CN113998810A - Drinking water defluorination process - Google Patents
Drinking water defluorination process Download PDFInfo
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- CN113998810A CN113998810A CN202111193026.9A CN202111193026A CN113998810A CN 113998810 A CN113998810 A CN 113998810A CN 202111193026 A CN202111193026 A CN 202111193026A CN 113998810 A CN113998810 A CN 113998810A
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F9/00—Multistage treatment of water, waste water or sewage
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/001—Processes for the treatment of water whereby the filtration technique is of importance
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
- C02F1/5236—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
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- C02F2101/00—Nature of the contaminant
- C02F2101/10—Inorganic compounds
- C02F2101/12—Halogens or halogen-containing compounds
- C02F2101/14—Fluorine or fluorine-containing compounds
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2303/00—Specific treatment goals
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Abstract
The invention provides a drinking water defluorination process. The process adopts a combined process of online adding a fluorine removal agent and a membrane filtration method to remove fluorine in raw water, and obtains a certain set value of fluoride in produced water, wherein the set value can be stably controlled below 1.0mg/L, and the fluoride meets the requirements of national sanitary Standard for Drinking Water GB 5749-2006. Compared with the fluorine removal by an adsorption method, the combined fluorine removal process provided by the invention has the advantages of high qualified rate of produced water, convenience in operation, no need of too much labor, capability of realizing full-automatic operation or remote control, low overall treatment cost and the like; on the other hand, compared with the method for removing fluorine by a nanofiltration or reverse osmosis membrane, the method has the advantages of extremely low energy consumption, high water yield of more than 95 percent, low wastewater rate, easy treatment, difficult blockage of a filter membrane, good performance recovery after cleaning, long service life, low treatment cost and the like, and simultaneously, the produced water has better retention of mineral elements beneficial to human bodies.
Description
Technical Field
The invention relates to the technical field of drinking water treatment, and mainly relates to a drinking water defluorination process.
Background
Fluorine is widely present in natural water and is one of trace elements necessary for human bodies. The concentration of fluoride in domestic drinking water is regulated to be not more than 1.0mg/L by the national sanitary Standard for domestic Drinking Water GB5749-2006, and the proper fluorine content in the drinking water is generally considered to be 0.5-1.0 mg/L. When the fluorine content in the drinking water is lower than 0.5mg/L, decayed teeth can appear; if drinking water with fluorine concentration higher than 1.0mg/L for a long time, dental fluorosis and fluorosis can be caused; if the water with the fluorine concentration of more than 5-10 mg/L is drunk for a long time, the typical fluoroossoma can be developed. Nearly one hundred million people live in high fluorine areas in China, fluorine victims can reach tens of millions of people, and the fluorine intake mainly comes from drinking water. At present, in drinking water sources in many areas at home and abroad, the fluorine content exceeds the health standard, even exceeds dozens of times of the health standard, and the fluorine removal of drinking water is closely related to the health of people, so that the fluorine removal of drinking water has great demand.
Fluorine is present in drinking water primarily in the form of fluoride ions. The method for removing fluorine in water is various, and mainly comprises an adsorption method, a precipitation method, an electrocoagulation method, an electrodialysis method, reverse osmosis, nanofiltration and the like. The common defluorination methods in the drinking water industry at present include membrane filtration and adsorption.
The frequent regeneration of the defluorination filter material in the adsorption method is a key factor influencing the long-term function of the defluorination equipment in the adsorption method, and because the defluorination filter material is often limited in adsorption capacity and continuously attenuates, the regeneration period of the defluorination equipment is shorter and shorter, and a large amount of labor cost is frequently consumed in the regeneration operation. Meanwhile, the phenomenon of water outlet pause or unqualified fluorine in the saturated regeneration stage of the defluorination filtering material can be caused, namely the qualified rate of water quality can not reach 100 percent, the regeneration process can also generate fluorine-containing wastewater with high PH value and high concentration, the wastewater treatment operation is complex, the full-automatic operation or remote control is difficult to realize, and the total operation cost is high.
In the membrane filtration method, a large amount of electric energy is consumed for fluorine removal, the total water yield is low and generally ranges from 75% to 85%, serious water resource waste is caused, agents such as scale inhibitors are supplemented, filter elements and membranes are frequently replaced, so the total operation cost is high, meanwhile, the nanofiltration membranes and the reverse osmosis membranes are easy to form dirt and block, the cleaning and replacement cost can be increased, the salt content of wastewater is high, the wastewater is difficult to treat, a large amount of mineral elements beneficial to human bodies in a water body are simultaneously filtered while fluorine removal, and the health is not facilitated after long-term drinking. In short, membrane-process defluorination to remove fluoride with a not high total salt content in water is a total desalination method, which has high reliability, but has higher treatment cost and lower efficiency, and can cause serious water resource waste, so the practical application range is greatly limited.
In order to solve the technical problems in the prior art, the drinking water defluorination process which has reliable performance, low treatment cost, simple operation, convenient realization of automatic control and suitability for large-scale popularization and use is urgently needed to be developed in the technical field.
Disclosure of Invention
In order to solve the technical problems in the prior art, the invention provides a novel drinking water defluorination process. The process provides a novel drinking water defluorination process by adopting a mode of on-line adding defluorination medicament and membrane filtration combination, can stably remove the fluorine for a long time, can realize full-automatic operation and remote control, has simple operation method, short reaction time, low operation cost and good defluorination effect, and simultaneously has better overall water quality after treatment and no problem of excessive residual aluminum. The specific contents are as follows:
the invention provides a drinking water defluorination process, which adopts a combined process of on-line adding defluorination agent and membrane filtration to remove fluorine in raw water;
wherein, the online adding of the fluorine removal agent comprises the following steps: adding a fluorine removal agent into raw water on line, and coagulating the fluorine removal agent and fluorine in the raw water to obtain water containing floccules;
the membrane filtration is that: and a self-cleaning filter and a membrane filter are sequentially adopted to intercept floccules in the floccule-containing water.
Optionally, the water containing the flock passes through the self-cleaning filter and the membrane filter in sequence under the hydraulic pressure of the raw water.
Optionally, the defluorination agent is an aqueous aluminum salt solution; wherein the mass percentage of the aluminum salt in the aluminum salt aqueous solution is 25-50%; the aluminum salt in the aluminum salt aqueous solution is polyaluminium chloride and/or aluminum sulfate.
Optionally, a mixing pipe is provided before the self-cleaning filter, and the fluorine-removing chemical and the raw water flowing into the mixing pipe are mixed by the mixing pipe.
Optionally, the initial dosage of the fluorine-removing agent is determined according to the fluorine content in the raw water;
the on-line dosage of the fluorine removal agent is determined according to the fluorine content in the water intercepted by the membrane filtration method.
Optionally, the diameter of the filter screen in the self-cleaning filter is 100-200 microns;
the aperture of the filtering membrane in the membrane filter is 0.001-0.1 micron.
Optionally, the process comprises the steps of:
step 1, introducing raw water into a pipeline;
step 2, adding a fluorine removal agent to the raw water in the pipeline on line;
step 3, the effluent of the pipeline is connected into a pipeline mixer, and the raw water and the defluorination agent are coagulated in the pipeline mixer to obtain a water body containing floccules;
step 4, enabling the water body containing the floccules to flow into a self-cleaning filter, and intercepting the floccules in the water body through the self-cleaning filter to obtain a primary treated water body;
and 5, accessing the primary treated water body to a membrane filter for secondary interception to obtain the treated water body.
Optionally, the process further comprises:
monitoring the fluorine content in the treated water body by an online monitoring device;
and if the monitored fluorine content deviates from a set value in a preset range, the online monitoring equipment adjusts the online adding amount of the fluorine removal agent in the step 2.
Optionally, the process further comprises:
when the pressure difference between the front and the back of the membrane filter is larger than the preset pressure difference, flushing a filtering membrane in the membrane filter; and/or
Flushing a filtering membrane in the membrane filter according to a preset time interval; and/or
And flushing the filtering membrane in the membrane filter according to the accumulated value of the treated water quantity.
Optionally, in the step 1, the water inlet pressure of the raw water is less than or equal to 0.3 Mpa;
in the step 2, the mass percentage of the fluorine removal agent is 25-50%.
The invention provides a novel drinking water defluorination process. The process adopts a combined process of on-line adding fluorine removal agent and membrane filtration to remove fluorine in raw water, and fluoride in the obtained produced water can be stably controlled to a certain set value below 1.0mg/L, thereby meeting the requirements of national sanitary Standard for Drinking Water GB 5749-2006. Wherein, the online adding of the fluorine removal agent refers to: and (3) adding a fluorine removal agent into the raw water on line, and coagulating the fluorine removal agent and fluorine in the raw water to obtain water containing floccules. The membrane filtration means: and a self-cleaning filter and a membrane filter are sequentially adopted to intercept floccules in the water containing the floccules.
The drinking water defluorination process provided by the invention adopts a combined process of on-line adding of a defluorination medicament and membrane filtration, firstly utilizes the on-line adding of the defluorination medicament to convert the fluorine in the raw water into floccules, and then utilizes the effect of membrane filtration to remove turbidity to remove the generated floccules, so as to achieve the purpose of indirectly removing the fluorine in the raw water. Compared with the prior art, the process has at least the following advantages:
1. the combined process removes the generated floccules by utilizing the effect of removing turbidity through membrane filtration, so that the used filtering aperture (the filtering aperture can be the filtering aperture of a self-cleaning filter and can be the membrane aperture of a filtering membrane in the membrane filter) is relatively large, so that the energy consumption in the actual process is greatly saved (specifically, the energy consumption can be reduced to 15 to 30 percent of the original energy consumption) based on large-aperture filtration, meanwhile, the water quality qualification rate can reach 100 percent, the water yield is high, and the problems of water waste, high energy consumption and easy pollution and blockage in the existing membrane method are solved.
2. In the process provided by the invention, the adopted membrane filter is of an external pressure type, the cavity in the membrane shell is relatively large, pollutants such as floccules and the like trapped on the filtering membrane in the membrane shell are easily washed away, and the membrane pollution and the membrane fouling blockage are not easily formed, so that the service life of the filtering membrane is prolonged, and the replacement frequency of the filtering membrane is reduced. Moreover, the aperture of the filtering membrane is larger, so that the membrane flux is larger, the water flux of the membrane is higher in operation, and the membrane area of the filtering membrane is correspondingly reduced for filtering raw water with the same volume, so that the membrane equipment investment and the later-stage operation cost are reduced.
3. The method of adding the defluorinating agent on line is adopted, so that the coagulating sedimentation process based on a coagulating basin is omitted, the process flow is shortened, the equipment investment cost is reduced, the retention time consumed by coagulating sedimentation is saved, and the treatment efficiency is improved. Meanwhile, based on the combination of the large-aperture filtering membrane and online feeding, the raw water pressure can be utilized, the water body can directly pass through the filtering membrane without pressure release, so that the pressure release and the required secondary pressurization operation caused by coagulating sedimentation based on a coagulation tank are avoided, the operation energy consumption is greatly reduced, and the investment cost of a pressurization device is saved.
4. The process has the advantages that the process discharges and intercepts the floccules, so the discharged wastewater does not contain high fluorine and high alkali, and the discharged wastewater only contains turbidity caused by floccules (the turbidity can be removed by a simple process, such as filtration or precipitation, in the wastewater treatment process), so the process also has the advantage of relatively easy wastewater treatment process.
5. On one hand, compared with the defluorination by an adsorption method, the process has the advantages of high qualified rate of produced water, convenient operation, no need of much labor, realization of full-automatic operation or remote control, low overall treatment cost and the like; on the other hand, compared with the fluorine removal by a nanofiltration or reverse osmosis membrane method, the process has the advantages of extremely low energy consumption, water yield of over 95 percent, water resource saving, low wastewater rate, easy treatment, difficult blockage of the filter membrane, good performance recovery after cleaning, long service life, low treatment cost and the like, and simultaneously, the produced water has good retention of beneficial mineral elements for human bodies. Therefore, the process can effectively avoid the defects of the two conventional mainstream fluorine removal methods, and simultaneously, the long process flow is changed into the short process flow by the online adding mode, so that the problem of high energy consumption caused by the coagulating sedimentation method is solved.
In conclusion, the process has the advantages that: the method has the advantages of high qualified rate of produced water, capability of ensuring that the fluoride is 100 percent qualified, convenient operation, no need of too much labor, capability of realizing full-automatic operation or remote control, low overall treatment cost, extremely low process energy consumption, high water production rate (up to more than 95 percent), low wastewater rate, easy wastewater treatment, difficult blockage of a filter membrane, good performance recovery after cleaning, long service life, low treatment cost and better retention of beneficial mineral elements in water for a human body.
Drawings
FIG. 1 shows a process flow diagram of a drinking water defluorination process in an embodiment of the present invention;
fig. 2 shows a process flow diagram of another drinking water defluorination process in an embodiment of the present invention.
Detailed Description
The following examples are provided to further understand the present invention, not to limit the scope of the present invention, but to provide the best mode, not to limit the content and the protection scope of the present invention, and any product similar or similar to the present invention, which is obtained by combining the present invention with other prior art features, falls within the protection scope of the present invention.
The embodiment of the invention provides a drinking water defluorination process, which adopts a combined process of online adding a defluorination agent and membrane filtration to remove fluorine in raw water;
wherein, the online adding of the fluorine removal agent comprises the following steps: adding a fluorine removal agent into raw water on line, and coagulating the fluorine removal agent and fluorine in the raw water to obtain water containing floccules;
the membrane filtration is that: and a self-cleaning filter and a membrane filter are sequentially adopted to intercept floccules in the floccule-containing water.
The fluorine removal process provided by the embodiment of the invention is a composite drinking water fluorine removal process, adopts a fluorine removal medicament for pretreatment, converts fluorine in raw water into a complex, then traps coagulating sedimentation (formed on the basis of the complex) in the water through a self-cleaning filter, and finally enables the turbidity of produced water to be stabilized below 0.1NTU through a filter membrane so as to achieve the aim of indirectly removing the fluorine in the raw water.
The process provided by the embodiment of the invention can realize real-time online monitoring, and the dosage of the dosing agent is adjusted according to the water inlet amount or the fluorine content of the produced water, so that the fluorine content in the produced water is qualified and reaches a set target value.
In the practical implementation process, after the fluorine removal agent is added into the raw water, the fluorine removal agent is automatically and uniformly mixed with the raw water under the action of the water flow of the raw water and fully reacts with fluorine in the raw water to generate a complex and form floccule, and then the water containing the floccule continuously passes through the self-cleaning filter and the membrane filter in sequence under the action of the water pressure of the raw water. That is to say, in this embodiment, the defluorination agent is added to the raw water, and then mixed in the pipeline, and then enters the filtration process, the whole process is a continuous automatic operation, and the pressure is not released in the middle link, and the secondary pressurization is not needed, so the energy consumption is low, and the equipment investment is low.
In practical implementation, optionally, the fluorine removal agent is an aluminum salt aqueous solution; wherein the mass percentage of the aluminum salt in the aluminum salt aqueous solution is 25-50%. Preferably, the aluminum salt in the aluminum salt aqueous solution is polyaluminum chloride and/or aluminum sulfate.
In specific implementation, the fluorine removal agent comprises one or two mixtures of polyaluminium chloride and aluminum sulfate, namely, the aluminum salt aqueous solution can contain other components besides aluminum salt and water so as to achieve other purposes.
The online feeding is as follows: the method has the advantages that the medicament is directly added into the raw water flowing on line, the raw water is not subjected to retention treatment, and the on-line process flow that the raw water directly reaches the drinking water standard after flowing on line is realized. Therefore, in order to realize online addition, the reagent can quickly react with ions in raw water after being added, and the characteristic that turbidity is easy to remove is required. Therefore, in this embodiment, the main effective component of the fluorine removal agent is polyaluminum chloride and/or aluminum sulfate.
The polyaluminium chloride or aluminium sulfate can quickly form a complex which is easy to intercept and discharge pollution with fluorine, so that the application scene of online feeding is met (in the continuous flow of raw water, the water flow flows fast under the action of pressure, if the reaction is slow, the water flow pressure of the raw water is combined, the water directly enters a water producing side before the reaction, so that a good removing effect cannot be achieved, and if the reaction is too slow, a sedimentation tank needs to be additionally arranged in the process flow, and a secondary pressurizing device is further additionally arranged on the basis of the addition of the sedimentation tank).
In actual operation, optionally, a mixing pipe is provided before the self-cleaning filter, and the fluorine-removing agent and the raw water flowing into the mixing pipe are mixed by the mixing pipe.
In this embodiment, in order to ensure that the fluorine-removing agent and the fluorine in the raw water react sufficiently on the basis of on-line addition, the applicant sets a mixing pipeline with a larger pipe diameter before the self-cleaning filter, and the pipe diameter of the mixing pipeline is larger than that of the pipeline where the fluorine-removing agent is added, so that the water containing the fluorine-removing agent can utilize the buffer action of flowing from a small pipe diameter to a large pipe diameter to achieve the sufficient reaction of the fluorine-removing agent and the fluorine, and further achieve the effect that the fluorine almost completely reacts with the fluorine-removing agent to form floccules when the water body reaches the self-cleaning filter and the membrane filter. Then, the floccules are discharged along with respective sewage discharge ports of the self-cleaning filter and the membrane filter (3-5% of sewage discharge is reserved in the membrane filter in actual operation), and in addition, 95-97% of water body passes through a filtering membrane in the membrane filter and reaches a water production side.
That is to say, in this embodiment, the online feeding can be realized in this process because the reaction speed of the aluminum salt is fast enough, and accordingly, after the online feeding is realized, based on the operation characteristics of the online feeding, the whole process flow can be made shorter, simpler, more convenient, and easier to realize the automatic control.
In the actual implementation process, the on-line dosage of the fluorine removal agent is determined according to the fluorine content in the water after being intercepted by the membrane filtration and can be automatically adjusted.
In this embodiment, since the fluorine removing agent contains a substance that reacts with fluorine, such as an aluminum salt polymer, if the fluorine removing agent is added in an excessive amount, the aluminum content in the water on the water producing side may be out of limits. Therefore, it is necessary to control the amount of the fluorine-removing agent to be added. Specifically, the requirement of the national sanitary Standard for Drinking Water is taken as a reference, the preset value range of the fluorine content in the water intercepted by the membrane filtration method is preset to be 0.5-0.99 mg/L, preferably 0.8-0.9 mg/L, and the actual value of the fluoride in the water intercepted by the membrane filtration method meets the requirement of the preset value range by regulating and controlling the on-line adding amount of the fluorine removal agent.
In the actual application process, the initial adding amount of the fluorine removal agent can be determined through a laboratory experiment to determine the ratio of the fluorine content in the raw water to the initial adding amount, and then in the actual application process, the initial adding amount to be added can be determined directly according to the fluorine content in the raw water and the water inlet flow of the raw water.
In practical implementation, the diameter of the filter mesh in the self-cleaning filter is optionally 100-200 microns; that is, the self-cleaning filter selected in this embodiment has an interception accuracy of 100 microns to 200 microns to filter out suspended substances and colloids in water.
The aperture of a filtering membrane in the membrane filter is 0.001-0.1 micron, and a filtering membrane with higher precision (such as a nano-filtering membrane or an ultrafiltration membrane) is used so as to completely filter suspended matters and partial metal ions in water. It should be noted that: if the defluorination agent is selected from polyaluminium chloride and/or aluminium sulphate, the residual aluminium is not intercepted, which may cause the aluminium content on the water production side to exceed the national standard of 0.2%, therefore, the pore size of 0.001-0.1 micron is selected, on one hand, to remove the turbidity in the water (i.e. to remove the smaller particle size in the water), on the other hand, to intercept part of the residual aluminium.
In this embodiment, adjust the input of defluorination agent through the fluorine content of real-time on-line monitoring aquatic, under the dual function of self-cleaning filter and filtration membrane, aluminium in the defluorination agent forms the floc with the fluorine in the former aquatic and discharges from sewage pipes, even there is a few to remain also can be held back by the filtration membrane, and can not get into the water production side through the filtration membrane, and the residual aluminium of having ensured the product water can not exceed standard, and the product water reaches national drinking water health standard. Meanwhile, the turbidity in the discharged sewage is a main unqualified item, and the discharged sewage can be treated to reach the standard by a simple precipitation and filtration method.
Fig. 1 shows a flow diagram of a method for removing fluorine from drinking water in an embodiment of the invention. As shown in fig. 1, an embodiment of the present invention provides a drinking water defluorination process, including the following steps:
step 1(S1) of introducing raw water into a pipe; the raw water contains fluorine.
And 2(S2), adding a fluorine removal agent to the raw water in the pipeline on line. The initial adding amount of the fluorine removal agent is determined according to the inflow of raw water and the fluorine content in the raw water; the specific implementation method for determining the adding amount can be carried out by a small experiment. And determining the online adding value of the fluorine removal agent according to the fluorine content in the water on the water production side.
And 3(S3), the outlet water of the pipeline is connected into a pipeline mixer, and the raw water and the defluorination agent are coagulated in the pipeline mixer to obtain the water body containing the floccules.
And 4(S4), enabling the water body containing the floccules to flow into a self-cleaning filter, and intercepting the floccules in the water body through the self-cleaning filter to obtain a primary treated water body.
The self-cleaning filter in the implementation step can be a full-automatic self-cleaning filter, and the self-cleaning filter has the functions of automatically realizing the interception and pollution discharge process, further realizing the automation of the whole process, and specifically comprises the following steps: most of large-particle-size floccules are intercepted firstly, and then a small amount of small-particle-size floccules are reserved for the membrane filter to be intercepted, so that the intercepting workload of the membrane filter is relieved, the service life of the membrane filter is prolonged, the working time in the cycle is prolonged (because if the self-cleaning filter is not arranged, the membrane filter can cause membrane clogging due to more intercepted floccules), and the pollution degree of the membrane is reduced.
And 5(S5), accessing the primary treated water body to a membrane filter for secondary interception to obtain the treated water body.
In specific implementation, the implementation process of the above steps may be: introducing raw fluorine-containing water into a pipeline, wherein the water inlet pressure is less than or equal to 0.3Mpa, and the water inlet flow is set to be 2-4 tons/hour; adding a fluorine removal agent on line, wherein the flow rate is 1-2 liters per hour; raw water and a medicament enter a DN50 pipeline mixer for full mixing reaction; the water after the mixed reaction immediately flows into a self-cleaning filter, and flocculent precipitates formed after the reaction of the medicament and fluoride in the raw water are intercepted, wherein the precision can reach 100-200 microns; the water after passing through the self-cleaning filter enters a filter membrane for filtration, the aperture of the filter membrane is required to be less than or equal to 0.1 micron, and meanwhile, a certain retention and removal effect is exerted on aluminum, so that the treated water flows into a product water tank and meets the requirements of the national sanitary Standard for Drinking Water; the water yield is 95 percent, and the amount of the filtered waste water only accounts for 5 percent of the original water amount.
In an actual implementation process, optionally, the process further includes:
monitoring the fluorine content in the treated water body through online monitoring equipment;
and if the monitored fluorine content deviates from a set value in a preset range, the online monitoring equipment adjusts the online adding amount of the fluorine removal agent in the step 2.
For example, the preset range of the fluorine content is 0.5-0.99 mg/L, the preset value of the fluorine is 0.9mg/L, and the fluorine content in the treated water body is monitored to be 1.0mg/L by the online monitoring equipment; and then the online monitoring equipment judges that the 1.0mg/L is not within the preset range of 0.5-0.99 mg/L and is greater than the set value of 0.9mg/L, and the online adding amount of the fluorine removal agent in the step 2 is increased until the fluorine removal agent is stabilized at 0.9 mg/L.
In the practical implementation process, the filter membrane is washed at regular intervals, so that the fluidity of the filter membrane is maintained, and the filter membrane is prevented from being blocked by flocculent precipitates in the liquid. Thus, optionally, the process further comprises:
when the pressure difference between the front and the back of the membrane filter is larger than the preset pressure difference, flushing a filtering membrane in the membrane filter; and/or
Flushing a filtering membrane in the membrane filter according to a preset time interval; and/or
And flushing the filtering membrane in the membrane filter according to the accumulated value of the treated water quantity.
During flushing, water is fed from the water producing side of the filtering membrane, and water is discharged from the water inlet side of the filtering membrane, so that flushed clogging substances flow out from a sewage discharge channel at the water inlet side of the filtering membrane. The flushing in this example refers to: and backwashing the filtering membrane in a direction opposite to the forward flow direction of the water body. For example, if the filtering membrane in the membrane filter is a cylindrical filtering membrane which is vertically placed, the water inlet is arranged at the bottom of the water inlet side of the filtering membrane, the water producing port is arranged at the upper part of the water producing side of the filtering membrane, so that the water body is filtered from the filtering membrane from bottom to top, the filtering membrane is backwashed from the water producing side of the filtering membrane to the water inlet side from top to bottom, and the sludges washed by the backwashing are discharged from the sewage discharge channel at the water inlet side of the filtering membrane.
The flushing in this embodiment also includes positive flushing, which may be water positive flushing, gas positive flushing, or a combination of these two flushing methods. During positive flushing, water or gas enters from the water inlet side of the membrane and exits from the sewage outlet side. When the combination mode is adopted, the specific implementation process is as follows: the water-air mixture enters from the water inlet of the membrane, and the vibration generated after the water-air mixture impacts the sediment on the surface of the filtering membrane, so that the sediment intercepted on the filtering membrane falls down and is discharged from a sewage discharge outlet along with the cleaning liquid, and finally, the membrane surface of the filtering membrane is thoroughly cleaned through repeated backwashing and forward washing processes, and the membrane flux is recovered.
The washing can also be washing with a medicament, the medicament enters from the membrane water inlet side and stays for soaking for a period of time, the medicament reacts with the blocking precipitate on the filtering membrane, so that the precipitate is easier to peel off from the filtering membrane and is dissolved in water, and then the precipitate on the surface of the filtering membrane is washed by cleaning water, so that the precipitate intercepted on the filtering membrane is discharged from a sewage discharge outlet along with the cleaning liquid, the membrane surface of the filtering membrane is thoroughly cleaned, and the membrane flux is recovered.
In an actual implementation process, optionally, in the step 1, the water inlet pressure of the raw water is less than or equal to 0.3Mpa, and the water inlet flow of the raw water is 2-4 tons/hour;
in the step 2, the adding flow rate of the fluorine removal agent is 1-2 liters per hour, and the mass percentage of the fluorine removal agent is 25-50%.
Fig. 2 shows a flow diagram of another drinking water defluorination process in an embodiment of the present invention. As shown in figure 2, according to the drinking water defluorination process, the water inlet flow is set to be 2-4 tons/hour according to the concentration of fluoride ions in raw water, the water inlet pressure is less than or equal to 0.3Mpa, a certain defluorination medicament is added into a water inlet pipeline, the medicament injection flow is adjusted to be 1-2 liters/hour according to the concentration of the fluorine in the raw water, and the raw water is fully mixed and reacted in the pipeline. Introducing the effluent into a self-cleaning filter, wherein the operating pressure is 0.1-0.2Mpa, and intercepting flocs formed after the reaction of the medicament and the fluorine in the raw water. Then the low-turbidity water is introduced into a filter membrane for filtration, impurities intercepted by the filter membrane are discharged through a sewage discharge pipeline, and the treated water meets the requirements of the national sanitary Standard for Drinking Water.
The embodiment of the invention adopts a process combining fluorine removal agent and filter membrane filtration, the agent is added on line, the adding amount of the agent is set according to the fluorine content of raw water, the raw water is mixed in a pipeline and then enters a filtration process, continuous automatic operation is realized, no pressure relief is generated in an intermediate link, the energy consumption is low, the equipment investment is low, the fluorine content of produced water is stable, the water production rate is high, the wastewater rate is low, no pollution is caused, repeated regeneration is not needed, and the fluorine content and the aluminum content in water can be strictly controlled by a fine online monitoring device and a dosing mode, so that the fluorine content and the aluminum residue in the final effluent meet the requirements of the national sanitary standard for drinking water, the long-term stable fluorine removal effect of the whole process is ensured, and the drinking water safety is ensured. The method has the advantages of simple process, high water production rate of over 95 percent, on-line addition of the medicament, no intermediate pressure release, simple operation, full-automatic operation and remote control, low energy consumption and treatment cost, and better retention of mineral elements in the produced water which are beneficial to human bodies, is a brand new method for drinking water defluorination process, has extremely wide practical value, and must become a mainstream process for future drinking water defluorination and even industrial water treatment defluorination.
In order to make the present invention more understandable to those skilled in the art, the drinking water defluorination process provided by the present invention is illustrated by specific examples below.
Example 1: the fluorine content of raw water is 2.0mg/L, the treatment steps as shown in figure 1 are adopted, and the process is as follows:
(1) the flow rate of the inlet water is set to be 2 tons/hour, and the flow rate of the aluminum sulfate aqueous solution medicament is set to be 1.4 liters/hour;
(2) introducing DN50 into a pipeline mixer for mixing reaction, wherein the mixing time in the pipeline is about 5-10 seconds;
(3) the water after reaction passes through a self-cleaning filter of 200 microns, and coagulative precipitates are intercepted;
(4) the water after passing through the self-cleaning filter enters a nanofiltration membrane for filtering, the filtering aperture reaches 0.003 micron, and meanwhile, the water-treatment agent has a certain interception and removal effect on residual aluminum in the water body, the water yield is 95 percent, and the treated water meets the index requirements of the national sanitary Standard for Drinking Water;
(5) and flushing the filter membrane every 30-45 minutes for about 30-60 seconds each time.
Through the treatment, the fluorine content of the effluent is 0.6mg/L, the turbidity is less than 0.1NTU, the aluminum content is 0.115mg/L, and the fluoride content meets the requirement of fluoride index in the national sanitary Standard for Drinking Water.
Example 2, the fluorine content of the raw water was 3.0mg/L, and the treatment procedure as described in fig. 1 was carried out as follows:
(1) the flow rate of water inlet is set to be 2 tons/hour, and the flow rate of the polyaluminium chloride aqueous solution medicament is set to be 2.2 liters/hour;
(2) introducing DN50 pipeline mixer for mixing reaction in the pipeline, wherein the mixing time in the pipeline is about 5-10 seconds;
(3) the water after reaction passes through a self-cleaning filter of 150 microns, and coagulative precipitates are intercepted;
(4) the water after passing through the self-cleaning filter enters an ultrafiltration membrane for filtering, the filtering aperture reaches 0.01 micron, meanwhile, the water has a certain interception and removal effect on residual aluminum in the medicinal agent in the water body, the water yield is 95 percent, and the treated water meets the index requirements of the national sanitary Standard for Drinking Water;
(5) and flushing the filter membrane every 30-45 minutes for about 30-60 seconds each time.
Through the treatment, the fluorine content of the effluent is 0.6mg/L, the turbidity is less than 0.1NTU, the aluminum content is 0.103mg/L, and the requirements of corresponding indexes in the national sanitary Standard for Drinking Water are met.
Example 3 raw water with a fluorine content of 4.0mg/L was treated as described in fig. 1, with the following procedure:
(1) the flow rate of the inlet water is set to be 2 tons/hour, and the flow rate of the mixed liquid of the polyaluminium chloride and the aluminium sulfate is set to be 1.8 liters/hour;
(2) introducing DN50 into a pipeline mixer for mixing reaction, wherein the mixing time in the pipeline is about 5-10 seconds;
(3) the water after reaction passes through a 100-micron self-cleaning filter to intercept coagulating sedimentation;
(4) the water after passing through the self-cleaning filter enters an ultrafiltration membrane for filtering, the filtering aperture reaches 0.03 micron, meanwhile, the water has a certain interception and removal effect on residual aluminum in the medicinal agent in the water body, the water yield is 95 percent, and the obtained treated water meets the index requirements of the national sanitary Standard for Drinking Water;
(5) and flushing the filter membrane every 30-45 minutes for about 30-60 seconds each time.
Through the treatment, the fluorine content of the effluent is 0.9mg/L, the turbidity is less than 0.1NTU, the aluminum content is 0.089mg/L, and the requirements of corresponding indexes in the national sanitary Standard for Drinking Water are met.
Example 4 raw water with a fluorine content of 3.0mg/L was treated as described in fig. 1, with the following procedure:
(1) the water inlet flow is set to be 4 tons/hour, and the polyaluminium chloride aqueous solution medicament flow is set to be 3.3 liters/hour;
(2) introducing DN50 into a pipeline mixer for mixing reaction, wherein the mixing time in the pipeline is about 5-10 seconds;
(3) the water after reaction passes through a 100-200 micron self-cleaning filter to intercept coagulating sedimentation;
(4) the water after passing through the self-cleaning filter enters an ultrafiltration membrane for filtering, the filtering aperture reaches 0.01 micron, meanwhile, the water has a certain interception and removal effect on residual aluminum in the medicinal agent in the water body, the water yield is 95 percent, and the obtained treated water meets the index requirements of the national sanitary Standard for Drinking Water;
(5) and flushing the filter membrane every 30-45 minutes for about 30-60 seconds each time.
Through the treatment, the fluorine content of the effluent is 0.8mg/L, the turbidity is less than 0.1NTU, the aluminum content is 0.133mg/L, and the requirement of corresponding indexes in the national sanitary Standard for Drinking Water is met.
The amount of the fluorine-removing agent added varies depending on the raw water, and therefore, the amount of the fluorine-removing agent added needs to be adjusted according to the actual fluorine content of the raw water to be treated.
The applicant states that the present invention is illustrated by the detailed process flow of the present invention through the above examples, but the present invention is not limited to the above detailed process flow, that is, it does not mean that the present invention must rely on the above detailed process flow to be implemented. It will be understood by those skilled in the art that any simple modification, equivalent substitution of each raw material and addition of auxiliary components, selection of specific modes and the like, of the product of the present invention falls within the scope and disclosure of the present invention.
For simplicity of explanation, the method embodiments are described as a series of acts or combinations, but those skilled in the art will appreciate that the present invention is not limited by the order of acts, as some steps may occur in other orders or concurrently in accordance with the invention. Further, those skilled in the art will appreciate that the embodiments described in the specification are preferred embodiments and that the acts and elements referred to are not necessarily required to practice the invention.
The drinking water defluorination process provided by the present invention is described in detail above, and the principle and the implementation mode of the present invention are explained in the present text by using specific examples, and the description of the above examples is only used to help understanding the method and the core idea of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.
Claims (10)
1. A drinking water defluorination process is characterized in that a combined process of online adding defluorination agent and membrane filtration is adopted to remove fluorine in raw water;
wherein, the online adding of the fluorine removal agent comprises the following steps: adding a fluorine removal agent into raw water on line, and coagulating the fluorine removal agent and fluorine in the raw water to obtain water containing floccules;
the membrane filtration is that: and a self-cleaning filter and a membrane filter are sequentially adopted to intercept floccules in the floccule-containing water.
2. The process of claim 1, wherein the water containing the flock passes through the self-cleaning filter and the membrane filter in sequence under the hydraulic pressure of the raw water.
3. The process of claim 1 wherein the fluorine removal agent is an aqueous aluminum salt solution; wherein the aluminum salt in the aluminum salt aqueous solution is polyaluminium chloride and/or aluminum sulfate, and the mass percentage of the aluminum salt is 25-50%.
4. The process as set forth in claim 1 wherein a mixing pipe is provided before the self-cleaning filter, and the fluorine-removing agent and the raw water flowing into the mixing pipe are mixed by the mixing pipe.
5. The process according to claim 1 or 2, wherein the amount of fluorine-removing agent added on-line is determined according to the fluorine content in the water after retention by the membrane filtration.
6. The process of claim 1, wherein the filter mesh size in the self-cleaning filter is from 100 microns to 200 microns;
the aperture of the filtering membrane in the membrane filter is 0.001-0.1 micron.
7. The process according to any one of claims 1 to 6, characterized in that it comprises the following steps:
step 1, introducing raw water into a pipeline;
step 2, adding a fluorine removal agent to the raw water in the pipeline on line;
step 3, the effluent of the pipeline is connected into a pipeline mixer, and the raw water and the defluorination agent are coagulated in the pipeline mixer to obtain a water body containing floccules;
step 4, enabling the water body containing the floccules to flow into a self-cleaning filter, and intercepting the floccules in the water body through the self-cleaning filter to obtain a primary treated water body;
and 5, accessing the primary treated water body to a membrane filter for secondary interception to obtain the treated water body.
8. The process of claim 7, further comprising:
monitoring the fluorine content in the treated water body through online monitoring equipment;
and if the monitored fluorine content deviates from a set value in a preset range, the online monitoring equipment adjusts the online adding amount of the fluorine removal agent in the step 2.
9. The process of claim 7, further comprising:
when the pressure difference between the front and the back of the membrane filter is larger than the preset pressure difference, flushing a filtering membrane in the membrane filter; and/or
Flushing a filtering membrane in the membrane filter according to a preset time interval; and/or
And flushing the filtering membrane in the membrane filter according to the accumulated value of the treated water quantity.
10. The process according to claim 7,
in the step 1, the water inlet pressure of the raw water is less than or equal to 0.3 Mpa;
in the step 2, the mass percentage of the fluorine removal agent is 25-50%.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115925152A (en) * | 2022-11-08 | 2023-04-07 | 中煤科工西安研究院(集团)有限公司 | Membrane chemical reaction equipment, coal mine water defluorination treatment system and process |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102701475A (en) * | 2012-05-24 | 2012-10-03 | 江苏永冠给排水设备有限公司 | Combined defluorination water treatment equipment |
| CN203768163U (en) * | 2014-03-26 | 2014-08-13 | 北京国中科创环境科技有限责任公司 | Water supply system with functions of removing fluorine and reducing turbidity |
| CN206783439U (en) * | 2017-05-11 | 2017-12-22 | 河海大学 | A kind of integral type fluorin-removing apparatus for drinking water |
-
2021
- 2021-10-13 CN CN202111193026.9A patent/CN113998810A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102701475A (en) * | 2012-05-24 | 2012-10-03 | 江苏永冠给排水设备有限公司 | Combined defluorination water treatment equipment |
| CN203768163U (en) * | 2014-03-26 | 2014-08-13 | 北京国中科创环境科技有限责任公司 | Water supply system with functions of removing fluorine and reducing turbidity |
| CN206783439U (en) * | 2017-05-11 | 2017-12-22 | 河海大学 | A kind of integral type fluorin-removing apparatus for drinking water |
Non-Patent Citations (1)
| Title |
|---|
| 刘莹;: "超滤膜在污水深度处理中的应用" * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115925152A (en) * | 2022-11-08 | 2023-04-07 | 中煤科工西安研究院(集团)有限公司 | Membrane chemical reaction equipment, coal mine water defluorination treatment system and process |
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