Operation method of active coke adsorption tank for advanced sewage treatment

Abstract

The invention belongs to the technical field of sewage treatment, and discloses an operation method of an active coke adsorption tank for advanced sewage treatment, which comprises the following steps: obtaining COD (Chemical Oxygen Demand) removal rates of the active coke adsorption tank corresponding to different operation times; dividing operation priorities of the active coke adsorption tanks, and recording the number of the active coke adsorption tanks corresponding to each operation priority; constructing an actual COD removal rate calculation formula of the active coke adsorption tank; the method comprises the following steps: monitoring an inflow COD value of to-be-treated water of a current active coke process system, setting an effluent COD value according to effluent quality requirements, and calculating a preset total removal rate of COD; and calculating the number of the active coke adsorption tanks to be put into operation in each put into operation priority according to an actual removal rate calculation formula of the COD of the active coke adsorption tanks to obtain a dynamic put into operation strategy of the current active coke process system. According to the invention, a dynamic gradient commissioning operation mode is adopted, so that the adsorption capacity of all active coke in the system is consumed in a balanced manner, and the operation cost is reduced.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology and relates to an operation method of an activated coke adsorption tank for advanced wastewater treatment. Background Technology

[0002] After primary and secondary treatment, the raw water from urban wastewater treatment plants is required to meet the Class B or Class A standards of the "Discharge Standard of Pollutants for Urban Wastewater Treatment Plants" (GB 18918-2002). However, as the requirements for discharge standards of raw water treatment plants in some regions and industries have gradually increased, some indicators of the raw water after primary and secondary treatment still fail to meet the discharge standards, thus requiring advanced treatment.

[0003] Activated coke is a carbon-based adsorbent material mainly prepared from coke through high-temperature activation. It possesses adsorption properties similar to activated carbon, with a well-developed pore structure and abundant surface functional groups, making it increasingly widely used in advanced wastewater treatment. When activated coke is used for adsorption, the effluent quality is good, with some indicators meeting the Class III water standard of the "Surface Water Environmental Quality Standard" (GB3838-2002). Furthermore, it can be recycled through regeneration.

[0004] However, the operation of activated coke process systems is relatively crude, with two common methods. The first is to fix the number of activated coke adsorption tanks in operation. For example, if there are 10 rows of activated coke adsorption tanks in total, 8 rows are operated normally. When the COD of the influent and effluent are basically the same, it is considered that the adsorption capacity of the activated coke has reached saturation and needs to be replaced. This operating mode leads to: 1) Inability to adjust according to the actual influent pollution load, operating all tanks during low-load periods, resulting in wasted energy and premature saturation and failure of the activated coke, making the coke tank operation uneconomical; 2) The fixed operation mode makes it difficult to cope with fluctuations in influent water quality. When COD suddenly increases, insufficient treatment capacity may lead to effluent exceeding standards, resulting in poor resistance to shock loads; 3) Inability to adjust according to operating time may cause some activated coke adsorption tanks to operate under overload for a long time and reach saturation prematurely, while some activated coke adsorption tanks remain unsaturated and require replacement. The second method is to adjust the number of adsorption tanks in operation according to the influent flow rate. For example, the number of operating tanks is adjusted in real time according to the influent flow rate, which involves more frequent operations. This model only considers water volume and fails to make intelligent decisions based on multi-dimensional information such as water quality and activated carbon operating status. Therefore, neither of these two activated carbon adsorption tank operation modes can maximize the utilization of activated carbon adsorption performance, increases the frequency of activated carbon replacement, and results in waste of activated carbon operating power, materials, and manpower, thereby increasing the operating costs of the activated carbon process. Summary of the Invention

[0005] This invention addresses the technical problem of increased operating costs caused by unreasonable operation modes of activated carbon adsorption tanks. It provides an operation method for activated carbon adsorption tanks used in deep wastewater treatment, which adopts a dynamic gradient operation mode. This allows the number of activated carbon adsorption tanks in operation to be dynamically adjusted according to complex water conditions, ensuring that the adsorption capacity of all activated carbon in the system is consumed evenly, extending the carbon replacement cycle, improving the overall service life of the activated carbon tanks, reducing the frequency of purchasing new carbon, and lowering operating costs.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides an operation method for an activated carbon adsorption tank for advanced wastewater treatment, comprising the following steps: 1) Regularly record the operating time of each activated coke adsorption tank in the activated coke process system of a wastewater treatment plant, and take samples to test the COD values ​​of the influent and effluent to obtain the COD removal rate of the activated coke adsorption tank corresponding to different operating times. 2) According to the activated coke replacement cycle and the COD removal rate of the activated coke adsorption tank, divide the operation priority of the activated coke adsorption tank and record the number of activated coke adsorption tanks corresponding to each operation priority. 3) Based on the amount of water to be treated in the activated coke process system, the commissioning priority of the activated coke adsorption tank, the average COD removal rate of the activated coke adsorption tank corresponding to each commissioning priority, and the recorded value of the number of activated coke adsorption tanks corresponding to each commissioning priority, construct a formula for calculating the actual COD removal rate of the activated coke adsorption tank. 4) Monitor the influent COD value of the activated coke process system and set the effluent COD value according to the effluent quality requirements, and calculate the preset total COD removal rate. 5) Based on the calculation formula for the actual COD removal rate of the activated coke adsorption tank, calculate the number of activated coke adsorption tanks to be put into operation in each operation priority, and obtain the dynamic operation strategy of the current activated coke process system.

[0007] To achieve precise control of the activated coke adsorption tank, this invention can prioritize the operation of the activated coke adsorption tank by quarter, month, or half-month.

[0008] In one technical solution, if the activated coke replacement cycle is n Months, divided into units of months n If there is a priority for commissioning, then the longer the operating time and the lower the COD removal rate of the activated carbon adsorption tank, the higher the commissioning priority of the activated carbon adsorption tank.

[0009] In one technical solution, the formula for calculating the actual COD removal rate of the activated carbon adsorption tank is expressed as follows: , , , , in, This represents the actual total COD removal rate. This represents the preset total COD removal rate. , COD 进 The COD value of the influent to the activated coke process system. COD 出 Set the effluent COD value for the activated coke process system; They are respectively number 1 to number 2. n Average COD removal rate corresponding to each commissioning priority; They are respectively number 1 to number 2. n Recorded values ​​for the number of activated coke adsorption tanks corresponding to each commissioning priority; They are respectively number 1 to number 2. n The number of activated coke adsorption tanks to be put into operation in each commissioning priority; m This represents the total number of activated carbon adsorption cells in a wastewater treatment plant. Q The volume of water to be treated in the activated coke process system; q This refers to the water treatment capacity of a single-cell activated carbon adsorption cell.

[0010] In one technical solution, if the activated coke replacement cycle is 15 months, and four commissioning priorities are divided into four 4-month units, then the activated coke adsorption tank with an operating time of more than 12 months is the first commissioning priority; the activated coke adsorption tank with an operating time of 9-11 months is the second commissioning priority; the activated coke adsorption tank with an operating time of 5-8 months is the third commissioning priority; and the activated coke adsorption tank with an operating time of 1-4 months is the fourth commissioning priority.

[0011] In the above technical solution, the formula for calculating the actual COD removal rate of the activated carbon adsorption tank is as follows: , , , , in, This represents the actual total COD removal rate. This represents the preset total COD removal rate. , COD 进 The COD value of the influent to the activated coke process system. COD 出 Set the COD value of the effluent for the activated coke process system; These represent the number of activated coke adsorption tanks to be put into operation in the first to fourth priority levels, respectively. These are the recorded values ​​for the number of activated coke adsorption tanks corresponding to the 1st to 4th commissioning priorities, respectively. These represent the number of activated coke adsorption tanks to be put into operation in the first to fourth priority levels, respectively. m This represents the total number of activated carbon adsorption cells in a wastewater treatment plant. Q The volume of water to be treated in the activated coke process system; q This refers to the water treatment capacity of a single activated carbon adsorption cell. It is worth noting that... , All are integers.

[0012] When designing the formula for calculating the actual COD removal rate of the activated coke adsorption tank, a safety margin needs to be designed to ensure that the effluent quality of the activated coke process system meets the standards. That is, the actual COD removal rate should be slightly higher than the preset COD removal rate. Generally, the actual COD removal rate should be 2 percentage points higher than the preset COD removal rate. This ensures that the effluent meets the standards while avoiding waste caused by over-operation.

[0013] In addition, the amount of water to be treated in the activated coke process system Q And the processing capacity of a single-cell activated carbon adsorption cell. q These are also factors to consider for the precise operation of activated carbon adsorption tanks. Q / q This represents the minimum number of activated coke adsorption tanks to be put into operation each time. If the maximum number of activated coke adsorption tanks corresponding to the previous operation priority is greater than [the maximum number of activated coke adsorption tanks to be put into operation], then [the maximum number of activated coke adsorption tanks to be put into operation each time is greater than ... Q / q If the activated carbon adsorption tanks of that priority need to be partially put into operation, then the number of activated carbon adsorption tanks to be put into operation for that priority can be calculated. If the maximum number of activated carbon adsorption tanks corresponding to the previous priority is less than [the previous priority], then [the next priority] will be determined by the calculation of the number of activated carbon adsorption tanks to be put into operation for that priority. Q / q If the activated carbon adsorption tanks of that priority are all put into operation, then the number of activated carbon adsorption tanks of the next priority should be calculated as a supplement, and the activation should be carried out dynamically in a gradient according to the priority.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: The dynamic gradient operation mode of this invention, on the one hand, fully considers the safety margin, ensuring that the effluent meets the standards while avoiding waste caused by excessive operation; on the other hand, it also fully considers the amount of water to be treated and the COD of the influent and effluent, so that the number of activated coke adsorption tanks in operation can be dynamically adjusted for complex water conditions, realizing the leap from "extensive control" to "refined intelligent control" of the activated coke process.

[0015] This invention prioritizes the operation of activated coke adsorption tanks (old coke tanks) with longer operating times and degraded adsorption performance, while ensuring the removal rate of activated coke adsorption tanks (new coke tanks) with shorter operating times, under the premise of ensuring that the COD of the effluent meets the standards. This allows the adsorption capacity of all activated coke in the system to be consumed evenly, extends the coke replacement cycle, improves the overall service life of the activated coke tanks, reduces the frequency of purchasing new coke, and lowers operating costs.

[0016] Compared to the operation mode of designing the number of activated coke tanks under a fixed normal water volume (such as 320 tanks) or putting a large number of new activated coke tanks into operation, the dynamic gradient operation mode of this invention can effectively reduce the power consumption per unit. At the same time, it can dynamically adjust the number of activated coke adsorption tanks with different priorities according to the water volume to be treated and the fluctuation of the influent water quality, which greatly improves the operating space of the activated coke process system. This not only improves the ability to resist shock loads, but also improves the stability of effluent water quality and reduces the risk of COD exceeding the standard in the effluent. Detailed Implementation

[0017] The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of protection of the present invention. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art. Unless otherwise specified, the test methods in the following embodiments are conventional methods.

[0018] Example 1 This embodiment takes the activated carbon process system of a sewage treatment plant in Zhengzhou as an example, and the total number of activated carbon adsorption tanks is as follows: m =400 grids, then the designed number of activated coke adsorption tanks under normal water volume is 400 * 0.8 = 320 grids. That is, the sum of the recorded values ​​of the number of activated coke adsorption tanks corresponding to all operational priorities is 320. =320.

[0019] The water treatment capacity of the single-cell activated carbon adsorption tank in this factory q =200 m³ / h, activated carbon replacement cycle is 15 months, daily monitoring and recording of COD values ​​in the activated carbon influent and effluent, and COD removal rate of activated carbon. Statistical analysis revealed the relationship between different operating times and COD removal rates. Specifically, the average COD removal rate of the activated carbon adsorption tanks in this plant, operating for more than 12 months, remained around 15%. =15%, which is the first priority for commissioning; the average COD removal rate of activated coke adsorption tanks with an operating time of 9-11 months remains at around 20%, that is... =20%, which is the second priority for commissioning; the average COD removal rate of activated coke adsorption tanks with an operating time of 5-8 months remains at around 30%, that is... =30%, which is the third priority for commissioning; the average COD removal rate of activated coke adsorption tanks with an operating time of 1-4 months remains at around 40%, that is... =30%, which is the fourth priority for commissioning.

[0020] The recorded number of activated coke adsorption tanks that have been in operation for more than 12 months is [value missing]. =121 cells, the recorded number of activated coke adsorption cells with an operating time of 9-11 months is [value missing]. =78 cells, the recorded number of activated coke adsorption cells with an operating time of 5-8 months is [value missing]. =63 cells, the recorded number of activated carbon adsorption cells with an operating time of 1-4 months is [value missing]. =58 grids.

[0021] The volume of water to be treated in the activated coke process Q= 50000 m³ / h, influent COD value COD 进 =18 mg / L, set the effluent COD value COD 出 =16 mg / L, then =11.11%, =11%*(1+2%)=11.33%.

[0022] because Q / q= 250> Therefore, all 121 activated carbon adsorption cells with the highest commissioning priority must be put into operation; because < Q / q= 250 < Therefore, all 78 activated coke adsorption cells of the second priority should also be put into operation. The remaining number of activated coke adsorption cells will be supplemented by activated coke adsorption cells of the third priority. The number of activated coke adsorption cells of the third priority is calculated to be 8.39, which is rounded up to 9.

[0023] The embodiments described above are merely preferred embodiments of the present invention and are only used to explain the present invention. They are not intended to limit the scope of the present invention. For those skilled in the art, other implementation methods can be easily made by substitution or modification based on the technical content disclosed in this specification. Therefore, all changes and improvements made on the principle of the present invention should be included within the scope of the patent application of the present invention.

Claims

1. An operating method for an activated carbon adsorption tank for advanced wastewater treatment, characterized in that, Includes the following steps: 1) Regularly record the operating time of each activated coke adsorption tank in the activated coke process system of a wastewater treatment plant, and take samples to test the COD values ​​of the influent and effluent to obtain the COD removal rate of the activated coke adsorption tank corresponding to different operating times. 2) According to the activated coke replacement cycle and the COD removal rate of the activated coke adsorption tank, divide the operation priority of the activated coke adsorption tank and record the number of activated coke adsorption tanks corresponding to each operation priority. 3) Based on the amount of water to be treated in the activated coke process system, the commissioning priority of the activated coke adsorption tank, the average COD removal rate of the activated coke adsorption tank corresponding to each commissioning priority, and the recorded value of the number of activated coke adsorption tanks corresponding to each commissioning priority, construct a formula for calculating the actual COD removal rate of the activated coke adsorption tank. 4) Monitor the influent COD value of the activated coke process system and set the effluent COD value according to the effluent quality requirements, and calculate the preset total COD removal rate. 5) Based on the calculation formula for the actual COD removal rate of the activated coke adsorption tank, calculate the number of activated coke adsorption tanks to be put into operation in each operation priority, and obtain the dynamic operation strategy of the current activated coke process system.

2. The operating method according to claim 1, characterized in that, If the active coke replacement cycle is n Months, divided into units of months n If there is a priority for commissioning, then the longer the operating time and the lower the COD removal rate of the activated carbon adsorption tank, the higher the commissioning priority of the activated carbon adsorption tank.

3. The operating method according to claim 1 or 2, characterized in that, The formula for calculating the actual COD removal rate of the activated carbon adsorption tank is as follows: ， ， ， ， in, This represents the actual total COD removal rate. This represents the preset total COD removal rate. , COD 进 The COD value of the influent to the activated coke process system. COD 出 Set the COD value of the effluent for the activated coke process system; They are respectively number 1 to number 2. n Average COD removal rate corresponding to each commissioning priority; They are respectively number 1 to number 2. n Recorded values ​​for the number of activated coke adsorption tanks corresponding to each commissioning priority; They are respectively number 1 to number 2. n The number of activated coke adsorption tanks to be put into operation in each commissioning priority; m This represents the total number of activated carbon adsorption cells in a wastewater treatment plant. Q The volume of water to be treated in the activated coke process system; q This refers to the water treatment capacity of a single-cell activated carbon adsorption cell.

4. The operating method according to claim 1, characterized in that, If the activated coke replacement cycle is 15 months, and four commissioning priorities are divided into four 4-month units, then activated coke adsorption tanks with an operating time of more than 12 months are the first commissioning priority; activated coke adsorption tanks with an operating time of 9-11 months are the second commissioning priority; activated coke adsorption tanks with an operating time of 5-8 months are the third commissioning priority; and activated coke adsorption tanks with an operating time of 1-4 months are the fourth commissioning priority.

5. The operating method according to claim 4, characterized in that, The formula for calculating the actual COD removal rate of the activated carbon adsorption tank is as follows: ， ， ， ， in, This represents the actual total COD removal rate. This represents the preset total COD removal rate. , COD 进 The COD value of the influent to the activated coke process system. COD 出 Set the COD value of the effluent for the activated coke process system; These represent the number of activated coke adsorption tanks to be put into operation in the first to fourth priority levels, respectively. These are the recorded values ​​for the number of activated coke adsorption tanks corresponding to the 1st to 4th commissioning priorities, respectively. These represent the number of activated coke adsorption tanks to be put into operation in the first to fourth priority levels, respectively. m This represents the total number of activated carbon adsorption cells in a wastewater treatment plant. Q The volume of water to be treated in the activated coke process system; q This refers to the water treatment capacity of a single-cell activated carbon adsorption cell.

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