阅读说明：本技术 人工合成水铁矿及其在新型光-Fenton体系中的应用方法 (Artificially synthesized ferrihydrite and application method thereof in novel photo-Fenton system ) 是由 谢宏杰 于 2019-11-01 设计创作，主要内容包括：本发明公开了人工合成水铁矿及其在新型光-Fenton体系中的应用方法,所述水铁矿的制备方法是：将Fe(NO<Sub>3</Sub>)<Sub>3</Sub>·9H<Sub>2</Sub>O溶于去离子水中,再加入KOH溶液,调pH至7.4-7.6搅拌并将所得的胶体离心处理,弃去上清液,用去离子水冲洗所得的固体,摇匀,离心处理,弃去上清液,如此重复5次后于40℃烘干。所述水铁矿在新型光-Fenton体系中的应用方法是：1)将目标污染物BPA置于烧杯中；2)在烧杯中加入羧酸；3)再加入水铁矿；4)加入过氧化氢；5)最后加入可见光,组成水铁矿-羧酸/光-Fenton体系,应用于BPA的降解。本发明将水铁矿和羧酸引入光-Fenton体系中,克服了传统均相Fenton技术铁泥产生量大,pH适用范围窄的缺点,减少了过氧化氢氧化剂的使用量,具有经济性和环境友好的特点,有很好的应用前景。(The invention discloses a synthetic ferrihydrite and an application method thereof in a novel photo-Fenton system, wherein the preparation method of the ferrihydrite comprises the following steps: mixing Fe (NO) 3 ) 3 ·9H 2 Dissolving O in deionized water, adding KOH solution, adjusting pH to 7.4-7.6, stirring, centrifuging the obtained colloid, discarding supernatant, washing the obtained solid with deionized water, shaking, centrifuging, discarding supernatant, repeating the above steps for 5 times, and oven drying at 40 deg.C. The application method of the ferrihydrite in the novel photo-Fenton system comprises the following steps: 1) placing a target contaminant BPA in a beaker; 2) adding carboxylic acid into a beaker; 3) then adding ferrihydrite; 4) adding hydrogen peroxide; 5) finally adding visible light to form waterThe iron ore-carboxylic acid/light-Fenton system is applied to degradation of BPA. According to the invention, the ferrihydrite and the carboxylic acid are introduced into the photo-Fenton system, so that the defects of large iron mud generation amount and narrow pH application range in the traditional homogeneous phase Fenton technology are overcome, the usage amount of the hydrogen peroxide oxidant is reduced, and the method has the characteristics of economy and environmental friendliness and has a good application prospect.)

1. The artificial synthetic ferrihydrite is characterized in that the preparation method comprises the following steps:

40.0g Fe (NO) was weighed₃)₃·9H₂Dissolving O in 500mL of deionized water, adding 310mL of KOH solution with the concentration of 1mol/L, continuously adjusting the pH of the solution to 7.4-7.6 by using 1mol/L of KOH, violently stirring for 1h, centrifuging the obtained colloid for 12min, discarding the supernatant, washing the obtained solid with deionized water, shaking up, centrifuging for 12min, discarding the supernatant, repeating the steps for 5 times, and drying at 40 ℃ to obtain the artificially synthesized ferrihydrite.

2. The synthetic ferrihydrite according to claim 1, wherein KOH solution is added at a rate of 100 mL/min; the centrifugation treatment was carried out at 4000 rpm.

3. The application method of the synthetic ferrihydrite in the novel photo-Fenton system according to claim 1 or 2, characterized in that it comprises the following steps:

(1) placing the target contaminant BPA in a large beaker;

(2) adding carboxylic acid into a large beaker;

(3) then adding the artificially synthesized ferrihydrite;

(4) adding hydrogen peroxide into the mixed solution;

(5) and finally, adding visible light to form a ferrihydrite-carboxylic acid/light-Fenton system and degrade the environmental endocrine disruptor BPA.

4. The application method of the synthetic ferrihydrite in the novel photo-Fenton system according to claim 3, wherein in step 1), the concentration of the target pollutant BPA is 20 μmol/L.

5. The application method of the synthetic ferrihydrite in the novel photo-Fenton system according to claim 3, wherein in the step 2), the carboxylic acid is ethylenediamine disuccinic acid (EDDS), and the concentration of the carboxylic acid in the mixed system is 0.5-2.5 mmol/L.

6. The method for applying the synthetic ferrihydrite in the novel photo-Fenton system according to claim 3, wherein in the step 3), the concentration of the synthetic ferrihydrite in the system is 0.2-1.0 g/L, and after aeration is carried out to fully complex the ferrihydrite and the carboxylic acid, the pH value is adjusted to 7.0 +/-0.1.

7. The application method of the synthetic ferrihydrite in the novel photo-Fenton system according to claim 3, wherein in the step 4), the concentration of the added hydrogen peroxide in the system is 0.1-1.0 mmol/L.

8. The method for applying the synthetic ferrihydrite in the novel photo-Fenton system according to claim 3, wherein in step 5), the visible light is irradiated by a metal halide lamp in an internal irradiation mode.

Technical Field

The invention belongs to the technical field of environmental protection and treatment, and particularly relates to artificially synthesized ferrihydrite and an application method thereof in a novel photo-Fenton system.

Background

Environmental Endocrine Disruptors (EDCs) are a class of exogenous harmful chemicals that affect the stability in the body and are widely present in the environment. By the predation effect of organisms, the EDCs enter the organisms through a digestive system, and the action mechanism of endogenous hormones in the organisms is destroyed, so that the normal growth and reproduction of the organisms are influenced. China mainly uses surface water as main drinking water, so that the reduction or removal of EDCs in the surface water is very important for the life and health of human bodies. BPA is an estrogen-like substance, is a representative EDCs, and is one of the most widely used chemical industries. Its effect on the human body is a constantly accumulating, irreversible process with a lasting hazard. Therefore, a treatment technique for efficiently degrading environmental endocrine pollutants represented by BPA is urgently sought.

Advanced Oxidation Processes (AOPs) are an environmentally friendly Advanced treatment technology that has been widely used to degrade organic and inorganic pollutants in water, soil and air. Wherein the Fenton oxidation technology is mature and widely applied to Fe²⁺And H₂O₂In the Fenton reagent composition, Fe²⁺Catalysis H₂O₂Generates hydroxyl free radical (OH) with extremely high oxidation activity, leads the hydroxyl free radical to act on high molecular organic pollutants and directly mineralize the high molecular organic pollutants into nontoxic and harmless small molecular substances, and realizes the degradation of the pollutants. However, the traditional Fenton oxidation technology has many disadvantages, such as narrow pH application range and general requirement of acidic condition. In addition, a large amount of iron mud is generated after the wastewater reacts, so that iron resources are wasted, and the subsequent treatment difficulty and cost are increased. In addition, H in the system₂O₂The use amount is high, and the operation cost is increased.

The photo-Fenton oxidation technology is to introduce ultraviolet light or visible light into a Fenton system to improve H₂O₂The utilization efficiency of (1) is reduced by Fe²⁺The use of the method greatly enhances the oxidation efficiency of the traditional Fenton method and achieves the purpose of reducing the reaction cost. At present, the photo-Fenton oxidation technology is applied to treatment of refractory organic industrial wastewater such as paper making, metallurgy, dye, landfill leachate and the like. However, the photo-Fenton method also has the traditional Fenton defect of the subsequent treatment of iron ions after sewage treatment.

Therefore, a technology capable of overcoming the defects of narrow pH application range and generation of a large amount of iron mud in the traditional Fenton method is urgently needed.

Disclosure of Invention

The invention aims to solve the technical problem of providing an artificially synthesized ferrihydrite and an application method thereof in a novel photo-Fenton system, wherein the method can accelerate Fe under the irradiation of neutral pH and visible light³⁺And Fe²⁺Thereby accelerating Fe²⁺Catalysis H₂O₂The rate of generating OH improves the degradation efficiency of BPA and reduces the amount of oxidant H₂O₂The amount of (2) used.

The invention solves the technical problems by the following technical scheme:

the preparation method of the artificially synthesized ferrihydrite comprises the following steps:

40.0g Fe (NO) was weighed₃)₃·9H₂Dissolving O in 500mL of deionized water, adding 310mL of KOH solution with the concentration of 1mol/L, continuously adjusting the pH of the solution to 7.4-7.6 by using 1mol/L of KOH, violently stirring for 1h, centrifuging the obtained colloid for 12min, discarding the supernatant, washing the obtained solid with deionized water, shaking up, centrifuging for 12min, discarding the supernatant, repeating the steps for 5 times, and drying at 40 ℃ to obtain the artificially synthesized ferrihydrite.

The KOH solution is added at the speed of 100 mL/min; the centrifugation treatment was carried out at 4000 rpm.

The invention relates to an application method of artificially synthesized ferrihydrite in a novel photo-Fenton system, which comprises the following operation steps:

(1) placing the target contaminant BPA in a large beaker;

(2) adding carboxylic acid into a large beaker;

(3) then adding the artificially synthesized ferrihydrite;

(4) adding hydrogen peroxide into the mixed solution;

(5) and finally, adding visible light to form a ferrihydrite-carboxylic acid/light-Fenton system and degrade the environmental endocrine disruptor BPA.

In the step 1), the concentration of the target pollutant BPA is 20 mu mol/L.

In the step 2), the carboxylic acid is ethylenediamine disuccinic acid (EDDS), and the concentration of the carboxylic acid in the mixed system is 0.5-2.5 mmol/L.

In the step 3), the concentration of the artificially synthesized ferrihydrite in the system is 0.2-1.0 g/L, and after the ferrihydrite and the carboxylic acid are fully complexed by aeration, the pH value is adjusted to 7.0 +/-0.1.

In the step 4), the concentration of the added hydrogen peroxide in the system is 0.1-1.0 mmol/L.

In the step 5), the visible light is irradiated by a metal halide lamp, and the irradiation mode is internal irradiation.

Compared with the prior art, the invention has the following advantages:

1) the invention can overcome the defects of narrow pH application range and generation of a large amount of iron mud in the traditional Fenton method, and adopts a heterogeneous Fenton system formed by complexing iron oxide and carboxylic acid and a photo-Fenton system, so that the pH value range can be widened, the generation of iron mud is reduced, and the light absorption performance is higher.

2) The method is simple and convenient to operate, the carboxylic acid is added into the BPA solution, the ferrihydrite is added into the mixed solution of the BPA and the carboxylic acid, the complex is formed by aeration, and then the Fe in the reaction is irradiated by adjusting the pH value, adding the hydrogen peroxide and applying a metal halide lamp²⁺Catalysis H₂O₂Generates a large amount of OH with extremely strong oxidation performance, and the OH acts on BPA to degrade the BPA.

3) When the method is used, the pH is not required to be adjusted to 2-3, and the addition of the ferrihydrite and the carboxylic acid accelerates the Fe³⁺With Fe²⁺The redox cycle of (1) accelerates Fe²⁺Catalysis H₂O₂The rate of OH generation is increased, and iron oxide and H are increased₂O₂Utilization ratio of (2), reducing the oxidant H₂O₂The reagent is greatly saved by using the amount of the reagent.

4) The degradation rate of BPA in the invention can reach 85.1%, and the invention has simple and convenient process, wide sources of adopted experimental reagents and raw materials, easy purchase and low price.

Drawings

Fig. 1 is an X-ray diffraction (XRD) analysis pattern of the artificially synthesized ferrihydrite of example 1 of the present invention.

Fig. 2 is a graph of the application analysis and determination of the synthetic ferrihydrite in the novel photo-Fenton system in example 2 of the invention.

FIG. 3 is a diagram of the application, analysis and determination of the synthetic ferrihydrite in the novel photo-Fenton system in example 3 of the present invention.

FIG. 4 is a diagram of the application, analysis and determination of the synthetic ferrihydrite in the novel photo-Fenton system in example 4 of the present invention.

Detailed Description

The method of the present invention is further described with reference to the accompanying drawings and specific examples.