CN106830273A - A kind of method for treating water using iodo accessory substance during single persulfate in-situ control chloramines disinfection - Google Patents

Abstract

A kind of method for treating water using iodo accessory substance during single persulfate in-situ control chloramines disinfection, is related to method for treating water, solves the problems, such as easily to form iodo accessory substance during chloramines disinfection.Method for treating water of the invention：Added in accessing pending water chloramines carry out disinfection treatment when, while add single persulfate solution, stir, using the oxidisability of single persulfate, iodide ion is oxidized to hypoiodous acid, and hypoiodous acid is further oxidized to nontoxic iodate, that is, complete the control to iodo accessory substance.The present invention has advantages below：Iodide ion quickly can be oxidized to hypoiodous acid by single persulfate, and by the inoxidizable hypoiodous acid rapid oxidation of chloramines be further nontoxic iodate；And single persulfate does not consume chloramines, can be coexisted with chloramines；Single persulfate formally lists drinking water disinfection agent catalogue in by country, can be applied in water treatment plant and pipe network；Simple to operate, processing cost is low.

Description

A method for in-situ control of iodine by-products in chloramine disinfection using monopersulfate water treatment method

technical field

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

Background technique

As a disinfectant, chloramine has good stability and stronger penetrating ability than chlorine. It lasts for a long time in the pipe network and can effectively control the reproduction of harmful microorganisms and the formation of biofilm in the pipe network. It rarely produces trihalomethanes ( THMS) and haloacetic acids (HAAs), there are fewer carcinogenic and mutagenic compounds. Chloramine can oxidize iodide ions (I ^- ) in water to hypoiodous acid (HOI), but cannot rapidly oxidize it to iodate (IO ₃ ^- ), so the generated hypoiodous acid will react with natural organic matter in water (NOM) reacts to form iodine by-products, which affects the safety of drinking water. At present, the method of controlling iodine by-products is mainly to use strong oxidizing free radicals to oxidatively degrade precursors or formed by-products.

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 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 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 iodinated organic matter through deiodination Hydroxylation products, ozone and persulfate oxidize iodide ions to generate hypoiodous acid, and ozone further quickly reacts with hypoiodous acid to generate non-toxic and harmless iodate, so as to inhibit the reaction between hypoiodous acid and organic matter in water to form iodized by-products generated purpose.

Therefore, in the research, it is generally believed that monopersulfate can only oxidize iodide ion (I ^- ) to hypoiodous acid (HOI), and cannot be further oxidized into non-toxic and harmless iodate (IO ₃ ^2- ), as in patent CN106045007A , but in the research of this patent, it is found that monopersulfate can oxidize iodide ion (I ^- ) to hypoiodous acid (HOI), and further oxidize it to iodate (IO ₃ ^2- ).

Contents of the invention

The purpose of the present invention is to solve the problem that iodized by-products are easily formed in the chloramine disinfection process, and provide a water treatment method for controlling the iodized by-products in the chloramine disinfection process by using monopersulfate in situ.

A kind of water treatment method of the present invention utilizes monopersulfate in situ to control the iodized by-products in the chloramine disinfection process is realized through the following steps: when adding chloramine to the water to be treated for disinfection treatment, adding monopersulfate at the same time The persulfate solution is kept in a stirring state to complete the water treatment method of using monopersulfate in-situ control of iodine by-products in the chloramine disinfection process, wherein the concentration of monopersulfate is 0.1 to 100mg/L, The water to be treated is filtered water or effluent from a sewage treatment plant.

In the water treatment method of the present invention, the monopersulfate is one or both of potassium monopersulfate and sodium monopersulfate for in-situ control of iodized by-products in the chloramine disinfection process. A mixture composed in any ratio.

In a kind of water treatment method utilizing monopersulfate in-situ control of iodized by-products in the chloramine disinfection process of the present invention, said monopersulfate is replaced by a compound salt of monopersulfate and alkali, wherein monopersulfate The molar ratio of alkali to alkali is 1:1-10, and the addition of alkali can adjust the pH value of the water treatment system to 6-9, which is beneficial to the ionization of monopersulfate; among them, the alkali is potassium hydroxide, sodium hydroxide, hydroxide Calcium, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate or a mixture of several of them in any ratio; permonosulfate is one or both of potassium persulfate and sodium persulfate A mixture composed in any ratio.

A kind of principle of the water treatment method that utilizes monopersulfate in situ to control the iodized by-product in the chloramine disinfection process of the present invention: in the chloramine disinfection process, because its oxidizing property is relatively weak, only the iodide ion ( ^1- ) is oxidized to hypoiodous acid (HOI), and the hypoiodous acid generated will react with natural organic matter (NOM) in water to form iodo disinfection by-products; when carrying out chloramine disinfection, add monopersulfate (PMS), Utilizing its oxidative properties, iodide ions (I ^- ) can be oxidized to hypoiodous acid (HOI), and further rapidly oxidized hypoiodous acid to non-toxic and harmless iodate (IO ₃ ^2- ), thereby controlling the iodine Generation of disinfection by-products.

A kind of water treatment method that utilizes monopersulfate in-situ control chloramine disinfection process in the water treatment method of iodo by-product has the following advantages: (1) monopersulfate has been formally included in the list of drinking water disinfectant products by the country, It can be applied in water purification plants and pipe networks; (2) monopersulfate can quickly oxidize iodide ions (I ^- ) to hypoiodous acid (HOI), and further rapidly oxidize hypoiodous acid that cannot be oxidized by chloramines It is non-toxic and harmless iodate (IO ₃ ^2- ); (3) monopersulfate does not consume chloramine and can coexist with chloramine; (4) is simple and convenient to operate and low in treatment cost.

Description of drawings

Figure 1 is a schematic diagram of a water treatment method using monopersulfate to control iodo by-products in the chloramine disinfection process.

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 monopersulfate in situ to control the iodized by-products in the chloramine disinfection process, which is achieved by the following steps: adding chloramine to the water to be treated During disinfection treatment, add monopersulfate solution simultaneously, keep stirring state, promptly finish the water treatment method that utilizes monopersulfate in-situ control chloramine disinfection process of iodo by-product, wherein, monopersulfate The concentration is 0.1-100 mg/L, and 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 using monopersulfate in situ to control the iodized by-products in the chloramine disinfection process: in the chloramine disinfection process, due to its relatively weak oxidation, only iodide ions present in the water can be removed. (I ^- ) is oxidized to hypoiodous acid (HOI), and the generated hypoiodous acid will react with natural organic matter (NOM) in water to form iodized disinfection by-products; add monopersulfate (PMS) when performing chloramine disinfection , using its oxidizing properties to oxidize iodide ions (I ^- ) to hypoiodous acid (HOI), and further rapidly oxidize hypoiodous acid to non-toxic and harmless iodate (IO ₃ ^2- ), thus controlling the iodine Generation of disinfection by-products.

A kind of water treatment method utilizing monopersulfate in situ to control iodized by-products in the chloramine disinfection process of this embodiment has the following advantages: (1) monopersulfate has been officially included in the catalog of drinking water disinfectant products by the state , can be applied in water purification plants and pipe networks; (2) monopersulfate can quickly oxidize iodide ion (I ^- ) to hypoiodous acid (HOI), and further quickly oxidize hypoiodous acid that cannot be oxidized by chloramine Oxidation to non-toxic and harmless iodate (IO ₃ ^2- ); (3) Monopersulfate does not consume chloramine and can coexist with chloramine; (4) Simple and convenient operation and low treatment cost.

Embodiment 2: This embodiment differs from Embodiment 1 in that: the concentration of monopersulfate 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 concentration of monopersulfate 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 concentration of monopersulfate 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 Embodiment 1 to Embodiment 4 in that: the concentration of monopersulfate 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 concentration of monopersulfate 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 concentration of monopersulfate 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 concentration of monopersulfate 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 concentration of monopersulfate 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 monopersulfate is potassium monopersulfate and sodium monopersulfate or a mixture of the two in any ratio. Other steps and parameters are the same as one of the specific embodiments 1 to 9.

Embodiment 11: This embodiment differs from Embodiments 1 to 10 in that the monopersulfate is replaced by a compound salt of monopersulfate and alkali, wherein the molar ratio of monopersulfate to alkali is 1:1-10 , wherein 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 in any ratio, monopersulfate It is one of potassium monopersulfate and sodium monopersulfate or a mixture of the two in any ratio. Other steps and parameters are the same as those in Embodiments 1 to 11.

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.

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

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

Take 1L of distilled water, in which iodide ion (I ^- ) concentration is 10μmol/L, humic acid (HA) concentration is 4mgC/L, keep stirring, add chloramine, concentration is 5mg/L, add potassium monopersulfate (PMS ) solution with a concentration of 5 mg/L, and measure the concentration of the iodo by-product after 24 h of reaction. The experimental results show that when chloramine is oxidized alone, the iodized by-product is 10 μmol/L when reacted for 24 hours. When chloramine and potassium monopersulfate are added at the same time, the iodized by-product is hardly detected.

It can be seen that monopersulfate can well control the generation of iodo disinfection by-products in the process of chloramine disinfection.

Claims (10)

1. a kind of method for treating water using iodo accessory substance during single persulfate in-situ control chloramines disinfection, its feature exists The method for treating water of iodo accessory substance is by following step during a kind of persulfate in-situ control chloramines disinfection using list Rapid realization：Added in accessing pending water chloramines carry out disinfection treatment when, while adding single persulfate solution, be kept stirring for shape State, that is, complete the method for treating water using iodo accessory substance during single persulfate in-situ control chloramines disinfection, wherein, The concentration of single persulfate is 0.1~100mg/L, and the accessing pending water is water or sewage disposal plant effluent after filtration treatment.

2. according to claim 1 a kind of using iodo accessory substance during single persulfate in-situ control chloramines disinfection Method for treating water, it is characterised in that single persulfate is that one or two in Potassium peroxysulfate, single sodium peroxydisulfate press any ratio The mixture of composition.

3. according to claim 1 and 2 a kind of using iodo by-product during single persulfate in-situ control chloramines disinfection The method for treating water of thing, it is characterised in that single persulfate concentration is 0.5~90mg/L.

4. according to claim 1 and 2 a kind of using iodo by-product during single persulfate in-situ control chloramines disinfection The method for treating water of thing, it is characterised in that single persulfate concentration is 1~80mg/L.

5. according to claim 1 and 2 a kind of using iodo by-product during single persulfate in-situ control chloramines disinfection The method for treating water of thing, it is characterised in that single persulfate concentration is 5~50mg/L.

6. according to claim 1 and 2 a kind of using iodo by-product during single persulfate in-situ control chloramines disinfection The method for treating water of thing, it is characterised in that single persulfate concentration is 10~40mg/L.

7. according to claim 1 and 2 a kind of using iodo by-product during single persulfate in-situ control chloramines disinfection The method for treating water of thing, it is characterised in that single persulfate concentration is 20~30mg/L.

8. a kind of method for treating water using iodo accessory substance during single persulfate in-situ control chloramines disinfection, its feature exists The method for treating water of iodo accessory substance is by following step during a kind of persulfate in-situ control chloramines disinfection using list Rapid realization：Added in accessing pending water chloramines carry out disinfection treatment when, while add the mixed solution of single persulfate and alkali, State is kept stirring for, that is, completes the water process using iodo accessory substance during single persulfate in-situ control chloramines disinfection Method, wherein, the mol ratio of single persulfate and alkali is 1:1~10, alkali is potassium hydroxide, NaOH, calcium hydroxide, carbonic acid One kind or wherein several by any mixture than composition in sodium, potassium carbonate, sodium acid carbonate, saleratus, it is described pending Water is water or sewage disposal plant effluent after filtration treatment.

9. according to claim 8 a kind of using iodo accessory substance during single persulfate in-situ control chloramines disinfection Method for treating water, is characterised by that single persulfate is one or two in Potassium peroxysulfate, single sodium peroxydisulfate by arbitrarily comparing group Into mixture.

10. according to claim 8 a kind of using iodo accessory substance during single persulfate in-situ control chloramines disinfection Method for treating water, it is characterised in that the mol ratio of single persulfate and alkali be 1:3~8.