A composite drug, its preparation method and application

Abstract

This invention relates to the field of phosphoric acid wastewater purification technology, and discloses a composite agent, its preparation method, and its application. The composite agent contains calcium-containing substances, iron-containing substances, aluminum-containing compounds, diatomaceous earth, and activated carbon. The calcium-containing substances are calcium-containing compounds and / or calcium-containing minerals, and the iron-containing substances are iron-containing compounds and / or iron-containing minerals. Based on the total weight of the composite agent, the content of the calcium-containing substances is 30wt%~75wt%, the content of the iron-containing substances is 5wt%~15wt%, the content of the aluminum-containing compounds is 10wt%~20wt%, the content of the diatomaceous earth is 5wt%~25wt%, and the content of the activated carbon is 5wt%~25wt%. This composite agent can achieve efficient removal of phosphorus, acid, and organic matter from wastewater, while improving the degree of process automation, resulting in stable treatment effects and reduced treatment costs.

Description

Technical Field

[0001] This invention relates to the field of phosphoric acid wastewater purification technology, specifically to a composite agent, its preparation method, and its application. Background Technology

[0002] During the production of maleic anhydride, phosphorus loss from the phosphorus-containing catalyst results in a large amount of phosphoric acid-containing wastewater during heat exchanger cleaning. This wastewater also contains certain amounts of fumaric acid, maleic acid, acetic acid, propionic acid, and acrylic acid, leading to high COD and acidity. Sometimes, the wastewater also contains high levels of H+. + The concentration can reach 1.3 mol / L. If this wastewater is discharged directly without effective treatment, the phosphate ions will cause eutrophication, leading to excessive algae growth and disrupting the aquatic ecological balance; the acidic substances will alter the pH value of the water, corrode pipes and surrounding facilities, and cause serious harm to the environment and infrastructure. To solve this problem, this solution utilizes the characteristics of a mixed adsorbent that reacts chemically with phosphoric acid, phosphate ions, and organic acids, and adsorbs organic matter, to achieve deacidification, dephosphorization, and deorganization of the wastewater, ensuring that the treated wastewater meets discharge standards.

[0003] Currently, the main methods for treating phosphorus- and acidic wastewater include chemical precipitation, adsorption, and biological methods. Among these, chemical precipitation is widely used due to its advantages such as simple operation, high treatment efficiency, and strong adaptability. Commonly used chemical dephosphorization agents include calcium salts, iron salts, and aluminum salts. Calcium salts can react with phosphate ions to form insoluble calcium phosphate precipitates, while also neutralizing the acids in the wastewater. Iron salts and aluminum salts adsorb phosphate ions and form precipitates through the hydroxides produced by hydrolysis.

[0004] However, existing technologies often employ single agents or simple mixtures of agents for treatment, which has several shortcomings: when using a single calcium salt, the phosphorus removal efficiency is limited, especially for removing low concentrations of phosphorus; when using a single iron or aluminum salt, a large amount of reagent is required to neutralize the acidity of the wastewater, resulting in high treatment costs and poor sludge settling performance; in addition, the addition of reagents in existing processes is mostly manually controlled, leading to inaccurate dosage and unstable treatment effects, making it difficult to guarantee that the effluent meets standards, and the above technologies cannot remove organic matter from the wastewater.

[0005] Therefore, developing a highly efficient compound dephosphorylation and deorganization agent, along with a highly automated and stable process, is of great significance for the compliant treatment of phosphorus-containing, acidic, and organic wastewater. Summary of the Invention

[0006] The purpose of this invention is to address the problems of low phosphorus removal efficiency, inability to remove organic matter, and low degree of process automation in existing technologies, and to provide a composite agent, its preparation method, and its application. This composite agent can achieve highly efficient removal of phosphorus, acid, and organic matter from wastewater, while improving the degree of process automation, resulting in stable treatment effects and reduced treatment costs.

[0007] To achieve the above objectives, the first aspect of the present invention provides a composite agent containing calcium-containing substances, iron-containing substances, aluminum-containing compounds, diatomaceous earth, and activated carbon, wherein the calcium-containing substances are calcium-containing compounds and / or calcium-containing minerals, and the iron-containing substances are iron-containing compounds and / or iron-containing minerals. Based on the total weight of the composite agent, the content of the calcium-containing substance is 30wt%~75wt%, the content of the iron-containing substance is 5wt%~15wt%, the content of the aluminum-containing compound is 10wt%~20wt%, the content of diatomaceous earth is 5wt%~25wt%, and the content of activated carbon is 5wt%~25wt%.

[0008] Preferably, the calcium-containing compound is selected from at least one of calcium oxide, calcium hydroxide, calcium sulfate, calcium carbonate, and calcium nitrate.

[0009] Preferably, the calcium-containing mineral is selected from at least one of calcite, dolomite, and anorthite.

[0010] Preferably, the iron-containing compound is selected from at least one of ferric sulfate, polyferric sulfate, and iron oxide.

[0011] Preferably, the iron-bearing mineral is selected from at least one of pyroxene, bauxite, limonite, and siderite.

[0012] Preferably, the aluminum-containing compound is selected from at least one of aluminum sulfate, sodium aluminate, and aluminum ferric sulfate.

[0013] Preferably, the diatomaceous earth has a particle size of 200 mesh or more, and more preferably 300-500 mesh.

[0014] Preferably, the activated carbon has a particle size of 200 mesh or more, more preferably 300-500 mesh; a specific surface area of ​​not less than 800 m² / g, more preferably 900-1100 m² / g; and an iodine value of not less than 800, more preferably 900-1000.

[0015] A second aspect of the present invention provides a method for preparing the aforementioned composite agent, the method comprising: pulverizing the calcium-containing substance, the iron-containing substance, the aluminum-containing compound, the diatomaceous earth, and the activated carbon separately, and then mixing them.

[0016] A third aspect of this invention provides a method for treating phosphorus- and acid-containing organic wastewater, the method comprising the following steps: (1) The composite agent described above is mixed with phosphorus- and acid-containing organic wastewater and reacted, wherein the amount of the composite agent added is 0.5wt%-10wt% of the phosphorus- and acid-containing organic wastewater; (2) The product obtained in step (1) is subjected to pressure filtration to separate the filtrate and sludge; (3) Mix the acid and / or salt with the filtrate, and then test the pH, phosphorus concentration and COD of the mixture. Discharge after the mixture meets the standards.

[0017] Preferably, in step (1), the pH value of the phosphorus-containing acidic organic wastewater is 0.5~5, the phosphorus content is 1000~10000mg / L, and the COD is 500~5000mg / L.

[0018] Preferably, in step (1), the reaction conditions include: a temperature of 15~35℃, a time of 10~60min, and a pH value >10.

[0019] Preferably, in step (2), the pressure filtration conditions include: pressure of 0.3~1MPa and time of 30~120min.

[0020] Preferably, in step (3), the acid is selected from at least one of sulfuric acid, sulfurous acid, and hydrochloric acid; Preferably, the salt is selected from at least one of sodium bisulfate, aluminum sulfate, calcium sulfate, ferric sulfate, and magnesium sulfate.

[0021] Preferably, the weight ratio of the acid and / or salt to the filtrate is 0.005 to 0.05:1.

[0022] The composite agent prepared by this invention can achieve efficient removal of phosphorus, acid and organic matter from wastewater, while improving the degree of process automation, making the treatment effect stable and reducing the treatment cost. Detailed Implementation

[0023] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0024] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0025] The composite agent of the present invention contains calcium-containing substances, iron-containing substances, aluminum-containing compounds, diatomaceous earth and activated carbon, wherein the calcium-containing substances are calcium-containing compounds and / or calcium-containing minerals, and the iron-containing substances are iron-containing compounds and / or iron-containing minerals. Based on the total weight of the composite agent, the content of the calcium-containing substance is 30wt%~75wt%, the content of the iron-containing substance is 5wt%~15wt%, the content of the aluminum-containing compound is 10wt%~20wt%, the content of diatomaceous earth is 5wt%~25wt%, and the content of activated carbon is 5wt%~25wt%.

[0026] In this invention, based on the total weight of the composite agent, the content of the calcium-containing substance is 40wt%~70wt%, the content of the iron-containing substance is 5wt%~10wt%, the content of the aluminum-containing compound is 10wt%~15wt%, the content of diatomaceous earth is 5wt%~25wt%, and the content of activated carbon is 10wt%~20wt%. In this invention, when the content of each component in the composite agent is within the above ranges, phosphorus and organic matter in phosphorus-containing and acidic organic wastewater can be removed more efficiently and thoroughly.

[0027] In this invention, the calcium-containing compound may be at least one of calcium oxide, calcium hydroxide, calcium sulfate, calcium carbonate, and calcium nitrate.

[0028] In this invention, the calcium-containing mineral can be at least one of calcite, dolomite, and anorthite.

[0029] In this invention, the iron-containing compound can be at least one of ferric sulfate, polyferric sulfate, and iron oxide.

[0030] In this invention, the iron-bearing mineral can be at least one of pyroxene, bauxite, limonite and siderite.

[0031] In this invention, the aluminum-containing compound can be at least one of aluminum sulfate, sodium aluminate, and aluminum ferric sulfate.

[0032] In this invention, the particle size of the diatomaceous earth can be 200 mesh or more, more preferably 300-500 mesh.

[0033] In this invention, the particle size of the activated carbon can be 200 mesh or more, more preferably 300-500 mesh; the specific surface area is not less than 800 m² / g, more preferably 900-1100 m² / g; and the iodine value is not less than 800, more preferably 900-1000.

[0034] In some specific embodiments, the composite agent contains 30wt%~75wt% calcium hydroxide, 5wt%~15wt% polyferric sulfate, 10wt%~20wt% sodium aluminate, 5wt%~25wt% diatomaceous earth, and 5wt%~25wt% activated carbon. In these specific embodiments, when the composite agent contains the above-mentioned components, it can more efficiently and thoroughly remove phosphorus and organic matter from phosphorus-containing and acidic organic wastewater.

[0035] In some specific embodiments, the composite agent contains 30wt%~75wt% calcium oxide, 5wt%~15wt% polyferric sulfate, 10wt%~20wt% sodium aluminate, 5wt%~25wt% diatomaceous earth, and 5wt%~25wt% activated carbon. In these specific embodiments, when the composite agent contains the above-mentioned components, it can more efficiently and thoroughly remove phosphorus and organic matter from phosphorus-containing and acidic organic wastewater.

[0036] In some specific embodiments, the composite agent contains 15wt%~37.5wt% calcium oxide, 15wt%~37.5wt% calcium hydroxide, 5wt%~15wt% polyferric sulfate, 10wt%~20wt% sodium aluminate, 5wt%~25wt% diatomaceous earth, and 5wt%~25wt% activated carbon. In these specific embodiments, when the composite agent contains the above-mentioned components, it can more efficiently and thoroughly remove phosphorus and organic matter from phosphorus-containing and acidic organic wastewater.

[0037] In some specific embodiments, the composite agent contains 30wt%~75wt% calcium hydroxide, 2.5wt%~7.5wt% polyferric sulfate, 2.5wt%~7.5wt% iron oxide, 10wt%~20wt% sodium aluminate, 5wt%~25wt% diatomaceous earth, and 5wt%~25wt% activated carbon. In these specific embodiments, when the composite agent contains the above-mentioned components, it can more efficiently and thoroughly remove phosphorus and organic matter from phosphorus-containing and acidic organic wastewater.

[0038] In some specific embodiments, the composite agent contains 30wt%~75wt% calcium hydroxide, 5wt%~15wt% polyferric sulfate, 5wt%~10wt% sodium aluminate, 5wt%~10wt% aluminum sulfate, 5wt%~25wt% diatomaceous earth, and 5wt%~25wt% activated carbon. In these specific embodiments, when the composite agent contains the above-mentioned components, it can more efficiently and thoroughly remove phosphorus and organic matter from phosphorus-containing and acidic organic wastewater.

[0039] In some specific embodiments, the composite agent contains 15wt%~37.5wt% calcium oxide, 15wt%~37.5wt% calcium hydroxide, 2.5wt%~7.5wt% polyferric sulfate, 2.5wt%~7.5wt% iron oxide, 5wt%~10wt% sodium aluminate, 5wt%~10wt% aluminum sulfate, 5wt%~25wt% diatomaceous earth, and 5wt%~25wt% activated carbon. In these specific embodiments, when the composite agent contains the above-mentioned components, it can more efficiently and thoroughly remove phosphorus and organic matter from phosphorus-containing and acidic organic wastewater.

[0040] In some specific embodiments, the composite agent contains 30wt%~75wt% calcite, 5wt%~15wt% calcium iron pyroxene, 10wt%~20wt% sodium aluminate, 5wt%~25wt% diatomaceous earth, and 5wt%~25wt% activated carbon. In these specific embodiments, when the composite agent contains the above-mentioned components, it can more efficiently and thoroughly remove phosphorus and organic matter from phosphorus-containing and acidic organic wastewater.

[0041] In some specific embodiments, the composite agent contains 15wt%~37.5wt% calcite, 15wt%~37.5wt% calcium hydroxide, 2.5wt%~7.5wt% polyferric sulfate, 2.5wt%~7.5wt% calcium iron pyroxene, 10wt%~20wt% sodium aluminate, 5wt%~25wt% diatomaceous earth, and 5wt%~25wt% activated carbon. In these specific embodiments, when the composite agent contains the above-mentioned components, it can more efficiently and thoroughly remove phosphorus and organic matter from phosphorus-containing and acidic organic wastewater.

[0042] The preparation method of the composite agent of the present invention includes: pulverizing the calcium-containing substance, the iron-containing substance, the aluminum-containing compound, the diatomaceous earth and the activated carbon respectively, and then mixing them.

[0043] In the method described in this invention, the calcium-containing substance, the iron-containing substance, the aluminum-containing compound, the diatomaceous earth, and the activated carbon are respectively pulverized to 200-400 mesh.

[0044] The method for treating phosphorus- and acid-containing organic wastewater according to the present invention includes the following steps: (1) The composite agent described above is mixed with phosphorus- and acid-containing organic wastewater and reacted, wherein the amount of the composite agent added is 0.5wt%-10wt% of the phosphorus- and acid-containing organic wastewater; (2) The product obtained in step (1) is subjected to pressure filtration to separate the filtrate and sludge; (3) Mix the acid and / or salt with the filtrate, and then test the pH, phosphorus concentration and COD of the mixture. Discharge after the mixture meets the standards.

[0045] In this invention, in step (1), the pH value of the phosphorus-containing acidic organic wastewater can be 0.5~5, the phosphorus content can be 1000~10000 mg / L, and the COD can be 500~5000 mg / L.

[0046] In the method described in this invention, in step (1), the amount of the composite agent added can be 5wt%-10wt% of the phosphorus-containing and acidic organic wastewater. In the method described in this invention, when the amount of the composite agent added is within the above range, phosphorus and organic matter in the phosphorus-containing and acidic organic wastewater can be removed more efficiently and thoroughly.

[0047] In the method described in this invention, the reaction conditions in step (1) may include: a temperature of 15~35℃, a time of 10~60min, and a pH value >10, preferably 10~11. In the method described in this invention, when the reaction conditions are within the above ranges (especially the preferred ranges), phosphorus and organic matter in phosphorus-containing and acidic organic wastewater can be removed more efficiently and thoroughly.

[0048] In the method described in this invention, the conditions for pressure filtration in step (2) may include: pressure of 0.3~1MPa and time of 30~120min.

[0049] In this invention, in step (3), the acid can be at least one of sulfuric acid, sulfurous acid and hydrochloric acid.

[0050] In this invention, the salt can be at least one of sodium bisulfate, aluminum sulfate, calcium sulfate, ferric sulfate, and magnesium sulfate; In the method described in this invention, the weight ratio of the acid and / or salt to the filtrate can be 0.005 to 0.05:1.

[0051] In the method described in this invention, the mixed liquid that meets the emission standards has a pH value of 7-9, a phosphorus content of 0.1-5 mg / L, and a COD of 600-1000 mg / L.

[0052] The following examples further illustrate the composite pharmaceutical agent, its preparation method, and its application according to the present invention. These examples are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures; however, the scope of protection of the present invention is not limited to the following examples.

[0053] Unless otherwise specified, the experimental methods described in the following embodiments are conventional methods in the art.

[0054] Unless otherwise specified, all experimental materials used in the following examples are commercially available.

[0055] The various chemical reagents used in the following examples were purchased from Sinopharm Reagent Co., Ltd.; the phosphorus-containing, acid-containing, and COD-containing wastewater was taken from the maleic anhydride unit of Sinopec Qingdao Refining & Chemical Co., Ltd. (phosphorus content: 6000 mg / L, COD: 1800 mg / L, pH=1.23).

[0056] Example 1 Preparation of compound drugs: (1) Mix 40g calcium hydroxide, 5g polyferric sulfate, 10g sodium aluminate, 25g diatomaceous earth calcined at 650℃ and 20g powdered activated carbon (specific surface area 1000m² / g, iodine value 920) together and pulverize to 350 mesh. Then put them into a mixer and mix evenly to obtain a composite agent.

[0057] Treatment of phosphorus- and acid-containing organic wastewater: (2) 1.8L of phosphorus-containing wastewater taken from Qingdao Refining & Chemical Co., Ltd. was put into a 2L reactor, and the stirring device was turned on at a stirring speed of 100r / min; (3) The above-mentioned composite agent was slowly added into the reactor by a screw feeder and stirred continuously at 25°C for 30 minutes. During the reaction, the pH value was monitored in real time by an online pH monitor. The pH value of the reaction system was stable at 10.5. After weighing, the amount of agent added was 3.7% of the weight of the phosphorus-containing wastewater. (4) After the reaction is complete, the mixture is fed into a small plate and frame filter press and filtered for 60 minutes under a pressure of 0.6 MPa to obtain sludge with a water content of 55%. (5) Pass the filter press filtrate into the pH adjustment tank, add dilute sulfuric acid through the metering pump, and adjust the pH of the filtrate to 7.2. After testing, the phosphorus concentration of the effluent is 0.2 mg / L and the COD is 650 mg / L.

[0058] Example 2 Preparation of compound drugs: (1) Mix 70g calcium oxide, 5g polyferric sulfate, 10g sodium aluminate, 5g diatomaceous earth calcined at 650℃ and 10g powdered activated carbon (specific surface area 1000m² / g, iodine value 920) together and pulverize to 350 mesh. Then put them into a mixer and mix evenly to obtain a composite agent.

[0059] Treatment of phosphorus- and acid-containing organic wastewater: (2) 1.8L of phosphorus-containing wastewater taken from Qingdao Refining & Chemical Co., Ltd. was put into a 2L reactor, and the stirring device was turned on at a stirring speed of 100r / min; (3) The above-mentioned composite agent was slowly added into the reactor by a screw feeder and stirred continuously at 25°C for 30 minutes. During the reaction, the pH value was monitored in real time by an online pH monitor. The pH value of the reaction system was stable at 10.8. After weighing, the amount of agent added was 2.6% of the weight of the phosphorus-containing wastewater. (4) After the reaction is complete, the mixture is fed into a small plate and frame filter press and filtered for 60 minutes under a pressure of 0.6 MPa to obtain sludge with a water content of 51%. (5) Pass the filter press filtrate into the pH adjustment tank, add dilute sulfuric acid through the metering pump, and adjust the pH of the filtrate to 8.1. After testing, the phosphorus concentration of the effluent is 0.5 mg / L and the COD is 1260 mg / L.

[0060] Example 3 Preparation of compound drugs: (1) Mix 60g calcium hydroxide, 10g polyferric sulfate, 10g sodium aluminate, 10g diatomaceous earth calcined at 650℃ and 10g powdered activated carbon (specific surface area 900m² / g, iodine value 800) together and pulverize to 350 mesh, then put into a mixer and mix evenly to obtain a composite agent.

[0061] Treatment of phosphorus- and acid-containing organic wastewater: (2) 1.8L of phosphorus-containing wastewater taken from Qingdao Refining & Chemical Co., Ltd. was put into a 2L reactor, and the stirring device was turned on at a stirring speed of 100r / min; (3) The above-mentioned composite agent was slowly added into the reactor by a screw feeder and stirred continuously at 25°C for 30 minutes. During the reaction, the pH value was monitored in real time by an online pH monitor. The pH value of the reaction system was stable at 11. The amount of agent added was 3.3% of the weight of the phosphorus-containing wastewater. (4) After the reaction is complete, the mixture is fed into a small plate and frame filter press and filtered for 60 minutes under a pressure of 0.6 MPa to obtain sludge with a water content of 56%. (5) Pass the filter press filtrate into the pH adjustment tank, add dilute sulfuric acid through the metering pump, and adjust the pH of the filtrate to 8.5. After testing, the phosphorus concentration of the effluent is 2.3 mg / L and the COD is 890 mg / L.

[0062] Example 4 Preparation of compound drugs: (1) Mix 50g calcium oxide, 5g polyferric sulfate, 10g sodium aluminate, 10g diatomaceous earth calcined at 650℃ and 25g powdered activated carbon (specific surface area 1100m² / g, iodine value 1000) together and pulverize to 350 mesh, then put into a mixer and mix evenly to obtain a composite agent.

[0063] Treatment of phosphorus- and acid-containing organic wastewater: (2) 1.8L of phosphorus-containing wastewater taken from Qingdao Refining & Chemical Co., Ltd. was put into a 2L reactor, and the stirring device was turned on at a stirring speed of 100r / min; (3) The above-mentioned composite agent was slowly added into the reactor by a screw feeder and stirred continuously at 25°C for 30 minutes. During the reaction, the pH value was monitored in real time by an online pH monitor. The pH value of the reaction system was stable at 10.4. After weighing, the amount of agent added was 4.1% of the weight of the phosphorus-containing wastewater. (4) After the reaction is complete, the mixture is fed into a small plate and frame filter press and filtered for 60 minutes under a pressure of 0.6 MPa to obtain sludge with a water content of 65%. (5) Pass the filter press filtrate into the pH adjustment tank, add dilute sulfuric acid through the metering pump, and adjust the pH of the filtrate to 8.1. The phosphorus concentration of the effluent is 3.1 mg / L and the COD is 360 mg / L.

[0064] Example 5 This embodiment is implemented according to the method described in Example 1, except that the components of the composite agent are: 30g calcium hydroxide, 15g polyferric sulfate, 20g sodium aluminate, 10g diatomaceous earth calcined at 650℃, and 25g powdered activated carbon (specific surface area 1000m² / g, iodine value 920). The effluent pH was measured to be 6.7, phosphorus concentration 4.8mg / L, and COD 750mg / L.

[0065] Example 6 This embodiment is implemented according to the method described in Example 1, except that the components of the composite agent are: 20g calcium hydroxide, 20g calcium oxide, 5g polyferric sulfate, 10g sodium aluminate, 25g diatomaceous earth calcined at 650℃, and 20g powdered activated carbon (specific surface area 1000m² / g, iodine value 920). The effluent pH was 7.5, phosphorus concentration was 0.2mg / L, and COD was 660mg / L.

[0066] Example 7 This embodiment is implemented according to the method described in Example 1, except that the components of the composite agent are: 40g calcium hydroxide, 2.5g polyferric sulfate, 2.5g iron oxide, 10g sodium aluminate, 25g diatomaceous earth calcined at 650℃, and 20g powdered activated carbon (specific surface area 1000m² / g, iodine value 920). The effluent pH was 7.3, phosphorus concentration was 2.3mg / L, and COD was 690mg / L.

[0067] Example 8 This embodiment is implemented according to the method described in Example 1, except that the composite agent consists of: 40g calcium hydroxide, 5g polyferric sulfate, 5g sodium aluminate, 5g aluminum sulfate, 25g diatomaceous earth calcined at 650℃, and 20g powdered activated carbon (specific surface area 1000m² / g, iodine value 920). The effluent was tested and found to have a pH of 7.4, a phosphorus concentration of 1.1mg / L, and a COD of 680mg / L.

[0068] Example 9 This embodiment is implemented according to the method described in Example 1, except that the components of the composite agent are: 20g calcium hydroxide, 20g calcium oxide, 2.5g polyferric sulfate, 2.5g ferric oxide, 5g sodium aluminate, 5g aluminum sulfate, 25g diatomaceous earth calcined at 650℃, and 20g powdered activated carbon (specific surface area 1000m² / g, iodine value 920). The effluent pH was 7.0, phosphorus concentration was 0.8mg / L, and COD was 670mg / L.

[0069] Example 10 This embodiment is implemented according to the method described in Example 1, except that the composite agent consists of: 40g calcite, 5g calcium iron pyroxene, 10g sodium aluminate, 25g diatomaceous earth calcined at 650℃, and 20g powdered activated carbon (specific surface area 1000m² / g, iodine value 920). The effluent was tested and found to have a pH of 7.3, a phosphorus concentration of 4.2mg / L, and a COD of 710mg / L.

[0070] Example 11 This embodiment is implemented according to the method described in Example 1, except that the composite agent consists of: 20g calcium hydroxide, 20g calcite, 2.5g polyferric sulfate, 2.5g calcium iron pyroxene, 10g sodium aluminate, 25g diatomaceous earth calcined at 650℃, and 20g powdered activated carbon (specific surface area 1000m² / g, iodine value 920). The effluent was tested and found to have a pH of 7.1, a phosphorus concentration of 3.3mg / L, and a COD of 690mg / L.

[0071] Example 12 This embodiment is implemented according to the method described in Embodiment 1, except that in step (3), the amount of reagent added is 10% of the weight of the phosphorus-containing wastewater. The pH value of the effluent was 7.8, the phosphorus concentration was 0.08 mg / L, and the COD was 350 mg / L.

[0072] Example 13 This embodiment is implemented according to the method described in Embodiment 1, except that in step (3), the above-mentioned composite agent is slowly added to the reactor by a screw feeder and continuously stirred at 5°C for 100 min. The pH of the effluent was 7.5, the phosphorus concentration was 15 mg / L, and the COD was 620 mg / L.

[0073] Example 14 This embodiment is implemented according to the method described in Embodiment 1, except that in step (3), the above-mentioned composite agent is slowly added to the reaction vessel by a screw feeder and continuously stirred at 50°C for 5 minutes. The pH of the effluent was 7.3, the phosphorus concentration was 45 mg / L, and the COD was 1130 mg / L.

[0074] Comparative Example 1 This comparative example was carried out according to the method described in Example 1, except that the composite agent consisted of: 10g calcium hydroxide, 20g polyferric sulfate, 25g sodium aluminate, 30g diatomaceous earth calcined at 650℃, and 15g powdered activated carbon (specific surface area 1000m² / g, iodine value 920). The effluent was tested and found to have a pH of 6.5, a phosphorus concentration of 120mg / L, and a COD of 830mg / L.

[0075] Comparative Example 2 This comparative example was carried out according to the method described in Example 1, except that the composite agent consisted of: 90g calcium hydroxide, 2.5g polyferric sulfate, 2.5g sodium aluminate, 2.50g diatomaceous earth calcined at 650℃, and 2.5g powdered activated carbon (specific surface area 1000m² / g, iodine value 920). The effluent was tested and found to have a pH of 7.8, a phosphorus concentration of 123mg / L, and a COD of 1040mg / L.

[0076] Comparative Example 3 This comparative example was carried out according to the method described in Example 1, except that calcium hydroxide was not added to the composite agent. The effluent was tested and found to have a pH of 3.8, a phosphorus concentration of 760 mg / L, and a COD of 950 mg / L.

[0077] Comparative Example 4 This comparative example was carried out according to the method described in Example 1, except that polyferric sulfate was not added to the composite agent. The effluent was tested and found to have a pH of 7.5, a phosphorus concentration of 118 mg / L, and a COD of 795 mg / L.

[0078] Comparative Example 5 This comparative example was carried out according to the method described in Example 1, except that sodium aluminate was not added to the composite agent. The effluent was tested and found to have a pH of 7.6, a phosphorus concentration of 133 mg / L, and a COD of 810 mg / L.

[0079] Comparative Example 6 This comparative example was carried out according to the method described in Example 1, except that in step (3), the amount of reagent added was 0.1% of the weight of the phosphorus-containing wastewater. The pH value of the effluent was 1.69, the phosphorus concentration was 5650 mg / L, and the COD was 1730 mg / L.

[0080] Comparative Example 7 This comparative example was carried out according to the method described in Example 1, except that in step (3), the amount of reagent added was 15% of the weight of the phosphorus-containing wastewater. The pH value of the effluent was 7.9, the phosphorus concentration was 125 mg / L, and the COD was 895 mg / L.

[0081] Test Example 1 This test case tested the pH value, phosphorus concentration, and COD value of the effluent obtained from Examples 1-16 and Comparative Examples 1-5. The results are shown in Table 1.

[0082] Table 1

[0083] As shown in Table 1, the technical solution of this invention can achieve efficient removal of phosphorus and organic matter from phosphorus-containing and acidic organic wastewater. Specifically, the phosphorus removal rate in Examples 1-14 can reach over 99%, and the organic matter removal rate can reach over 56%. However, in Comparative Examples 1 and 2, the phosphorus and organic matter removal rates decreased to some extent because the ratio of the composite agent was not within the optimal range. In Comparative Examples 3-5, the phosphorus and organic matter removal rates were lower than in Examples 1-14 because calcium hydroxide, polyferric sulfate, and sodium aluminate were not added to the composite agent, respectively. In Comparative Examples 6 and 7, the phosphorus and organic matter removal rates were lower than in Examples 1-14 because the dosage of the composite agent was either too low or too high, respectively.

[0084] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A compound agent, characterized in that, The composite agent contains calcium-containing substances, iron-containing substances, aluminum-containing compounds, diatomaceous earth, and activated carbon, wherein the calcium-containing substances are calcium-containing compounds and / or calcium-containing minerals, and the iron-containing substances are iron-containing compounds and / or iron-containing minerals. Based on the total weight of the composite agent, the content of the calcium-containing substance is 30wt%~75wt%, the content of the iron-containing substance is 5wt%~15wt%, the content of the aluminum-containing compound is 10wt%~20wt%, the content of diatomaceous earth is 5wt%~25wt%, and the content of activated carbon is 5wt%~25wt%.

2. The composite agent according to claim 1, characterized in that, The calcium-containing compound is selected from at least one of calcium oxide, calcium hydroxide, calcium sulfate, calcium carbonate, and calcium nitrate; and / or, The calcium-containing mineral is selected from at least one of calcite, dolomite, and anorthite; and / or, The iron-containing compound is selected from at least one of ferric sulfate, polyferric sulfate, and iron oxide; and / or, The iron-bearing mineral is selected from at least one of pyroxene, bauxite, limonite, and siderite; and / or, The aluminum-containing compound is selected from at least one of aluminum sulfate, sodium aluminate, and aluminum ferric sulfate.

3. The compound agent according to claim 1, characterized in that, The diatomaceous earth has a particle size of 200 mesh or larger, preferably 300-500 mesh; and / or, The activated carbon has a particle size of 200 mesh or more, preferably 300-500 mesh; a specific surface area of ​​not less than 800 m² / g, preferably 900-1100 m² / g; and an iodine value of not less than 800, preferably 900-1000.

4. A method for preparing the composite agent according to any one of claims 1-3, characterized in that, The method includes: pulverizing the calcium-containing substance, the iron-containing substance, the aluminum-containing compound, the diatomaceous earth, and the activated carbon separately, and then mixing them.

5. A method for treating phosphorus- and acid-containing organic wastewater, characterized in that, The method includes the following steps: (1) The composite agent according to any one of claims 1-3 is mixed with phosphorus-containing and acid-containing organic wastewater and reacted, wherein the amount of the composite agent added is 0.5wt%-10wt% of the phosphorus-containing and acid-containing organic wastewater; (2) The product obtained in step (1) is subjected to pressure filtration to separate the filtrate and sludge; (3) Mix the acid and / or salt with the filtrate, and then test the pH, phosphorus concentration and COD of the mixture. Discharge after the mixture meets the standards.

6. The method according to claim 5, characterized in that, In step (1), the pH value of the phosphorus-containing acidic organic wastewater is 0.5~5, the phosphorus content is 1000~10000mg / L, and the COD is 500~5000mg / L.

7. The method according to claim 5, characterized in that, In step (1), the reaction conditions include: temperature of 15~35℃, time of 10~60min, and pH value >10.

8. The method according to claim 5, characterized in that, In step (2), the pressure filtration conditions include: pressure of 0.3~1MPa and time of 30~120min.

9. The method according to claim 5, characterized in that, In step (3), the acid is selected from at least one of sulfuric acid, sulfurous acid, and hydrochloric acid; and / or, The salt is selected from at least one of sodium bisulfate, aluminum sulfate, calcium sulfate, ferric sulfate, and magnesium sulfate.

10. The method according to claim 5, characterized in that, In step (3), the weight ratio of the acid and / or salt to the filtrate is 0.005 to 0.05:1.

Images