Method for reducing 2-methylisoborneol in the production of drinking water by means of a carbon sand filter

Abstract

The present application relates to a method for reducing 2-methylisoborneol in the production of drinking water by using a carbon sand filter, wherein quartz sand and activated carbon are filled into the filter according to a height ratio of 0.25-1.0 m:0.75-1.2 m, the particle size of the quartz sand is 0.5-2.5 mm, and the particle size of the activated carbon is 1.2-2.5 mm or 8-30 broken carbon. The present application has a significant effect on the treatment of 2-methylisoborneol in raw water, can reduce the content of 2-methylisoborneol in finished water, and is easy to modify without the need for special equipment.

Description

[0001] This invention is a divisional application based on the application filed on August 9, 2024, with application number 202411091914.3, entitled "Method for reducing 2-methylisoborneol in the production of drinking water using a carbon sand filter". Technical Field

[0002] This invention relates to the field of drinking water production technology, specifically to a method for reducing 2-methylisoborneol in the process of drinking water production using a carbon sand filter. Background Technology

[0003] Currently, the conventional drinking water production process using surface water as a source mainly includes four stages: coagulation, sedimentation, filtration, and disinfection. Water treated through these four stages generally meets the "National Drinking Water Quality Standard" (GB5749-2022). However, this new standard adds a 2-methylisoborneol (2-methylisoborneol) indicator, which is not present in the "Surface Water Environmental Quality Standard" (GB3838-2002). If the raw water quality is poor and the 2-methylisoborneol concentration exceeds a certain level, conventional processes cannot effectively remove it, resulting in substandard treated water. This situation is particularly serious when reservoirs that were previously used for fish farming are used as drinking water sources. Adding powdered activated carbon can reduce the 2-methylisoborneol concentration in treated water to some extent, but the dosage is large, and the effect is not always good due to site limitations. Furthermore, powdered activated carbon is for single use, resulting in high costs. Advanced ozone-activated carbon treatment processes require even greater investment. Summary of the Invention

[0004] The technical problem to be solved by this invention is that the concentration of 2-methylisoborneol in raw water is high, and the water quality after treatment is not easy to meet national standards. The purpose of this invention is to provide a method for reducing 2-methylisoborneol in drinking water production using a carbon sand filter. This method has a significant effect on reducing 2-methylisoborneol in raw water, can improve water quality, is easy to modify, and does not require special equipment.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A method for reducing 2-methylisoborneol in the production of drinking water using a carbon sand filter, wherein the carbon sand filter is filled with activated carbon and quartz sand from top to bottom, and the height ratio of quartz sand to activated carbon is 0.25-1.0m:0.75-1.2m; The activated carbon has an iodine adsorption value of over 1000 mg / g, a strength of over 95%, and a packing density of over 480 g / L. The activated carbon is coal-based, wood-based, coconut shell carbon, or fruit shell carbon. The carbon sand filter can treat raw water with a 2-methylisoborneol concentration of less than 80 ng / L.

[0006] Preferably, the quartz sand has a particle size of 0.5-2.5 mm.

[0007] Preferably, the quartz sand is sea sand or river sand.

[0008] Preferably, the activated carbon has a particle size of 1.2-2.5 mm or 8-30 mesh crushed carbon.

[0009] Preferably, the carbon sand filter can handle raw water with a flow rate of less than 1.3 m / min.

[0010] Preferably, the carbon sand filter requires backwashing after 48 hours of use, with an air flushing intensity of 14 L / (m²). 2 The water flushing intensity at room temperature should be 10 L / (m²) for 5 minutes (s). 2 ·s), lasting 10 minutes.

[0011] Preferably, the carbon sand filter has water entering from the top and exiting from the bottom.

[0012] This invention modifies the filter bed by filling it with a ratio of quartz sand and activated carbon at a height of 0.25-1.0m:0.75-1.2m. The quartz sand particle size is 0.5-2.5mm, and the activated carbon particle size is 1.2-2.5mm or 8-30 mesh crushed carbon. The activated carbon has an iodine adsorption value of over 1000mg / g, a strength of over 95%, and a packing density of over 480g / L.

[0013] As shown above, the type and height of activated carbon are crucial in the above methods. If the type and height of activated carbon are not properly selected, 2-methylisoborneol cannot be effectively removed. If the activated carbon is not hard enough, it is prone to carbon runoff, affecting turbidity; if the iodine value or packing height is insufficient, the adsorption effect of 2-methylisoborneol will be poor; if the packing density is low, quartz sand and activated carbon are prone to mixing during backwashing. Based on numerous experiments, this invention concludes that the type and height of activated carbon must be appropriately selected for a significant reduction in 2-methylisoborneol.

[0014] Compared with the prior art, the present invention has the following advantages and effects: 1. Compared with adding powdered activated carbon, it has lower cost and better effect.

[0015] 2. It requires less investment compared to ozone activated carbon deep treatment processes.

[0016] 3. Easy to modify, no special equipment required. Attached Figure Description

[0017] Figure 1 This invention relates to the filling method and water flow direction of the carbon sand filter. Detailed Implementation

[0018] The principles and features of the present invention are described below. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0019] The method of using this invention is as follows: ① Modify the filter bed to fill it with a ratio of quartz sand and activated carbon with a height of 0.25-1.0m:0.75-1.2m; ② The quartz sand particle size is 0.5-2.5mm, and the activated carbon particle size is 1.2-2.5mm or 8-30 mesh crushed carbon; ③ The activated carbon has an iodine adsorption value of over 1000mg / g, a strength of over 95%, and a filling density of over 480g / L.

[0020] The selection of particle size and height for the quartz sand and activated carbon described in this invention is crucial. If the particle size is too large or the height too small, the removal rate of 2-methylisoborneol and turbidity will be low. When the quartz sand particle size is small, the height can be appropriately lower; when the particle size is large, the height needs to be appropriately increased. Similarly, when the activated carbon particle size is small, the height can be appropriately reduced. Therefore, the appropriate selection of the particle size and height of the quartz sand and activated carbon determines the removal effect of 2-methylisoborneol. The filter was modified to have a quartz sand to activated carbon height ratio of 0.25-1.0m:0.75-1.2m; a quartz sand particle size of 0.5-2.5mm; and an activated carbon particle size of 1.2-2.5mm or 8-30 mesh crushed carbon. The activated carbon iodine adsorption value was above 1000mg / g, the strength was above 95%, and the packing density was above 480g / L. These results were obtained based on multiple experiments.

[0021] Example 1 A method for reducing 2-methylisoborneol in drinking water production using carbon sand filters involves modifying the filter bed to use a ratio of quartz sand and activated carbon with a height of 0.25-1.0m:0.75-1.2m. The quartz sand particle size is 0.5-2.5mm, and the activated carbon particle size is 1.2-2.5mm or 8-30 mesh crushed carbon. The activated carbon has an iodine value of over 1000mg / g, a strength of over 95%, and a packing density of over 480g / L.

[0022] The filter bed was modified to use 0.5mm diameter quartz sand with a height of 0.25m; activated carbon with a diameter of 1.5mm and a height of 0.75m; activated carbon with an iodine adsorption value of 1062mg / g, a strength of 97%, and a packing density of 492g / L.

[0023] Water source conditions at the site of use: A waterworks in Jingmen City, Hubei Province; water source: reservoir water; 2-methylisoborneol concentration: 67 ng / L; water intake flow rate: 500 tons / h; water flow velocity: below 1.3 m / min; 2-methylisoborneol concentration in filtered water: 4.7 ng / L.

[0024] The method of use is as follows: When the concentration of 2-methylisoborneol in the raw water is 60-80 ng / L, the method of use of this invention is as follows: the filter bed is modified to be made of quartz sand with a particle size of 0.5 mm and a height of 0.25 m; the activated carbon has a particle size of 1.5 mm and a height of 0.75 m; the activated carbon has an iodine adsorption value of 1062 mg / g, a strength of 97%, and a packing density of 492 g / L.

[0025] The effect was as follows: after 3 hours, the 2-methylisoborneol content in the filter effluent decreased from 62.3 ng / L to 4.7 ng / L, which met the national standard requirements.

[0026] Example 2 A method for reducing 2-methylisoborneol in drinking water production using carbon sand filters involves modifying the filter bed to use a ratio of quartz sand and activated carbon with a height of 0.25-1.0m:0.75-1.2m. The quartz sand particle size is 0.5-2.5mm, and the activated carbon particle size is 1.2-2.5mm or 8-30 mesh crushed carbon. The activated carbon has an iodine value of over 1000mg / g, a strength of over 95%, and a packing density of over 480g / L.

[0027] The filter bed was modified to use quartz sand with a particle size of 0.8 mm and a height of 0.5 m; activated carbon with a particle size of 1.5 mm and a height of 0.8 m; the activated carbon had an iodine adsorption value of 1034 mg / g, a strength of 95.6%, and a packing density of 487 g / L.

[0028] Water source conditions at the site of use: A waterworks in Jingmen City, Hubei Province; water source: reservoir water; 2-methylisoborneol concentration: 48.8 ng / L; water intake flow rate: 800 tons / h; water flow velocity: below 1.3 m / min; 2-methylisoborneol concentration in filtered water: 5.6 ng / L.

[0029] The method of use is as follows: When the concentration of 2-methylisoborneol in the raw water is 48.8 ng / L, the method of use of this invention is as follows: The filter bed is modified to use 0.8 mm diameter quartz sand with a height of 0.5 m; the activated carbon has a particle size of 1.5 mm and a height of 0.8 m; the activated carbon has an iodine adsorption value of 1046 mg / g, a strength of 96.2%, and a packing density of 485 g / L. The effect is: after 3 hours, the concentration of 2-methylisoborneol in the filter effluent decreased from 48.8 ng / L to 5.6 ng / L, which meets the national standard requirements.

[0030] Example 3 A method for reducing 2-methylisoborneol in drinking water production using carbon sand filters involves modifying the filter bed to use a ratio of quartz sand and activated carbon with a height of 0.25-1.0m:0.75-1.2m. The quartz sand particle size is 0.5-2.5mm, and the activated carbon particle size is 1.2-2.5mm or 8-30 mesh crushed carbon. The activated carbon has an iodine value of over 1000mg / g, a strength of over 95%, and a packing density of over 480g / L.

[0031] The filter bed was modified to use quartz sand with a particle size of 1.25 mm and a height of 0.75 m; activated carbon with a particle size of 2.0 mm and a height of 1.0 m; the activated carbon had an iodine adsorption value of 1023 mg / g, a strength of 96.1%, and a packing density of 490 g / L.

[0032] Water source conditions at the site of use: A waterworks in Jingmen City, Hubei Province; water source: reservoir water; 2-methylisoborneol concentration: 39.2 ng / L; water intake flow rate: 1000 tons / h; water flow velocity: below 1.3 m / min; 2-methylisoborneol concentration in filtered water: 5.3 ng / L.

[0033] The method of use is as follows: When the concentration of 2-methylisoborneol in the raw water is 39.2 ng / L, the method of use of this invention is as follows: the filter bed is modified to be filled with quartz sand with a particle size of 1.25 mm and a height of 0.75 m; the activated carbon has a particle size of 2.0 mm and a height of 1.0 m; the activated carbon has an iodine adsorption value of 1023 mg / g, a strength of 96.1%, and a packing density of 490 g / L.

[0034] The effect was as follows: after 3 hours, the 2-methylisoborneol content in the filter effluent decreased from 39.2 ng / L to 5.3 ng / L, which met the national standard requirements.

[0035] Example 4 A method for reducing 2-methylisoborneol in drinking water production using carbon sand filters involves modifying the filter bed to use a ratio of quartz sand and activated carbon with a height of 0.25-1.0m:0.75-1.2m. The quartz sand particle size is 0.5-2.5mm, and the activated carbon particle size is 1.2-2.5mm or 8-30 mesh crushed carbon. The activated carbon has an iodine value of over 1000mg / g, a strength of over 95%, and a packing density of over 480g / L.

[0036] The filter bed was modified to use quartz sand with a particle size of 2.0 mm and a height of 1.0 m; activated carbon with a particle size of 1.5 mm and a height of 1.0 m; activated carbon with an iodine adsorption value of 1032 mg / g, a strength of 96.5%, and a packing density of 488 g / L.

[0037] Water source conditions at the site of use: A waterworks in Jingmen City, Hubei Province; water source: reservoir water; 2-methylisoborneol concentration: 31.2 ng / L; water intake flow rate: 1000 tons / h; water flow velocity: below 1.3 m / min; 2-methylisoborneol concentration in filtered water: 6.7 ng / L.

[0038] The method of use is as follows: When the concentration of 2-methylisoborneol in the raw water is 31.2 ng / L, the method of use of this invention is as follows: the filter bed is modified to be filled with quartz sand with a particle size of 2.0 mm and a height of 1.0 m; the activated carbon has a particle size of 1.5 mm and a height of 1.0 m; the activated carbon has an iodine adsorption value of 1032 mg / g, a strength of 96.5%, and a packing density of 488 g / L.

[0039] The effect was as follows: after 3 hours, the 2-methylisoborneol content in the filter effluent decreased from 31.2 ng / L to 6.7 ng / L, which met the national standard requirements.

[0040] Example 5 A method for reducing 2-methylisoborneol in drinking water production using carbon sand filters involves modifying the filter bed to use a ratio of quartz sand and activated carbon with a height of 0.25-1.0m:0.75-1.2m. The quartz sand particle size is 0.5-2.5mm, and the activated carbon particle size is 1.2-2.5mm or 8-30 mesh crushed carbon. The activated carbon has an iodine value of over 1000mg / g, a strength of over 95%, and a packing density of over 480g / L.

[0041] The filter bed was modified to use 0.5mm diameter quartz sand with a height of 0.5m; coal-based crushed activated carbon of 8-18 mesh with a height of 1.2m; the activated carbon had an iodine adsorption value of 1087mg / g, a strength of 96.2%, and a packing density of 481g / L.

[0042] Water source conditions at the site of use: A waterworks in Jingmen City, Hubei Province; water source: reservoir water; 2-methylisoborneol concentration: 30.9 ng / L; water intake flow rate: 1000 tons / h; water flow velocity: below 1.3 m / min; 2-methylisoborneol concentration in filtered water: 4.4 ng / L.

[0043] The method of use is as follows: When the concentration of 2-methylisoborneol in the raw water is 30.9 ng / L, the method of use of this invention is as follows: the filter bed is modified to be filled with 0.5 mm quartz sand with a height of 0.5 m; the activated carbon is crushed to 8-18 mesh with a height of 1.2 m; the activated carbon has an iodine adsorption value of 1087 mg / g, a strength of 97.2%, and a packing density of 490 g / L.

[0044] The effect was as follows: after 3 hours, the 2-methylisoborneol content in the filter effluent decreased from 30.9 ng / L to 4.4 ng / L, which met the national standard requirements.

[0045] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for reducing 2-methylisoborneol in the production of drinking water using a carbon sand filter, characterized in that, The carbon sand filter is filled with activated carbon and quartz sand from top to bottom, and the height ratio of quartz sand to activated carbon is 0.25-1.0m:0.75-1.2m. The activated carbon has an iodine adsorption value of over 1000 mg / g, a strength of over 95%, and a packing density of over 480 g / L. The activated carbon is coal-based, wood-based, coconut shell carbon, or fruit shell carbon. The carbon sand filter can treat raw water with a 2-methylisoborneol concentration of less than 80 ng / L.

2. The method for reducing 2-methylisoborneol in the production of drinking water using a carbon sand filter according to claim 1, characterized in that, The quartz sand has a particle size of 0.5-2.5 mm.

3. The method for reducing 2-methylisoborneol in the production of drinking water using a carbon sand filter according to claim 1, characterized in that, The quartz sand is either sea sand or river sand.

4. The method for reducing 2-methylisoborneol in the production of drinking water using a carbon sand filter according to claim 1, characterized in that, The activated carbon has a particle size of 1.2-2.5 mm or 8-30 mesh crushed carbon.

5. The method for reducing 2-methylisoborneol in the production of drinking water using a carbon sand filter according to claim 1, characterized in that, The carbon sand filter can handle raw water with a flow rate of less than 1.3 m / min.

6. The method for reducing 2-methylisoborneol in the production of drinking water using a carbon sand filter according to claim 1, characterized in that, The carbon sand filter requires backwashing after 48 hours of use, with an air flushing intensity of 14 L / (m²). 2 The water flushing intensity at room temperature should be 10 L / (m²) for 5 minutes (s). 2 ·s), lasting 10 minutes.

7. The method for reducing 2-methylisoborneol in the production of drinking water using a carbon sand filter according to claim 1, characterized in that, The carbon sand filter has water entering from the top and exiting from the bottom.

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