Calcium-based enhanced dephosphorization filler, its preparation method and application thereof

Abstract

The present application relates to a kind of calcium-based reinforced dephosphorization filler and its preparation method and its application.The raw material formula includes ultrasonic modified calcium-based bentonite 40-70% by mass percentage, modified dolomite powder 10-30%, zeolite powder 10-20%, kaolin 10-20%, wherein, the water solution of dolomite powder calcined at 800-1500 DEG C and aluminum chloride solution are mixed, then at 60-100 DEG C, pH is adjusted to 10-11 using alkaline substance, then washed to neutral by suction filtration, dry, ground to obtain modified dolomite powder.The calcium-based reinforced dephosphorization filler of the present application can efficiently release calcium ions into water body, and the total phosphorus removal rate of water body is higher and the efficient dephosphorization time is longer.The calcium-based reinforced dephosphorization filler of the present application belongs to environment-friendly material, which can be directly added to river or laid in ecological pond, and can be quickly supplemented and maintained less in later period, thereby reducing water treatment cost.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of phosphorus removal fillers, and particularly relates to a calcium-based reinforced phosphorus removal filler and a preparation method and application thereof. BACKGROUND

[0002] When a water body is eutrophicated, algae and other phytoplankton in the water body are prone to burst, and water bloom or red tide phenomenon occurs, the water body has a decreased dissolved oxygen and transparency, and water quality is deteriorated, and the main control indexes of eutrophication of the water body are N and P, and reducing the total phosphorus (TP) content in the water body is a key to controlling eutrophication of the water body.

[0003] Main measures for reducing the TP content in the water body include artificial wetlands, water treatment reinforced treatment facilities (coagulation and sedimentation), and the like. The water treatment reinforced treatment facilities mainly remove the TP content in the water body by adding chemicals, and a large amount of chemical sludge is generated in the removal process, which causes secondary pollution to the environment, and the treatment cost is relatively high. The artificial wetland can purify the water body by selecting different substrates and planting different plants according to actual conditions, and utilizing the unique ecological environment formed by different substrates, plants, microorganisms and animals in the system, and the operation and treatment cost is relatively low. However, the artificial wetland also has obvious shortcomings.

[0004] The artificial wetland mainly removes TP through adsorption and sedimentation of fillers, and therefore the selection of the phosphorus removal filler is crucial. Traditional artificial wetland fillers include limestone, volcanic rock, zeolite, shale, and ceramic particles, and in the case of a hydraulic retention time of 1 day, the TP removal rate is about 30%, and the traditional artificial wetland fillers have the disadvantages of large land occupation and low TP removal efficiency. In order to improve the TP treatment efficiency of the wetland, high-efficiency phosphorus removal fillers are mostly prepared by modifying or mixing Fe, activated carbon, ceramic particles, aluminum salt, zeolite and the like as basic materials, and the fillers are mostly filled in the subsurface wetland filler layer by physical adsorption, and when the adsorption volume is saturated, the treatment efficiency will decrease or disappear, and the effective phosphorus removal time is relatively short, and part of the fillers need to be replaced frequently, and the wetland has great difficulty in replacing the fillers and needs to replant emergent plants, and the water body treatment cost is very high.

[0005] Therefore, developing a reinforced phosphorus removal filler with better phosphorus removal effect, longer high-efficiency phosphorus removal time and direct use is a key to realizing simple and efficient phosphorus removal. SUMMARY

[0006] The application aims to provide a calcium-based reinforced phosphorus removal filler with better phosphorus removal effect and longer high-efficiency phosphorus removal time.

[0007] Another object of the application is to provide a preparation method of the calcium-based reinforced phosphorus removal filler.

[0008] Still another object of the application is to provide application of the calcium-based reinforced phosphorus removal filler in water body treatment.

[0009] To achieve the above object, the technical scheme adopted by the present application is:

[0010] A calcium-based reinforced dephosphorization filler, the raw material formula of the calcium-based reinforced dephosphorization filler includes, in percentage by mass, ultrasonic modified calcium-based bentonite 40-70%, modified dolomite powder 10-30%, zeolite powder 10-20%, and kaolin 10-20%, wherein the preparation method of the modified dolomite powder is: mixing the aqueous solution of dolomite powder calcined at 800-1500 DEG C and the aluminum chloride solution to obtain a mixture, then adjusting the pH value of the mixture to 10-11 at 60-100 DEG C using an alkaline substance, then washing to neutral by suction filtration, and then drying and grinding to obtain the modified dolomite powder.

[0011] Preferably, the raw material formula of the calcium-based reinforced dephosphorization filler includes, in percentage by mass, ultrasonic modified calcium-based bentonite 50-60%, modified dolomite powder 20-25%, zeolite powder 10-20%, and kaolin 10-20%.

[0012] Preferably, the mass ratio of the ultrasonic modified calcium-based bentonite and the modified dolomite powder is (2-3):1.

[0013] Preferably, the preparation method of the ultrasonic modified calcium-based bentonite is: treating the aqueous solution of calcium-based bentonite under ultrasonic waves at a frequency of 25-40 kHz for at least 35 min, then drying at a drying temperature lower than 60 DEG C, and then grinding to obtain the ultrasonic modified calcium-based bentonite.

[0014] Further preferably, the calcium-based bentonite is calcium-based bentonite screened through a 180-240 mesh screen.

[0015] Further preferably, the aqueous solution of calcium-based bentonite is mixed by mixing calcium-based bentonite and water at a volume ratio of (0.8-1.2):1.

[0016] Preferably, in the preparation method of the modified dolomite powder, the concentration of the aqueous aluminum chloride solution is 0.8-1.2 mol / L.

[0017] Preferably, the aqueous aluminum chloride solution is added at a molar ratio of calcium ions to aluminum ions of (2-4):1.

[0018] Preferably, in the preparation method of the modified dolomite powder, the alkaline substance is an aqueous sodium hydroxide solution with a concentration of 1.5-2.5 mol / L.

[0019] Preferably, the preparation method of the modified dolomite powder specifically includes the following steps:

[0020] (1) dolomite powder is calcined at 800-1500°C for 40-80 min, and then ground and mixed with water to form a mixture a, wherein the volume ratio of water to dolomite powder is (0.8-1.2):1;

[0021] (2) the mixture a is mixed with an aluminum chloride solution of 0.8-1.2 mol / L to obtain a mixture b, wherein the molar ratio of calcium ions to aluminum ions is (2-4):1;

[0022] (3) the mixture b is simultaneously added into a same container with a sodium hydroxide solution of 1.5-2.5 mol / L at 60-100°C under magnetic stirring, and the pH value is controlled at 10-11 during the addition, and the stirring is continued for 1.5-3 h after the titration is completed, and then the mixture is washed to neutral, and then dried and ground to obtain the modified dolomite powder.

[0023] Preferably, the ultrasonic modified calcium bentonite, the modified dolomite powder, the zeolite powder and the kaolin are respectively screened through a 180-240 mesh screen.

[0024] The application further provides a preparation method of the calcium-based reinforced phosphorus removal filler, which comprises the following steps: uniformly mixing the ultrasonic modified calcium bentonite, the modified dolomite powder, the zeolite powder and the kaolin, mixing the mixture with water according to a water content of 20-30%, and then naturally airing and grinding the mixture and screening the mixture through a 180-240 mesh screen to obtain the calcium-based reinforced phosphorus removal filler.

[0025] The application further provides an application of the calcium-based reinforced phosphorus removal filler in water body treatment.

[0026] According to some embodiments, the calcium-based reinforced phosphorus removal filler is added into a river channel according to an addition amount of 400-600 g per cubic meter of water body, and the hydraulic retention time is 20-30 h.

[0027] According to other embodiments, the calcium-based reinforced phosphorus removal filler is laid in a submersed pond, the laying thickness is 0.5-5 cm, and submersed plants are planted on the calcium-based reinforced phosphorus removal filler, and the water depth of the submersed pond is 0.8-2 m.

[0028] Preferably, the submersed plants are mainly hornworts and potamogetons, and the coverage rate of the submersed plants in the submersed pond is greater than 80%, and the hornworts and the potamogetons should be mainly used and account for not less than 50%.

[0029] According to other embodiments, the calcium-based reinforced phosphorus removal filler is mixed with water and compressed to form circular particles, and the circular particles are used in an alkalinity adjustment chain of a submerged biological reactor.

[0030] Of course, in other embodiments, the calcium-based reinforced phosphorus removal filler can also be used as a filler of a constructed wetland, and the number of maintenance times in the later period is less.

[0031] In the present application, the calcium-based reinforced dephosphorization filler mainly releases calcium ions into water by mixing modified calcium bentonite and modified dolomite powder in a mass ratio of 2:1 to 3:1, and the calcium ions react with phosphates in water to form precipitates that are difficult to dissolve in water, thereby achieving the purpose of removing TP from water.

[0032] The cavitation effect of the ultrasonic wave increases the interlayer spacing of the bentonite crystal, loosens the structure, and improves the ability of the bentonite to adsorb phosphates in water. Meanwhile, the Ca + reacts with the phosphate ions to form a complex that is difficult to dissolve in water, thereby achieving the purpose of removing TP from water. The increased swelling of bentonite in water improves the contact area between calcium ions in the filler and phosphate ions in water, and the dephosphorization efficiency is improved by 10% to 20% compared with using modified dolomite powder alone.

[0033] The dolomite powder is modified from the original hexagonal crystal mainly composed of calcium carbonate and magnesium carbonate into a layered double metal hydroxide (hydrotalcite-like substance) mainly composed of calcium and aluminum, forming a hexagonal lamellar structure. The high adsorption property of the hydrotalcite-like substance improves the adsorption capacity of the phosphate ions, and the Ca + reacts with the phosphate ions to form a precipitate that is difficult to dissolve in water, which is then removed.

[0034] Zeolite and kaolin serve as carriers for the ultrasonic wave modified calcium bentonite and modified dolomite powder to accelerate the release of calcium ions. They can adsorb phosphate ions and other ions in water and react with the calcium ions released by the calcium bentonite and dolomite powder to achieve the purpose of deep dephosphorization.

[0035] The carbonates and oxides in the ultrasonic wave modified calcium bentonite and modified dolomite powder release calcium ions into water while generating bicarbonate, which can adjust the pH value and alkalinity of the water, making the water weakly alkaline to accelerate the precipitation reaction.

[0036] The calcium-based reinforced dephosphorization filler of the present application is used in combination with submerged plants. The insoluble precipitates generated adhere to the submerged plants and are transferred with the harvesting of the submerged plants, without causing secondary pollution to the environment.

[0037] The reaction time of the calcium-based reinforced dephosphorization filler of the present application is 3 to 6 times longer than that of adsorption-based fillers. Under the same hydraulic retention time, the TP removal rate is improved by more than 50%.

[0038] Thanks to the above technical solutions, the present application has the following advantages compared with the prior art:

[0039] The calcium-based reinforced phosphorus removal filler mainly uses calcium ion precipitation reaction, can efficiently release calcium ions into the water body, and has higher total phosphorus removal rate and longer efficient phosphorus removal time under the same hydraulic retention time. The calcium-based reinforced phosphorus removal filler can be used cooperatively with aquatic plants and aquatic animals, and belongs to an environment-friendly material. The calcium-based reinforced phosphorus removal filler can be directly added into a river or laid in an ecological pond, and can be quickly supplemented and maintained less frequently, so that the water treatment cost is greatly reduced. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 A total phosphorus removal rate comparison result chart of the fillers of the examples and the comparative examples. DETAILED DESCRIPTION

[0041] Hereinafter, only certain exemplary embodiments are simply described. As can be appreciated by those skilled in the art, the described embodiments can be modified in various different ways without departing from the spirit or scope of the embodiments of the present application. Therefore, the description is considered to be exemplary in nature rather than limiting.

[0042] In the present application, all the raw materials described can be prepared by commercial purchase or / and known means, and meet the requirements of standard chemical products without special description.

[0043] In the present application, the content of the main component calcium carbonate in the dolomite powder is about 56%.

[0044] In the present application, the experimental methods are conventional methods unless otherwise specified.

[0045] In the present application, the total phosphorus content detection method refers to the national standard GB-T 11893-1989.

[0046] In the present application, “%” refers to mass percentage unless otherwise specified.

[0047] Example 1

[0048] The present embodiment provides a calcium-based reinforced phosphorus removal filler, and a preparation method thereof is as follows:

[0049] 1. The calcium-based bentonite, dolomite powder, zeolite powder and kaolin are respectively sieved through a 200-mesh screen.

[0050] 2. The calcium-based bentonite is subjected to ultrasonic modification treatment to obtain modified calcium-based bentonite, and the specific steps are as follows:

[0051] 2.1. The calcium-based bentonite sieved through a 200-mesh screen is dispersed in distilled water and uniformly stirred, and the volume ratio of the distilled water to the calcium-based bentonite is 1:1.

[0052] 2.2, the mixture obtained in step 2.1 is treated with ultrasonic waves at a frequency of 30 kHz at room temperature for 45 min;

[0053] 2.3, the mixture after ultrasonic treatment is dried at a drying temperature below 60℃, and the obtained solid is ground and sieved through a 200-mesh screen to obtain the modified calcium-based bentonite.

[0054] 3, dolomite powder is modified to obtain modified dolomite powder, and the specific steps are as follows:

[0055] 3.1, dolomite powder sieved through a 200-mesh screen is calcined at 900℃ for 60 min, and then mixed with distilled water to form a mixture a, the volume ratio of distilled water to dolomite powder being 1:1;

[0056] 3.2, mixture a is mixed with 1 mol / L aluminum chloride solution to obtain mixture b, the molar ratio of calcium ions to aluminum ions being about 3:1;

[0057] 3.3, mixture b and 2 mol / L NaOH are simultaneously added to the same container under the condition of high temperature at 95℃, and are stirred by magnetic stirring, the pH value is controlled at 10-11 during the addition, and after the titration is completed, the stirring is continued for 2 h, and then the mixture is washed by water filtration for 2-3 times until the pH value is 7, and finally, the modified dolomite powder is obtained by drying, grinding and sieving through a 200-mesh screen.

[0058] 4, the modified calcium-based bentonite 50%, the modified dolomite powder 25%, the zeolite powder 10%, and the kaolin 15% are mixed uniformly, and then distilled water is added to obtain mixture c, and the amount of distilled water added is 25% of the water content.

[0059] 5, the mixture c is naturally air-dried, ground and sieved through a 200-mesh screen to obtain the calcium-based reinforced phosphorus removal filler.

[0060] Example 2

[0061] The example provides a calcium-based reinforced phosphorus removal filler, and the preparation method is basically the same as that of example 1, and the difference is only that the amount in step 4 is adjusted to modified calcium-based bentonite 60%, modified dolomite powder 20%, zeolite powder 10%, and kaolin 10%.

[0062] Example 3

[0063] The example provides a calcium-based reinforced phosphorus removal filler, and the preparation method is basically the same as that of example 1, and the difference is only that the amount in step 4 is adjusted to modified calcium-based bentonite 50%, modified dolomite powder 20%, zeolite powder 15%, and kaolin 15%.

[0064] Example 4

[0065] The embodiment provides a calcium-based reinforced dephosphorization filler, and a preparation method thereof is basically same with that in the embodiment 1, and the only difference is that the amount of the modified calcium-based bentonite is 40%, the amount of the modified dolomite powder is 20%, the amount of the zeolite powder is 20%, and the amount of the kaolin is 20% in the step 4.

[0066] Embodiment 5

[0067] The embodiment provides a calcium-based reinforced dephosphorization filler, and a preparation method thereof is basically same with that in the embodiment 1, and the only difference is that the preparation method of the modified dolomite powder is slightly different, and specifically, the modified dolomite powder in the embodiment is prepared through the following steps:

[0068] 1), the dolomite powder screened through a 200-mesh screen is calcined at a high temperature of 1200 DEG C for 60 min, and after being ground, the dolomite powder is uniformly mixed with distilled water to form a mixture a, and the volume ratio of the distilled water to the dolomite powder is 1:1;

[0069] 2), the mixture a is mixed with an aluminum chloride solution with a concentration of 1 mol / L to obtain a mixture b, and the molar ratio of calcium ions to aluminum ions is about 1:1;

[0070] 3), the mixture b is simultaneously added into a same container with a NaOH solution with a concentration of 2 mol / L under a high temperature condition of 95 DEG C, and the pH value is controlled to be 10-11 during the adding process, and after the titration is completed, the mixture is continuously stirred for 2 h, and then the mixture is washed for 2-3 times through water filtration until the pH value is 7, finally, the modified dolomite powder is obtained through drying, grinding and screening through a 200-mesh screen.

[0071] Embodiment 6

[0072] The embodiment provides a calcium-based reinforced dephosphorization filler, and a preparation method thereof is basically same with that in the embodiment 1, and the only difference is that the preparation method of the modified dolomite powder is slightly different, and specifically, the modified dolomite powder in the embodiment is prepared through the following steps:

[0073] 1), the dolomite powder screened through a 200-mesh screen is calcined at a high temperature of 900 DEG C for 60 min, and after being ground, the dolomite powder is uniformly mixed with distilled water to form a mixture a, and the volume ratio of the distilled water to the dolomite powder is 1:1;

[0074] 2), the mixture a is mixed with an aluminum chloride solution with a concentration of 1 mol / L to obtain a mixture b, and the molar ratio of calcium ions to aluminum ions is about 1:1;

[0075] 3), the mixture b is simultaneously added into a same container with a NaOH solution with a concentration of 2 mol / L under a high temperature condition of 60 DEG C, and the pH value is controlled to be 10-11 during the adding process, and after the titration is completed, the mixture is continuously stirred for 2 h, and then the mixture is washed for 2-3 times through water filtration until the pH value is 7, finally, the modified dolomite powder is obtained through drying, grinding and screening through a 200-mesh screen.

[0076] Embodiment 7

[0077] This example provides a calcium-based enhanced phosphorus removal filler, the preparation method is basically the same as example 1, the difference is only that the ultrasonic treatment time in the preparation step of modified calcium-based bentonite is adjusted to 30 min, and the calcination temperature in the preparation step of modified dolomite powder is adjusted to 750℃.

[0078] Comparative Example 1

[0079] This comparative example provides a phosphorus removal filler, which is mixed by zeolite powder 50%, kaolin 50%, and the zeolite powder and kaolin are respectively screened through a 200 mesh screen.

[0080] Comparative Example 2

[0081] This comparative example provides a phosphorus removal filler, which is zeolite powder 100%, and the zeolite powder is screened through a 200 mesh screen.

[0082] Comparative Example 3

[0083] This comparative example provides a phosphorus removal filler, which is kaolin 100%, and the kaolin is screened through a 200 mesh screen.

[0084] Comparative Example 4

[0085] This comparative example provides a calcium-based enhanced phosphorus removal filler, the preparation method is as follows:

[0086] 1. Screen the calcium-based bentonite, dolomite powder, zeolite powder, and kaolin through a 200 mesh screen respectively;

[0087] 2. Modify the dolomite powder to obtain modified dolomite powder, the specific steps are as follows:

[0088] 2.1. Screen the dolomite powder through a 200 mesh screen, and calcine at 900℃ for 60 min, then mix and stir with distilled water to form a mixture a, the volume ratio of distilled water to dolomite powder is 1:1;

[0089] 2.2. Mix and stir mixture a with 1 mol / L aluminum chloride solution to obtain mixture b, the molar ratio of calcium ions to aluminum ions is about 3:1;

[0090] 2.3. Under the condition of 95℃ high temperature, add 2 mol / L NaOH to the same container as mixture b at the same time, and stir with magnetic stirring, control the pH value at 10-11 during the addition, continue to stir for 2h after titration, wash with water for 2-3 times until the pH value is 7, and finally dry, grind and screen through a 200 mesh screen to obtain modified dolomite powder.

[0091] 3. The calcium-based bentonite 50%, the modified dolomite powder 25%, the zeolite powder 10%, the kaolin 15% are mixed uniformly to obtain a mixture c, and the distilled water is added in an amount of 25% of the water content.

[0092] 4. The mixture c is naturally aired and ground through a 200-mesh screen to obtain a calcium-based reinforced phosphorus removal filler.

[0093] Comparative Example 5

[0094] The present comparative example provides a calcium-based reinforced phosphorus removal filler, and the preparation method is as follows:

[0095] 1. The calcium-based bentonite, dolomite powder, zeolite powder, and kaolin are respectively screened through a 200-mesh screen.

[0096] 2. The calcium-based bentonite is ultrasonically modified to obtain a modified calcium-based bentonite, and the specific steps are as follows:

[0097] 2.1. The calcium-based bentonite screened through a 200-mesh screen is dispersed in distilled water and stirred uniformly, and the volume ratio of distilled water to calcium-based bentonite is 1:1.

[0098] 2.2. The mixture obtained in step 2.1 is treated with ultrasonic waves at a frequency of 30 kHz for 45 min at room temperature.

[0099] 2.3. The mixture after ultrasonic treatment is dried at a drying temperature below 60°C, and the obtained solid is ground and then screened through a 200-mesh screen to obtain a modified calcium-based bentonite.

[0100] 3. The dolomite powder is modified to obtain a modified dolomite powder, and the specific steps are as follows:

[0101] 3.1. The dolomite powder screened through a 200-mesh screen is mixed with distilled water to form a mixture a, and the volume ratio of distilled water to dolomite powder is 1:1.

[0102] 3.2. The mixture a is mixed with 1 mol / L aluminum chloride solution to obtain a mixture b, and the molar ratio of calcium ions to aluminum ions is about 3:1.

[0103] 3.3. The mixture b and 2 mol / L NaOH are simultaneously added to the same container under high temperature conditions of 95°C, and are stirred with a magnetic stirrer. The pH value is controlled at 10-11 during the addition, and the stirring is continued for 2 h after the titration is completed. The mixture is washed with water by suction filtration for 2-3 times until the pH value is 7. Finally, the modified dolomite powder is obtained by drying, grinding, and screening through a 200-mesh screen.

[0104] 4. After mixing the above modified calcium bentonite 50%, the above modified dolomite powder 25%, zeolite powder 10%, kaolin 15% uniformly, add distilled water to obtain mixture c, and the amount of distilled water is added according to the water content of 25%.

[0105] 5. After natural airing of the mixture c, grind through a 200 mesh screen to obtain a calcium-based reinforced phosphorus removal filler.

[0106] Comparative Example 6

[0107] This comparative example provides a calcium-based reinforced phosphorus removal filler, and the preparation method is as follows:

[0108] 1. The calcium-based bentonite, dolomite powder, zeolite powder, and kaolin are respectively screened through a 200 mesh screen.

[0109] 2. The calcium-based bentonite is ultrasonically modified to obtain a modified calcium-based bentonite, and the specific steps are as follows:

[0110] 2.1. The calcium-based bentonite screened through a 200 mesh screen is dispersed in distilled water and stirred uniformly, and the volume ratio of distilled water to calcium-based bentonite is 1:1.

[0111] 2.2. The mixture obtained in step 2.1 is treated with ultrasonic waves at a frequency of 30 kHz for 45 min at room temperature.

[0112] 2.3. The mixture after ultrasonic treatment is dried at a drying temperature below 60°C, and the obtained solid is ground and then screened through a 200 mesh screen to obtain a modified calcium-based bentonite.

[0113] 3. The dolomite powder is modified to obtain a modified dolomite powder, and the specific steps are as follows:

[0114] 3.1. The dolomite powder screened through a 200 mesh screen is calcined at 900°C for 60 min, and after grinding, it is mixed with distilled water to form a mixture a, and the volume ratio of distilled water to dolomite powder is 1:1.

[0115] 3.2. The mixture a and 2 mol / L NaOH are simultaneously added to the same container under the condition of 95°C high temperature, and stirred with a magnetic stirrer, and the pH value is controlled at 10-11 during the addition, and after titration, the stirring is continued for 2 h, and the washing is carried out with water for 2-3 times until the pH value is 7, and finally dried, ground and screened through a 200 mesh screen to obtain a modified dolomite powder.

[0116] 4. After mixing the above modified calcium bentonite 50%, the above modified dolomite powder 25%, zeolite powder 10%, kaolin 15% uniformly, add distilled water to obtain mixture c, and the amount of distilled water is added according to the water content of 25%.

[0117] 5. The mixture c is naturally air-dried and ground to pass through a 200 mesh screen to obtain the calcium-based reinforced phosphorus removal filler.

[0118] Comparative Example 7

[0119] The present comparative example provides a calcium-based reinforced phosphorus removal filler, which is prepared by the following method:

[0120] 1. The calcium-based bentonite, dolomite powder, zeolite powder, and kaolin are respectively sieved through a 200 mesh screen.

[0121] 2. The calcium-based bentonite is ultrasonically modified to obtain modified calcium-based bentonite, and the specific steps are as follows:

[0122] 2.1. The calcium-based bentonite sieved through a 200 mesh screen is dispersed in distilled water and stirred uniformly, and the volume ratio of distilled water to calcium-based bentonite is 1:1.

[0123] 2.2. The mixture obtained in step 2.1 is treated with ultrasonic waves at a frequency of 30 kHz for 45 min at room temperature.

[0124] 2.3. The mixture after ultrasonic treatment is dried at a drying temperature below 60°C, and the obtained solid is ground and then sieved through a 200 mesh screen to obtain modified calcium-based bentonite.

[0125] 3. The dolomite powder is modified to obtain modified dolomite powder, and the specific steps are as follows:

[0126] 3.1. The dolomite powder sieved through a 200 mesh screen is calcined at 900°C for 60 min, and then ground and mixed with distilled water to form a mixture a, and the volume ratio of distilled water to dolomite powder is 1:1.

[0127] 3.2. The mixture a is mixed with 1 mol / L aluminum chloride solution to obtain a mixture b, and the molar ratio of calcium ions to aluminum ions is about 3:1.

[0128] 3.3. The calcium-based reinforced phosphorus removal filler is dried, ground, and then sieved through a 200 mesh screen to obtain modified dolomite powder.

[0129] 4. The modified calcium-based bentonite 50%, the modified dolomite powder 25%, the zeolite powder 10%, and the kaolin 15% are mixed uniformly, and then distilled water is added to obtain a mixture c, and the amount of distilled water added is 25% of the water content.

[0130] 5. The mixture c is naturally air-dried and ground to pass through a 200 mesh screen to obtain the calcium-based reinforced phosphorus removal filler.

[0131] The simulated sewage treatment experiment was carried out by using the calcium-based enhanced phosphorus removal fillers of examples 1 to 7 and comparative examples 1 to 7 respectively, and a simulated river device was constructed, which mainly comprises a base, a water tank arranged on the base, a water inlet pipe communicated with one end of the water tank, a water outlet pipe communicated with the other end of the water tank, and a water pump arranged on the water inlet pipe. Before sewage treatment, the calcium-based enhanced phosphorus removal filler was first put into the water tank, and then the sewage to be treated was introduced. The dosage of the calcium-based enhanced phosphorus removal filler was 500 g per cubic meter of water, the hydraulic retention time was controlled to be 24 h, the initial total phosphorus concentration of the sewage to be treated was about 0.7 mg / L, and the total phosphorus concentration of the effluent was tested every 1 day. The total phosphorus removal rate was calculated by comparing the initial total phosphorus content. The total phosphorus removal rate changes of the calcium-based enhanced phosphorus removal fillers of the above examples and comparative examples are shown in the following table. Figure 1 , Figure 1 The horizontal coordinate is the running day, and the vertical coordinate is the total phosphorus removal rate, Figure 1 The results show that the total phosphorus removal rate and the effect durability of the calcium-based enhanced phosphorus removal fillers of each example are obviously higher than those of the comparative examples. Among them, the effect durability of the calcium-based enhanced phosphorus removal fillers of examples 1 to 4 is better, and after stable running for 1 month after one-time feeding, the total phosphorus removal rate of the effluent is still as high as 50% or more. The frequency of filler replacement can be reduced in the later period, and the difficulty and cost of sewage treatment can be reduced.

[0132] The calcium-based enhanced phosphorus removal filler of example 1 was laid in a subsurface pond with a laying thickness of about 2 cm, and submerged plants such as Vallisneria and Potamogeton were planted thereon, and the water depth was controlled to be 0.8-2 m. Vallisneria and Potamogeton accounted for about 60%, and were planted in March-April and harvested in August-September. The produced sediment was difficult to dissolve in water and would adhere to the submerged plants, and was transferred with the submerged plants during harvesting. The total phosphorus content of the water body was reduced from 0.7 mg / L to 0.2 mg / L, and the filler could be temporarily replaced, and the submerged plants could be replanted after supplementing a small amount of filler.

[0133] In other embodiments, the calcium-based enhanced phosphorus removal filler can also be mixed with water and compressed into circular particles for use in the alkalinity adjustment chain of the submerged biological reactor.

[0134] The above examples are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and to implement it, and cannot limit the protection scope of the present application. Any equivalent changes or modifications made according to the spirit and essence of the present application shall be covered within the protection scope of the present application.

Claims

1. A calcium-based, reinforced, dephosphorizing filler, characterized in that, The raw material formula of the calcium-based reinforced dephosphorization filler by mass percentage comprises ultrasonic modified calcium-based bentonite 40%-70%, modified dolomite powder 10%-30%, zeolite powder 10%-20%, and kaolin 10%-20%, The preparation method of the modified dolomite powder is as follows: a water solution of dolomite powder calcined at 900 DEG C and an aluminum chloride water solution are mixed to obtain a mixture, the aluminum chloride water solution is added according to a calcium ion and aluminum ion molar ratio of (2-4):1, then the pH value of the mixture is adjusted to 10-11 at 95 DEG C by using an alkaline substance, and the mixture is washed by suction filtration until neutral, and then dried and ground to obtain the modified dolomite powder, The preparation method of the ultrasonic modified calcium-based bentonite is as follows: a water solution of calcium-based bentonite is treated by ultrasonic waves at a frequency of 25-40 kHz for at least 35 min, then dried at a drying temperature lower than 60 DEG C, and then ground to obtain the ultrasonic modified calcium-based bentonite.

2. The calcium-based, reinforced, dephosphorizing filler of claim 1, wherein, The mass ratio of the ultrasonic modified calcium-based bentonite to the modified dolomite powder is (2-3):

1.

3. The calcium-based enhanced dephosphorizing filler of claim 1, wherein, In the preparation method of the modified dolomite powder, the concentration of the aluminum chloride water solution is 0.8-1.2 mol / L.

4. The calcium-based, reinforced, dephosphorizing filler of claim 1, wherein, In the preparation method of the modified dolomite powder, the alkaline substance is a sodium hydroxide water solution with a concentration of 1.5-2.5 mol / L.

5. The calcium-based, reinforced, dephosphorizing filler of claim 1, wherein, The preparation method of the modified dolomite powder specifically comprises the following steps: (1) dolomite powder is calcined at 900 DEG C for 40-80 min, then ground and mixed with water to form a mixture a, and the volume ratio of water to dolomite powder in the mixture a is (0.8-1.2):1; (2) the mixture a is mixed with an aluminum chloride water solution with a concentration of 0.8-1.2 mol / L to obtain a mixture b, and the molar ratio of calcium ion to aluminum ion in the mixture b is (2-4):1; (3) the mixture b and a sodium hydroxide water solution with a concentration of 1.5-2.5 mol / L are simultaneously added dropwise into the same container at 95 DEG C, and stirred by a magnetic stirrer, the pH value is controlled at 10-11 during the dropwise adding, and the stirring is continued for 1.5-3 h after the titration is completed, then the mixture is washed by suction filtration until neutral, and then dried and ground to obtain the modified dolomite powder.

6. The calcium-based, reinforced, dephosphorizing filler of claim 1, wherein, The ultrasonic modified calcium-based bentonite, the modified dolomite powder, the zeolite powder, and the kaolin are respectively screened through a 180-240 mesh screen.

7. The method of producing a calcium-based, reinforced dephosphorizing filler according to claim 1, characterized in that, The ultrasonic modified calcium-based bentonite, the modified dolomite powder, the zeolite powder, and the kaolin are uniformly mixed, then mixed with water according to a water content of 20%-30%, and then naturally air-dried and ground, and screened through a 180-240 mesh screen to obtain the calcium-based reinforced dephosphorization filler.

8. The calcium-based reinforced dephosphorization filler in the water body treatment according to claim 1.

9. Use according to claim 8, characterized in that, The calcium-based reinforced dephosphorization filler is added into a river channel according to a dosage of 400-600 g per cubic meter of water body, and the hydraulic retention time is 20-30 h; Or, the calcium-based reinforced dephosphorization filler is laid in a subsurface pond with a laying thickness of 0.5-5 cm, and submerged plants are planted thereon, and the water depth of the subsurface pond is 0.8-2 m. Or, the calcium-based enhanced dephosphorization filler is mixed with water and compressed into round particles for use in the alkalinity adjustment chain of the submerged biological reactor.

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