CN106830281A - The method for treating water of instability halogenated disinfection by-products during a kind of utilization persulfate in-situ control liquid chlorine/chloramines disinfection - Google Patents

Abstract

The invention discloses a water treatment method for controlling non-stable halogenated disinfection by-products in liquid chlorine/chloramine disinfection process in situ by using persulfate, which relates to a water treatment method. The invention solves the problems that the halogenated disinfection by-products and their precursors need to be oxidized and the nucleophilic reagents easily cause secondary pollution of drinking water or large consumption of liquid chlorine/chloramine. The water treatment method of the present invention: when adding liquid chlorine or chloramine to the water to be treated for disinfection treatment, add persulfate solution at the same time, stir, and use the nucleophilic hydrolysis of persulfate to form non-stable halogenated The disinfection by-products are decomposed and detoxified, which is completed. The invention has the following advantages: persulfate has extremely strong nucleophilic ability, can quickly decompose non-stable halogenated disinfection by-products, and does not consume liquid chlorine and chloramine, and can realize in-situ efficient conversion of halogenated disinfection by-products Detoxification; and persulfate has been officially included in the catalog of drinking water disinfectant products by the country, and can be applied in water purification plants and pipe networks.

Description

An in-situ control of instability in liquid chlorine/chloramine disinfection using persulfate Water treatment method for halogenated disinfection by-products

technical field

The invention relates to a water treatment method, in particular to a water treatment method for controlling non-stable halogenated disinfection by-products in the disinfection process.

Background technique

Liquid chlorine and chloramine disinfection are easy to form disinfection by-products, especially some non-stable halogenated disinfection by-products, such as: haloquinones (HBQs), haloacetonitriles (HANs), haloacetamides (HAcAms), etc. These new findings Disinfection by-products that have not been included in the corresponding national management regulations are far more harmful to the human body than trihalomethanes (THMs) and haloacetic acids (HAAs), which have been included in regulations, and often exist at the level of μg/L In disinfected drinking water, although its average concentration is about a fraction to a few tenths of trihalomethanes, their chronic cytotoxicity and acute genotoxicity are hundreds to thousands of times that of trihalomethanes , seriously endangering people's drinking water health. Therefore, how to control the non-stable halogenated disinfection by-products (halogenated quinones, halogenated acetonitriles, halogenated acetamides) in drinking water is a hot spot and difficult point in the field of water treatment research.

There are two main methods for controlling halogenated disinfection by-products: one is pretreatment before disinfection to remove the precursors of disinfection by-products in water, but this method has the disadvantage of not being able to completely remove the precursors in water; The method is to remove the generated disinfection by-products. Even if some oxidation techniques can be used to mineralize the halogenated disinfection by-products, due to the presence of liquid chlorine and precursors, halogenated disinfection by-products will still be generated.

Patent CN102381740A discloses a method for removing nitrogen-containing disinfection by-products in water based on persulfate/light coupling, using a large number of free radicals generated by persulfate/photo-coupling to attack nitrogen-containing disinfection by-products to achieve denitrification and dehalogenation . Patent CN105668880A discloses a method for controlling chlorinated nitrogen-containing disinfection by-products in water, using ultraviolet radiation to activate persulfate to generate highly oxidative sulfate radicals to remove precursors of chlorinated disinfection by-products. Patent CN105712549A discloses a method for inhibiting the formation of brominated nitrogen-containing disinfection by-products in water, using ultraviolet light irradiation and adding an oxidant (hydrogen peroxide or sodium percarbonate) to remove the precursors of brominated nitrogen-containing by-products in water. Patent CN103359851A discloses a method for removing halogenated nitrogen-containing disinfection by-products in drinking water. Persulfate and hydrogen peroxide are added to the reaction system to generate highly active sulfate radicals under the action of a hydroxylated surface catalyst Free radicals and hydroxyl radicals, the sulfate radicals and hydroxyl radicals produced are further reacted with carbonates to generate carbonate radicals, using the characteristics of selective oxidation of sulfate radicals and carbonate radicals, respectively for halogenated organic compounds And nitrogen-containing organic compounds have better selective degradation performance. Patent CN105906097A discloses a method and system for controlling iodized disinfection by-products in water, using iron salts to activate sulfate radicals produced by persulfates, oxidizing iodide ions in water into non-toxic and harmless iodates, and synchronously Precursors are removed, and the generation of iodo disinfection by-products is controlled.

Unstable halogenated disinfection by-products (such as: halogenated quinones, halogenated acetonitriles, halogenated acetamides) have the characteristics that the carbon atoms connected to halogens in the molecule are easily attacked by nucleophiles, and are prone to nucleophilic hydrolysis for detoxification. There is no research report on the use of nucleophilic hydrolysis properties to control the halogenated disinfection by-products produced in the liquid chlorine/chloramine disinfection process. Common nucleophiles include methanol, hydrogen peroxide, etc., but because these nucleophiles are likely to cause secondary pollution of drinking water or a large amount of liquid chlorine consumption, it is difficult to apply them in water purification plants.

Contents of the invention

The purpose of the present invention is to provide a kind of water treatment method that utilizes persulfate in situ to control the non-stable halogenated disinfection by-products in the liquid chlorine/chloramine disinfection process, and solve the need to carry out halogenated disinfection by-products and their precursors. Oxidation treatment and nucleophilic reagents are likely to cause secondary pollution of drinking water or large consumption of liquid chlorine/chloramines.

A kind of water treatment method of the present invention utilizes persulfate in situ to control the non-stable halogenated disinfection by-products in the liquid chlorine/chloramine disinfection process is realized by the following steps: adding liquid chlorine or chloramine to the water to be treated When carrying out disinfection treatment, add persulfate solution simultaneously, keep stirring state, promptly finish the water treatment method of described non-stable halogenated disinfection by-product in the in-situ control liquid chlorine/chloramine disinfection process utilizing persulfate, wherein , the concentration of persulfate is 0.1-100mg/L, and the water to be treated is filtered water, sewage treatment plant effluent or groundwater.

In a kind of water treatment method using persulfate in-situ control liquid chlorine/chloramine disinfection process of non-stable halogenated disinfection by-products of the present invention, said persulfate is persulfate, persulfate A mixture of one or two mixed in any ratio, wherein the persulfate is potassium persulfate and sodium persulfate or a mixture of two mixed in any ratio, and the peroxodisulfate is potassium peroxodisulfate , Sodium peroxodisulfate, or a mixture of two in any ratio.

In a kind of water treatment method utilizing persulfate in-situ control of non-stable halogenated disinfection by-products in liquid chlorine/chloramine disinfection process of the present invention, said persulfate is replaced by a compound salt of persulfate and alkali, wherein The molar ratio of persulfate to alkali is 1:1-10, and the addition of alkali can adjust the pH value of the water treatment system at 6-9, which is conducive to the ionization of persulfate; wherein, persulfate is persulfate and/or Or peroxodisulfate, the alkali is one of potassium hydroxide, sodium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate or a mixture of several of them mixed in any ratio; Sulphate is a mixture of one or two of potassium persulfate and sodium persulfate in any ratio, and peroxodisulfate is one or two of potassium persulfate and sodium persulfate in any ratio. Mixed mixture.

The principle of the present invention is a water treatment method using persulfate in situ to control the non-stable halogenated disinfection by-products in the liquid chlorine/chloramine disinfection process: liquid chlorine or chloramine will form an unstable halogenated disinfection By-products (such as: halogenated quinones, halogenated acetonitriles, halogenated acetamides), the carbon atoms connected to the halogens in the molecule are vulnerable to the attack of the nucleophilic reagent persulfate, which can quickly undergo nucleophilic hydrolysis and detoxification, and achieve non-toxic In situ control of stable halogenated disinfection by-products. That is to say, once the non-stable halogenated disinfection by-products are formed, they will quickly undergo nucleophilic hydrolysis with persulfate and be decomposed and detoxified.

A kind of water treatment method utilizing persulfate in-situ control liquid chlorine/chloramine disinfection process of non-stable halogenated disinfection by-products has the following advantages: (1) persulfate has been officially included in drinking water by the country Disinfectant product catalog, which can be applied in water purification plants and pipe networks; (2) Persulfate has a strong nucleophilic ability and can quickly decompose non-stable halogenated disinfection by-products; (3) Persulfate is not Consume liquid chlorine and chloramine, and can coexist with liquid chlorine and chloramine; (4) can realize in-situ efficient conversion and detoxification of non-stable halogenated disinfection by-products; (5) simple and convenient operation, no need for additional equipment, The processing cost is low.

Description of drawings

Fig. 1 is the effect diagram of the removal of halogenated disinfection by-product haloquinones in the in-situ control liquid chlorine disinfection process using persulfate in Example 1; wherein, ■ represents the halogenated quinones formed in the liquid chlorine disinfection process, and □ represents over Potassium monosulfate removes haloquinones formed during liquid chlorine disinfection.

detailed description

The technical solution of the present invention is not limited to the specific embodiments listed below, but also includes any combination of the specific embodiments.

Embodiment 1: This embodiment is a water treatment method using persulfate in situ to control the non-stable halogenated disinfection by-products in the liquid chlorine/chloramine disinfection process, which is realized by the following steps: When adding liquid chlorine or chloramine in water for disinfection treatment, add persulfate solution at the same time and keep stirring, that is, complete the non-stable halogenation disinfection in the process of using persulfate in-situ control liquid chlorine/chloramine disinfection A water treatment method for by-products, wherein the concentration of persulfate is 0.1-100 mg/L, and the water to be treated is filtered water, sewage treatment plant effluent or groundwater.

The principle of this embodiment is a water treatment method that utilizes persulfate in situ to control the non-stable halogenated disinfection by-products in the liquid chlorine/chloramine disinfection process: liquid chlorine or chloramine disinfection will form unstable halogenated Disinfection by-products (such as: halogenated quinones, halogenated acetonitriles, halogenated acetamides), the carbon atoms connected to the halogens in the molecule are vulnerable to the attack of the nucleophilic reagent persulfate, which can quickly undergo nucleophilic hydrolysis and detoxification, and achieve In situ control of non-stable halogenated disinfection by-products. That is to say, once the non-stable halogenated disinfection by-products are formed, they will quickly undergo nucleophilic hydrolysis with persulfate and be decomposed and detoxified.

A water treatment method using persulfate in situ to control the non-stable halogenated disinfection by-products in the liquid chlorine/chloramine disinfection process of this embodiment has the following advantages: (1) persulfate has been officially listed by the country as drinking water Water disinfectant product catalog, which can be applied in water purification plants and pipe networks; (2) Persulfate has a strong nucleophilic ability and can quickly decompose non-stable halogenated disinfection by-products; (3) Persulfate It does not consume liquid chlorine and chloramine, and can coexist with liquid chlorine and chloramine; (4) It can realize in-situ efficient conversion and detoxification of non-stable halogenated disinfection by-products; (5) The operation is simple and convenient, and no additional equipment is required , Low processing cost.

Embodiment 2: This embodiment differs from Embodiment 1 in that: the persulfate concentration in the water to be treated is 0.2-90 mg/L. Others are the same as in the first embodiment.

Embodiment 3: This embodiment differs from Embodiment 1 or Embodiment 2 in that: the persulfate concentration in the water to be treated is 0.5-80 mg/L. Others are the same as in the first or second embodiment.

Embodiment 4: This embodiment differs from Embodiments 1 to 3 in that: the persulfate concentration in the water to be treated is 1-70 mg/L. Others are the same as those in the first to third specific embodiments.

Embodiment 5: This embodiment differs from Embodiments 1 to 4 in that: the persulfate concentration in the water to be treated is 2-60 mg/L. Others are the same as one of the specific embodiments 1 to 4.

Embodiment 6: This embodiment differs from Embodiment 1 to Embodiment 5 in that: the persulfate concentration in the water to be treated is 5-50 mg/L. Others are the same as one of the specific embodiments 1 to 5.

Embodiment 7: This embodiment differs from Embodiment 1 to Embodiment 6 in that: the persulfate concentration in the water to be treated is 10-40 mg/L. Others are the same as one of the specific embodiments 1 to 6.

Embodiment 8: This embodiment differs from Embodiments 1 to 7 in that: the persulfate concentration in the water to be treated is 15-30 mg/L. Others are the same as one of the specific embodiments 1 to 7.

Embodiment 9: This embodiment differs from Embodiment 1 to Embodiment 8 in that: the persulfate concentration in the water to be treated is 20 mg/L. Others are the same as one of the specific embodiments 1 to 8.

Embodiment 10: This embodiment is different from Embodiment 1 to Embodiment 9 in that: the persulfate is permonosulfate and/or peroxodisulfate. Other steps and parameters are the same as one of the specific embodiments 1 to 9.

In the present embodiment, when the persulfate is a mixture of peroxomonosulfate and peroxodisulfate, both are mixed in an arbitrary ratio. Wherein the permonosulfate is potassium persulfate and sodium persulfate or a mixture of two mixed in any ratio, peroxodisulfate is one or both of potassium peroxodisulfate and sodium peroxodisulfate A mixture mixed in any ratio.

Embodiment 11: The difference between this embodiment and Embodiment 1 to 10 is that persulfate is persulfate, wherein persulfate is one or both of potassium persulfate and sodium persulfate. mixture of species. Other steps and parameters are the same as those in Embodiments 1 to 11.

In the present embodiment, when the peroxymonosulfate is a mixture, it is mixed in an arbitrary ratio.

Embodiment 12: The difference between this embodiment and Embodiment 1 to Eleven is that the persulfate is peroxodisulfate, wherein the peroxodisulfate is one of potassium peroxodisulfate, sodium peroxodisulfate or A mixture of the two. Other steps and parameters are the same as those in Embodiments 1 to 11.

In this embodiment, when peroxodisulfate is a mixture, it mixes in arbitrary ratios.

Specific embodiment thirteen: The difference between this embodiment and one of specific embodiments 1 to 12 is that persulfate is persulfate and peroxodisulfate, wherein persulfate is potassium persulfate and sodium persulfate One or a mixture of two, the peroxodisulfate is one or a mixture of potassium peroxodisulfate and sodium peroxodisulfate. Other steps and parameters are the same as those in Embodiments 1 to 12.

In the present embodiment, the permonosulfate and the peroxodisulfate are mixed in an arbitrary ratio, and when the peroxymonosulfate is a mixture, the mixture is mixed in an arbitrary ratio, and when the peroxodisulfate is a mixture, the mixture is mixed in an arbitrary ratio.

Embodiment 14: The difference between this embodiment and Embodiments 1 to 13 is that the persulfate is replaced by a compound salt of persulfate and alkali, wherein the molar ratio of persulfate and alkali is 1:1-10, wherein , the persulfate is persulfate and/or peroxodisulfate, and the alkali is one of potassium hydroxide, sodium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate or A mixture of several of them. Other steps and parameters are the same as those in Embodiments 1 to 13.

In the present embodiment, when the persulfate is a peroxomonosulfate and a peroxodisulfate, they are mixed in an arbitrary ratio. When the base is a mixture of several of them, it is mixed in any ratio.

The addition of alkali in this embodiment can adjust the pH value of the water treatment system to 6-9, which is beneficial to the ionization of persulfate and enhances the ability to induce decomposition of halogenated disinfection by-products.

In this embodiment, the molar ratio of persulfate to alkali is preferably 1:3-8, most preferably 1:5.

Embodiment 15: The difference between this embodiment and Embodiments 1 to 14 is that persulfate is replaced by a compound salt of persulfate and alkali, wherein the molar ratio of persulfate and alkali is 1:1-10 , wherein the persulfate is one or a mixture of potassium persulfate, sodium persulfate and ammonium persulfate. Other steps and parameters are the same as those in Embodiments 1 to 14.

In the present embodiment, when the peroxymonosulfate is a mixture of some of them, it is mixed in an arbitrary ratio.

In this embodiment, the molar ratio of persulfate to alkali is preferably 1:3-8, and the most preferable is 1:5.

Specific Embodiment Sixteen: The difference between this embodiment and Embodiments 1 to 15 is that persulfate is replaced by a compound salt of persulfate and alkali, wherein the molar ratio of persulfate and alkali is 1:1-10, Wherein the peroxodisulfate is one or a mixture of potassium peroxodisulfate, sodium peroxodisulfate and ammonium peroxodisulfate. Other steps and parameters are the same as those in Embodiments 1 to 15.

In this embodiment, when peroxodisulfate is a mixture, it mixes in arbitrary ratios.

In this embodiment, the molar ratio of peroxodisulfate to alkali is preferably 1:3-8, most preferably 1:5.

Specific embodiment seventeen: The difference between this embodiment and specific embodiments one to sixteen is that the persulfate is replaced by a compound salt of persulfate, peroxodisulfate and alkali, wherein persulfate and peroxodisulfate are combined The ratio of the molar weight to the alkali is 1:1 to 10, wherein the peroxomonosulfate is a mixture of one or more of potassium peroxosulfate, sodium peroxomonosulfate and ammonium peroxomonosulfate, and the peroxodisulfate is One or a mixture of potassium peroxodisulfate, sodium peroxodisulfate and ammonium peroxodisulfate.

In the present embodiment, when the peroxymonosulfate is a mixture of some of them, it is mixed in an arbitrary ratio. In this embodiment, when peroxodisulfate is a mixture, it mixes in arbitrary ratios.

In this embodiment, the ratio of the total molar weight of peroxomonosulfate and peroxodisulfate to the molar weight of alkali is preferably 1:3-8, and the best is 1:5.

Verify the beneficial effects of the present invention through the following examples:

A water treatment method using persulfate in situ to control the non-stable halogenated disinfection by-products in the disinfection process of liquid chlorine/chloramine in this embodiment is realized through the following steps: adding liquid to the water after filtration treatment Chlorine is carried out disinfection treatment, adds potassium persulfate and sodium hydroxide solution simultaneously, keeps stirring, promptly finishes the water treatment method of halogenated disinfection by-product in the described utilization persulfate in-situ control liquid chlorine/chloramine disinfection process, Wherein, the concentration of potassium persulfate is 5mg/L, and the molar ratio of potassium persulfate and sodium hydroxide is 1:2.

See soil 1 for the effect of using persulfate in situ to control halogenated disinfection by-products haloquinones (HBQs) in the liquid chlorine disinfection process in this embodiment. As can be seen from Figure 1, in the process of liquid chlorine disinfection, halogenated quinones are gradually generated along with the reaction time, and the cumulative concentration of halogenated quinones reaches 5 μg/L during 30 minutes of reaction; Potassium peroxymonosulfate and sodium hydroxide solutions were added simultaneously during the process, and the formation of haloquinones was hardly detected.

It can be seen that the water treatment method of this embodiment using persulfate in situ to control the non-stable halogenated disinfection by-products in the liquid chlorine/chloramine disinfection process has relatively prominent advantages.

Claims (10)

1. A water treatment method utilizing persulfate in-situ control liquid chlorine/chloramine disinfection process for non-stable halogenated disinfection by-products, characterized in that it utilizes persulfate in-situ control liquid chlorine/chloramine disinfection The water treatment method of non-stable halogenated disinfection by-products in the process is realized by the following steps: when adding liquid chlorine or chloramines to the water to be treated for disinfection, simultaneously add persulfate solution and keep stirring, that is Complete the water treatment method using persulfate in-situ control liquid chlorine/chloramine disinfection process of non-stable halogenated disinfection by-products, wherein the concentration of persulfate is 0.1 ~ 100mg/L, the water to be treated It is filtered water, sewage treatment plant effluent or ground water. 2. a kind of water treatment method utilizing persulfate in-situ control liquid chlorine/chloramine disinfection process of non-stable halogenated disinfection by-product according to claim 1, it is characterized in that persulfate is permonosulfate 1. One or two kinds of peroxodisulfates mixed in any ratio, wherein peroxomonosulfate is one or two kinds of peroxomonosulfate potassium peroxosulfate, sodium peroxosulfate or a mixture of two kinds mixed in any ratio. Sulphate is one of potassium peroxodisulfate and sodium peroxodisulfate or a mixture of the two in any ratio. 3. A kind of water treatment method utilizing persulfate in-situ control liquid chlorine/chloramine disinfection process according to claim 1 and 2, non-stable halogenated disinfection by-product, it is characterized in that persulfate concentration is 0.5 ~90mg/L. 4. A kind of water treatment method utilizing persulfate in-situ control liquid chlorine/chloramine disinfection process according to claim 1 and 2, characterized in that the persulfate concentration is 1 ~80mg/L. 5. a kind of water treatment method utilizing persulfate in-situ control liquid chlorine/chloramine disinfection process according to claim 1 and 2, non-stable halogenated disinfection by-product, it is characterized in that persulfate concentration is 5. ~50mg/L. 6. A kind of water treatment method utilizing persulfate in-situ control liquid chlorine/chloramine disinfection process according to claim 1 and 2, characterized in that persulfate concentration is 10 ~40mg/L. 7. A kind of water treatment method utilizing persulfate in-situ control liquid chlorine/chloramine disinfection process according to claim 1 and 2, characterized in that the persulfate concentration is 20 ~30mg/L. 8. A water treatment method utilizing persulfate in-situ control liquid chlorine/chloramine disinfection process of non-stable halogenated disinfection by-products, characterized in that it utilizes persulfate in-situ control liquid chlorine/chloramine disinfection The water treatment method of non-stable halogenated disinfection by-products in the process is realized through the following steps: when adding liquid chlorine or chloramine to the water to be treated for disinfection, simultaneously add a mixed solution of persulfate and alkali to keep Stirring state, that is to complete the water treatment method of the non-stable halogenated disinfection by-products in the in-situ control liquid chlorine/chloramine disinfection process using persulfate, wherein the molar ratio of persulfate and alkali is 1:1～ 10. The alkali is one of potassium hydroxide, sodium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate or a mixture of several of them mixed in any ratio, and the water to be treated is Filtered treated water, wastewater treatment plant effluent or groundwater. 9. a kind of water treatment method utilizing persulfate in-situ control liquid chlorine/chloramine disinfection process according to claim 8, is characterized in that persulfate is persulfate, One or two mixtures of peroxodisulfate in any ratio, wherein peroxomonosulfate is one of potassium persulfate and sodium persulfate or a mixture of two in any ratio, peroxodisulfate The salt is one of potassium peroxodisulfate and sodium peroxodisulfate or a mixture of the two in any ratio. 10. a kind of water treatment method utilizing persulfate in-situ control liquid chlorine/chloramine disinfection process of non-stable halogenated disinfection by-product according to claim 8, it is characterized in that the mol ratio of persulfate and alkali It is 1:3~8.