A supported red mud filter material for organic wastewater and a preparation method and application thereof

Abstract

The application provides a load type red mud filter material for organic wastewater and a preparation method and application thereof, wherein the load type red mud filter material comprises the following raw materials in the dry weight ratio: 25-55% of sulfonated coupling modified red mud, 15-30% of activated sludge, 12-25% of a pore forming agent, 5-10% of an expanding agent, 2-4% of a binder, 3-5% of a fluxing agent and 20-24% of deionized water. In addition, the application also provides an application of the load type red mud filter material in treating landfill leachate. The load type red mud filter material prepared by the technical scheme can effectively improve the adsorption removal rate of organic matter and ammonia nitrogen in the main functional indicators of the landfill leachate, still has strong adsorption regeneration after elution, and the preparation process is simple and the operation can realize industrial continuity.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of high-concentration organic wastewater treatment, and particularly relates to a loaded red mud filter material for organic wastewater, and a preparation method and application thereof. BACKGROUND

[0002] During the garbage landfill treatment process, high-concentration organic wastewater with complex components and difficult to treat is generated due to garbage decomposition and precipitation seepage, which is called garbage leachate. Among the common garbage leachate water quality indexes, the contents of organic matter and ammonia nitrogen are the most prominent. If the garbage leachate is discharged into water bodies or soil without treatment or incomplete treatment, it is extremely easy to cause water body eutrophication and change the structure and function of soil, causing serious ecological impact. At present, the main treatment method for garbage leachate is biochemical treatment, but due to the relatively low phosphorus content in the garbage leachate, it is difficult to meet the nutrient ratio requirement of biochemical reaction treatment, causing slow microbial degradation and difficulty in biochemical implementation. Therefore, necessary pretreatment methods need to be taken to remove and purify the organic matter and ammonia nitrogen. In the common treatment process, the adsorption method is suitable to be the best choice for this stage due to the advantages of low cost, simple operation, recyclability, and the like, combined with high-efficiency adsorbent materials.

[0003] Red mud is an industrial waste residue generated in the process of extracting alumina from bauxite, and the main components are calcium oxide, aluminum oxide and iron oxide, etc. It has the characteristics of fine particle size, large specific surface area, high stability, and the like, and has high adsorption capacity, and can be used as an adsorbent raw material to remove various pollutants in water bodies, such as heavy metal ions, phosphorus, nitrogen salts, and the like. Using red mud as an adsorbent for the main index purification pretreatment of garbage leachate can not only effectively reduce the proportion of organic matter and ammonia nitrogen in the effluent water quality to meet the functional biochemical requirements, but also solidify the metal elements contained in the red mud through pretreatment to reduce the pollution release risk, realize the technology of waste treatment with waste, and become a research hotspot in this field at home and abroad. However, at the same time, the application of powder particle red mud also faces problems such as difficulty in solid-liquid separation, easy saturation of adsorption, poor regeneration performance of filter material, and the like, which greatly restricts the continuity in the application implementation process. SUMMARY

[0004] To solve the above problems, the purpose of the present application is to provide a loaded red mud filter material for organic wastewater, and a preparation method and application thereof. Under the premise of implementing sulfonation coupling modification on the powder red mud, the red mud is subjected to loading granulation treatment by using a heat setting method, the adsorbability and practicability of the red mud filter material are improved, and a new idea is provided for the application of the loaded red mud filter material in the field of garbage leachate functional purification.

[0005] The purpose of the present application is achieved by the following technical solutions.

[0006] A kind of load type red mud filter material for organic wastewater, including the following dry weight proportion of raw materials: sulfonated coupling modified red mud 25-55%, activated sludge 15-30%, pore forming agent 12-25%, bulking agent 5-10%, binder 2-4%, fluxing agent 3-5% and 20-24% deionized water.

[0007] Further, the sulfonated coupling modified red mud includes the following preparation steps:

[0008] (1) take red mud powder particle and calcium oxide and mix in deionized water, stir and hydrate at 35-55 DEG C for 2h, filter, dry, grind and sieve, to obtain red mud base powder;

[0009] (2) uniformly mix the red mud base powder and modified coupling agent in deionized water, ultrasonic oscillation for 15 min, continue to add 6% 0.1mol / L initiator, hydrolysis reaction for 30 min in 40-50 DEG C water bath, then add 4%-8% poly (p-phenylene sulfonic acid) sodium as sulfonating agent, add appropriate amount of buffer to adjust the solution pH to 8.0, continue to react for 2h, then wash with ethanol and deionized water, suction filtration, dry at 70 DEG C and grind and sieve, to obtain sulfonated coupling modified red mud.

[0010] Further, the mass ratio of red mud powder particle, calcium oxide and deionized water in step (1) is 5:1:12.5.

[0011] Further, the mass percentage of red mud base powder, modified coupling agent and deionized water in step (2) is 9%-15%, 0.2%-0.4% and 84.6%-90.8% respectively.

[0012] Further,

[0013] The red mud powder particle is one or more kinds of particle size powder after grinding and sieving through 40-160 mesh;

[0014] The calcium oxide is building lime powder, with a density of 3.1-3.4 g / cm3;

[0015] The modified coupling agent is at least one of silane coupling agent, aluminate coupling agent and titanate coupling agent;

[0016] The initiator is at least one of potassium persulfate and sodium sulfide;

[0017] The buffer adjusting agent is one or more of sodium hydroxide, sodium carbonate and disodium hydrogen phosphate.

[0018] The present application provides a preparation method of the above-mentioned load type red mud filter material, including the following preparation steps:

[0019] The sulfonated coupling modified red mud is uniformly mixed with active sludge, a pore forming agent, an expanding agent, a binder, a fluxing agent, and deionized water, and then aged for 30 min, and stirred at a speed of 150 r / min until it becomes a slurry, and then injected into a 3-5 mm grid aperture granulator for extrusion cutting and granulation, and then heated and formed in a roller at 75-85 DEG C and a speed of 30 r / min, to obtain solidified spherical granules;

[0020] The solidified spherical granules are placed in a muffle furnace for heat curing treatment, with the temperature control conditions being: 200 DEG C for 5-10 min, 400 DEG C for 10-20 min, 700 DEG C for 10-15 min, 900 DEG C for 5-10 min, and 1050 DEG C for 5-15 min, and then cooled to room temperature;

[0021] The product obtained by the heat curing treatment is immersed in a 4-6% ethanol solution for ultrasonic rinsing for 15 min to remove impurities, and then sieved by using 3-5 mm aperture sieves, and then dried by hot air at 80-110 DEG C, to obtain red mud filter materials of different particle sizes.

[0022] Further, the active sludge is residual active sludge from a domestic sewage treatment plant, with an organic matter content of 15.23-18.77 g / kg, a water content of 60-80%, and a pH of 6.3-6.7.

[0023] Further, the pore forming agent is at least one of calcium carbonate and sodium bentonite;

[0024] The expanding agent is one or more of sodium bicarbonate, ammonium bicarbonate, calcium hydrogen phosphate, and starch.

[0025] The binder is polyvinyl alcohol with a viscosity of 21-33.

[0026] The fluxing agent is at least one of potassium carbonate, calcium oxide, and sodium tetraborate.

[0027] Further, the heat curing treatment is continuous heating without cooling in the middle.

[0028] The application further provides a use of the red mud filter material in treating landfill leachate.

[0029] Compared with the prior art, the application has the following beneficial effects:

[0030] The red mud filter material prepared by the technical scheme has the advantages of effectively improving the adsorption and removal rates of organic matter and ammonia nitrogen in the main functional indicators of landfill leachate, having strong adsorption regeneration after elution, simple preparation process, and industrial continuity of operation, and the initial pH of the leachate is adjusted to 8, and the volume of the filter material is 12.56 cm3 The adsorption amount of COD and ammonia nitrogen in the leachate is 80.06 mg / g and 19.99 mg / g respectively under the condition of a filler height of 4 cm and an adsorption operation time of 90 min, and the removal rates of adsorption are 87.57% and 72.05% respectively, and the adsorption purification efficiency is increased by more than 45% compared with the unmodified red mud filter material.

[0031] Compared with the general filter material without modification, the adsorption amount of the supported red mud filter material for COD and ammonia nitrogen is still 77.44 mg / g and 17.93 mg / g respectively after 36 h of continuous operation of the landfill leachate treated by the optimal condition and after 0.5 MPa water pressure flushing, and the regeneration rate is as high as 93.19-95.01%, and after the modification, the surface structure of the shallow gap hole is changed into a more compact through hole, new hydroxyl functional groups and sulfonated groups are introduced on the surface, there are a large number of adsorption and synthesis regeneration sites, and the removal and utilization efficiency is effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed for the description of the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments and effects of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0033] Figure 1 The infrared spectrum characteristics of the supported red mud filter material described in embodiment 1 and the unmodified red mud filter material are compared;

[0034] Figure 2 The adsorption purification efficiency of the supported red mud filter material described in embodiment 1 and the unmodified red mud filter material for the functional main indicators COD and ammonia nitrogen of landfill leachate under different initial pH values is compared;

[0035] Figure 3 The adsorption purification efficiency of the supported red mud filter material described in embodiment 1 and the unmodified red mud filter material for the functional main indicators COD and ammonia nitrogen of landfill leachate in a single stage operation time is compared;

[0036] Figure 4 The adsorption amount of the supported red mud filter material described in embodiment 1 and the unmodified red mud filter material for the functional main indicators COD and ammonia nitrogen of landfill leachate under different dosages is compared. DETAILED DESCRIPTION

[0037] The present application will be described in greater detail by the specific embodiments, and other advantages and effects of the present application can be easily understood by those skilled in the art from the contents disclosed in the specification. The described embodiments are only a part of the embodiments of the present application, but not all. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. Embodiment 1

[0038] The present embodiment provides a preparation method of a supported red mud filter material, which comprises the following steps:

[0039] (1) 20 g of red mud powder particles passing through a 60-mesh sieve is mixed with 4 g of calcium oxide in 50 ml of deionized water, stirred at 60 r / min, and hydrated at 35°C for 2 h. After filtration, drying, and grinding through a 60-mesh sieve, a red mud base powder is prepared.

[0040] (2) 10 g of the red mud base powder in step (1) is uniformly mixed with 0.4 g of KH560 silane coupling agent and placed in 89.6 ml of deionized water. Ultrasonic oscillation is performed for 15 min, 6 ml of 0.1 mol / L potassium persulfate solution is continuously added, and hydrolysis reaction is performed in a 40°C water bath for 30 min. Then, 4 ml of sulfonated agent sodium p-styrenesulfonate is added as a sulfonated agent, 1.5 g of disodium hydrogen phosphate is used as an acid buffer to adjust the pH of the solution to 8.0, and the reaction is continued for 2 h. After washing with ethanol and deionized water, suction filtration, drying at 70°C, and grinding through a 60-mesh sieve, a sulfonated and coupled modified red mud is prepared.

[0041] (3) The sulfonated and coupled modified red mud in step (2) is uniformly mixed with activated sludge (moisture content 60%, organic matter content 15.38 g / kg, pH 6.4), calcium carbonate, starch, polyvinyl alcohol (viscosity 23), and potassium carbonate. The specific mass dry mixing ratio is sulfonated and coupled modified red mud 8 g, activated sludge 4.5 g, calcium carbonate 3 g, starch 2 g, polyvinyl alcohol 0.5 g, and potassium carbonate 0.7 g. After adding 7.4 ml of deionized water and aging for 30 min, it is stirred to a slurry state at a speed of 150 r / min, and then injected into a 3 mm grid aperture granulator for extrusion cutting and granulation. After heating in a 75°C, 30 r / min roller, a solidified spherical granular material is prepared.

[0042] (4) The solidified spherical granular material prepared in step (3) is placed in a muffle furnace as a sintering carrier for heat curing treatment. The temperature control conditions are: 200°C for 5 min, 400°C for 10 min, 700°C for 15 min, 900°C for 8 min, and 1050°C for 12 min. After cooling to room temperature, the entire heat curing treatment process is a continuous heating process without cooling in the middle.

[0043] (5) The product obtained in step (4) is immersed in a 4% ethanol solution for ultrasonic rinsing for 15 min, impurities are removed, and sieving is performed using a 3 mm aperture sieve, and hot air drying is performed at 85°C to obtain the loaded red mud filter material example 1. Example 2

[0044] (1) 20 g of red mud powder with a particle size of 80 mesh is mixed with 4 g of calcium oxide in 50 ml of deionized water, stirred at 60 r / min, and allowed to react for 2 h under the condition of 35°C water, filtered, dried, ground through an 80 mesh sieve, and red mud base powder is prepared.

[0045] (2) 12 g of the red mud base powder in step (1) is uniformly mixed with 0.3 g of a titanate coupling agent and placed in 87.7 ml of deionized water, ultrasonic oscillation is performed for 15 min, 6 ml of 0.1 mol / L sodium sulfide solution is continuously added, hydrolysis is performed for 30 min in a 40°C water bath, 4 ml of sulfonated agent, sodium p-styrenesulfonate, is added, 1 g of sodium hydroxide is used as an acid buffer to adjust the pH of the solution to 8.0, and the reaction is continued for 2 h, then washing, suction filtration, drying at 70°C, and grinding through an 80 mesh sieve are performed, and a sulfonated and coupled modified red mud is prepared.

[0046] (3) The sulfonated and coupled modified red mud in step (2) is uniformly mixed with activated sludge (water content 80%, organic matter content 16.61 g / kg, pH 6.6), sodium-based bentonite, starch, polyvinyl alcohol (viscosity 26), and sodium tetraborate, and the specific mass dry mixing ratio is sulfonated and coupled modified red mud 6 g, activated sludge 4.8 g, sodium-based bentonite 3.8 g, starch 1.4 g, polyvinyl alcohol 0.48 g, and sodium tetraborate 0.96 g, 6 ml of deionized water is added and aged for 30 min, and stirring is performed at a speed of 150 r / min until a slurry is formed, the slurry is injected into a 5 mm grid aperture granulator for extrusion cutting and granulation, and the slurry is heated and formed in a 85°C, 30 r / min drum to obtain solidified spherical granules.

[0047] (4) The solidified spherical granules prepared in step (3) are placed in a muffle furnace for heat curing treatment using a graphite disc as a curing carrier, and the temperature control conditions are: 200°C for 10 min, 400°C for 15 min, 700°C for 10 min, 900°C for 5 min, and 1050°C for 10 min, and the product is cooled to room temperature after removal; the entire heat curing process is a continuous heating process without cooling in the middle.

[0048] (5) The product obtained in step (4) is immersed in a 6% ethanol solution for ultrasonic rinsing for 15 min, impurities are removed, and sieving is performed using a 5 mm aperture sieve, and hot air drying is performed at 105°C to obtain the loaded red mud filter material example 2. Example 3

[0049] (1) Take 20 g of red mud powder particles with a 140 mesh sieve and 4 g of calcium oxide and mix them in 50 ml of deionized water, stir at 60 r / min, and hydrate at 50°C for 2 h, filter, dry, and grind to pass through a 140 mesh sieve to prepare a red mud base powder.

[0050] (2) Take 15 g of the red mud base powder from step (1) and 0.3 g of an aluminate coupling agent and mix them evenly in 84.7 ml of deionized water, ultrasonic oscillate for 15 min, continue to add 6 ml of 0.1 mol / L potassium persulfate solution, and hydrolyze in a 50°C water bath for 30 min, then add 6 ml of sulfonated agent sodium p-styrenesulfonate as an acid buffer, adjust the solution pH to 8.0 with 1.8 g of sodium carbonate, continue to react for 2 h, then wash with ethanol and deionized water, filter, dry at 70°C, and grind to pass through a 140 mesh sieve to prepare a sulfonated and coupled modified red mud.

[0051] (3) Mix the sulfonated and coupled modified red mud from step (2) with activated sludge (water content 80%, organic matter content 16.77 g / kg, pH 6.3), calcium carbonate, calcium hydrogen phosphate, polyvinyl alcohol (viscosity 28), and calcium oxide, with a specific mass dry mixing ratio of sulfonated and coupled modified red mud 12 g, activated sludge 7.2 g, calcium carbonate 3.8 g, calcium hydrogen phosphate 1.9 g, polyvinyl alcohol 0.7 g, and calcium oxide 1 g, add 6.5 ml of deionized water and age for 30 min, stir at 150 r / min until it becomes a slurry, inject it into a 3 mm grid aperture granulator for extrusion cutting and granulation, and heat form in a 75°C, 30 r / min roller to prepare solidified spherical granules.

[0052] (4) Use a graphite disc as a firing carrier, place the solidified spherical granules prepared in step (3) in a muffle furnace for heat curing treatment, with temperature control conditions of 200°C for 6 min, 400°C for 12 min, 700°C for 10 min, 900°C for 10 min, and 1050°C for 12 min, and cool to room temperature after removal; the entire heat curing process is a continuous heating process without cooling in the middle.

[0053] (5) Soak the product obtained in step (4) in a 4% ethanol solution for ultrasonic rinsing for 15 min, remove impurities, screen with a 3 mm aperture screen, and dry with hot air at 75°C to prepare the supported red mud filter material example 3. Example 4

[0054] (1) Take 20 g of red mud powder particles with 4 g of calcium oxide mixed in 50 ml of deionized water, stirred at 60 r / min, and hydrolyzed at 45°C for 2 h. Filter, dry, and grind to pass through a 100 mesh sieve to prepare the red mud base powder.

[0055] (2) Take 9 g of red mud base powder from step (1) and 0.5 g of KH560 silane coupling agent and mix them evenly in 90.5 ml of deionized water. Ultrasonic oscillation for 15 min, continue to add 6 ml of 0.1 mol / L sodium sulfide solution, hydrolysis reaction in 40°C water bath for 30 min, then add 8 ml of sulfonated agent poly-p-styrene sodium sulfonate, and use 1.8 g of sodium carbonate and sodium hydroxide as acid buffer to adjust the solution pH to 8.0. Continue to react for 2 h, then wash with ethanol and deionized water, vacuum filtration, dry at 70°C, and grind to pass through a 100 mesh sieve to prepare the sulfonated and coupled modified red mud.

[0056] (3) Mix the sulfonated and coupled modified red mud from step (2) with activated sludge (water content 68%, organic matter content 18.03 g / kg, pH 6.5), sodium-based bentonite, ammonium bicarbonate, polyvinyl alcohol (viscosity 30), and sodium tetraborate. The specific mass dry mixing ratio is sulfonated and coupled modified red mud 6 g, activated sludge 3 g, sodium-based bentonite 2.4 g, ammonium bicarbonate 1 g, polyvinyl alcohol 0.4 g, and sodium tetraborate 1 g. Add 4.2 ml of deionized water and age for 30 min. Stir at 150 r / min until it becomes a slurry. Inject it into a 4 mm grid aperture granulator for extrusion cutting and granulation. Heat in a 85°C, 30 r / min roller to form a solidified spherical pellet.

[0057] (4) Use a graphite disc as a firing carrier. Place the solidified spherical pellet from step (3) in a muffle furnace for heat curing treatment. The temperature control conditions are: 200°C for 8 min, 400°C for 16 min, 700°C for 12 min, 900°C for 8 min, and 1050°C for 6 min. Cool to room temperature after removal. The entire heat curing process is a continuous heating process without cooling in between.

[0058] (5) Soak the product obtained in step (4) in a 5% ethanol solution for 15 min, remove the impurities, screen with a 4 mm aperture screen, and dry with hot air at 95°C to obtain the supported red mud filter material of Example 4. Example 5

[0059] (1) Take 20 g of red mud powder particles with 4 g of calcium oxide mixed in 50 ml of deionized water, stirred at 60 r / min, and hydrolyzed at 45°C for 2 h. Filter, dry, and grind to pass through a 100 mesh sieve to prepare the red mud base powder.

[0060] (2) Take 10 g of red mud base powder and 0.4 g of titanate coupling agent in step (1) and mix them uniformly, then put them in 89.6 ml of deionized water, ultrasonic oscillation for 15 min, continue to add 6 ml of 0.1 mol / L potassium persulfate solution, hydrolysis reaction for 30 min in a 45℃ water bath, then add 6 ml of sulfonating agent sodium polystyrene sulfonate, use 1.5 g of disodium hydrogen phosphate as an acid buffer to adjust the solution pH to 8.0, continue to react for 2 h, then wash with ethanol and deionized water, filter, dry at 70℃ and grind through a 160 mesh sieve, to obtain sulfonated and coupled modified red mud.

[0061] (3) Mix the sulfonated and coupled modified red mud in step (2) with activated sludge (moisture content 75%, organic matter content 17.87 g / kg, pH 6.4), calcium carbonate, sodium bicarbonate, polyvinyl alcohol (viscosity 32), and potassium carbonate uniformly, the specific dry weight mixing ratio is sulfonated and coupled modified red mud 8 g, activated sludge 4.5 g, calcium carbonate 1.8 g, sodium bicarbonate 0.75 g, polyvinyl alcohol 0.3 g, and potassium carbonate 0.45 g, add 4 ml of deionized water and age for 30 min, stir at a speed of 150 r / min until it becomes a slurry, then inject it into a 5 mm grid aperture granulator for extrusion cutting and granulation, heat molding in a 85℃, 30 r / min roller, to obtain solidified spherical granules.

[0062] (4) Use a graphite disc as a firing carrier, put the solidified spherical granules obtained in step (3) into a muffle furnace for heat curing treatment, the temperature control conditions are: 200℃ for 10 min, 400℃ for 16 min, 700℃ for 12 min, 900℃ for 8 min, and 1050℃ for 14 min, then take it out and cool to room temperature; the whole heat curing process is a continuous heating process, no cooling is needed in the middle.

[0063] (5) Soak the product obtained in step (4) in a 6% ethanol solution for ultrasonic rinsing for 15 min, remove impurities, screen with a 5 mm aperture sieve, and dry with hot air at 105℃, to obtain the supported red mud filter material example 5.

[0064] Examples 6-10:

[0065] The supported red mud filter materials obtained in examples 1-5 are applied in the treatment of landfill leachate.

[0066] In the application, the solid-liquid ratio of the supported red mud filter material to the landfill leachate is 60:1, that is, 60 g of supported red mud filter material is used to treat IL landfill leachate.

[0067] The landfill leachate used in the above examples is the raw liquid from the effluent adjusting tank of a general municipal landfill site, with an organic COD value ranging from 3500 to 8500 mg / L and an ammonia nitrogen value ranging from 800 to 3000 mg / L.

[0068] Effect experiment:

[0069] The landfill leachate used in the experiment is the raw liquid from the effluent adjusting tank of a general municipal landfill site, with an organic COD value ranging from 3500 to 8500 mg / L and an ammonia nitrogen value ranging from 800 to 3000 mg / L, which is used as the raw liquid to be adsorbed and purified in the experiment. The adsorption operation uses a dynamic adsorption method, with an adsorption column inner diameter of 2 cm and a filler height of 1-6 cm. After diluting the raw leachate by 10 times, it is extracted by a peristaltic pump and passed through the adsorption column at a speed of 10 ml / min through a separatory funnel. A 20 ml graduated cylinder is used to continuously take samples, and the sample is continuously measured. The dosage is set in a gradient range of 0-100 g / L, the initial pH value of the raw liquid is adjusted in a range of 5-10, the operating temperature range is 10-30°C, and the maximum operating period of a single stage is 180 min.

[0070] 1. Infrared spectrum comparison.

[0071] The infrared spectrum characteristics of the loaded red mud filter material and the unmodified red mud filter material described in Example 1 are measured respectively.

[0072] As shown in Figure 1 , after comparing the infrared spectrum characteristics of the loaded red mud filter material and the unmodified red mud filter material described in Example 1, it can be seen that the loaded red mud filter material described in Example 1 has many new component groups (new hydroxyl functional groups and sulfonated groups) compared with the unmodified red mud filter material. These new component groups have a large number of adsorption and synthesis regeneration sites, which improve the removal and utilization efficiency.

[0073] 2. Comparison experiment of adsorption and purification efficiency of main functional indicators COD and ammonia nitrogen of landfill leachate at different initial pH values.

[0074] (1) The landfill leachate with a functional main indicator COD value of 5485.6 mg / L and an ammonia nitrogen value of 1581.6 mg / L is selected as the functional adsorption raw liquid (experimental object).

[0075] (2) The obtained functional adsorption raw liquid is divided into two groups, namely RM group and SC-RM. Each group of functional adsorption raw liquid is divided into six parts, and the pH of the six parts of each group of functional adsorption raw liquid is adjusted to 5, 6, 7, 8, 9, and 10, respectively.

[0076] (3) In the six functional adsorption original solutions of the RM group, an equal amount of unmodified red mud filter material was added for adsorption purification treatment; the treatment time was 90 min, the solid-liquid ratio was 60 (60 g of unmodified red mud filter material was added per liter of landfill leachate, indicating that the addition amount was 60 g / L), and the treatment temperature was 20°C.

[0077] In the six functional adsorption original solutions of the SC-RM group, an equal amount of the loaded red mud filter material described in Example 1 was added. The treatment time was 90 min, the solid-liquid ratio was 60 (60 g of loaded red mud filter material was added per liter of landfill leachate, indicating that the addition amount was 60 g / L), and the treatment temperature was 20°C.

[0078] The amount of unmodified red mud filter material added to each functional adsorption original solution of the RM group was equal to the amount of the loaded red mud filter material described in Example 1 added to each functional adsorption original solution of the SC-RM group. The volume of filter material added to each functional adsorption original solution of the RM group and the SC-RM group was 12.56 cm 3 (high 4 cm).

[0079] After the treatment was completed, the infrared characteristics of the loaded red mud filter material prepared in Example 1 and the unmodified red mud filter material at different initial pH, as well as the adsorption purification efficiency of the functional main indicators COD and ammonia nitrogen in the leachate were recorded. The results are shown in Table 1 and Figure 2 .

[0080] Table 1 Adsorption purification efficiency (removal rate) of functional main indicators COD and ammonia nitrogen in landfill leachate at different initial pH

[0081]

[0082] As shown in Table 1 and Figure 2 , the adsorption purification efficiency of the loaded red mud filter material described in Example 1 for the functional main indicator COD at different initial pH was much higher than that of the unmodified red mud filter material, and the improvement in adsorption purification efficiency was more than 38%.

[0083] The adsorption purification efficiency of the loaded red mud filter material described in Example 1 for ammonia nitrogen at different initial pH was also much higher than that of the unmodified red mud filter material, and the improvement in adsorption purification efficiency was more than 26%.

[0084] Taking the adjustment of the initial pH of the leachate to 8 as an example, the adsorption removal rate of the loaded red mud filter material described in Example 1 for COD and ammonia nitrogen in the leachate was 87.57% and 72.05%, respectively, which was 45% and 27% higher than that of the unmodified red mud filter material, respectively.

[0085] 3. Comparative experiment of adsorption purification efficiency of main functional indicators COD and ammonia nitrogen of landfill leachate in single-stage running time.

[0086] (1) The landfill leachate with COD value of 5485.6 mg / L and ammonia nitrogen value of 1581.6 mg / L was selected as the functional adsorption original solution (experimental object).

[0087] (2) The obtained functional adsorption original solution was divided into two groups, namely RM group and SC-RM group, and each group of functional adsorption original solution was divided into six parts.

[0088] (3) In the six parts of functional adsorption original solution of the RM group, an equal amount of unmodified red mud filter material was added for adsorption purification treatment; the treatment time of the six parts of functional adsorption original solution of the RM group was 30 min, 60 min, 90 min, 120 min, 150 min and 180 min, respectively; the treatment temperature was 20℃, the solid-liquid ratio was 60 (60 g of unmodified red mud filter material was added in each liter of landfill leachate, indicating that the addition amount was 60 g / L), and the initial pH value of each part of the functional adsorption original solution was 8.

[0089] Similarly, in the six parts of functional adsorption original solution of the SC-RM group, an equal amount of the loaded red mud filter material described in Example 1 was added. The treatment time of the six parts of functional adsorption original solution of the SC-RM group was 30 min, 60 min, 90 min, 120 min, 150 min and 180 min, respectively; the treatment temperature was 20℃, the solid-liquid ratio was 60 (60 g of the loaded red mud filter material described in Example 1 was added in each liter of landfill leachate, indicating that the addition amount was 60 g / L), and the initial pH value of each part of the functional adsorption original solution was 8.

[0090] The amount of unmodified red mud filter material added in each part of the functional adsorption original solution of the RM group was equal to the amount of the loaded red mud filter material described in Example 1 added in each part of the functional adsorption original solution of the SC-RM group. The volume amount of filter material added in each part of the functional adsorption original solution of the RM group and each part of the functional adsorption original solution of the SC-RM group was 12.56 cm 3 (fill height 4 cm).

[0091] After the treatment, the infrared characteristics of the loaded red mud filter material prepared in Example 1, the adsorption amount and adsorption purification efficiency of the main functional indicators COD and ammonia nitrogen in the leachate, and the infrared characteristics of the unmodified red mud filter material, the adsorption amount and adsorption purification efficiency of the main functional indicators COD and ammonia nitrogen in the leachate were recorded in single-stage running time. The results are shown in Tables 2, 3 and Figure 3

[0092] Table 2 Adsorption amount of main functional indicators COD and ammonia nitrogen of landfill leachate in single-stage running time

[0093] ​

[0094] Table 3 Adsorption purification efficiency (removal rate) of the functional main indicators COD and ammonia nitrogen of landfill leachate in single-stage operation time

[0095]

[0096] As shown in Table 2, the adsorption capacity of the functional main indicator COD of the loaded red mud filter material described in Example 1 in the single-stage operation time is much greater than that of the unmodified red mud filter material, and the adsorption capacity is increased by more than 28 mg / g.

[0097] The adsorption capacity of the functional main indicator COD of the loaded red mud filter material described in Example 1 in the single-stage operation time is also greater than that of the unmodified red mud filter material, and the adsorption capacity is increased by more than 28 mg / g.

[0098] As shown in Table 3 and Figure 3 As shown in Table 3 and

[0099] The adsorption purification efficiency of the functional main indicator COD of the loaded red mud filter material described in Example 1 in the single-stage operation time is also much higher than that of the unmodified red mud filter material, and the adsorption purification efficiency is increased by more than 19%.

[0100] As an example of adsorption operation time of 90 min, in this time period, the adsorption capacity of the loaded red mud filter material described in Example 1 for COD and ammonia nitrogen in the leachate was 80.06 mg / g and 19.99 mg / g, respectively, and the adsorption removal rate was 87.57% and 72.05%, respectively. Compared with the unmodified red mud filter material, the adsorption purification efficiency of COD was increased by more than 45% and that of ammonia nitrogen was increased by more than 27%.

[0101] 4. Comparative experiment of adsorption capacity of functional main indicators COD and ammonia nitrogen of landfill leachate under different dosages.

[0102] (1) The landfill leachate with a functional main indicator COD value of 5485.6 mg / L and an ammonia nitrogen value of 1581.6 mg / L was selected as the functional adsorption stock solution (experimental object).

[0103] (2) The obtained functional adsorption stock solution was divided into two groups, namely RM group and SC-RM, and each group of functional adsorption stock solution was divided into six parts.

[0104] (3) In the six functional adsorption original solutions of the RM group, the unmodified red mud filter material was added in turn according to the dosages (solid-liquid ratio) of 10 g / L, 20 g / L, 40 g / L, 60 g / L, 80 g / L and 100 g / L for adsorption purification treatment; the initial pH value of each functional adsorption original solution was 8, the treatment temperature was 20℃, and the treatment time was 90 min.

[0105] Similarly, in the six functional adsorption original solutions of the SC-RM group, the loaded red mud filter material described in Example 1 was added in turn according to the dosages (solid-liquid ratio) of 10 g / L, 20 g / L, 40 g / L, 60 g / L, 80 g / L and 100 g / L for adsorption purification treatment; the initial pH value of each functional adsorption original solution was 8, the treatment temperature was 20℃, and the treatment time was 90 min.

[0106] After the treatment was completed, the infrared characteristics of the loaded red mud filter material prepared in Example 1 and the unmodified red mud filter material under different dosages, and the adsorption amount and adsorption purification efficiency of the functional main indicators COD and ammonia nitrogen in the leachate were recorded. The results are shown in Table 4 and Figure 4 .

[0107] As shown in Table 4, the adsorption amount of the loaded red mud filter material described in Example 1 for the functional main indicators COD and ammonia nitrogen under different dosages

[0108]

[0109] As shown in Table 4 and Figure 4 , the adsorption amount of the loaded red mud filter material described in Example 1 for the functional main indicators COD under different dosages was greater than that of the unmodified red mud filter material, and the increase in adsorption amount was more than 24 mg / g.

[0110] The adsorption amount of the loaded red mud filter material described in Example 1 for ammonia nitrogen under different dosages was also greater than that of the unmodified red mud filter material, and the increase in adsorption amount was more than 4 mg / g.

[0111] The adsorption purification efficiency of the loaded red mud filter material described in Example 1 for the functional main indicators COD under different dosages was also higher than that of the unmodified red mud filter material, and the maximum increase in adsorption purification efficiency was more than 45%.

[0112] The adsorption purification efficiency of the loaded red mud filter material described in Example 1 for ammonia nitrogen under different dosages was also higher than that of the unmodified red mud filter material, and the maximum increase in adsorption purification efficiency was more than 27%.

[0113] Other details of the present application are well known to those skilled in the art.

[0114] It is to be understood that the terms "including", "comprising", or any other variation thereof are intended to cover the non-exclusive inclusion such that processes, methods, articles, or apparatuses that comprise a list of elements are not required to comprise only those elements but can include other elements not expressly listed or inherent to such processes, methods, articles, or apparatuses.

[0115] The protection scope of the present application is not limited to the technical solutions disclosed in the specific embodiments, and any modification, equivalent replacement, improvement, etc. made to the above embodiments according to the technical essence of the present application all fall within the protection scope of the present application.

Claims

1. The application of a supported red mud filter media in the treatment of landfill leachate, characterized in that: The supported red mud filter media was added at a dosage of 60 g / L, with an initial pH of 8 and an adsorption time of 90 minutes. The removal rates of COD and ammonia nitrogen reached 87.57% and 72.05%, respectively, and the regeneration rate was 93.19-95.01%. The supported red mud filter media comprises the following raw materials in the following dry weight proportions: The mixture comprises 25-55% sulfonated coupling modified red mud, 15-30% activated sludge, 12-25% pore-forming agent, 5-10% expansion agent, 2-4% binder, 3-5% fluxing agent, and 20-24% deionized water, wherein the sum of the dry weight percentages of the raw materials is 100%. The preparation method of the supported red mud filter media includes the following preparation steps: After uniformly mixing sulfonated coupling modified red mud with activated sludge, pore-forming agent, swelling agent, binder and fluxing agent, deionized water was added and aged for 30 min. The mixture was stirred at 150 r / min until it became a slurry. The slurry was then injected into a granulator with a grid aperture of 3-5 mm for extrusion cutting and granulation. The solidified spherical granules were heated and shaped in a drum at 75-85℃ and 30 r / min to obtain solidified spherical granules. Using a graphite disc as a firing carrier, the above-mentioned cured spherical granules were placed in a muffle furnace for thermosetting. The temperature control conditions were as follows: 200℃ for 5-10 min, 400℃ for 10-20 min, 700℃ for 10-15 min, 900℃ for 5-10 min, and 1050℃ for 5-15 min. The granules were then removed and cooled to room temperature. The thermosetting process involved continuous heating without the need for intermediate cooling. The product obtained by the above thermosetting treatment was immersed in 4-6% ethanol solution and ultrasonically rinsed for 15 minutes to remove impurities. It was then sieved with a 3-5 mm mesh screen and dried with hot air at 80-110℃ to obtain red mud filter media with different particle size grades. The sulfonated coupling modified red mud includes the following preparation steps: (1) Mix red mud powder and calcium oxide at a mass ratio of 5:1, add deionized water, hydrate at 35-55℃ for 2 hours, filter, dry, grind and sieve to obtain red mud base powder; (2) Mix red mud base powder with modified coupling agent and deionized water at a mass percentage of 9-15% : 0.2-0.4% : 84.6-90.8%, sonicate for 15 minutes, add 0.1 mol / L initiator dropwise, react in a water bath at 40-50℃ for 30 minutes, add 4%-8% sodium poly(p-styrene sulfonate) as sulfonating agent, add an appropriate amount of buffer to adjust the pH of the solution to 8.0, continue the reaction for 2 hours, wash with ethanol and deionized water respectively, filter, dry at 70℃, grind and sieve to obtain sulfonated coupling modified red mud.

2. The application according to claim 1, characterized in that: The red mud powder is one or more types of powder with a particle size of 40-160 mesh after grinding; The calcium oxide mentioned is quicklime powder used in construction, with a density of 3.1-3.4 g / cm³. 3 ; The modified coupling agent is at least one of silane coupling agents, aluminate coupling agents, and titanate coupling agents; The initiator is at least one of potassium persulfate and sodium sulfide; The buffer regulator is one or more of sodium hydroxide, sodium carbonate, and disodium hydrogen phosphate.

3. The application according to claim 1, characterized in that: The activated sludge is residual activated sludge from a domestic wastewater treatment plant, with an organic matter content of 15.23-18.77 g / kg, a water content of 60-80%, and a pH of 6.3-6.

7.

4. The application according to claim 1, characterized in that: The pore-forming agent is at least one of calcium carbonate and sodium bentonite. The leavening agent is one or more of sodium bicarbonate, ammonium bicarbonate, calcium hydrogen phosphate, and starch. The adhesive is polyvinyl alcohol; The fluxing agent is at least one of potassium carbonate, calcium oxide, and sodium tetraborate.

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