CN106830272A - A kind of utilization wall erosion thing catalysis persulfate controls the method for treating water of halogenated disinfection by-products - Google Patents

Abstract

The invention relates to a water treatment method for controlling halogenated disinfection by-products by using pipe wall corrosion to catalyze persulfate, which relates to a water treatment method. The invention solves the problem that a large amount of halogenated disinfection by-products are produced in the disinfection process of liquid chlorine and chloramine. Water treatment method of the present invention: when adding liquid chlorine or chloramine in the water to be treated for disinfection treatment, add persulfate solution simultaneously, stir, utilize pipe wall corrosion to catalyze the sulfate radical free radical that persulfate produces, to The halogenated disinfection by-products are oxidatively degraded to realize the efficient transformation and detoxification of the halogenated disinfection by-products, which is completed. The invention has the following advantages: persulfate does not consume liquid chlorine and chloramine, no additional light sources or catalysts are needed, the pipe wall corrosion catalyzes it to generate sulfate radicals, and realizes the efficient conversion and detoxification of halogenated disinfection by-products. The operation is simple and convenient, and the treatment cost is low. At the same time, persulfate has been officially included in the catalog of drinking water disinfectants by the country, and can be applied in water purification plants and pipe networks.

Description

A kind of water that uses pipe wall corrosion to catalyze persulfate to control halogenated disinfection by-products Approach

technical field

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

Background technique

Liquid chlorine and chloramine disinfection are prone to form halogenated disinfection by-products, such as trihalomethanes, haloacetic acids, halogenated nitromethanes, nitrogen-containing disinfection by-products, etc., which pose a threat to the safety of drinking water. Therefore, how to control the halogenated disinfection by-products in water is a new challenge in the water treatment process.

The main method to control the halogenated disinfection by-products in water is to use sulfate radicals and hydroxyl radicals produced in different ways to oxidize and degrade them. 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 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 salt to activate sulfate radicals produced by persulfate, oxidizing iodide ions in water into non-toxic and harmless iodate, and synchronously Precursors are removed, and the formation of iodo disinfection by-products is controlled. Patent CN106045007A discloses a water treatment method using persulfate catalyzed ozonation to oxidize refractory iodinated organic matter to control iodized disinfection by-products, through persulfate catalyzed ozonolysis to produce hydroxyl radicals and sulfate radicals to oxidize iodized organic matter deiodination Hydroxylation product.

To sum up, for persulfate, a green oxidant, research mainly uses light, metal catalysts, etc. to catalyze persulfate to produce hydroxyl radicals and sulfate radicals to oxidize and degrade halogenated disinfection by-products. or catalyst issues.

At present, iron pipes such as cast iron pipes and galvanized steel pipes still exist in large quantities in my country's water supply pipe network. Due to serious corrosion, a thick layer of pipe wall corrosion has formed on the inner wall of the pipe, containing a large amount of iron, copper, Manganese, zinc and other metal oxides. If the pipe wall corrosion can be used as a catalyst for persulfate, it will achieve good results in the water treatment process, that is, the operation is simple and convenient, and the treatment cost is saved, and there will be no pollution caused by an external catalyst. .

Contents of the invention

The purpose of the present invention is to provide a water treatment method that uses pipe wall corrosion to catalyze persulfate to control halogenated disinfection by-products, so as to solve the problem of producing a large amount of halogenated disinfection by-products in the disinfection process of liquid chlorine and chloramine.

A water treatment method of the present invention that utilizes pipe wall corrosion to catalyze persulfate to control halogenated disinfection by-products is realized through the following steps: when adding liquid chlorine or chloramine to the water to be treated for disinfection, simultaneously adding The persulfate solution is kept in a stirring state, that is, the water treatment method for controlling halogenated disinfection by-products by catalyzing persulfate using pipe wall corrosion is completed, wherein the concentration of persulfate is 1 to 100 mg/L, and the described to-be The treated water is filtered water or sewage treatment plant effluent.

In a kind of water treatment method of the present invention, which utilizes pipe wall corrosion to catalyze persulfate to control halogenated disinfection by-products, said persulfate is one or both of persulfate and peroxodisulfate in any ratio. Mixed mixture, wherein the peroxomonosulfate is one of potassium peroxodisulfate and sodium peroxomonosulfate or a mixture of two mixed in any ratio, and the peroxodisulfate is one of potassium peroxodisulfate and sodium peroxodisulfate A mixture of one or two in any ratio.

In a water treatment method of the present invention that utilizes pipe wall corrosion to catalyze persulfate to control halogenated disinfection by-products, the persulfate is replaced by a compound salt of persulfate and alkali, wherein the molar ratio of persulfate to alkali is It 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 persulfate, and alkali is Potassium hydroxide, sodium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate or a mixture of several of them in any ratio; persulfate is potassium persulfate, One or two kinds of sodium peroxodisulfate are mixed in any ratio, and the peroxodisulfate is one or two kinds of potassium peroxodisulfate and sodium peroxodisulfate or a mixture of two kinds are mixed in any ratio.

The principle of a water treatment method that utilizes pipe wall corrosion to catalyze persulfate to control halogenated disinfection by-products: the catalytic action of persulfate on pipe wall corrosion (metal oxides such as iron, copper, manganese, and zinc) Sulfate radicals are generated under the environment, and sulfate radicals use their strong oxidizing properties to oxidatively degrade the halogenated disinfection by-products formed after liquid chlorine or chloramine disinfection treatment, so as to realize the efficient transformation and detoxification of halogenated disinfection by-products.

A kind of water treatment method that utilizes pipe wall corrosion to catalyze persulfate to control halogenated disinfection by-products of the present invention has the following advantages: (1) persulfate has been officially included in the catalog of drinking water disinfectant products by the country, and can be used in clean water Applied in water plants and pipe networks; (2) Persulfate does not consume liquid chlorine and chloramine, and can coexist with liquid chlorine and chloramine; (3) Using the strong oxidizing properties of sulfate radicals, it can realize halogenated disinfection High-efficiency conversion and detoxification of products; (4) use pipe wall corrosion as a catalyst for persulfate, without additional light sources or catalysts, simple and convenient operation, and low processing cost.

Description of drawings

Figure 1 is a diagram of the removal effect of trichloroacetic acid, a by-product of halogenated disinfection, controlled by monopersulfate catalyzed by pipe wall corrosion in the experiment.

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 that utilizes pipe wall corrosion to catalyze persulfate to control halogenated disinfection by-products, which is achieved through the following steps: adding liquid chlorine or chloramine to the water to be treated When carrying out disinfection treatment, add persulfate solution at the same time and keep stirring, that is, complete the water treatment method of utilizing pipe wall corrosion to catalyze persulfate to control halogenated disinfection by-products, wherein the concentration of persulfate is 1 ~100mg/L, the water to be treated is filtered water or effluent from a sewage treatment plant.

The principle of this embodiment is a water treatment method that utilizes pipe wall corrosion to catalyze persulfate to control halogenated disinfection by-products: the catalysis of persulfate on pipe wall corrosion (iron, copper, manganese, zinc and other metal oxides) Under the action, sulfate radicals are generated, and sulfate radicals use their strong oxidizing properties to oxidatively degrade the halogenated disinfection by-products formed after liquid chlorine or chloramine disinfection treatment, so as to realize the efficient transformation and detoxification of halogenated disinfection by-products.

A kind of water treatment method that utilizes pipe wall corrosion to catalyze persulfate to control halogenated disinfection by-products of this embodiment has the following advantages: (1) persulfate has been officially included in the catalog of drinking water disinfectant products by the country, and can be used in Applied in water purification plants and pipe networks; (2) Persulfate does not consume liquid chlorine and chloramine, and can coexist with liquid chlorine and chloramine; (3) Using the strong oxidation of sulfate radicals, it can realize halogenation disinfection Efficient conversion and detoxification of by-products; (4) Using pipe wall corrosion as a catalyst for persulfate, without additional light sources or catalysts, the operation is simple and convenient, and the treatment cost is low.

Embodiment 2: This embodiment differs from Embodiment 1 in that: the persulfate concentration in the water to be treated is 1.5-90 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 2-80 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 3-70 mg/L. Others are the same as those in the first to third specific embodiments.

Embodiment 5: This embodiment differs from Embodiment 1 to Embodiment 4 in that: the persulfate concentration in the water to be treated is 4-60 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 in any ratio, peroxodisulfate is one or both of potassium peroxodisulfate and sodium peroxodisulfate A mixture composed 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. A mixture composed in any ratio. 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.

Specific embodiment 12: The difference between this embodiment and specific embodiments 1 to 11 is that persulfate is peroxodisulfate, wherein peroxodisulfate is one of potassium peroxodisulfate and sodium peroxodisulfate Or a mixture of the two in any ratio. Other steps and parameters are the same as those in Embodiments 1 to 11.

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 of them or a mixture of two in any ratio, the peroxodisulfate is one of potassium peroxodisulfate and sodium peroxodisulfate or a mixture of two in any ratio. Other steps and parameters are the same as those in Embodiments 1 to 12.

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 17: The difference between this embodiment and specific embodiments 1 to 16 is that the persulfate is replaced by a compound salt of persulfate, peroxodisulfate and alkali, wherein persulfate and peroxodisulfate The ratio of the total molar amount to the molar amount of the base is 1:1-10, wherein the persulfate is a mixture of one or more of potassium persulfate, sodium persulfate and ammonium persulfate, and peroxodisulfate It 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 16.

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.

Can verify beneficial effect of the present invention by following experiment:

Take 1L of distilled water, add trichloroacetic acid at a concentration of 50μg/L, add pipe corrosion products from the inner wall of the pipe network at a concentration of 10mg/L, keep stirring, add potassium monopersulfate solution at a concentration of 20mg/L, and react differently Samples were taken over time to determine changes in TCA concentration. The experimental results are shown in Figure 1. As can be seen from Figure 1, as the reaction time progresses, the concentration of trichloroacetic acid gradually decreases, and at 60 min, the removal rate reaches more than 90%.

It can be seen that the water treatment method of controlling halogenated disinfection by-products by using pipe wall corrosion to catalyze persulfate is effective and feasible.

Claims (10)

1. A water treatment method utilizing pipe wall corrosion to catalyze persulfate to control halogenated disinfection by-products is characterized in that a kind of water treatment method utilizing pipe wall corrosion to catalyze persulfate to control halogenated disinfection by-products is by The following steps are implemented: when adding liquid chlorine or chloramine to the water to be treated for disinfection, add persulfate solution at the same time and keep stirring, that is, the use of pipe wall corrosion to catalyze persulfate to control halogenation disinfection A water treatment method for by-products, wherein the concentration of persulfate is 1-100 mg/L, and the water to be treated is filtered water or effluent from a sewage treatment plant. 2. A kind of water treatment method utilizing pipe wall corrosion to catalyze persulfate to control halogenated disinfection by-products according to claim 1, characterized in that persulfate is one of persulfate and peroxodisulfate One or two mixtures mixed in any ratio, wherein peroxomonosulfate is potassium peroxosulfate, sodium peroxosulfate or a mixture of two kinds mixed in any ratio, peroxodisulfate is potassium peroxodisulfate, One or two kinds of sodium persulfate mixed in any ratio. 3. A water treatment method for controlling halogenated disinfection by-products by using pipe wall corrosion to catalyze persulfate according to claim 1 or 2, characterized in that the concentration of persulfate is 1.5-90 mg/L. 4. A water treatment method for controlling halogenated disinfection by-products by using pipe wall corrosion to catalyze persulfate according to claim 1 or 2, characterized in that the concentration of persulfate is 2-80 mg/L. 5. A water treatment method for controlling halogenated disinfection by-products by using pipe wall corrosion to catalyze persulfate according to claim 1 or 2, characterized in that the concentration of persulfate is 5-50 mg/L. 6. A water treatment method for controlling halogenated disinfection by-products by using pipe wall corrosion to catalyze persulfate according to claim 1 or 2, characterized in that the concentration of persulfate is 10-40 mg/L. 7. A water treatment method for controlling halogenated disinfection by-products by using pipe wall corrosion to catalyze persulfate according to claim 1 or 2, characterized in that the concentration of persulfate is 20-30 mg/L. 8. A water treatment method utilizing pipe wall corrosion to catalyze persulfate to control halogenated disinfection byproducts is characterized in that a water treatment method utilizing pipe wall corrosion to catalyze persulfate to control halogenated disinfection byproducts is by The following steps are realized: when adding liquid chlorine or chloramine to the water to be treated for disinfection, add persulfate and alkali mixed solution at the same time, keep stirring, that is, complete the use of pipe wall corrosion to catalyze persulfate control A water treatment method for halogenated disinfection by-products, wherein the molar ratio of persulfate to alkali is 1:1 to 10, and the alkali is potassium hydroxide, sodium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate 1. One of potassium bicarbonate or a mixture of several of them in any ratio, and the water to be treated is filtered water or sewage treatment plant effluent. 9. A kind of water treatment method utilizing pipe wall corrosion to catalyze persulfate to control halogenated disinfection by-products according to claim 8, characterized in that persulfate is one of persulfate and peroxodisulfate Or two mixtures mixed in any ratio, wherein the peroxomonosulfate is potassium peroxosulfate, sodium peroxosulfate or a mixture of two in any ratio, and the peroxodisulfate is potassium peroxodisulfate, peroxodisulfate One or two mixtures of sodium disulfate in any ratio. 10. A water treatment method for controlling halogenated disinfection by-products by using pipe wall corrosion to catalyze persulfate according to claim 8, characterized in that the molar ratio of persulfate to alkali is 1:3-8.