Activated carbon multistage adsorption method with size matching of background pollutants and micropollutants
By using the coordinated interaction of modifier and water vapor in the activated carbon multi-stage adsorption method, the problem of large amount and high cost of activated carbon in the prior art is solved, and the effect of efficient removal of micro-contaminants is achieved.
Patent Information
- Application Number
- CN202510240975.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-03
- Publication Date
- 2025-06-24
AI Technical Summary
In the existing activated carbon adsorption process, due to the competition of background organic matter, the amount of activated carbon is greatly increased and the process operation cost is increased.
The multi-stage adsorption method of activated carbon with size matching background pollutants and micropollutants was adopted, and heat treatment and water vapor activation treatment were carried out by mixing coal mixing and modifiers to prepare raw coal activated carbon with excellent adsorption performance, and the adsorption efficiency was improved by using multi-stage dosing method.
It effectively reduces the total amount of raw coal activated carbon to absorb micropollutants, improves the removal effect of micropollutants, and reduces the cost of process operation.
Smart Images
Figure CN120191927A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of organic pollutant removal, and particularly relates to a multi-stage activated carbon adsorption method with size matching between background pollutants and micropollutants. Background Art
[0002] In the existing activated carbon adsorption process, a single addition method is usually adopted. Due to the competition of background organic matters, the dosage of activated carbon is greatly increased. To reduce the competition of background organic matters, a combination with other processes is usually adopted, such as ozone oxidation, biodegradation and other methods, but these methods increase the operation cost of the process. Therefore, it is necessary to provide a multi-stage activated carbon adsorption method with size matching between background pollutants and micropollutants. Based on the staged addition of activated carbon, by using the matching effect between the pore structure of activated carbon and the molecular weight of pollutants, a stepwise carbon addition method for further reducing the competition of background organic matters and improving the adsorption and removal effect of micropollutants is provided. Summary of the Invention
[0003] The purpose of the present invention is to provide a multi-stage activated carbon adsorption method with size matching between background pollutants and micropollutants.
[0004] The technical solution adopted by the present invention to achieve the above purpose is as follows: A preparation method of raw coal activated carbon, comprising: Mixing coal blending and a modifier for heat treatment, then performing steam activation treatment, washing and drying to obtain raw coal activated carbon; in the steam activation treatment, the temperature of the steam activation treatment is 900 - 1000 °C, and the activation time of the steam activation treatment is 20 - 100 min; The modifier includes at least one of polyoxyethylene lauryl ether carboxylic acid and disodium oleamide MEA sulfosuccinate. Among them, when polyoxyethylene lauryl ether carboxylic acid and disodium oleamide MEA sulfosuccinate are used as modifiers to participate in the preparation of raw coal activated carbon, the total dosage of raw coal activated carbon is significantly reduced when removing micropollutants. This is mainly attributed to the fact that the use of polyoxyethylene lauryl ether carboxylic acid and disodium oleamide MEA sulfosuccinate introduces a sulfur-containing structure into the raw coal activated carbon, and at the same time introduces a new structure formed by carboxyl groups and sulfonic acid groups into the raw coal activated carbon, thereby improving the adsorption performance of the raw coal activated carbon for micropollutants and effectively reducing the total dosage of raw coal activated carbon when adsorbing micropollutants.
[0005] Preferably, the raw coal activated carbon is at least one of microporous carbon and hierarchical porous carbon.
[0006] Preferably, the dosage of the coal blending is 2 - 8 parts by weight, and the dosage of the modifier is 0.2 - 3.6 parts by weight.
[0007] Preferably, the heat treatment includes two-stage heating. In the first-stage heating, the temperature is raised from room temperature to 400-800 °C and maintained for 0.5-1.5 h; in the second-stage heating, the temperature is raised from the holding temperature of the first-stage heating to 900-1000 °C.
[0008] A multi-stage adsorption method of activated carbon with background pollutants and micro-pollutants having a size match, comprising: Take 2 groups of prepared raw coal activated carbon to perform adsorption treatment on the water sample to be treated containing micro-pollutants. Divide each group of raw coal activated carbon into N equal parts and add them to the water sample to be treated for adsorption in sequence, and record the content C of micro-pollutants after the Nth adsorption treatment e , according to C e Calculate the adsorption capacity q of micro-pollutants e ; N is an integer greater than or equal to 2; According to C e and q e Use the Freundlich model to fit the adsorption isotherm: ; According to K F and the value of 1 / n, calculate the total dosage D of raw coal activated carbon required to remove micro-pollutants R , D R The calculation formula of is: , R represents the target removal rate of micro-pollutants.
[0009] Preferably, N is 2, the raw coal activated carbon is microporous carbon and multi-stage pore carbon, and the microporous carbon and multi-stage pore carbon are used in a mass ratio of 1:1.
[0010] More preferably, the first portion of raw coal activated carbon is multi-stage pore carbon, and the second portion of raw coal activated carbon is microporous carbon.
[0011] Preferably, R is 20-80%.
[0012] Preferably, the micro-pollutant is at least one of EDD, IMD, BDD, IPDD, BMD, MIB, and GSM.
[0013] Preferably, the water sample to be treated also contains natural organic matter (NOM).
[0014] The present invention provides a multi-stage adsorption method of activated carbon with background pollutants and micro-pollutants having a size match, comprising: mixing coal blending and a modifier for heat treatment, then performing steam activation treatment, washing and drying to obtain raw coal activated carbon, and using the matching effect of the pore structure of the raw coal activated carbon and the molecular weight of the pollutants and the multi-stage carbon addition method to effectively remove micro-pollutants.
[0015] Preferably, a preparation method of raw coal activated carbon is specifically: Mix the blended coal and the modifier and conduct heat treatment. Under a nitrogen atmosphere, the heat treatment process includes two heating processes. After the heating ends, turn off the nitrogen, conduct steam activation treatment, measure the flow rate of the steam, conduct constant-temperature activation, turn off the steam after the activation ends, introduce nitrogen, and cool to room temperature to obtain activated carbon. Wash the obtained activated carbon with dilute hydrochloric acid aqueous solution and ultrapure water, dry it, grind it, and sieve it to obtain raw coal activated carbon.
[0016] Preferably, the dosage of the blended coal is 2-8 parts by weight.
[0017] Preferably, the modifier is at least one of polyoxyethylene lauryl ether carboxylic acid, sodium oleamide MEA sulfosuccinate, and 2-amino-6-hydroxypyrimidine-4-carboxylic acid. Among them, when 2-amino-6-hydroxypyrimidine-4-carboxylic acid participates in the preparation of raw coal activated carbon, the total dosage of the raw coal activated carbon is significantly reduced when removing micro-pollutants. This is mainly attributed to the fact that the use of 2-amino-6-hydroxypyrimidine-4-carboxylic acid incorporates nitrogen elements into the structure of the raw coal activated carbon to form a new structure, thereby further improving the adsorption performance of the raw coal activated carbon and further effectively reducing the total dosage of the raw coal activated carbon when removing micro-pollutants.
[0018] More preferably, the modifier is polyoxyethylene lauryl ether carboxylic acid.
[0019] More preferably, the modifier is polyoxyethylene lauryl ether carboxylic acid and sodium oleamide MEA sulfosuccinate.
[0020] More preferably, the modifier is polyoxyethylene lauryl ether carboxylic acid, sodium oleamide MEA sulfosuccinate, and 2-amino-6-hydroxypyrimidine-4-carboxylic acid.
[0021] More preferably, the dosage of polyoxyethylene lauryl ether carboxylic acid is 0.2-1.2 parts by weight.
[0022] More preferably, the dosage of sodium oleamide MEA sulfosuccinate is 0.2-1.2 parts by weight.
[0023] More preferably, the dosage of 2-amino-6-hydroxypyrimidine-4-carboxylic acid is 0.2-1.2 parts by weight.
[0024] Preferably, the flow rate of nitrogen is 1000-3000 mL / min.
[0025] Preferably, the heat treatment includes two-stage heating treatment. In the first-stage heating, heat from room temperature to 400-800 °C and maintain for 0.5-1.5 h; in the second-stage heating, heat from the maintained temperature of the first-stage heating to 900-1000 °C.
[0026] More preferably, the heating rate is 5-15 °C / min.
[0027] Preferably, the flow rate of water vapor is 0.1~0.5 mL / min.
[0028] Preferably, the time for water vapor activation treatment is 20~100 min.
[0029] Preferably, the mass percentage of hydrochloric acid in the dilute hydrochloric acid aqueous solution is 0.1~0.5%, and the dosage of the dilute hydrochloric acid aqueous solution is 40~60 volume parts. Among them, the relationship between the dosage of blended coal and the dilute hydrochloric acid aqueous solution is 2~8 g: 40~60 mL.
[0030] Preferably, the dosage of ultrapure water is 80~120 volume parts.
[0031] Preferably, the drying temperature is 100~110 °C.
[0032] Preferably, the drying time is 20~30 h.
[0033] Preferably, the sieve diameter is 180~220 mesh.
[0034] Provide a multi-stage adsorption method of activated carbon with background pollutants and micro-pollutants of matching sizes, where the multiple dosing method is specifically as follows: (1) Add micro-pollutants to the raw water containing NOM to prepare a micro-pollutant-water mixture.
[0035] (2) Divide the total dosage of the raw coal activated carbon to be added into N equal parts, with weights of D1, D2,... D N-1 , D N .
[0036] (3) Measure the micro-pollutant-water mixture and perform the first addition of raw coal activated carbon, with the dosage of D1.
[0037] (4) After the first addition of raw coal activated carbon for adsorption treatment, perform the second addition of raw coal activated carbon, with the dosage of D2.
[0038] (5) After the second addition of raw coal activated carbon for adsorption treatment, continue to add and perform adsorption treatment in sequence according to the number of equal parts and the added weights of the total dosage of raw coal activated carbon until the added weight of the last part of raw coal activated carbon is D N After the adsorption treatment is completed, filter to remove the added raw coal activated carbon, collect the filtrate, and obtain the N-stage adsorbed water; measure the content of micro-pollutants in the N-stage adsorbed water as Ce.
[0039] (6) Calculate and determine the adsorption capacity of micro-pollutants on the raw coal activated carbon, which is: .
[0040] And according to the calculated and Draw the adsorption isotherm.
[0041] (7) Fit the adsorption isotherm using the Freundlich model: .
[0042] Determine the K F and 1 / n values, and calculate the total dosage D of raw coal activated carbon required to adsorb micro-pollutants at a certain target removal rate according to the K F and 1 / n values. The calculation formula is: R . .
[0043] Wherein, R represents the target removal rate of micro-pollutants, and R is 20 - 80%.
[0044] Preferably, the number of dosing times ≥ 2 during the dosing process of raw coal activated carbon by the multiple dosing method.
[0045] Preferably, the total dosage of raw coal activated carbon is evenly divided into N ≥ 2 portions.
[0046] Preferably, the raw coal activated carbon is at least one of microporous carbon and hierarchical porous carbon.
[0047] More preferably, the raw coal activated carbon is microporous carbon.
[0048] More preferably, the raw coal activated carbon is hierarchical porous carbon.
[0049] More preferably, the raw coal activated carbon is microporous carbon and hierarchical porous carbon.
[0050] More preferably, the combination of raw coal activated carbon includes any one of microporous carbon and hierarchical porous carbon, microporous carbon and microporous carbon, and hierarchical porous carbon and hierarchical porous carbon.
[0051] More preferably, the combination of raw coal activated carbon is microporous carbon and hierarchical porous carbon, the first portion of raw coal activated carbon is hierarchical porous carbon, and the second portion of raw coal activated carbon is microporous carbon.
[0052] Preferably, the number of portions of the micro-pollutant - water mixture during the removal of micro-pollutants is 5 - 7 portions.
[0053] Preferably, the total dosage of raw coal activated carbon is 1 - 80 mg / L.
[0054] Preferably, the micro-pollutants include at least one of EDD, IMD, BDD, IPDD, BMD, MIB, and GSM.
[0055] Preferably, the initial concentration of micro-pollutants in the micro-pollutant - water mixture is 100 - 800 ng / L.
[0056] Preferably, the initial concentration of NOM in the micro-pollutant - water mixture is 2 - 4 mg / L.
[0057] Since the raw coal activated carbon is prepared by the synergistic action of the modifier and water vapor in the present invention, the following beneficial effects are achieved: the cost of the present invention is low, the operation is simple, and the total dosage of the raw coal activated carbon for removing micro-pollutants is effectively reduced. Therefore, the present invention is an activated carbon multi-stage adsorption method with a size match between background pollutants and micro-pollutants. Description of the Drawings
[0058] Figure 1 It is the OCD chromatogram of the raw coal activated carbon adsorbing NOM raw water for 10 min.
[0059] Figure 2 It is the OCD chromatogram of PAC2 for NOM raw water at different adsorption times.
[0060] Figure 3 It is the SEM image of the raw coal activated carbon prepared in Example 9.
[0061] Figure 4 It is the total dosage diagram of the raw coal activated carbon in different carbon addition methods for removing micro-pollutants. Detailed Embodiments
[0062] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.
[0063] The concepts involved in the present application will be described below with reference to the accompanying drawings first. It should be noted here that the descriptions of the following concepts are only for making the content of the present application easier to understand, and do not represent the limitation of the protection scope of the present application; at the same time, without conflict, the embodiments and the features in the embodiments in the present application can be combined with each other. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.
[0064] Example 1: A preparation method of raw coal activated carbon.
[0065] Weigh the blended coal and load it into the tubular furnace. Use nitrogen as the protective gas. After the experiment starts, the tubular furnace undergoes two heating-up processes. After the heating-up is completed, turn off the nitrogen and introduce steam for activation. The peristaltic pump measures the flow rate of the introduced steam, and carry out isothermal activation. Finally, stop heating, turn off the steam and reintroduce nitrogen, and wait for it to cool naturally to room temperature. Wash the obtained activated carbon with dilute hydrochloric acid aqueous solution and ultrapure water, and dry it at a suitable temperature. Grind the dried activated carbon and sieve it through a sieve with a suitable mesh size to obtain raw coal activated carbon 1 (PAC1), and finally store it sealed. The dosage of the blended coal is 5 g, the flow rate of nitrogen as the protective gas is 2000 mL / min, the heating rate of the tubular furnace is 10 °C / min. The two heating-up processes include that in the first stage, when the temperature rises to 600 °C, maintain the temperature for 1 h, in the second stage, the temperature rises to 950 °C, the steam flow rate is 0.2 mL / min, the isothermal activation time is 30 min, the mass percentage of hydrochloric acid in the dilute hydrochloric acid aqueous solution is 0.2%, the dosage of the dilute hydrochloric acid aqueous solution is 50 mL, the dosage of ultrapure water is 100 mL, the drying temperature of PAC1 is 105 °C, the drying time of PAC1 is 24 h, and the particle size after grinding and sieving is 200 mesh.
[0066] Example 2: A preparation method of raw coal activated carbon.
[0067] The difference between this example and Example 1 is that the isothermal activation time is 45 min. Except for this, other conditions are the same as those in Example 1, and raw coal activated carbon 2 (PAC2) is obtained.
[0068] Example 3: A preparation method of raw coal activated carbon.
[0069] The difference between this example and Example 1 is that the isothermal activation time is 60 min. Except for this, other conditions are the same as those in Example 1, and raw coal activated carbon 3 (PAC3) is obtained.
[0070] Example 4: A preparation method of raw coal activated carbon.
[0071] The difference between this example and Example 1 is that the isothermal activation time is 75 min. Except for this, other conditions are the same as those in Example 1, and raw coal activated carbon 4 (PAC4) is obtained.
[0072] Example 5: A preparation method of raw coal activated carbon.
[0073] The difference between this example and Example 1 is that the isothermal activation time is 90 min. Except for this, other conditions are the same as those in Example 1, and raw coal activated carbon 5 (PAC5) is obtained.
[0074] Table 1 Influence of Different Activation Conditions on the Generation of Hierarchical Porous Structure of Raw Coal Activated Carbon
[0075] It can be seen from Table 1 that the microporous carbon is the raw coal activated carbon with a micropore ratio greater than 60%, and the hierarchical porous carbon is the raw coal activated carbon with a micropore ratio less than 60%.
[0076] Experimental Example 1: Target solution: Raw water containing NOM (abbreviated as NOM raw water) Concentration of NOM in NOM raw water: 3.2 mg / L Dosage of NOM raw water: 1 L Raw coal activated carbons: PAC2, PAC3 and PAC5 Dosage of raw coal activated carbon: 50 mg / L Adsorption time: 10 min and 48 h Add the raw coal activated carbon into the NOM raw water, adsorb for a certain time, and analyze the molecular weight distribution of each component in the NOM raw water and the change of absorbance of each component at UV 254 by OCD chromatography.
[0077] The NOM raw water can be mainly divided into 5 components, which are divided into biopolymer (BP), humic acid (HA), fulvic acid (FA), building blocks of humic acid substances (BB) and low molecular weight neutral substances (LMW) according to molecular weight. The molecular weight ranges of each component are shown in Table 2. In the present invention, BB and LMW are combined and called small molecule components (LMWs). Figure 1 It is the OCD chromatogram of the raw coal activated carbon adsorbing NOM raw water for 10 min. It can be seen that PACs cannot remove the BP component. For the HA and FA components, PAC2, PAC3 and PAC5 all have obvious removal effects at 10 min. For the LMWs component, PAC3 and PAC5 have obvious removal effects at 10 min, while for the LMWs component, the removal effect of PAC2 is not obvious at 10 min. Figure 2 It is the OCD chromatogram of PAC2 for different adsorption times of NOM raw water. It can be seen that with the extension of the adsorption time, the removal effect of PAC2 on the LMWs component is significantly improved. To sum up, the adsorption rate of the hierarchical porous carbon for each component of NOM is better than that of the microporous carbon. Moreover, the adsorption of the macromolecular NOM component by the microporous carbon at the initial stage causes the pore channels of the microporous carbon to be blocked, thus affecting the adsorption of the small molecule NOM component by the microporous carbon. Therefore, the microporous carbon is more suitable for adsorbing small molecule NOM components or micro-pollutants, and the hierarchical porous carbon is more suitable for adsorbing macromolecular NOM components.
[0078] Table 2 Molecular Weight Ranges of Each Component in NOM Raw Water
[0079] Example 6: A preparation method of raw coal activated carbon.
[0080] The difference between this example and Example 2 is that polyoxyethylene lauryl ether carboxylic acid and disodium oleamide MEA sulfosuccinate are added during the preparation process of raw coal activated carbon. Specifically: Weigh the blended coal, polyoxyethylene lauryl ether carboxylic acid and disodium oleamide MEA sulfosuccinate, mix them and load them into a tubular furnace. Use nitrogen as the protective gas. After the experiment starts, the tubular furnace undergoes two heating processes. After the heating is completed, turn off the nitrogen, introduce steam for activation, and use a peristaltic pump to measure the flow rate of the introduced steam, and carry out constant-temperature activation. Finally, stop heating, turn off the steam and re-introduce nitrogen, and wait for natural cooling to room temperature. Wash the obtained activated carbon with dilute hydrochloric acid aqueous solution and ultrapure water, and then dry it. Grind the dried activated carbon through a sieve with an appropriate mesh size to obtain raw coal activated carbon 6 (PAC6), and finally store it sealed. The dosage of the blended coal is 5 g, the dosage of polyoxyethylene lauryl ether carboxylic acid is 0.5 g, the dosage of disodium oleamide MEA sulfosuccinate is 0.5 g, the flow rate of nitrogen as the protective gas is 2000 mL / min, the heating rate of the tubular furnace is 10 °C / min. The two heating processes include that when the temperature rises to 600 °C in the first stage, keep the temperature for 1 h, in the second stage, the temperature rises to 950 °C, the steam flow rate is 0.2 mL / min, the constant-temperature activation time is 45 min, the mass percentage of hydrochloric acid in the dilute hydrochloric acid aqueous solution is 0.2%, the dosage of the dilute hydrochloric acid aqueous solution is 50 mL, the dosage of ultrapure water is 100 mL, the drying temperature of PAC6 is 105 °C, the drying time of PAC6 is 24 h, and the particle size after grinding and sieving is 200 mesh.
[0081] Example 7: A preparation method of raw coal activated carbon.
[0082] The difference between this example and Example 6 is that the dosages of both polyoxyethylene lauryl ether carboxylic acid and disodium oleamide MEA sulfosuccinate are 1 g during the preparation process of raw coal activated carbon. Except for this, other conditions are the same as those in Example 6. Obtain raw coal activated carbon 7 (PAC7).
[0083] Example 8: A preparation method of raw coal activated carbon.
[0084] The difference between this example and Example 7 is that 2-amino-6-hydroxypyrimidine-4-carboxylic acid is added during the preparation process of raw coal activated carbon. Specifically: Weigh the blended coal, polyoxyethylene lauryl ether carboxylic acid, disodium oleamide MEA sulfosuccinate, and 2-amino-6-hydroxypyrimidine-4-carboxylic acid, mix them, and load them into a tubular furnace. Use nitrogen as the protective gas. After the experiment starts, the tubular furnace undergoes two heating processes. After the heating is completed, turn off the nitrogen and introduce steam for activation. Use a peristaltic pump to measure the flow rate of the introduced steam and carry out activation at a constant temperature. Finally, stop heating, turn off the steam, and reintroduce nitrogen. Wait for it to cool naturally to room temperature. Wash the obtained activated carbon with dilute hydrochloric acid aqueous solution and ultrapure water, and then dry it. Grind the dried activated carbon through a sieve with an appropriate mesh size to obtain raw coal activated carbon 8 (PAC8), and finally store it sealed. The dosage of the blended coal is 5 g, the dosage of polyoxyethylene lauryl ether carboxylic acid is 1 g, the dosage of disodium oleamide MEA sulfosuccinate is 1 g, the dosage of 2-amino-6-hydroxypyrimidine-4-carboxylic acid is 0.5 g, the flow rate of nitrogen as the protective gas is 2000 mL / min, the heating rate of the tubular furnace is 10 °C / min. The two heating processes include that when the temperature rises to 600 °C in the first stage, maintain the temperature for 1 h, and in the second stage, the temperature rises to 950 °C, the steam flow rate is 0.2 mL / min, the constant temperature activation time is 45 min, the mass percentage of hydrochloric acid in the dilute hydrochloric acid aqueous solution is 0.2%, the dosage of the dilute hydrochloric acid aqueous solution is 50 mL, the dosage of ultrapure water is 100 mL, the drying temperature of PAC8 is 105 °C, the drying time of PAC8 is 24 h, and the particle size after grinding and sieving is 200 mesh.
[0085] Example 9: A method for preparing raw coal activated carbon.
[0086] The difference between this example and Example 8 is that the dosage of 2-amino-6-hydroxypyrimidine-4-carboxylic acid in the preparation process of raw coal activated carbon is 1 g. Except for this, other conditions are the same as those in Example 8. Raw coal activated carbon 9 (PAC9) is obtained.
[0087] Figure 3 SEM image of the raw coal activated carbon prepared in Example 9. It can be seen from the figure that the surface of the raw coal activated carbon has a rich pore structure, indicating that adding polyoxyethylene lauryl ether carboxylic acid, disodium oleamide MEA sulfosuccinate, and 2-amino-6-hydroxypyrimidine-4-carboxylic acid during the preparation process of raw coal activated carbon can enable the formation of a more complex spatial structure of the raw coal activated carbon, which has a beneficial effect on the surface morphology and properties of the raw coal activated carbon, and further improves the adsorption performance of the raw coal activated carbon for micro-pollutants.
[0088] Comparative Example 1: A method for preparing raw coal activated carbon.
[0089] The difference between this example and Example 2 is that polyoxyethylene lauryl ether carboxylic acid is used in the preparation process of raw coal activated carbon. The specific preparation process is as follows: Weigh the blended coal and polyoxyethylene lauryl ether carboxylic acid, then load them into a tube furnace. Use nitrogen as the protective gas. After the experiment starts, the tube furnace undergoes two heating-up processes. After the heating is completed, turn off the nitrogen and introduce steam for activation. A peristaltic pump measures the flow rate of the introduced steam, and keep the temperature constant for activation. Finally, stop heating, turn off the steam and reintroduce nitrogen, and wait for it to cool naturally to room temperature. Wash the obtained activated carbon with dilute hydrochloric acid aqueous solution and ultrapure water, and then dry it. Grind the dried activated carbon through a sieve with an appropriate mesh size to obtain raw coal activated carbon 10 (PAC10), and finally store it sealed. The dosage of the blended coal is 5 g, the dosage of polyoxyethylene lauryl ether carboxylic acid is 0.5 g, the flow rate of nitrogen as the protective gas is 2000 mL / min, the heating rate of the tube furnace is 10 °C / min. The two heating-up processes include: in the first stage, when the temperature rises to 600 °C, keep the temperature for 1 h; in the second stage, the temperature rises to 950 °C, the steam flow rate is 0.2 mL / min, the constant-temperature activation time is 45 min, the mass percentage of hydrochloric acid in the dilute hydrochloric acid aqueous solution is 0.2%, the dosage of the dilute hydrochloric acid aqueous solution is 50 mL, the dosage of ultrapure water is 100 mL, the drying temperature of PAC10 is 105 °C, the drying time of PAC10 is 24 h, and the particle size after grinding and sieving is 200 mesh.
[0090] Comparative Example 2: A preparation method of raw coal activated carbon.
[0091] The difference between this example and Example 2 is that sodium oleamide MEA sulfosuccinate is used in the preparation process of raw coal activated carbon. The specific preparation process is as follows: Weigh the blended coal and sodium oleamide MEA sulfosuccinate, then load them into a tube furnace. Use nitrogen as the protective gas. After the experiment starts, the tube furnace undergoes two heating-up processes. After the heating is completed, turn off the nitrogen and introduce steam for activation. A peristaltic pump measures the flow rate of the introduced steam, and keep the temperature constant for activation. Finally, stop heating, turn off the steam and reintroduce nitrogen, and wait for it to cool naturally to room temperature. Wash the obtained activated carbon with dilute hydrochloric acid aqueous solution and ultrapure water, and then dry it. Grind the dried activated carbon through a sieve with an appropriate mesh size to obtain raw coal activated carbon 11 (PAC11), and finally store it sealed. The dosage of the blended coal is 5 g, the dosage of sodium oleamide MEA sulfosuccinate is 0.5 g, the flow rate of nitrogen as the protective gas is 2000 mL / min, the heating rate of the tube furnace is 10 °C / min. The two heating-up processes include: in the first stage, when the temperature rises to 600 °C, keep the temperature for 1 h; in the second stage, the temperature rises to 950 °C, the steam flow rate is 0.2 mL / min, the constant-temperature activation time is 45 min, the mass percentage of hydrochloric acid in the dilute hydrochloric acid aqueous solution is 0.2%, the dosage of the dilute hydrochloric acid aqueous solution is 50 mL, the dosage of ultrapure water is 100 mL, the drying temperature of PAC11 is 105 °C, the drying time of PAC11 is 24 h, and the particle size after grinding and sieving is 200 mesh.
[0092] Example 10: A multi-stage activated carbon adsorption method with size matching of background pollutants and micropollutants.
[0093] The raw coal activated carbon includes: microporous carbon and hierarchical porous carbon. Among them, the microporous carbon is prepared in Example 2, and the hierarchical porous carbon is prepared in Example 5.
[0094] During the removal of micropollutants, 6 portions of micropollutant-water mixed solution are taken, and the total dosage of raw coal activated carbon for each portion of micropollutant-water mixed solution is added in the following 6 concentrations in sequence. The 6 concentrations are 2, 4, 8, 20, 40, and 80 mg / L for addition. The 6 adsorption results of micropollutants are used for calculation and fitting the adsorption isotherm.
[0095] The two-stage addition method has the following specific steps: (1) Add 7 kinds of micropollutants to the NOM raw water to configure a micropollutant-water mixed solution, where the initial concentration of each micropollutant is C0: 500 ng / L, and the initial concentration of NOM in the NOM raw water is C0: 3.2 mg / L. Among them, the 7 kinds of micropollutants are shown in Table 3, and the NOM in the NOM raw water includes five components: BP, HA, FA, BB, and LMW as shown in Table 2.
[0096] (2) Divide the total dosage of the raw coal activated carbon to be added into two equal parts, with weights of D A and D B .
[0097] (3) Accurately measure the micropollutant-water mixed solution and conduct the first addition of raw coal activated carbon. The raw coal activated carbon added is hierarchical porous carbon, and the dosage is D A .
[0098] (4) After the first addition of raw coal activated carbon for adsorption treatment, conduct the second addition of raw coal activated carbon. The raw coal activated carbon added is microporous carbon, and the dosage is D B .
[0099] (5) After the second addition of raw coal activated carbon for adsorption treatment, filter to remove the added raw coal activated carbon, collect the filtrate to obtain the second-stage adsorbed water; then measure the content of micropollutants in the second-stage adsorbed water as Ce.
[0100] (6) Calculate and determine the adsorption capacity of micropollutants on the raw coal activated carbon, which is: .
[0101] And according to the calculated and Draw the adsorption isotherm.
[0102] (7) Use the Freundlich model to fit the adsorption isotherm: .
[0103] Determine the K F and 1 / n values, and further calculate the dosage D of raw coal activated carbon required when the removal rate of the target micro-pollutant to be adsorbed reaches 80% according to the K F and 1 / n values. The calculation formula is: 80 . .
[0104] Example 11: A multi-stage adsorption method of activated carbon with matching sizes of background pollutants and micro-pollutants.
[0105] The two-stage addition method. The difference between this example and Example 10 is that the microporous carbon is prepared in Example 6. Except for this, other conditions are the same.
[0106] Example 12: A multi-stage adsorption method of activated carbon with matching sizes of background pollutants and micro-pollutants.
[0107] The two-stage addition method. The difference between this example and Example 10 is that the microporous carbon is prepared in Example 7. Except for this, other conditions are the same.
[0108] Example 13: A multi-stage adsorption method of activated carbon with matching sizes of background pollutants and micro-pollutants.
[0109] The two-stage addition method. The difference between this example and Example 10 is that the microporous carbon is prepared in Example 8. Except for this, other conditions are the same.
[0110] Example 14: A multi-stage adsorption method of activated carbon with matching sizes of background pollutants and micro-pollutants.
[0111] The two-stage addition method. The difference between this example and Example 10 is that the microporous carbon is prepared in Example 9. Except for this, other conditions are the same.
[0112] Comparative Example 3: A multi-stage adsorption method of activated carbon with matching sizes of background pollutants and micro-pollutants.
[0113] The two-stage addition method. The difference between this example and Example 10 is that the microporous carbon is prepared in Comparative Example 1. Except for this, other conditions are the same.
[0114] Comparative Example 4: A multi-stage adsorption method of activated carbon with matching sizes of background pollutants and micropollutants.
[0115] The two-time dosing method. The difference between this example and Example 10 is that the microporous carbon is prepared in Comparative Example 2. Except for this, other conditions are the same.
[0116] Comparative Example 5: A multi-stage adsorption method of activated carbon with matching sizes of background pollutants and micropollutants.
[0117] The raw coal activated carbon includes: microporous carbon and hierarchical porous carbon. Among them, the microporous carbon is prepared in Example 2, and the hierarchical porous carbon is prepared in Example 5.
[0118] During the removal of micropollutants, 6 portions of micropollutant-water mixed solutions are taken. The total dosage of raw coal activated carbon for each portion of the micropollutant-water mixed solution is sequentially added at the following 6 concentrations: 2, 4, 8, 20, 40, 80 mg / L. The 6 adsorption results for micropollutants are used for calculation , and fitting the adsorption isotherm.
[0119] Single-dose addition method: The difference between this example and Example 10 is that the dosing method of the raw coal activated carbon is to add the total dosage D of the raw coal activated carbon in the multi-dose addition method A +D B in one go into the micropollutant-water mixed solution. Except for this, other conditions are the same. Specifically: (1) The same as described in (1) of Example 10. Add 7 kinds of micropollutants to the NOM raw water to prepare a micropollutant-water mixed solution, where the initial concentration of each micropollutant is C0: 500 ng / L, and the initial concentration of NOM in the NOM raw water is C0: 3.2 mg / L. Among them, the 7 kinds of micropollutants are shown in Table 3, and the NOM in the NOM raw water includes five components: BP, HA, FA, BB, and LMW as shown in Table 2.
[0120] (2) The difference from (2) in Example 10 is that the total dosage of the raw coal activated carbon to be added is added to the micropollutant-water mixed solution at one time, where the total dosage of the raw coal activated carbon is D A +D B .
[0121] (3) The difference from (5) in Example 10 is that after the raw coal activated carbon adsorption treatment, filter to remove the added raw coal activated carbon, collect the filtrate, and at this time, the adsorbed water is obtained; then measure the content of micropollutants in the adsorbed water as Ce.
[0122] (4) The same as described in (6) of Example 10. Calculate and determine the adsorption capacity of the micropollutants on the raw coal activated carbon, which is: 。
[0123] And draw the adsorption isotherm according to the calculated and 。
[0124] (5) The same as described in (7) of Example 10. Use the Freundlich model to fit the adsorption isotherm: 。
[0125] Determine the K F and 1 / n values therein. According to the K F and 1 / n values, further calculate the dosage D of raw coal activated carbon required when the removal rate of the target micro-pollutant to be adsorbed is 80% 80 , and the calculation formula is: 。
[0126] Comparative Example 6: An activated carbon multi-stage adsorption method with the same size of background pollutants and micro-pollutants.
[0127] Two-stage addition method. The difference between this example and Example 10 is that only multi-stage pore carbon is used for the raw coal activated carbon, and the multi-stage pore carbon is prepared in Example 5. Except for this, other conditions are the same.
[0128] Comparative Example 7: An activated carbon multi-stage adsorption method with the same size of background pollutants and micro-pollutants.
[0129] Two-stage addition method. The difference between this example and Example 10 is that only microporous carbon is used for the raw coal activated carbon, and the microporous carbon is prepared in Example 2. Except for this, other conditions are the same.
[0130] Comparative Example 8: An activated carbon multi-stage adsorption method with the same size of background pollutants and micro-pollutants.
[0131] Two-stage addition method. The difference between this example and Example 10 is that the addition order of the raw coal activated carbon is to add microporous carbon for the first time and multi-stage pore carbon for the second time.
[0132] Comparative Example 9: An activated carbon multi-stage adsorption method with the same size of background pollutants and micro-pollutants.
[0133] Single-stage addition method: The difference between this example and Comparative Example 5 is that only multi-stage pore carbon is used for the raw coal activated carbon, and the multi-stage pore carbon is prepared in Example 5. Except for this, other conditions are the same.
[0134] Comparative Example 10: A multi-stage adsorption method of activated carbon with matching sizes of background pollutants and micropollutants.
[0135] Single dosing method: The difference between this example and Comparative Example 5 is that only microporous carbon is used for the raw coal activated carbon, and the microporous carbon is prepared in Example 2. Except for this, other conditions are the same.
[0136] The micropollutants removed in the above examples and comparative examples are shown in Table 3.
[0137] Table 3 Micropollutants, abbreviations and their molecular weights involved in the experiment
[0138] The total dosage of raw coal activated carbon in different carbon dosing methods for removing micropollutants in Example 10, Comparative Example 5, Comparative Example 6, Comparative Example 7, Comparative Example 9 and Comparative Example 10 is as Figure 4 shown, where the microporous carbon is PAC2, the multi-stage porous carbon is PAC5, and the initial concentration of the micropollutants is 500 ng / L.
[0139] From Figure 4 it can be seen that when removing micropollutants, the total dosage of raw coal activated carbon in the two-stage carbon dosing method is significantly lower than that in the single-stage carbon dosing method, and the carbon saving ratio is relatively high when the microporous carbon and the multi-stage porous carbon are combined; when the microporous carbon and the multi-stage porous carbon are combined to remove EDD, the total dosage of raw coal activated carbon in the two-stage carbon dosing method is 45.9% less than that in the single-stage carbon dosing method; when the microporous carbon and the multi-stage porous carbon are combined to remove MIB, the total dosage of raw coal activated carbon in the two-stage carbon dosing method is 38.7% less than that in the single-stage carbon dosing method; when the microporous carbon and the multi-stage porous carbon are combined to remove IPDD, the total dosage of raw coal activated carbon in the two-stage carbon dosing method is 34.7% less than that in the single-stage carbon dosing method; when the microporous carbon and the multi-stage porous carbon are combined to remove IMD, the total dosage of raw coal activated carbon in the two-stage carbon dosing method is 34.0% less than that in the single-stage carbon dosing method; when the microporous carbon and the multi-stage porous carbon are combined to remove GSM, the total dosage of raw coal activated carbon in the two-stage carbon dosing method is 33.3% less than that in the single-stage carbon dosing method; when the microporous carbon and the multi-stage porous carbon are combined to remove BDD, the total dosage of raw coal activated carbon in the two-stage carbon dosing method is 28.2% less than that in the single-stage carbon dosing method; when the microporous carbon and the multi-stage porous carbon are combined to remove BMD, the total dosage of raw coal activated carbon in the two-stage carbon dosing method is 32.2% less than that in the single-stage carbon dosing method. In summary, when the combination of raw coal activated carbon is microporous carbon and multi-stage porous carbon, the carbon saving ratio of the two-stage carbon dosing method is relatively high compared to the single-stage carbon dosing method when removing EDD and MIB.
[0140] Through the above analysis, it is found that when the combination of raw coal activated carbon is microporous carbon and multi-stage porous carbon, the carbon saving ratio of the two-stage carbon dosing method is relatively high compared to the single-stage carbon dosing method when removing EDD and MIB. Here, taking EDD and MIB as representatives, the total dosage of raw coal activated carbon in different carbon dosing methods for removing micropollutants is summarized, and the results are shown in Tables 4-5: Table 4 Total dosage of raw coal activated carbon in removing EDD by different carbon addition methods
[0141] As can be seen from Table 4, comparing the five groups of results of Examples 10 to 14, the order of the total dosage of raw coal activated carbon in removing EDD from high to low is Example 10 > Example 11 > Example 12 > Example 13 > Example 14, indicating that when polyoxyethylene lauryl ether carboxylic acid and disodium N-(2-hydroxyethyl)-N-methyl-N-sulfooxysuccinamate are added during the preparation of raw coal activated carbon, the prepared raw coal activated carbon is more conducive to the removal of EDD. At the same time, the higher the dosage of polyoxyethylene lauryl ether carboxylic acid and disodium N-(2-hydroxyethyl)-N-methyl-N-sulfooxysuccinamate, the more conducive it is to the removal of EDD; in addition, the raw coal activated carbon modified with 2-amino-6-hydroxypyrimidine-4-carboxylic acid is more conducive to the removal of EDD, and the higher the dosage of 2-amino-6-hydroxypyrimidine-4-carboxylic acid, the more conducive it is to the removal of EDD; comparing the three groups of results of Example 10 and Comparative Examples 3 to 4, there is no obvious reduction in the total dosage of raw coal activated carbon in Comparative Examples 3 to 4 compared with Example 10 when removing EDD, indicating that adding polyoxyethylene lauryl ether carboxylic acid or disodium N-(2-hydroxyethyl)-N-methyl-N-sulfooxysuccinamate alone during the preparation of raw coal activated carbon is not conducive to the removal of EDD; comparing the four groups of results of Example 10 and Comparative Examples 5 to 7, the total dosage of raw coal activated carbon in Example 10 when removing EDD is lower, indicating that in the removal of EDD, the total dosage of raw coal activated carbon by the two-time carbon addition method is significantly lower than that by the single-time carbon addition method, and the total dosage of raw coal activated carbon is lower when the microporous carbon and the hierarchical porous carbon are combined in the two-time carbon addition method, indicating that the two-time carbon addition method with the combination of microporous carbon and hierarchical porous carbon is more conducive to the removal of EDD. Comparing the two groups of results of Example 10 and Comparative Example 8, the total dosage of raw coal activated carbon in Example 10 when removing EDD is lower, indicating that the carbon addition order of raw coal activated carbon is more conducive to the removal of EDD when the hierarchical porous carbon is added for the first time and the microporous carbon is added for the second time.
[0142] Table 5 Total dosage of raw coal activated carbon in removing MIB by different carbon addition methods
[0143] As can be seen from Table 5, in the comparison of the results of five groups of Examples 10 to 14, the order of the total dosage of raw coal activated carbon for removing MIB from high to low is Example 10 > Example 11 > Example 12 > Example 13 > Example 14, indicating that when polyoxyethylene lauryl ether carboxylic acid and disodium N-(2-(methylamino)ethyl)-N-(2-sulfoethyl)-N-methylsulfosuccinamate are added during the preparation of raw coal activated carbon, the prepared raw coal activated carbon is more conducive to the removal of MIB. At the same time, the higher the dosage of polyoxyethylene lauryl ether carboxylic acid and disodium N-(2-(methylamino)ethyl)-N-(2-sulfoethyl)-N-methylsulfosuccinamate, the more conducive it is to the removal of MIB; in addition, the raw coal activated carbon modified with 2-amino-6-hydroxypyrimidine-4-carboxylic acid is more conducive to the removal of MIB, and at the same time, the higher the dosage of 2-amino-6-hydroxypyrimidine-4-carboxylic acid, the more conducive it is to the removal of MIB; in the comparison of the results of three groups of Example 10 and Comparative Examples 3 to 4, there is no obvious decrease in the total dosage of raw coal activated carbon for removing MIB in Comparative Examples 3 to 4 compared with Example 10, indicating that adding polyoxyethylene lauryl ether carboxylic acid or disodium N-(2-(methylamino)ethyl)-N-(2-sulfoethyl)-N-methylsulfosuccinamate alone during the preparation of raw coal activated carbon is not conducive to the removal of MIB; in the comparison of the results of four groups of Example 10 and Comparative Examples 5 to 7, the total dosage of raw coal activated carbon for removing MIB in Example 10 is lower, indicating that in the removal of MIB, the total dosage of raw coal activated carbon by the two-stage dosing method is significantly lower than that by the single-stage dosing method, and the total dosage of raw coal activated carbon is lower when microporous carbon and hierarchical porous carbon are combined in the two-stage dosing method, indicating that the two-stage dosing method with the combination of microporous carbon and hierarchical porous carbon is more conducive to the removal of MIB. In the comparison of the results of two groups of Example 10 and Comparative Example 8, the total dosage of raw coal activated carbon for removing MIB in Example 10 is lower, indicating that the dosing order of raw coal activated carbon is more conducive to the removal of MIB when hierarchical porous carbon is added for the first time and microporous carbon is added for the second time.
[0144] The above-described embodiments and / or implementation manners are only used to illustrate the preferred embodiments and / or implementation manners for implementing the technology of the present invention, and do not impose any formal restrictions on the implementation manners of the technology of the present invention. Any person skilled in the art, without departing from the scope of the technical means disclosed in the content of the present invention, may make some changes or modifications to other equivalent embodiments, but should still be regarded as the same technology or embodiment as the present invention in essence.
[0145] In this article, specific examples are used to elaborate on the principles and implementation manners of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application. The above is only the preferred implementation manner of the present application. It should be noted that due to the limited nature of literal expression and the objectively infinite specific structures, for those of ordinary skill in the art, without departing from the principles of the present application, several improvements, refinements or changes can be made, or the above technical features can be combined in an appropriate manner; these improvements, refinements, changes or combinations, or directly applying the inventive concept and technical solution to other occasions without improvement, shall all be regarded as the protection scope of the present application.
Claims
1. A method for preparing raw coal activated carbon, comprising: The blended coal and the modifier are mixed and heat treated, and then steam activated, washed and dried to obtain raw coal activated carbon; In the steam activation treatment, the temperature of the steam activation treatment is 900-1000° C., and the activation time of the steam activation treatment is 20-100 min; The modifier includes at least one of polyoxyethylene lauryl ether carboxylic acid and disodium oleamide MEA sulfosuccinate.
2. The method for preparing raw coal activated carbon according to claim 1, characterized in that: The raw coal activated carbon is at least one of microporous carbon and multi-porous carbon.
3. The method for preparing raw coal activated carbon according to claim 1, characterized in that: The amount of the blended coal is 2-8 parts by weight, and the amount of the modifier is 0.2-3.6 parts by weight.
4. The method for preparing raw coal activated carbon according to claim 1, characterized in that: The heat treatment includes two stages of temperature rise treatment. In the first stage of temperature rise, the temperature is raised from room temperature to 400-800°C and maintained for 0.5-1.5h; in the second stage of temperature rise, the temperature is raised from the maintained temperature of the first stage of temperature rise to 900-1000°C.
5. An activated carbon multi-stage adsorption method for matching the size of background pollutants and micropollutants, comprising: Take two or more groups of raw coal activated carbon prepared by any one of the preparation methods of claims 1 to 4 to perform adsorption treatment on the water sample to be treated containing micropollutants, divide each group of raw coal activated carbon into N parts and add them to the water sample to be treated for adsorption, and record the micropollutant content C of the Nth part after adsorption treatment e , according to C e Calculation of the adsorption capacity q of micropollutants e ; N is an integer greater than or equal to 2; According to C e and q e The Freundlich model was used to fit the adsorption isotherm: ; According to K F and 1 / n value to calculate the total amount of raw coal activated carbon required to remove micropollutants D R , D R The calculation formula is: , R represents the target removal rate of micropollutants.
6. The method of multi-stage activated carbon adsorption for matching the size of background pollutants and micro-pollutants according to claim 5, characterized in that: The N is 2, the raw coal activated carbon is microporous carbon and multi-level porous carbon, and the microporous carbon and the multi-level porous carbon are used in a mass ratio of 1:
1.
7. The method of multi-stage activated carbon adsorption for matching the size of background pollutants and micropollutants according to claim 6, characterized in that: The first batch of raw coal activated carbon is multi-porous carbon, and the second batch of raw coal activated carbon is microporous carbon.
8. The method of multi-stage activated carbon adsorption for matching the size of background pollutants and micro-pollutants according to claim 5, characterized in that: The R is 20~80%.
9. The method of multi-stage activated carbon adsorption for matching the sizes of background pollutants and micropollutants according to claim 5, characterized in that: The micropollutant is at least one of EDD, IMD, BDD, IPDD, BMD, MIB and GSM.
10. The method of multi-stage activated carbon adsorption for matching the size of background pollutants and micro-pollutants according to claim 5, characterized in that: The water sample to be treated also contains natural organic matter.