Activated carbon composition as well as preparation method and application thereof

Abstract

The invention discloses an activated carbon composition as well as a preparation method and application thereof, and belongs to the technical field of sewage treatment. The active carbon composition comprises the following components: 5-30 parts of corncob active carbon, 2-20 parts of permanganate, 1-6 parts of a polysilicate ferric coagulant and 0.5-13 parts of an inorganic coagulant. The corncob powder activated carbon is cooperatively used with permanganate and a coagulant, so that oxidation-adsorption-coagulation synergistic interaction is realized, the problems of loose floc, low settling speed, secondary pollution caused by residual metal ions, poor activated carbon adsorption effect and the like of a traditional inorganic coagulant are solved, the corncob is used as the activated carbon, the adsorption effect is good, and the adsorption efficiency is high. The pollutant removal rate is high, meanwhile, the problem of agricultural waste treatment is solved, and waste recycling is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of sewage treatment, and specifically relates to an activated carbon composition and a preparation method and application thereof. The combined use of activated carbon and a coagulant works synergistically to achieve efficient removal of pollutants. Background Art

[0002] With the acceleration of industrialization and urbanization, the problem of sewage treatment is becoming increasingly serious. Activated carbon is widely used to remove organic pollutants, heavy metal ions and odor substances in water due to its high specific surface area and adsorption performance. Traditional activated carbon is mostly made of wood, coal or coconut shells, but it has the problems of limited adsorption capacity and low efficiency in synergistic removal of complex pollutants. In recent years, biomass-based activated carbon (such as corn cobs) has attracted much attention due to its wide source, low cost and adjustable pore structure, but it is easy to saturate when used alone, and its selective adsorption capacity for some difficult-to-degrade pollutants is insufficient.

[0003] In the prior art, the treatment effect is often improved by combining oxidants and coagulants. For example, in the patent with application number CN201110211724.7, permanganate can be used as a strong oxidant to pre-oxidize and decompose macromolecular organic matter, but it is easy to produce manganese oxide residues when used alone, and some pollutants are not completely oxidized. Although coagulants (such as polyaluminium chloride and aluminium sulfate) can promote the aggregation and sedimentation of suspended matter, traditional inorganic coagulants have problems such as loose flocs, slow sedimentation rate, and residual metal ions causing secondary pollution. In addition, the synergistic mechanism of oxidants and coagulants has not been fully optimized, and often needs to be added in steps, resulting in complex processes and increased costs.

[0004] The activated carbon composite materials reported in the existing literature mostly focus on single function enhancement, such as enhancing catalytic performance by loading metal oxides, or improving mechanical strength by compounding with polymers, but less attention is paid to the systematic design of activated carbon pore structure, oxidant and coagulant multi-component synergy. Therefore, it is necessary to invent a composite material with high pollutant removal efficiency, low cost, and synergistic effect of activated carbon and coagulant. Summary of the invention

[0005] The purpose of the present invention is to provide an activated carbon composition, corn cob powder activated carbon is used in conjunction with permanganate and coagulant to solve the problems of loose flocs, slow sedimentation rate, secondary pollution caused by residual metal ions, and poor adsorption effect of activated carbon in traditional inorganic coagulants. The use of corn cobs as activated carbon has good adsorption effect and high pollutant removal rate, and also solves the problem of agricultural waste treatment and realizes waste recycling. Another purpose of the present invention is to provide a preparation method of an activated carbon composition, which has simple process, easy-to-control conditions, and is green and environmentally friendly.

[0006] To achieve the above object, the present invention adopts the following technical solutions: An activated carbon composition comprises the following components: 5-30 parts of corn cob activated carbon, 2-20 parts of permanganate, 1-6 parts of polysilicate iron coagulant, and 0.5-13 parts of inorganic coagulant.

[0007] Preferably, the activated carbon composition comprises the following components: 10-20 parts of corn cob activated carbon, 5-10 parts of permanganate, 1.5-2 parts of polysilicate iron coagulant, and 1-5 parts of inorganic coagulant.

[0008] Preferably, the permanganate is at least one of potassium permanganate and sodium permanganate.

[0009] Permanganate is a strong oxidant that can oxidize organic pollutants in water, destroy their chemical structure, and oxidize large organic molecules into small molecules, making them easier to be adsorbed by activated carbon and subsequently biodegraded, thereby improving the biodegradability of wastewater. The combination of permanganate and activated carbon can further improve the removal effect of organic matter through the synergistic effect of oxidation-adsorption.

[0010] Preferably, the inorganic coagulant is at least one of aluminum sulfate, polyaluminum sulfate, polyaluminum chloride, and polyferric sulfate.

[0011] Inorganic coagulants (such as polyaluminium chloride and polyferric sulfate) are often used in the solid-liquid separation process in sewage treatment. They can effectively remove suspended solids and colloidal particles in water and improve the biodegradability of sewage through electrical neutralization, adsorption bridging and netting. In the pretreatment stage, coagulants can remove most suspended solids and some organic matter, reducing the burden of subsequent treatment processes. Polyferric silicate, as an inorganic coagulant, is used to flocculate suspended solids and colloidal particles in sewage and promote the precipitation of pollutants. Inorganic coagulants can further enhance the coagulation effect and remove suspended solids and some organic matter in sewage.

[0012] Preferably, the mass ratio of the polysilicate iron coagulant to the inorganic coagulant is (1:1)-(2:1).

[0013] Preferably, the specific surface area of ​​the corncob is 2000m 2 / g or above, micropores account for more than 70%, and mesopores account for 15-28%.

[0014] The present invention also adopts another technical solution: A method for preparing an activated carbon composition comprises the following steps: S1: Clean the corn cob, remove impurities and dry it, grind it into a particle size of 75-95μm, mix it with a phosphoric acid solution with a mass fraction of 27.9%, stir it evenly, and place it in a 75-80℃ oven to dry for 15 hours; put the dried sample into a muffle furnace, heat it up under nitrogen protection, and keep it for 2 hours; after cooling to room temperature, wash it with water until it is neutral, and dry it to obtain corn cob powder activated carbon; S2: Add corn cob activated carbon powder into water, add permanganate, stir evenly, then add coagulant solution and stir thoroughly.

[0015] Preferably, in S1, corn cobs and phosphoric acid are mixed in a mass ratio of 1:6, and the heating rate is 4-5°C / min to 600-820°C.

[0016] Corncob is an agricultural waste. Chemical activation (such as phosphoric acid or sulfuric acid activation) can further develop the pore structure of the carbonized product and improve its adsorption performance. Studies have shown that corncob activated carbon has a good adsorption effect on heavy metals (such as Cr(VI)) and organic matter (such as aniline) in wastewater.

[0017] Preferably, in S1, the stirring speed is 100-120 rpm, in S2, the stirring speed is 200-250 rpm, and the stirring time is 5-8 min.

[0018] Permanganate oxidizes wastewater, destroys the structure of organic pollutants, and increases the redox potential of the water.

[0019] Add coagulants to remove suspended solids and some organic matter in the water through flocculation, reducing the load of subsequent treatment. Use corn cob activated carbon to deeply adsorb the water after oxidation and flocculation to remove residual organic matter, heavy metals and odor.

[0020] An application of an activated carbon composition is applied in a sewage treatment process, with an addition amount of 30-100 mg / L.

[0021] Therefore, the present invention has the following beneficial effects: (1) Using corn cobs as activated carbon raw materials, high-value utilization of agricultural waste is achieved and raw material costs are reduced. Phosphoric acid activation combined with nitrogen protection and high-temperature carbonization (600-820°C) is used to form a rich pore structure, thereby increasing the specific surface area and adsorption capacity; the micropore-dominated structure enhances the retention of small molecular pollutants, and the reasonable proportion of mesopores ensures the adsorption of colloidal particles and some large molecular pollutants, broadening the scope of application. (2) The compounding of polysilicate iron and inorganic coagulants reduces the dosage of a single coagulant and reduces the residual aluminum / iron ions; the manganese dioxide generated after oxidation of permanganate can be adsorbed by activated carbon to avoid the dissolution of manganese ions and ensure the safety of the effluent. (3) The oxidation, adsorption, and coagulation processes are completed in an integrated manner, avoiding the equipment complexity and energy consumption problems of step-by-step addition in traditional processes. DETAILED DESCRIPTION

[0022] The present invention is further described below by means of specific embodiments, but the protection scope of the present invention is not limited thereto.

[0023] Overall embodiment The present embodiment provides an activated carbon composition, comprising the following components: 5-30 parts of corn cob activated carbon, 2-20 parts of permanganate, 1-6 parts of polysilicate iron coagulant, and 0.5-13 parts of inorganic coagulant.

[0024] In some embodiments provided by the present invention, the activated carbon composition comprises the following components: 10-20 parts of corn cob activated carbon, 5-10 parts of permanganate, 1.5-2 parts of polysilicate iron coagulant, and 1-5 parts of inorganic coagulant.

[0025] In some embodiments provided by the present invention, the permanganate is at least one of potassium permanganate and sodium permanganate. Preferably, the inorganic coagulant is at least one of aluminum sulfate, polyaluminum sulfate, polyaluminum chloride, and polyferric sulfate.

[0026] In some embodiments provided by the present invention, the mass ratio of the polysilicate iron coagulant to the inorganic coagulant is (1:1)-(2:1).

[0027] In some embodiments provided by the present invention, the specific surface area of ​​the corncob is 2000m 2 / g or above, micropores account for more than 70%, and mesopores account for 15-28%.

[0028] This embodiment also provides a method for preparing the above-mentioned activated carbon composition, comprising the following steps: S1: Clean the corn cob, remove impurities and dry it, grind it into a particle size of 75-95μm, mix it with a phosphoric acid solution with a mass fraction of 27.9%, stir it evenly, and place it in a 75-80℃ oven to dry for 15 hours; put the dried sample into a muffle furnace, heat it up under nitrogen protection, and keep it for 2 hours; after cooling to room temperature, wash it with water until it is neutral, and dry it to obtain corn cob powder activated carbon.

[0029] S2: Add corn cob activated carbon powder into water, add permanganate, stir evenly, then add coagulant solution and stir thoroughly.

[0030] In some embodiments provided by the present invention, in S1, corn cobs and phosphoric acid are mixed in a mass ratio of 1:6, and the heating rate is 4-5°C / min, and the temperature is raised to 600-820°C.

[0031] In some embodiments provided by the present invention, in S1, the stirring speed is 100-120 rpm / min, in S2, the stirring speed is 200-250 rpm / min, and the stirring time is 5-8 min.

[0032] Example 1 An activated carbon composition comprises the following components: 5 parts of corn cob activated carbon, 2 parts of potassium permanganate, 1 part of polysilicate ferric coagulant, and 0.5 parts of polyaluminium sulfate.

[0033] A method for preparing an activated carbon composition comprises the following steps: S1: cleaning corn cobs, removing impurities and drying them, crushing them to a particle size of 80 μm, mixing them with a phosphoric acid solution with a mass fraction of 27.9% at a mass ratio of 1:6, stirring them evenly at a stirring speed of 100 rpm / min, and drying them in a 75°C oven for 15 hours; placing the dried sample in a muffle furnace, heating it to 700°C under nitrogen protection, and maintaining it for 2 hours; after cooling to room temperature, washing it with water until it is neutral, and drying it to obtain corn cob powder activated carbon, wherein the specific surface area of ​​the corn cob is 2126 m 2 / g, micropores account for 74% and mesopores account for 22%; S2: Add corn cob activated carbon powder into water, add potassium permanganate, stir evenly, then add polyaluminium sulfate and polyferric silicate coagulants, stir thoroughly, stirring at a speed of 200 rpm / min for 6 minutes.

[0034] Example 2 An activated carbon composition comprises the following components: 30 parts of corn cob activated carbon, 20 parts of sodium permanganate, 6 parts of polysilicate ferric coagulant and 13 parts of polyaluminium chloride.

[0035] A method for preparing an activated carbon composition comprises the following steps: S1: cleaning corn cobs, removing impurities and drying them, crushing them to a particle size of 75 μm, mixing them with a phosphoric acid solution with a mass fraction of 27.9% at a mass ratio of 1:6, stirring them evenly at a stirring speed of 100 rpm / min, and drying them in a 75°C oven for 15 hours; placing the dried sample in a muffle furnace, heating it to 700°C under nitrogen protection, and maintaining it for 2 hours; after cooling to room temperature, washing it with water until it is neutral, and drying it to obtain corn cob powder activated carbon, wherein the specific surface area of ​​the corn cob is 2221m 2 / g, micropores account for 77% and mesopores account for 20%; S2: Add corn cob activated carbon powder into water, add sodium permanganate, stir evenly, then add polyaluminium sulfate and polyferric silicate coagulants, stir well, stirring at a speed of 200 rpm / min for 6 minutes.

[0036] Example 3 An activated carbon composition comprises the following components: 5 parts of corn cob activated carbon, 2 parts of potassium permanganate, 1 part of polysilicate ferric coagulant, and 0.5 part of polyferric sulfate.

[0037] A method for preparing an activated carbon composition comprises the following steps: S1: cleaning corn cobs, removing impurities and drying them, crushing them to a particle size of 75 μm, mixing them with a phosphoric acid solution with a mass fraction of 27.9% at a mass ratio of 1:6, stirring them evenly at a stirring speed of 105 rpm / min, and drying them in a 75°C oven for 15 hours; placing the dried sample in a muffle furnace, heating it to 750°C under nitrogen protection, and maintaining it for 2 hours; after cooling to room temperature, washing it with water until it is neutral, and drying it to obtain corn cob powdered activated carbon, wherein the specific surface area of ​​the corn cob is 2236 m 2 / g, micropores account for 77% and mesopores account for 21%; S2: Add corn cob activated carbon powder into water, add potassium permanganate, stir evenly, then add polyferric sulfate and polyferric silicate coagulants, stir well, stirring at a speed of 200 rpm / min for 5 minutes.

[0038] Example 4 An activated carbon composition comprises the following components: 10 parts of corn cob activated carbon, 5 parts of potassium permanganate, 1.5 parts of polysilicate ferric coagulant and 3 parts of polyaluminium chloride.

[0039] A method for preparing an activated carbon composition comprises the following steps: S1: cleaning corn cobs, removing impurities and drying them, crushing them to a particle size of 76 μm, mixing them with a phosphoric acid solution with a mass fraction of 27.9% at a mass ratio of 1:6, stirring them evenly at a stirring speed of 100 rpm / min, and drying them in a 75°C oven for 15 hours; placing the dried sample in a muffle furnace, heating it to 720°C under nitrogen protection, and maintaining it for 2 hours; after cooling to room temperature, washing it with water until it is neutral, and drying it to obtain corn cob powder activated carbon, wherein the specific surface area of ​​the corn cob is 2396 m 2 / g, micropores account for 78%, mesopores account for 20%, S2: Add corn cob activated carbon powder into water, add potassium permanganate, stir evenly, then add polyaluminium chloride and polyferric silicate coagulants, stir well, the stirring speed is 200rpm / min, and stir for 6min.

[0040] Example 5 An activated carbon composition comprises the following components: 5 parts of corn cob activated carbon, 6 parts of sodium permanganate, 1 part of polysilicate ferric coagulant and 0.5 part of polyaluminium sulfate.

[0041] A method for preparing an activated carbon composition comprises the following steps: S1: cleaning corn cobs, removing impurities and drying them, crushing them to a particle size of 75 μm, mixing them with a phosphoric acid solution with a mass fraction of 27.9% at a mass ratio of 1:6, stirring them evenly at a stirring speed of 100 rpm / min, and drying them in a 75°C oven for 15 hours; placing the dried sample in a muffle furnace, heating it to 700°C under nitrogen protection, and maintaining it for 2 hours; after cooling to room temperature, washing it with water until it is neutral, and drying it to obtain corn cob powder activated carbon, wherein the specific surface area of ​​the corn cob is 2260 m 2 / g, micropores account for 77% and mesopores account for 19%; S2: Add corn cob activated carbon powder into water, add sodium permanganate, stir evenly, then add polyaluminium sulfate and polyferric silicate coagulants, stir well, stirring at a speed of 200 rpm / min for 6 minutes.

[0042] Example 6 An activated carbon composition comprises the following components: 5 parts of corn cob activated carbon, 2 parts of potassium permanganate, 1 part of polysilicate ferric coagulant, 1 part of polyaluminium sulfate and 0.5 part of aluminium sulfate.

[0043] A method for preparing an activated carbon composition comprises the following steps: S1: cleaning corn cobs, removing impurities and drying them, crushing them to a particle size of 80 μm, mixing them with a phosphoric acid solution with a mass fraction of 27.9% at a mass ratio of 1:6, stirring them evenly at a stirring speed of 100 rpm / min, and drying them in a 75°C oven for 15 hours; placing the dried sample in a muffle furnace, heating it to 700°C under nitrogen protection, and maintaining it for 2 hours; after cooling to room temperature, washing it with water until it is neutral, and drying it to obtain corn cob powder activated carbon, wherein the specific surface area of ​​the corn cob is 2126 m 2 / g, micropores account for 74% and mesopores account for 22%; S2: Add corn cob activated carbon powder into water, add potassium permanganate, stir evenly, then add polyaluminium sulfate, aluminium sulfate and polyferric silicate coagulant and stir thoroughly at a stirring speed of 250 rpm / min for 5 minutes.

[0044] Example 7 An activated carbon composition comprises the following components: 5 parts of corn cob activated carbon, 2 parts of potassium permanganate, 1 part of polysilicate ferric coagulant, and 0.5 parts of polyaluminium sulfate.

[0045] A method for preparing an activated carbon composition comprises the following steps: S1: cleaning corn cobs, removing impurities and drying them, crushing them to a particle size of 80 μm, mixing them with a phosphoric acid solution with a mass fraction of 27.9% at a mass ratio of 1:6, stirring them evenly at a stirring speed of 100 rpm / min, and drying them in a 75°C oven for 15 hours; placing the dried sample in a muffle furnace, heating it to 700°C under nitrogen protection, and maintaining it for 2 hours; after cooling to room temperature, washing it with water until it is neutral, and drying it to obtain corn cob powder activated carbon, wherein the specific surface area of ​​the corn cob is 2221 m 2 / g, micropores account for 75% and mesopores account for 22%; S2: Add corn cob activated carbon powder into water, add potassium permanganate, stir evenly, then add polyaluminium sulfate and polyferric silicate coagulants, stir thoroughly, stirring at a speed of 200 rpm / min for 6 minutes.

[0046] Example 8 An activated carbon composition comprises the following components: 5 parts of corn cob activated carbon, 1 part of potassium permanganate, 1 part of sodium permanganate, 1 part of polysilicate ferric coagulant, and 0.5 part of polyaluminium sulfate.

[0047] A method for preparing an activated carbon composition comprises the following steps: S1: cleaning corn cobs, removing impurities and drying them, crushing them to a particle size of 80 μm, mixing them with a phosphoric acid solution with a mass fraction of 27.9% at a mass ratio of 1:6, stirring them evenly at a stirring speed of 120 rpm / min, and drying them in a 75°C oven for 15 hours; placing the dried sample in a muffle furnace, heating it to 820°C under nitrogen protection, and maintaining it for 2 hours; after cooling to room temperature, washing it with water until it is neutral, and drying it to obtain corn cob powder activated carbon, wherein the specific surface area of ​​the corn cob is 2302 m 2 / g, micropores account for 77% and mesopores account for 21%; S2: Add corn cob activated carbon powder into water, add potassium permanganate and sodium permanganate, stir evenly, then add polyaluminium sulfate and polyferric silicate coagulants, stir thoroughly, stirring at a speed of 250 rpm / min for 8 minutes.

[0048] Comparative Example 1 An activated carbon composition comprises the following components: 10 parts of corn cob activated carbon, 1.5 parts of polysilicate iron coagulant and 3 parts of polyaluminium chloride.

[0049] A method for preparing an activated carbon composition comprises the following steps: S1: cleaning corn cobs, removing impurities and drying them, crushing them to a particle size of 75 μm, mixing them with a phosphoric acid solution with a mass fraction of 27.9% at a mass ratio of 1:6, stirring them evenly at a stirring speed of 100 rpm / min, and drying them in a 75°C oven for 15 hours; placing the dried sample in a muffle furnace, heating it to 720°C under nitrogen protection, and maintaining it for 2 hours; after cooling to room temperature, washing it with water until it is neutral, and drying it to obtain corn cob powder activated carbon, wherein the specific surface area of ​​the corn cob is 2366 m 2 / g, micropores account for 77% and mesopores account for 20%; S2: Add corn cob activated carbon powder into water, add polyaluminium chloride and polyferric silicate coagulants, stir thoroughly at a speed of 200 rpm / min for 6 minutes.

[0050] The difference between this comparative example and Example 4 is that no permanganate is added in this comparative example.

[0051] Comparative Example 2 An activated carbon composition comprises the following components: 10 parts of corn cob activated carbon, 5 parts of potassium permanganate and 3 parts of polyaluminium chloride.

[0052] A method for preparing an activated carbon composition comprises the following steps: S1: cleaning corn cobs, removing impurities and drying them, crushing them to a particle size of 75 μm, mixing them with a phosphoric acid solution with a mass fraction of 27.9% at a mass ratio of 1:6, stirring them evenly at a stirring speed of 100 rpm / min, and drying them in a 75°C oven for 15 hours; placing the dried sample in a muffle furnace, heating it to 720°C under nitrogen protection, and maintaining it for 2 hours; after cooling to room temperature, washing it with water until it is neutral, and drying it to obtain corn cob powder activated carbon, wherein the specific surface area of ​​the corn cob is 2297 m 2 / g, micropores account for 73% and mesopores account for 25%; S2: Add corn cob activated carbon powder into water, add potassium permanganate, stir evenly, then add polyaluminium chloride, stir thoroughly, stirring at a speed of 200 rpm / min for 6 minutes.

[0053] The difference between this comparative example and Example 4 is that in this comparative example, no polysilicate iron coagulant is added, and only a single inorganic coagulant is used.

[0054] Comparative Example 3 An activated carbon composition comprises the following components: 3 parts of corn cob activated carbon, 5 parts of potassium permanganate, 1.5 parts of polysilicate ferric coagulant and 0.5 parts of polyferric sulfate.

[0055] A method for preparing an activated carbon composition comprises the following steps: S1: cleaning corn cobs, removing impurities and drying them, crushing them to a particle size of 76 μm, mixing them with a phosphoric acid solution with a mass fraction of 27.9% at a mass ratio of 1:6, stirring them evenly at a stirring speed of 100 rpm / min, and drying them in a 75°C oven for 15 hours; placing the dried sample in a muffle furnace, heating it to 720°C under nitrogen protection, and maintaining it for 2 hours; after cooling to room temperature, washing it with water until it is neutral, and drying it to obtain corn cob powder activated carbon, wherein the specific surface area of ​​the corn cob is 2242 m 2 / g, micropores account for 70% and mesopores account for 23%; S2: Add corn cob activated carbon powder into water, add potassium permanganate, stir evenly, then add polyaluminium chloride and polyaluminium chloride, stir well, the stirring speed is 200rpm / min, and stir for 6min.

[0056] The difference between this comparative example and Example 4 is that the number of portions of corn cob activated carbon in this comparative example is 3 portions, thereby reducing the amount of corn cob activated carbon used.

[0057] Comparative Example 4 An activated carbon composition comprises the following components: 10 parts of corn cob activated carbon, 5 parts of potassium permanganate, 1.5 parts of polysilicate ferric coagulant and 0.5 parts of polyferric sulfate.

[0058] A method for preparing an activated carbon composition comprises the following steps: S1: cleaning corn cobs, removing impurities and drying them, crushing them to a particle size of 75 μm, and drying them in a 75°C oven for 15 hours; placing the dried sample in a muffle furnace, heating it to 800°C under nitrogen protection, and maintaining it for 2 hours to obtain corn cob powdered activated carbon, wherein the specific surface area of ​​the corn cobs is 1500 m 2 / g, micropores account for 60% and mesopores account for 35%; S2: Add corn cob activated carbon powder into water, add potassium permanganate, stir evenly, then add polyaluminium chloride, stir thoroughly, stirring at a speed of 200 rpm / min for 6 minutes.

[0059] The difference between this comparative example and Example 4 is that the corncob powder activated carbon is not activated in this comparative example.

[0060] Effect test Take a sewage sample, add the activated carbon composition at 30-100 mg / L, stir the reaction, and measure the COD removal rate, suspended solids removal rate, heavy metal removal rate, and turbidity. The results are shown in Table 1. COD removal rate (%) Suspended matter removal rate (%) Heavy metal removal rate (%) Turbidity (NTU) Example 1 97.6 98.0 97.9 4 Example 2 97.5 97.6 98.3 5 Example 3 98.2 98.1 97.5 5 Example 4 99.2 99.4 99.1 3 Example 5 98.1 97.9 98.4 4 Example 6 97.9 98.3 97.1 4 Example 7 97.7 97.2 98.7 5 Example 8 98.3 97.8 97.2 4 Comparative Example 1 91.5 89.6 89.7 9 Comparative Example 2 90.6 90.2 89.3 8 Comparative Example 3 91.1 91.0 87.1 8 Comparative Example 4 90.9 89.9 89.2 10

[0061] As shown in Table 1, the sewage treatment effect of the embodiment is significantly better than that of the comparative example. The removal rates of various items (COD, suspended solids, heavy metals) of the embodiment are generally high, and the turbidity is also controlled at a low level. Example 4 performs best, with COD, suspended solids, and heavy metal removal rates all ≥ 99%, and turbidity as low as 3NTU, which verifies that corn cob activated carbon (specific surface area 2396m 2 / g, micropore 78%) and potassium permanganate, polysilicate ferric coagulant, inorganic coagulant synergistic effect; the removal rate of the comparative example is relatively low, the turbidity is also high, and the sewage treatment effect is not ideal. Compared with Example 4, in Comparative Example 1, no permanganate was added, and the COD / heavy metal removal rate was significantly reduced, indicating the necessity of oxidants for organic matter degradation and heavy metal oxidation; no polysilicate ferric was added, only a single coagulant was used, the suspended matter removal rate was low, and the turbidity was high, proving the effect of polysilicate ferric on the density and sedimentation rate of flocs; in Comparative Example 3, the amount of corn cob activated carbon was insufficient, resulting in insufficient adsorption capacity and a significant reduction in heavy metal removal rate; in Comparative Example 4, the corn cob was not activated with phosphoric acid, and the specific surface area was only 1500m 2 / g, the adsorption performance deteriorated and the COD removal rate decreased (99.2% vs. 90.9%), indicating that activation treatment of corn cob activated carbon can effectively optimize the pore structure of corn cob activated carbon, increase the specific surface area and enhance the adsorption effect.

[0062] Therefore, the activated carbon composition of the present invention uses corn cob powder activated carbon in conjunction with permanganate and a coagulant to achieve synergistic oxidation-adsorption-coagulation efficiency, and solves the problems of loose flocs, slow sedimentation rate, secondary pollution caused by residual metal ions, and poor activated carbon adsorption effect of traditional inorganic coagulants. Using corn cobs as activated carbon has good adsorption effect and high pollutant removal rate. It also solves the problem of agricultural waste treatment and realizes waste recycling.

Claims

1. An activated carbon composition, characterized in that The invention comprises the following components: 5-30 parts of corn cob activated carbon, 2-20 parts of permanganate, 1-6 parts of polysilicate iron coagulant and 0.5-13 parts of inorganic coagulant.

2. The activated carbon composition according to claim 1, characterized in that The invention comprises the following components: 10-20 parts of corn cob activated carbon, 5-10 parts of permanganate, 1.5-2 parts of polysilicate ferric coagulant and 1-5 parts of inorganic coagulant.

3. The activated carbon composition according to claim 1 or 2, characterized in that The permanganate is at least one of potassium permanganate and sodium permanganate.

4. The activated carbon composition according to claim 1 or 2, characterized in that The inorganic coagulant is at least one of aluminum sulfate, polyaluminum sulfate, polyaluminum chloride, and polyferric sulfate.

5. The activated carbon composition according to claim 1, characterized in that The mass ratio of the polysilicate iron coagulant to the inorganic coagulant is (1:1)-(2:1).

6. The activated carbon composition according to claim 1, characterized in that The specific surface area of ​​the corncob is 2000m 2 / g or above, micropores account for more than 70%, and mesopores account for 15-28%.

7. A method for preparing an activated carbon composition, characterized in that: The following steps are involved: S1: Clean the corn cob, remove impurities and dry it, grind it into a particle size of 75-95μm, mix it with a phosphoric acid solution with a mass fraction of 27.9%, stir it evenly, and place it in a 75-80℃ oven to dry for 15 hours; put the dried sample into a muffle furnace, heat it up under nitrogen protection, and keep it for 2 hours; after cooling to room temperature, wash it with water until it is neutral, and dry it to obtain corn cob powder activated carbon; S2: Add corn cob activated carbon powder into water, add permanganate, stir evenly, then add coagulant solution and stir thoroughly.

8. The method for preparing an activated carbon composition according to claim 7, characterized in that: In S1, corn cobs and phosphoric acid are mixed in a mass ratio of 1:6, and the temperature is increased to 600-820°C at a heating rate of 4-5°C / min.

9. The method for preparing an activated carbon composition according to claim 7, characterized in that: In the S1, the stirring speed is 100-120 rpm, in the S2, the stirring speed is 200-250 rpm, and the stirring time is 5-8 min.

10. An application of an activated carbon composition, characterized in that: Applied in sewage treatment process, the addition amount is 30-100mg / L.