soda ash, 80 parts of water, 12% zirconium oxychloride, 7% lanthanum cerium chloride, and additionally 24 parts of sodium hydroxide are added.

[0052] The mass ratio of zirconium oxychloride to lanthanum cerium chloride is 7:9; the mass ratio of soda ash to zirconium oxychloride is 5:2.

[0053] (1) The operation steps are as follows:

[0054] Step 1: Mix kaolin, bentonite, soda ash, and water, stir, wash until neutral, and dry at 105 °C for standby.

[0055] Step 2: Mix zirconium oxychloride, lanthanum cerium chloride, and water to form a solution, and slowly add it to step (1) and stir.

[0056] Step 3: For the stirring in step 2, use a heating rod to raise the temperature of the stirring tank for stirring. After completion, filter press, dry, and pulverize to obtain the finished product.

[0057] (2) Adjust the acidity and alkalinity in the flocculant.

[0058] Step 1: Use flocculants in combination. First, add an inorganic flocculant for preliminary treatment, and then add a high-molecular-weight flocculant for fine treatment.

[0059] Step 2: First, add polyaluminum chloride inorganic flocculant and adjust the pH value to 6 - 8.

[0060] Step 3: Then, add an organic high-molecular-weight flocculant and adjust the pH to 4 - 9.

[0061] Example 4:

[0062] The flocculant consists of the following components in proportion: 50% kaolin, 30% bentonite, 8% soda ash, 100 parts of water, 15% zirconium oxychloride, 10% lanthanum cerium chloride, and additionally 26 parts of sodium hydroxide are added.

[0063] The mass ratio of zirconium oxychloride to lanthanum cerium chloride is 7:9; the mass ratio of soda ash to zirconium oxychloride is 5:2.

[0064] (1) The operation steps are as follows:

[0065] Step 1: Mix kaolin, bentonite, soda ash, and water, stir, wash with water until neutral, and dry at 105 °C for standby.

[0066] Step 2: Mix zirconium oxychloride, lanthanum cerium chloride, and water to form a solution, and slowly add it to step (1), then stir.

[0067] Step 3: For the stirring in step 2, use a heating rod to raise the temperature of the stirring tank and stir. After completion, press-filter, dry, and pulverize to obtain the finished product.

[0068] (2) Adjust the acidity and alkalinity of the flocculant.

[0069] Step 1: Use the flocculant in combination. First, add an inorganic flocculant for preliminary treatment, and then add a high-molecular-weight flocculant for fine treatment.

[0070] Step 2: First, add polyaluminum chloride inorganic flocculant and adjust the pH value to 6 - 8.

[0071] Step 3: Then add an organic high-molecular-weight flocculant and adjust the pH to 4 - 9.

[0072]

[0073] In summary, by comparing the above Examples 1, 2, 3, and 4, the higher the removal rate of sewage impurities is with the more sodium hydroxide added. Therefore, adding sodium hydroxide to the flocculant can effectively improve the treatment effect of impurities in sewage under extremely acidic conditions.

[0074]

[0075] Based on the above experimental results, ammonia nitrogen and phosphorus are removed simultaneously through the triple mechanisms of chemical precipitation, adsorption, and ion exchange. When adding a single flocculant and a combined flocculant respectively, for the sewage treatment effect, the result shows that when using a combined flocculant, when a single flocculant alone cannot achieve the expected effect under extremely acidic conditions, the effect can be improved by using different types of flocculants in combination.

[0076] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A flocculant for simultaneous removal of ammonia nitrogen and phosphorus, characterized in that: The flocculant comprises the following in proportion: 40-50% kaolin, 20-30% bentonite, 5-8% soda ash, 70-100 parts water, 10-15% zirconium oxychloride, 5-10% lanthanum cerium chloride, and 20-26 parts sodium hydroxide. The mass ratio of zirconium oxychloride to lanthanum cerium chloride is 7:9; the mass ratio of soda ash to zirconium oxychloride is 5:

2.

2. The method for preparing a flocculant for simultaneously removing ammonia nitrogen and phosphorus according to claim 1, characterized in that: (1) The operation steps are as follows: Step 1, kaolin, bentonite, soda ash and water are mixed and stirred, washed with water until neutral, and dried at 105°C for later use; Step 2, zirconium oxychloride, lanthanum cerium chloride, and water are added to form a solution, which is slowly added to step (1) and stirred; Step 3: For the stirring in step 2, the stirring box is heated and stirred by using a heating rod, and after completion, the finished product is obtained by filter pressing, drying and crushing; (2) Adjust the acidity and alkalinity of the flocculant; Step 1: Combined use of flocculants: first add an inorganic flocculant for preliminary treatment, and then add a high molecular weight flocculant for fine treatment; Step 2, first add polyaluminium chloride inorganic flocculant and adjust the pH value to 6-8; Step 3: Add an organic high molecular weight flocculant and adjust the pH to 4-9.

3. The method for preparing a flocculant for simultaneously removing ammonia nitrogen and phosphorus according to claim 2, characterized in that: The stirring time is 24-28 hours, the stirring speed is 200-400 revolutions per minute, and the temperature in step 3 is raised to 230-280°C.

4. The method for preparing a flocculant for simultaneously removing ammonia nitrogen and phosphorus according to claim 2, characterized in that: In the step 1, kaolin and bentonite are pretreated, crushed by a crushing roller to 200 mesh, and soaked in 5% hydrochloric acid for 2 hours to remove impurities, wherein the impurities are Fe2O3 and CaCO3.

5. The method for preparing a flocculant for simultaneously removing ammonia nitrogen and phosphorus according to claim 2, characterized in that: In the step 3, the drying temperature is 320-360° C. and the crushing is 240 mesh.

6. The method for preparing a flocculant for simultaneously removing ammonia nitrogen and phosphorus according to claim 2, characterized in that: In step 2, zirconium oxychloride and cerium lanthanum chloride are dissolved in deionized water in proportion, with a concentration of 0.5-1.0 mol / L.

7. The use of a flocculant for simultaneous removal of ammonia nitrogen and phosphorus according to claim 1, characterized in that: Used to treat wastewater containing ammonia nitrogen and phosphorus.

Images