CN106904727A - Method and the application in water-supply systems that Fenton-type reagent is degraded to tetrachloro-ethylene are constituted based on growth ring and hydrogen peroxide - Google Patents

Abstract

Based on the method for degrading tetrachlorethylene by a Fenton-like reagent composed of a growth ring and hydrogen peroxide and its application in urban water supply systems, the present invention relates to the degradation of tetrachlorethylene by a Fenton-like reagent formed by a growth ring of a water supply pipe network and hydrogen peroxide. The invention discloses a method and application for degrading ethylene, which solves the problems of high cost and high requirements for equipment in existing methods for removing perchlorethylene in drinking water. The degradation method is to add growth rings and H ₂ O ₂ to raw water containing tetrachlorethylene, generate Fenton-like reagents during water treatment, and react to remove tetrachlorethylene in water. The application is to add H ₂ O ₂ to the clean water tank of the urban water supply plant. The H ₂ O ₂ in the water reacts with the growth ring in the water supply pipe network to form a Fenton-like reagent, and removes tetrachlorethylene in the water with the water supply cycle. The hydroxyl free radicals produced by the growth ring-Fenton-like reagent of the present invention have a high removal rate of tetrachlorethylene, and only need to add H ₂ O ₂ to utilize the growth ring waste, and the equipment requirements are simple.

Description

Degradation method of tetrachlorethylene based on growth ring and hydrogen peroxide constituting Fenton-like reagent Method and its application in urban water supply system

technical field

The invention relates to a method and application for degrading tetrachlorethylene (PCE) by using a Fenton-like reagent composed of a growth ring of a water supply pipe network and hydrogen peroxide.

Background technique

Perchlorethylene (PCE) is an important organochlorine product with strong dissolving power. It is mainly used as dry cleaning agent for fabrics, as well as metal degreasing detergent, desiccant, paint remover, insect repellent and general Solvents, organic synthesis intermediates, etc. Due to some reasons such as improper production, use, storage or disposal, it enters the atmosphere, soil, and groundwater through volatilization, leakage, wastewater discharge, pesticide use, and combustion of chlorine-containing organic products, becoming one of the main sources of environmental pollution. Perchlorethylene can invade the human body through the respiratory tract and skin, causing infertility and high miscarriage. Exposure to low-concentration tetrachlorethylene vapor can irritate the skin, mucous membranes, eyes, and respiratory tract. Long-term low-dose inhalation can cause dysfunction of the human neuroendocrine and immune systems; high concentrations can cause central nervous system depression, liver and kidney function damage, and lead to Dizziness, nausea, headache and confusion, severe cases can cause death. Perchlorethylene will also affect the glucose metabolism and lipid metabolism of the contacts.

In order to solve this problem, many methods for degrading tetrachlorethylene have been gradually developed, such as: physical method, the advantage is that it can quickly and effectively remove pollutants, and can be used as an emergency treatment technology for effectively removing tetrachlorethylene, but the price of adsorbent activated carbon It is more expensive and not suitable for large-scale pollution remediation, and physical methods can transfer tetrachlorethylene from one place to another, but cannot completely turn it into a harmless product.

In addition, chemical methods can use permanganate, ozone and other oxidants to continuously destroy pollutants, change the structure of pollutants, and completely remove them from the environment, but some transformation products of tetrachlorethylene may be more toxic than the parent; microorganisms It can degrade and destroy the molecular structure of pollutants, so that they can be finally transformed into non-toxic and harmless stable substances, but biological methods also have disadvantages such as long repair time and poor environmental adaptability of external strains. The above methods have problems such as poor safety, high requirements for equipment, difficult operation, high operating cost, and long repair time. Therefore urgently need a safe, reasonable, environmentally friendly, economical and effective method to remove perchlorethylene in drinking water to ensure people's health and living environment.

Contents of the invention

The purpose of the present invention is to solve the problems of high cost, poor safety and high requirements for equipment in the existing method for removing tetrachlorethylene in drinking water, and propose a fen-like compound based on the growth ring of the water supply pipe network and hydrogen peroxide. A method and application for removing tetrachlorethylene in drinking water with a reagent.

The method for degrading tetrachlorethylene based on the Fenton-like reagent composed of growth rings and hydrogen peroxide in the present invention is to add growth rings and H ₂ O ₂ with a mass concentration of 3% to 10% in the raw water containing tetrachlorethylene, In the process of water treatment, Fenton-like reagents are generated and reacted to remove perchlorethylene in water.

The application of the method for degrading tetrachlorethylene by the Fenton-like reagent composed of growth ring and hydrogen peroxide in the urban water supply system of the present invention is to add H ₂ O ₂ to the clear water tank of the urban water supply plant, and the added H ₂ The mass concentration of O ₂ is 3%-10%. H ₂ O ₂ in the water reacts with the growth ring in the water supply pipe network to form a Fenton-like reagent, and removes tetrachlorethylene in the water along with the water supply cycle.

In the present invention, the growth ring is an existing substance in the water supply pipe network, and the material is cheap and easy to obtain, and the cost of H2O2 is low _; the _{Fenton -} like system composed of the growth ring and _H2O2 can effectively remove tetrachlorethylene in drinking water , and tetrachlorethylene can be completely mineralized, enhancing the safety of drinking water.

The H ₂ O ₂ used in the present invention is a colorless transparent liquid, and is a strong oxidant. H ₂ O ₂ itself cannot burn, but the oxygen released during decomposition can strongly support combustion. When it decomposes, it can produce a large volume of oxygen, and the uncontrolled decomposition can cause the pressure of the equipment to explode. Therefore, in the present invention, the concentration achieved after the addition of H ₂ O ₂ needs to be reasonably controlled.

The higher the purity of H ₂ O ₂ , the better the stability, but the more sensitive to the existing impurities; in the low concentration range, H ₂ O ₂ is harmless, for example, the aqueous solution with a mass concentration of less than 3% can be used for oral disinfection. H ₂ O ₂ reacts with the growth ring in the pipe network for a long time, and the concentration of H ₂ O ₂ is low when the drinking water reaches the user, which is harmless to the human body. And under normal circumstances, it will decompose into water and oxygen, but the decomposition speed is extremely slow. H ₂ O ₂ transportation is non-hazardous, easy to prepare and cheap.

The method for degrading tetrachlorethylene by the Fenton-like system formed by the pipe network growth ring and hydrogen peroxide of the present invention includes the following beneficial effects:

1. The hydroxyl radicals produced by the growth ring-Fenton-like reagent have a high removal rate of tetrachlorethylene, and after 8 hours of water treatment reaction (water supply cycle), the degradation rate reaches more than 65%;

2. Perchlorethylene is almost completely mineralized and does not produce toxic products, which greatly enhances the safety of drinking water;

3. H ₂ O ₂ and growth rings are cheap and easy to obtain. In addition, the growth rings act as catalysts in the Fenton-like system and can be used for waste, and only need to add H ₂ O ₂ in the later stage; the equipment requirements are simple, Low energy loss, saving input and operating costs.

detailed description

Embodiment 1: In this embodiment, the Fenton-like reagent composed of growth rings and hydrogen peroxide degrades tetrachlorethylene by adding growth rings and a mass concentration of 3% to 10% in raw water containing tetrachlorethylene. H ₂ O ₂ in the water treatment process generates a Fenton-like reagent and reacts to remove tetrachlorethylene in water.

The reaction mechanism of the Fenton-like reaction described in the present embodiment is as follows:

Fe ²⁺ +H ₂ O ₂ →Fe ³⁺ +OH ^- +OH ^- (1)

Fe ³⁺ +H ₂ O ₂ →HO ₂ ^- +Fe ²⁺ +H ⁺ (2)

OH ^- +Fe ²⁺ →Fe ³⁺ +OH ^- (3)

Fe ³⁺ +HO ₂ ^- →Fe ²⁺ +O ₂ +H ⁺ (4)

OH ^- +H ₂ O ₂ →H ₂ O+HO ₂ ^- (5)

It can be seen from formula (5) that divalent iron ions catalyze hydrogen peroxide to form hydroxyl radicals, and divalent iron is oxidized to ferric iron. Ferric ions react with hydrogen peroxide to generate ferrous ions, and the reaction cycle proceeds. In the urban water supply network, there is no need to add other catalysts, and there are no by-products harmful to the human body.

Embodiment 2: This embodiment differs from Embodiment 1 in that the mass concentration of H ₂ O ₂ is 5% to 10%.

Embodiment 3: This embodiment is different from Embodiment 2 in that the mass concentration of H ₂ O ₂ is 10%.

Embodiment 4: This embodiment differs from Embodiment 1 to Embodiment 3 in that growth rings and H ₂ O ₂ with a mass concentration of 3% to 10% are added to the raw water containing tetrachlorethylene, wherein the growth rings and The mass ratio of H ₂ O ₂ with a mass concentration of 3%-10% is (1-4):(3-10).

Specific implementation mode five: the application of the method for degrading tetrachlorethylene based on the Fenton-like reagent composed of growth ring and hydrogen peroxide in the urban water supply system in this embodiment is to add H ₂ O ₂ to the clear water tank of the urban water supply plant , the mass concentration of the added H ₂ O ₂ is 3%-10%, the H ₂ O ₂ in the water reacts with the growth ring in the water supply pipe network to form a Fenton-like reagent, and removes the tetrachlorethylene in the water with the water supply cycle.

Embodiment 6: This embodiment differs from Embodiment 5 in that 50-150 mL of H ₂ O ₂ with a mass concentration of 3%-10% is added to each liter of water in the clear water pool.

Embodiment 7: This embodiment differs from Embodiment 6 in that 80-120 mL of H ₂ O ₂ with a mass concentration of 3%-10% is added to each liter of water in the clear water pool.

Embodiment 8: This embodiment is different from Embodiment 5 to Embodiment 7 in that the tetrachlorethylene in the water is removed with the water supply cycle for 6-20 hours.

Embodiment 9: This embodiment is different from Embodiment 8 in that the tetrachlorethylene in the water is removed with the water supply cycle for 8-15 hours.

Example 1: In this example, 10 μL of tetrachlorethylene is added to 50 mL of water as raw water, 5 ml of _hydrogen peroxide solution with a mass concentration of ₃ % and 0.1 g of growth rings are added to the raw water, and the H2O2 in the water reacts with the growth rings to form Fenton's reagent, detects perchlorethylene in water after 8 hours.

In this example, the PCE concentration in the water was reduced from 205.31 mg/L to 45.79 mg/L, and the degradation rate was about 77.61%.

Example 2: In this example, 10 μL of tetrachlorethylene is added to 50 mL of water as raw water, 5 ml of _hydrogen peroxide solution with a mass concentration of 5% and 0.4 _g of growth rings are added to the raw water, and H2O2 in the water reacts with the growth rings to form Fenton's reagent, detects perchlorethylene in water after 8 hours.

In this embodiment, the PCE concentration in the water is reduced from 199.21 mg/L to 41.22 mg/L, and the degradation rate is about 79.31%.

Example 3: In this example, 10 μL of tetrachlorethylene is added to 50 mL of water as the raw water, and 10 ml of hydrogen peroxide solution with a mass concentration of 5% and 0.1 g of growth rings are added to the raw water, and H ₂ O ₂ in the water reacts with the growth rings to form Fenton's reagent, detects perchlorethylene in water after 8 hours.

In this embodiment, the concentration of PCE in water is reduced from 207.75 mg/L to 71.98 mg/L, and the degradation rate is about 65.35%.

Example 4: In this example, 10 μL of tetrachlorethylene is added to 50 mL of water as raw water, 15 ml of _hydrogen peroxide solution with a mass concentration of 5% and 0.2 _g of growth rings are added to the raw water, and H2O2 in the water reacts with the growth rings to form Fenton's reagent, detects perchlorethylene in water after 8 hours.

In this embodiment, the concentration of PCE in water is reduced from 209.36 mg/L to 23.67 mg/L, and the degradation rate is about 88.69%.

Example 5: In this example, 10 μL of tetrachlorethylene was added to 50 mL of water as raw water, and 10 ml of _hydrogen peroxide solution with a mass concentration of 10% and 0.4 _g of growth rings were added to the raw water, and the H2O2 in the water reacted with the growth rings to form Fenton's reagent, detects perchlorethylene in water after 8 hours.

In this embodiment, the concentration of PCE in water is reduced from 203.65 mg/L to 40.04 mg/L, and the degradation rate is about 88.34%.

Claims (9)

1. the method that the Fenton-type reagent for being constituted based on growth ring and hydrogen peroxide is degraded to tetrachloro-ethylene, it is characterised in that the party Method is growth ring to be added in the raw water containing tetrachloro-ethylene and H that mass concentration is 3%~10%₂O₂, in water treatment procedure Generation Fenton-type reagent, is reacted, so as to remove the tetrachloro-ethylene in water removal.

2. the Fenton-type reagent constituted based on growth ring and hydrogen peroxide according to claim 1 is degraded to tetrachloro-ethylene Method, it is characterised in that H₂O₂Mass concentration be 5%~10%.

3. the Fenton-type reagent constituted based on growth ring and hydrogen peroxide according to claim 2 is degraded to tetrachloro-ethylene Method, it is characterised in that H₂O₂Mass concentration be 10%.

4. the Fenton-type reagent constituted based on growth ring and hydrogen peroxide according to claim 1 is degraded to tetrachloro-ethylene Method, it is characterised in that growth ring is added in the raw water containing tetrachloro-ethylene and H that mass concentration is 3%~10%₂O₂, its Middle growth ring and mass concentration are 3%~10% H₂O₂Mass ratio be (1~4)：(3~10).

5. the method that the Fenton-type reagent for being constituted based on growth ring and hydrogen peroxide is degraded to tetrachloro-ethylene is in water-supply systems In application, it is characterised in that the application is to add H in the clear water reserviors of urban water supply factory₂O₂, the H for adding₂O₂Mass concentration It is 3%~10%, the H in water₂O₂Growth ring reaction generation Fenton-type reagent with water supply network, water removal is gone with watering cycle In tetrachloro-ethylene.

6. the Fenton-type reagent constituted based on growth ring and hydrogen peroxide according to claim 5 is degraded to tetrachloro-ethylene Application of the method in water-supply systems, it is characterised in that addition 50~150mL mass concentrations are in every liter of water in clear water reserviors 3%~10% H₂O₂。

7. the Fenton-type reagent constituted based on growth ring and hydrogen peroxide according to claim 6 is degraded to tetrachloro-ethylene Application of the method in water-supply systems, it is characterised in that addition 80~120mL mass concentrations are in every liter of water in clear water reserviors 3%~10% H₂O₂。

8. the Fenton-type reagent constituted based on growth ring and hydrogen peroxide according to claim 5 is degraded to tetrachloro-ethylene Application of the method in water-supply systems, it is characterised in that with the tetrachloro-ethylene that 6~20h of watering cycle is gone in water removal.

9. the Fenton-type reagent constituted based on growth ring and hydrogen peroxide according to claim 8 is degraded to tetrachloro-ethylene Application of the method in water-supply systems, it is characterised in that with the tetrachloro-ethylene that 8~15h of watering cycle is gone in water removal.