A sewage treatment material, a preparation method thereof and application thereof

Abstract

The present application relates to a kind of sewage treatment materials, its preparation method and its application in sewage treatment.The sewage treatment material includes the following raw materials: non-metallic mineral, adhesive, low-boiling alcohol, pore-forming agent, bacterial solution.The preparation method of the material includes, first non-metallic mineral is mixed with pore-forming agent, then add adhesive and low-boiling alcohol to form viscous material, finally by into mould, drying, acid soaking, cleaning, load microorganism, dry and so on Process forms the material.The relative density of the material is 0.8-1.2, pore size is 10-200nm, specific surface area is greater than 10000m 2 / m 3 , diameter is 1-30mm.The material can be directly added in sewage, and input proportion is only 1%-10% of pool capacity, less than 25%-60% of ordinary filler filling rate, thereby greatly reduce cost;And in aeration state, the material start-up time is short, can be suspended up and down, so mixing effect is good, not easy to lose, with higher biochemical conversion efficiency.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of sewage treatment, and in particular to a sewage treatment material, a preparation method thereof and an application thereof in sewage treatment. Background Art

[0002] Rural domestic sewage primarily comes from household wastewater, kitchen wastewater, toilet flushing water, livestock washing water, manure, and leachate from the careless storage of villagers' garbage. Rural domestic sewage has unique household characteristics. Compared to urban areas, housing and water sources are more dispersed. Rural domestic sewage discharge typically has three peak periods daily: morning, noon, and evening. Compared to urban domestic sewage, rural domestic sewage has a simpler composition, generally free of toxic substances. It primarily contains nitrogen, phosphorus, organic matter, bacteria, viruses, and parasites. Water quality also varies seasonally. Therefore, rural domestic sewage has the following characteristics: 1) small, dispersed sewage production with diverse composition; 2) significant temporal and spatial variation in sewage discharge, and influenced by rainy weather, with instantaneous flow rates reaching several times the design flow rate; 3) biochemical treatability; 4) dispersed sewage, making centralized treatment difficult; and 5) low carbon-to-nitrogen ratio, resulting in extremely low treatment efficiency.

[0003] As the country's requirements for sewage treatment gradually increase, integrated sewage treatment equipment has become the most common application equipment for treating rural domestic sewage. Compared with traditional large-scale domestic sewage treatment equipment, it has significant advantages, such as low investment, small footprint, easy management, high treatment rate, and high degree of integration. At present, there are many types of integrated sewage treatment processes widely used in rural areas, especially A 2 / O-MBBR process is more typical and widely used.

[0004] A 2 The / O-MBBR process has the following advantages: 1) The sludge concentration in the reactor is relatively high, which is generally 5 to 10 times that of the ordinary activated sludge process and can be as high as 30 to 40 g / L, with a high treatment load; 2) The oxidation tank volume is small, which reduces capital construction investment; 3) No backwash equipment is required, which reduces equipment investment, is easy to operate, and reduces sewage operating costs; 4) The sludge yield of the MBBR process is relatively low, which reduces sludge disposal costs; 5) The MBBR process does not require a filler support and can be added directly, saving installation time and costs.

[0005] However, A 2 / O-MBBR process also has the following problems: 1) the efficiency of simultaneous nitrification and denitrification is not high, especially depending on the filling rate of the filler. 2) The start-up time is long, generally about 7 days, and some as long as a month; 3) The filling rate of the filler is high. The filling rate is generally required to be greater than 15%, and the filling rate of the suspended carrier in the aerobic tank in the actual project is generally 25% to 60%; 4) There are aeration dead angles, and the mixing is not good, and increasing the aeration amount will increase the energy consumption cost and other problems.

[0006] Patent CN113736770A proposes a kind of granular strain and its preparation method and application in sewage biochemical treatment, but its adhesive is preferably selected from one or combination of chitosan and chitin, while chitosan and chitin have low coating efficiency, difficult drying, and film forming has problems such as poor strength; At the same time, the composition of the granular strain is simple, so the adsorption effect is poor. SUMMARY

[0007] In view of the problems existing in the prior art, the present application provides a preparation method of a porous granular sewage treatment material with high-efficiency simultaneous nitrification and denitrification, short start-up time, ultra-high specific surface area, and density close to water, and its application in rural domestic sewage.

[0008] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0009] The first invention point of the present application is to provide a sewage treatment material.

[0010] Further, the sewage treatment material is a porous granular sewage treatment material.

[0011] Further, the porous granular sewage treatment material comprises the following raw materials by weight:

[0012] Non-metallic mineral 20-50 parts, adhesive 30-50 parts, low-boiling alcohol 10-25 parts, pore-forming agent 0.1-2 parts and bacterial liquid 50-100 parts.

[0013] Further, the relative density of the granular sewage treatment material is 0.8-1.2, the pore size is 10-200 nm, the specific surface area is not less than 10000 m 2 / m 3 , the diameter is 1-30 mm, preferably 1-5 mm.

[0014] Further, the non-metallic mineral is a hydrous silicate mineral, specifically one or more of diatomite, kaolin, bentonite, attapulgite and sepiolite.

[0015] Further, the adhesive is selected from one or more of polyvinyl alcohol, epoxy resin, urea-formaldehyde resin, phenol-formaldehyde resin and polysodium silicate.

[0016] Preferably, the epoxy resin is a colorless transparent viscous liquid, with relative density close to 1, good hydrophilicity, but not soluble in water, long service life.

[0017] Preferably, the adhesive is only soluble in organic solvents, and the low boiling point alcohol is easy to volatilize, so that the porous granular sewage treatment material obtained after low temperature drying has a large number of pores, and the specific surface area is greater than 10000m 2 / m 3 .

[0018] Further, the low boiling point alcohol is one or more of methanol, ethanol, n-propanol, isopropanol, n-butanol and isobutyl alcohol.

[0019] Further, the pore-forming agent is selected from one or more of metallic elements, sodium peroxide, potassium peroxide, ammonium carbonate, ammonium bicarbonate, calcium carbonate, calcium bicarbonate, sodium sulfite, sodium bisulfite.

[0020] Further, the bacterial solution is an engineering bacteria suspension; the mass ratio of nitrifying bacteria to denitrifying bacteria in the engineering bacteria suspension is (0.5-3):4, and the number of bacterial colonies is not less than 1*10 9 cfu / ml.

[0021] The second invention point of the present application is to provide a preparation method of the porous granular sewage treatment material.

[0022] The method comprises the following steps:

[0023] S1, uniformly mixing non-metallic minerals with pore-forming agents;

[0024] S2, adding adhesive and low boiling point alcohol to the mixture obtained in S1, and stirring to form a viscous mixture;

[0025] S3, loading the mixture obtained in S2 into a mold and drying;

[0026] S4, demolding, and soaking the obtained demolding product in a dilute acid solution;

[0027] S5, soaking the demolding product obtained in S4 in a bacterial solution after taking it out, and then taking it out and drying.

[0028] Further, in step S3, the mixture obtained in S2 is loaded into a mold and dried at 50-80℃ for 3-6 hours.

[0029] Further, in step S4, the demolding product is soaked in a 2% dilute acid solution for 1 hour.

[0030] The porous granular sewage treatment material obtained by the above preparation method has an ultra-high specific surface area, a short activation time during the water treatment process, high biochemical efficiency, strong impact resistance, and is not easy to disintegrate and cause sludge swelling. At the same time, the added chemical agents do not affect the biological activity of the bacteria.

[0031] The third invention of the present invention is to provide the application of the sewage treatment material in sewage treatment.

[0032] Further, the sewage treatment material is applied to the 2 / O-MBBR coupling technology integrated sewage treatment equipment, the treatment process of the integrated sewage treatment equipment is anaerobic-anoxic-aerobic process, anoxic-aerobic process, SBR process or CASS process.

[0033] Furthermore, the input ratio of the sewage treatment material is 1%-10% of the tank volume. Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. Based on chemical means such as gluing and pore formation and microbial loading technology, the present invention proposes a porous granular sewage treatment material with controllable size and ultra-high specific surface area. This material is a high-efficiency biochemical bacterial strain of millimeter-scale particles with the advantages of good sedimentation, better control of filamentous bacteria expansion, degradability to provide some nutrients required for biochemical treatment, and no environmental pollution. The microbial system provided by the porous granular sewage treatment material can cooperate with indigenous nitrification and denitrification bacteria, thereby enhancing the biochemical treatment capacity of the entire biochemical treatment system. At the same time, under the condition of a smaller aeration volume, the material has a short start-up time and can be suspended up and down, so the mixing is more uniform, thereby achieving a better adsorption effect. The material can be directly added to the sewage, and the input ratio is only 1%-10% of the pool volume, which is less than the 25%-60% filling rate of ordinary fillers, thereby greatly reducing costs.

[0035] 2. After the porous granular sewage treatment material of the present invention is put into a water body, due to the structural characteristics of the porous granular sewage treatment material, the dissolved oxygen varies in different parts of the sludge. The active cell layer living on the outside of the porous granular sewage treatment material consumes most of the oxygen, so there is no oxygen in the core of the porous granular sewage treatment material. The concentration of oxygen molecules in the porous granular sewage treatment material decreases from the outside to the inside, forming an aerobic-anoxic-anaerobic treatment unit. Therefore, the porous granular sewage treatment material can achieve good biological denitrification and phosphorus removal effects and maintain a good organic matter removal rate.

[0036] 3. The raw materials selected in the porous granular sewage treatment material of the present invention have good hydrophilicity and bioaffinity. By adjusting the raw material ratio and pore-forming technology, the relative density of the porous granular sewage treatment material is controlled to be close to 1g / cm 3The size of the porous granular sewage treatment material can be controlled within 3-30mm according to the size of the mold or free cutting and crushing. It is only necessary to maintain the aeration volume of 2-3mg / L of dissolved oxygen in the equipment to make the porous granular sewage treatment material suspended without dead corners.

[0037] 4. The present invention has the characteristics of cost saving, efficient treatment, and green environmental protection. The porous granular sewage treatment material has good sedimentation performance and has a high efficiency in removing water pollutants. Therefore, the porous granular sewage treatment material of the present invention can be used in various types of sewage biochemical treatment: it can be used in the biochemical treatment stage of agricultural sewage integrated equipment. The porous granular sewage treatment material with high specific surface area increases the number of effective microorganisms per unit volume in the form of microbial load, breaking through the defect of MBBR filler startup time of more than 7 days on the market, shortening the startup time of integrated equipment to about 3 days, and the average removal rates of COD, ammonia nitrogen, total phosphorus, and total nitrogen can reach 90%, 85%, 65%, and 80% or more, respectively. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a photo of the porous granular sewage treatment material of the present invention.

[0039] Figure 2 This is a photo of the porous granular sewage treatment material of the present invention after long-term use in sewage. DETAILED DESCRIPTION

[0040] The present invention is further described in detail below to make the purpose, technical solutions and advantages of the present invention clearer. However, it should be understood that the description herein is only for explaining the present invention and is not intended to limit the scope of the present invention.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention pertains. The terms used in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The reagents and instruments used herein are all commercially available. The characterization methods involved can be found in the relevant descriptions in the prior art and will not be described in detail herein.

[0042] 1. Experimental materials

[0043] Material factory Non-metallic minerals Lingshou County Aotai Mineral Products Processing Plant adhesive Guangzhou Huitu New Materials Co., Ltd. Low boiling point alcohol Jinan Xinke Chemical Co., Ltd. pore-forming agent Tianjin Zhonghe Shengtai Chemical Co., Ltd. bacterial liquid BioVofeng Biotechnology (Guangdong) Co., Ltd.

[0044] 2. Experimental instruments and equipment

[0045] Material factory Blast drying oven Shanghai Dute Scientific Instrument Co., Ltd. Electric mechanical stirrer Shanghai Titan Technology Co., Ltd. High-precision automatic dispensing machine Yichuanlong Electronics Co., Ltd. silicone mold Guangzhou Weijia Technology Co., Ltd.

[0046] 3. Detect the purification effect of water samples

[0047] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0048] The following table lists the ingredients and proportions of the materials in the examples and comparative examples for reference:

[0049]

[0050]

[0051] *Note: Example 2 is a preparation method and is not listed in the table.

[0052] Example 1

[0053] This embodiment provides a porous granular sewage treatment material for rural domestic sewage treatment, comprising the following raw materials in parts by weight:

[0054] 20-50 parts of non-metallic minerals, 30-50 parts of adhesives, 10-25 parts of low-boiling-point alcohols, 0.1-1 parts of pore-forming agents, and 50-100 parts of bacterial liquid.

[0055] The relative density of the granular sewage treatment material is 0.8-1.2, the pore size is 10-200nm, and the specific surface area is not less than 10000m 2 / m 3 , with a diameter of 1-30 mm, more preferably 1-5 mm.

[0056] The adhesive is selected from one or more of polyvinyl alcohol, epoxy resin, urea-formaldehyde resin, phenolic resin, and sodium polysilicate, with epoxy resin being preferred, and colorless and transparent epoxy resin being more preferred. Upon contact with a corresponding curing agent, the epoxy resin exhibits good initial fluidity and ease of handling. Upon prolonged contact time or heating, it forms an acid- and alkali-resistant solid, with a service life of up to 10 years.

[0057] The pore-forming agent is selected from one or more of metal elements, sodium peroxide, potassium peroxide, ammonium carbonate, ammonium bicarbonate, calcium carbonate, calcium bicarbonate, sodium sulfite, and sodium bisulfite, preferably calcium carbonate, which has a mild reaction and is cheap and easily available.

[0058] The bacterial liquid is an engineered bacterial suspension; the mass ratio of nitrifying bacteria to denitrifying bacteria in the engineered bacterial suspension is (0.5-3):4, and the colony count is not less than 1*10 9 cfu / ml. Nitrifying bacteria are preferably Nitrosomonas and Nitrobacter, and denitrifying bacteria are preferably Pseudomonas and Alcaligenes.

[0059] The non-metallic mineral is a hydrous silicate mineral, specifically one or more of diatomaceous earth, kaolin, bentonite, attapulgite, and sepiolite. Diatomaceous earth is preferred, and diatomaceous earth with a mesh size of 800 or greater is more preferred. Diatomaceous earth is porous and chemically stable, which gives the sewage treatment material a large specific surface area and good stability.

[0060] The low-boiling-point alcohol is one or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, and isobutanol, preferably ethanol. Ethanol has a lower boiling point (78.3°C), which can reduce the drying temperature and save energy. It is also less toxic than methanol and is safer.

[0061] The raw materials selected in the porous granular bacterial material have good hydrophilicity and bioaffinity. By adjusting the raw material ratio and pore-forming technology, the relative density of the porous granular bacterial material is controlled to be close to 1g / cm 3 The size of the porous granular material can be controlled within 3-30mm according to the size of the mold or free cutting and crushing. It is only necessary to maintain the aeration volume of 2-3mg / L of dissolved oxygen in the equipment to make the porous granular bacterial material suspended without dead corners.

[0062] After the porous granular bacterial material is put into the water body, due to the structural characteristics of the porous granular bacterial material, the dissolved oxygen varies in different parts of the sludge. The active cell layer living on the outside of the porous granular bacterial material consumes most of the oxygen, so there is no oxygen in the core of the granular bacterial material. The concentration of oxygen molecules decreases from the outside to the inside of the porous granular bacterial material, forming an aerobic-anoxic-anaerobic treatment unit. Therefore, the porous granular bacterial material can achieve good biological denitrification and phosphorus removal effects and maintain a good organic matter removal rate.

[0063] The material has the characteristics of cost saving, high processing efficiency, and green environmental protection. The porous granular bacterial strain material has good sedimentation performance and has a high efficiency in removing water pollutants.

[0064] Therefore, the porous granular bacterial strain material can be used in the biochemical treatment of various types of sewage: it can be used in the biochemical treatment stage of agricultural sewage integrated equipment. The porous granular bacterial strain material with high specific surface area increases the number of effective microorganisms per unit volume in the form of microbial load, breaking through the defect of MBBR filler on the market that the startup time is more than 7 days, shortening the startup time of the integrated equipment to about 3 days, and the average removal rates of COD, ammonia nitrogen, total phosphorus and total nitrogen can reach 90%, 85%, 65% and 80% respectively.

[0065] Example 2

[0066] This embodiment provides a method for preparing the material as described in Example 1, comprising the following steps:

[0067] S1, mixing non-metallic minerals with pore-forming agents;

[0068] In some embodiments, 20-50 parts of non-metallic mineral and 0.1-1 part of pore former are mixed evenly.

[0069] S2, add adhesive and low boiling point alcohol to the mixture obtained in S1, stir and set aside

[0070] In some embodiments, 30-50 parts of an adhesive and 10-25 parts of a low-boiling-point alcohol are added and stirred for 10-15 minutes to form a viscous mixture.

[0071] S3, putting the mixture obtained in S2 into a mold and drying it;

[0072] In some embodiments, the mixture obtained in S2 is placed into a mold and dried in a forced air drying oven at 50° C.-80° C. for 3-6 hours, preferably at 60° C. for 6 hours.

[0073] S4, demoulding, and immersing the demoulded product in a dilute acid solution;

[0074] In some embodiments, the demoulded product is immersed in a 2% dilute acid solution for 1 hour.

[0075] S5, taking out the demoulding product soaked in the dilute acid solution obtained in S4 and soaking it in a bacterial solution, then taking out the product from the bacterial solution and drying it to obtain the material.

[0076] In some embodiments, the demoulding product obtained in S4 and soaked in the dilute acid solution is taken out, washed 2-3 times, soaked in 50 parts of bacterial solution for 1 day, taken out and naturally dried to obtain a porous granular bacterial seed material.

[0077] The porous granular bacterial strain material obtained by the above preparation method has an ultra-high specific surface area, a short activation time during the water treatment process, high biochemical efficiency, strong impact resistance, and is not easy to disintegrate and cause sludge swelling. At the same time, the added chemical agents do not affect the biological activity of the bacteria.

[0078] Preferably, the adhesive may be, but is not limited to, polyvinyl alcohol, epoxy resin, urea-formaldehyde resin, phenolic resin, sodium polysilicate, etc.

[0079] Preferably, the epoxy resin is a colorless, transparent, viscous liquid with a relative density close to 1, is insoluble in water, and has a long service life.

[0080] In the porous granular bacterial material of the present invention, the adhesive is only soluble in organic solvents, and the low-boiling point alcohol of the present invention is easy to volatilize. Therefore, the porous granular bacterial material obtained will have more pores after drying, making the specific surface area greater than 10,000 m 2 / m3 .

[0081] The dilute acid solution is one or more of sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, hydrofluoric acid, and boric acid. The mass concentration of the dilute acid solution is 1-10%, preferably hydrochloric acid. Hydrochloric acid reacts with the pore-forming agent calcium carbonate without producing other solids and does not affect the material ratio.

[0082] The sewage treatment material is prepared by mixing porous non-metallic minerals with adhesives, pore-forming agents, and low-molecular alcohols, using a mold to control the material size, and preparing the porous material at a relatively low temperature. The denser pore-forming agents are then removed by dilute acid soaking and the pores are further unblocked, forming an interconnected three-dimensional network structure inside the material to obtain an ultra-high specific surface area. Functional bacteria are then loaded to increase the number of microbial colonies per unit volume, thereby improving the biochemical efficiency of sewage treatment.

[0083] Example 3

[0084] A porous granular sewage treatment material comprises the following raw materials in parts by weight: 25 parts of non-metallic minerals, 30 parts of adhesives, 10 parts of low-boiling-point alcohols, 0.5 parts of pore-forming agents, and 50 parts of bacterial liquids.

[0085] A method for preparing a porous granular sewage treatment material comprises the following steps:

[0086] Step 1: Mix 25 parts of non-metallic mineral and 0.5 parts of pore-forming agent;

[0087] Step 2: Add 30 parts of adhesive and 10 parts of low-boiling alcohol and stir for 10-15 minutes until it becomes viscous.

[0088] Step 3: Place in a mold and dry in a 60°C environment for 6 hours;

[0089] Step 4: demoulding and soaking in 2% dilute acid solution for 1 hour;

[0090] Step 5: Wash 2-3 times, soak in 50 parts of bacterial solution for 1 day, take out and dry naturally to obtain porous granular sewage treatment material.

[0091] Biochemical effect comparison test:

[0092] Take one portion each of the porous granular sewage treatment material and commercially available MBBR filler (purchased from Zungguan Environmental Protection Technology Co., Ltd.) and add them in a volume ratio of 1 / 10 and 2 / 5 respectively. The initial MLSS is 500-1000 mg / L. Rural domestic sewage is used as the influent. The cycle alternating operation mode of aeration (DO = 2-3 mg / L) 4h-anoxic (DO = 0.2-0.6 mg / L) stirring 4h-aeration (DO = 2-3 mg / L) 4h is adopted, and the operation time is 3 days.

[0093] raw material COD / ppm [COD] / mg TP / ppm TN / ppm Water ingress 346 35.9 0.584 81.46 Commercially available MBBR filler, biochemical treatment for 3 days 27.68 5.67 0.23 23.22 Porous granular sewage treatment materials for biochemical treatment for 3 days 17.3 2.58 0.16 11.89

[0094] It was measured that the COD removal rate of the porous granular sewage treatment material described in this embodiment was increased by 3% compared with the commercially available MBBR filler after treatment, the NH3-N removal rate was increased by 8.6%, the TP removal rate was increased by 12%, and the TN removal rate was increased by 13.9%. Moreover, after the 3-day biochemical process was completed, the external dimensions of the porous granular sewage treatment material were consistent with those when it was put into use without much loss, and obvious biofilm was formed, and it could still be mixed evenly.

[0095] Example 4

[0096] A porous granular sewage treatment material comprises the following raw materials in parts by weight: 35 parts of non-metallic minerals, 40 parts of adhesives, 15 parts of low-boiling-point alcohols, 0.75 parts of pore-forming agents, and 75 parts of bacterial liquids.

[0097] The preparation method of the porous granular sewage treatment material is as follows:

[0098] Step 1: Mix 35 parts of non-metallic mineral and 0.75 parts of pore-forming agent;

[0099] Step 2: Add 40 parts of adhesive and 15 parts of low-boiling alcohol and stir for 10-15 minutes to form a viscous mixture;

[0100] Step 3: Place in a mold and dry in a 70°C environment for 4 hours;

[0101] Step 4: demoulding and soaking in 4% dilute acid solution for 1 hour;

[0102] Step 5: Wash 2-3 times, soak in 75 parts of bacterial solution for 1 day, take out and dry naturally to obtain porous granular sewage treatment material.

[0103] Biochemical effect comparison test:

[0104] Take one portion each of the porous granular sewage treatment material and commercially available MBBR filler (purchased from Zungguan Environmental Protection Technology Co., Ltd.) and add them in a volume ratio of 5 / 100 and 1 / 5 respectively. The initial MLSS is 500-1000 mg / L. Rural domestic sewage is used as the influent. The cycle alternating operation mode of aeration (DO = 2-3 mg / L) 4h-anoxic (DO = 0.2-0.6 mg / L) stirring 4h-aeration (DO = 2-3 mg / L) 4h is adopted, and the operation time is 3 days.

[0105] raw material COD / ppm <![CDATA[NH3-N / ppm]]> TP / ppm TN / ppm Water ingress 346 35.9 0.584 81.46 Commercially available MBBR filler, biochemical treatment for 3 days 40.48 9.62 0.22 25.66 Porous granular sewage treatment material, biochemical treatment for 3 days 23.53 4.38 0.167 13.52

[0106] It was measured that the COD removal rate of the porous granular sewage treatment material described in this embodiment was increased by 4.9% compared with the commercially available MBBR filler after treatment, the NH3-N removal rate was increased by 14.6%, the TP removal rate was increased by 9.2%, and the TN removal rate was increased by 14.9%. After the 3-day biochemical process was completed, the external dimensions of the porous granular sewage treatment material were consistent with those when it was put into use without much loss, and obvious biofilm was formed, and it could still be mixed evenly.

[0107] Example 5

[0108] A porous granular sewage treatment material comprises the following raw materials in parts by weight: 45 parts of non-metallic minerals, 50 parts of adhesives, 25 parts of low-boiling-point alcohols, 1 part of pore-forming agents, and 100 parts of bacterial liquids.

[0109] The preparation method of the porous granular sewage treatment material is as follows:

[0110] Step 1: Mix 45 parts of non-metallic mineral and 1 part of pore-forming agent evenly;

[0111] Step 2: Add 50 parts of adhesive and 25 parts of low-boiling alcohol and stir for 10-15 minutes to form a viscous mixture;

[0112] Step 3: Place in a mold and dry in an 80°C environment for 3 hours;

[0113] Step 4: demoulding and soaking in 8% dilute acid solution for 1 hour;

[0114] Step 5: Wash 2-3 times, soak in 100 parts of bacterial solution for 3 days, take out and dry naturally to obtain porous granular sewage treatment material.

[0115] Biochemical effect comparison test:

[0116] Take one portion each of the porous granular sewage treatment material and commercially available MBBR filler (purchased from Zunguan Environmental Protection Technology Co., Ltd.) and add them in a volume ratio of 2 / 100 and 1 / 10 respectively. The initial MLSS is 500-1000 mg / L. Rural domestic sewage is used as the influent. The cycle alternating operation mode of aeration (DO = 2-3 mg / L) 4h-anoxic (DO = 0.2-0.6 mg / L) stirring 4h-aeration (DO = 2-3 mg / L) 4h is adopted, and the operation time is 3 days.

[0117]

[0118] The COD removal rate of the porous granular sewage treatment material of the present embodiment is increased by 6.2% compared with the commercially available MBBR filler, the NH3-N removal rate is increased by 16.1%, the TP removal rate is increased by 10%, and the TN removal rate is increased by 14.1%. After 3 days of biochemical process, the outer size of the porous granular sewage treatment material is consistent with that when it is put in, and there is no great loss, and obvious biofilm is formed, and it can still be mixed uniformly.

[0119] Comparative Example 1

[0120] The preparation method is basically the same as that of Example 3, except that the amount of adhesive epoxy resin is 10 parts and the amount of low-boiling alcohol ethanol is 5 parts. The sewage treatment material prepared has low strength and the surface cracks after drying, because the adhesive is insufficient to firmly bond the other materials together.

[0121] Comparative Example 2

[0122] The preparation method is basically the same as that of Example 4, except that the amount of non-metallic mineral diatomite is 10 parts and the amount of pore-forming agent calcium carbonate is 10 parts. The surface of the prepared material is smooth and non-porous, because the adhesive epoxy resin is in serious excess when the amount of non-metallic mineral diatomite is small, resulting in the formation of a dense film on the surface of the material, and the dilute acid cannot fully react with the pore-forming agent. A certain amount of sewage treatment material is crushed and then soaked in dilute acid, and still a large amount of bubbles emerge, and the calcium ion content in the dilute acid is as high as 18500 mg / L, which also proves that there is a large amount of pore-forming agent remaining in the material.

[0123] Comparative Example 3

[0124] The preparation method is basically the same as that of Example 5, except that the amount of non-metallic mineral diatomite is 25 parts and the amount of low-boiling alcohol ethanol is 40 parts. The sewage treatment material prepared has an irregular shape, is gourd-shaped, and has obvious larger pores, but has high hardness, because the amount of low-boiling alcohol ethanol is too large, and the volatilization speed is fast at 70°C, causing the material to expand excessively.

[0125] One part of the material prepared in Comparative Example 3 and one part of commercially available MBBR filler (purchased from Zenguan Environmental Protection Technology Co., Ltd.) are added respectively at a volume ratio of 5 / 100 and 1 / 5. The initial MLSS is 500-1000 mg / L. Rural domestic sewage is used as the influent. The cycle alternating operation mode is 4h of aeration (DO=2-3 mg / L) - 4h of anoxic stirring (DO=0.2-0.6 mg / L) - 4h of aeration (DO=2-3 mg / L). The operation time is 3 days.

[0126] raw material COD / ppm <![CDATA[NH3-N / ppm]]> TP / ppm TN / ppm Water ingress 346 35.9 0.584 81.46 Commercially available MBBR filler, biochemical treatment for 3 days 40.48 9.62 0.22 25.66 Porous granular sewage treatment material, biochemical treatment for 3 days 38.5 6.45 0.20 18.52

[0127] The COD removal rate of the porous granular wastewater treatment material of the present example is 0.57% higher than that of the commercially available MBBR filler, the NH3-N removal rate is 8.8% higher, the TP removal rate is 3.4% higher, and the TN removal rate is 8.77% higher. After 3 days of biochemical process, the porous granular wastewater treatment material can be seen to have a biofilm, but the outer size is damaged and the loss rate is about 10%.

[0128] Comparative Example 4

[0129] The preparation method is basically the same as that of Example 5, except that the material is not soaked in the bacterial solution and the shape of the material is basically the same.

[0130] Take one portion of the material prepared in Comparative Example 4 and one portion of commercially available MBBR filler (purchased from Zenguan Environmental Protection Technology Co., Ltd.) and add them according to a volume ratio of 2 / 100 and 1 / 10, respectively. The initial MLSS is 500-1000 mg / L. The rural domestic wastewater is used as the influent. The cycle alternating operation mode is 4 h of aeration (DO = 2-3 mg / L) - 4 h of stirring under anoxic conditions (DO = 0.2-0.6 mg / L) - 4 h of aeration (DO = 2-3 mg / L). The operation time is 3 days.

[0131] raw material COD / ppm <![CDATA[NH3-N / ppm]]> TP / ppm TN / ppm Water ingress 346 35.9 0.584 81.46 Commercially available MBBR filler, biochemical treatment for 3 days 50.86 10.02 0.209 26.64 Porous granular sewage treatment material, biochemical 3 days 36.82 9.46 0.182 25.62

[0132] The COD removal rate of the porous granular wastewater treatment material of the present example is 0.57% higher than that of the commercially available MBBR filler, the NH3-N removal rate is 8.8% higher, the TP removal rate is 3.4% higher, and the TN removal rate is 8.77% higher. After 3 days of biochemical process, the porous granular wastewater treatment material can be seen to have a biofilm, but the outer size is damaged and the loss rate is about 10%.

[0133] It is apparent for those skilled in the art that the present application is not limited to the details of the foregoing exemplary embodiments, and that the present application can be implemented in other particular forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be considered in all respects as illustrative and not restrictive, the scope of the present application being defined by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

[0134] In addition, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that those skilled in the art can understand.

Claims

1. A method for preparing a sewage treatment material, characterized in that: The preparation method comprises the following steps: S1, mixing non-metallic minerals with pore-forming agents; S2, adding an adhesive and a low-boiling-point alcohol to the mixture obtained in S1, stirring and setting aside; S3, putting the mixture obtained in S2 into a mold and drying it; S4, demoulding, and immersing the demoulded product in a dilute acid solution; S5, taking out the demoulding product soaked in the dilute acid solution in S4 and soaking it in a bacterial solution, then taking it out and drying it; The sewage treatment material is a granular porous material, comprising the following raw materials in parts by weight: 30-50 parts by weight of adhesive; 50-100 parts by weight of bacterial liquid; 20-50 parts by weight of non-metallic minerals; 10-25 parts by weight of low-boiling-point alcohol; 0.1-2 parts by weight of pore-forming agent; The relative density of the sewage treatment material is 0.8-1.2, the pore size is 10-200nm, and the specific surface area is not less than 10000m 2 / m 3 , diameter 1-30mm; The adhesive is selected from one or more of polyvinyl alcohol, epoxy resin, urea-formaldehyde resin, phenolic resin, and sodium polysilicate; the pore-forming agent is selected from one or more of metal elements, sodium peroxide, potassium peroxide, ammonium carbonate, ammonium bicarbonate, calcium carbonate, calcium bicarbonate, sodium sulfite, and sodium bisulfite; The non-metallic minerals are hydrous silicate minerals.

2. The preparation method according to claim 1, characterized in that The bacterial liquid is an engineered bacterial suspension; the mass ratio of nitrifying bacteria to denitrifying bacteria in the engineered bacterial suspension is (0.5-3):4, and the colony count is not less than 1*10 9 cfu / ml.

3. The preparation method according to claim 1, characterized in that The non-metallic minerals are one or more of diatomaceous earth, kaolin, bentonite, attapulgite and sepiolite, and the low-boiling point alcohol is one or more of methanol, ethanol, n-propanol, isopropanol, n-butanol and isobutanol.

4. The preparation method according to claim 1, characterized in that In step S3, the mixture obtained in S2 is placed in a mold and dried at 50°C-80°C for 3-6 hours; in step S4, the demoulded product is immersed in a 2% dilute acid solution for 1 hour.

5. A sewage treatment material obtained by the preparation method according to any one of claims 1 to 4.

6. Use of the sewage treatment material obtained by the preparation method according to any one of claims 1 to 4 or the sewage treatment material according to claim 5 in sewage treatment.

7. The use according to claim 6, characterized in that The sewage treatment material is applied to 2 / O-MBBR coupling technology integrated sewage treatment equipment.

8. The use according to claim 7, characterized in that The input ratio of the sewage treatment materials is 1%-10% of the pool capacity.

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