Preparation method and application of iron-straw biochar micro-electrolysis filler

Abstract

The application discloses a preparation method of iron-straw bio-carbon micro-electrolysis filler and application thereof, and belongs to the technical field of environmental protection.The preparation method uses sponge iron and straw as carbon raw materials, and then a certain amount of a binder and a catalyst are added, mixed uniformly, granulated, and then subjected to anaerobic high-temperature calcination, so that the granulated sintered product is formed into regular iron-carbon micro-electrolysis filler.The iron-carbon micro-electrolysis filler can not only overcome the defects of the existing iron-carbon filler, such as high cost, easy hardening and easy passivation, but also can be applied to the treatment of electroplating wastewater, and the efficiency reaches 80% to 92.5%, and the wastewater COD index reaches the national electroplating pollutant discharge standard (GB 21900-2008).

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of sewage treatment, and more particularly to a preparation method of iron-straw bio-carbon micro-electrolysis filler and application thereof. BACKGROUND

[0002] At present, the industrial wastewater pollution in China is severe, and more than 80% of the more than 500 major rivers in China are polluted to a certain extent. The electroplating industry is one of the three major industrial wastewater pollutions in the world, and the discharge amount of the electroplating wastewater accounts for about 10% of the total industrial wastewater discharge amount. However, less than 50% of the wastewater is effectively treated before being discharged. At present, with the increasing scale of electroplating enterprises, the composition of the generated wastewater is more and more complex, and the treatment difficulty is more and more great. The wastewater pollution problem has seriously restricted the survival and development of the electroplating enterprises in China. In addition, the untreated wastewater seriously affects the water environment and human health in China, and also greatly restricts the sustainable development of the related industries in China. Therefore, it is particularly necessary to study the treatment technology and process of the complex electroplating wastewater with high complexing compound concentration.

[0003] The iron-carbon micro-electrolysis technology is a better process technology for treating pollutants in wastewater by using the electrochemical corrosion principle of metal. The closely contacted iron and carbon are soaked in the wastewater, and a potential difference of about 1.2v is formed between the iron and the carbon, so that a large number of micro-batteries are formed to accelerate the reaction. The related mechanism is as follows: the anode iron loses electrons and dissolves Fe 2+ , the cathode carbon obtains electrons to form H2O2 under acidic and aerobic conditions, Fe 2+ forms a Fenton system with H2O2 to oxidize pollutants, and Fe 2+ can be oxidized to Fe 3+ , so that the pollutant particles are coagulated together, and the suspended colloids are precipitated through adsorption and sweeping effects.

[0004] At present, a large number of experimental studies show that the traditional electrolysis technology formed by simply mixing the reducing iron powder and the activated carbon powder often has the shortcomings of filler hardening and passivation, thereby causing the micro-electrolysis efficiency to decrease and affecting the treatment effect. SUMMARY

[0005] The application discloses a preparation method of iron-straw bio-carbon micro-electrolysis filler and application thereof, so as to solve any of the above and other potential problems in the prior art.

[0006] In order to solve the above technical problems, the technical scheme provided by the present application is: a preparation method of iron-straw bio-carbon micro-electrolysis filler, which takes sponge iron and straw as carbon raw materials, and then adds a certain amount of binder and catalyst, mixes uniformly, granulates, and then is baked at high temperature in an anaerobic atmosphere, and after sintering, granulation is carried out to form regular iron-carbon micro-electrolysis filler.

[0007] Further, the weight fraction of the sponge iron is 30-65 parts, the weight fraction of the porous bio-carbon prepared from straw is 35-60 parts, the weight fraction of the binder is 15-20 parts, and the weight fraction of the catalyst is 2-8 parts.

[0008] Further, the binder is sodium silicate or bentonite; and the catalyst is zinc powder.

[0009] Further, the anaerobic high-temperature baking is carried out under an inert atmosphere, and the sintering temperature is 400-800 DEG C.

[0010] Further, the particle size of the sponge iron is 110-170 mesh;

[0011] The particle size of the porous bio-carbon prepared from straw is 110-140 mesh;

[0012] The particle size of the sodium carbonate or bentonite is 90-110 mesh;

[0013] The particle size of the zinc powder is 110-170 mesh.

[0014] Further, the preparation process of the straw into a porous carbon material is as follows: the straw is cut and crushed, then placed in a quartz boat, baked in a tube furnace under a nitrogen atmosphere at a temperature of 200-700 DEG C for 2.5-4 hours, and then naturally cooled to room temperature under a nitrogen atmosphere, and the sample is ground to 100-150 mesh sieve, thereby obtaining the porous bio-carbon.

[0015] The present application has the following beneficial effects: due to the above technical scheme, the porosity of the iron-carbon micro-electrolysis filler of the present application is not less than 65%; when treating electroplating wastewater, the removal efficiency of COD content in the electroplating wastewater treated by the iron-straw bio-carbon micro-electrolysis filler reaches 93%-99%, and the wastewater COD index reaches the national electroplating pollutant discharge standard GB 21900-2008. DETAILED DESCRIPTION

[0016] The technical scheme of the present application will be further described in detail below through specific embodiments.

[0017] Example 1

[0018] The preparation method of the iron-straw biochar micro-electrolysis filler in this embodiment is as follows: the mixing ratio of each material is 40 parts of sponge iron powder, 40 parts of straw-prepared biochar, 16 parts of sodium silicate, and 4 parts of zinc powder. After granulation and drying, sintering is performed at a sintering temperature of 500°C. The porosity of the filler is 0.65.

[0019] Example 2

[0020] The preparation method of the iron-straw biochar micro-electrolysis filler in this embodiment is different from the above-mentioned embodiments in that the mixing ratio of the materials is 50 parts of sponge iron powder, 30 parts of straw-prepared biochar, 14 parts of sodium silicate, and 6 parts of zinc powder, and the sintering temperature is set to 600°C. The porosity of the filler is 0.66.

[0021] Example 3

[0022] The preparation method of the iron-straw biochar micro-electrolysis filler in this embodiment is different from the above-mentioned embodiments in that the mixing ratio of the materials is 55 parts of reducing iron powder, 25 parts of straw-prepared biochar, 15 parts of bentonite, and 5 parts of zinc powder, and the sintering temperature is 800°C. The porosity of the filler is 0.67.

[0023] The following examples are regularized iron-carbon micro-electrolysis materials prepared by the above-mentioned preparation method, which are applied to the treatment of electroplating wastewater.

[0024] Example 4

[0025] Accurately measure 500 mL of electroplating wastewater with a COD content of 200 mg / L, and simultaneously weigh a certain mass of regularized iron-carbon micro-electrolysis filler to treat the wastewater. A large number of research experiments show that when the regularized iron-carbon filler dosage is 5 g / L and the reaction time is 30 min, the COD removal efficiency is as high as 80%, and the effect is good.

[0026] Table 1 shows the water quality indicators before and after the treatment of wastewater using the iron-sludge-based biochar micro-electrolysis filler prepared in this embodiment.

[0027] pH COD Before wastewater treatment (mg / L) 3.2 200 After wastewater treatment (mg / L) 4.0 40 Removal rate / 80%

[0028] Example 5

[0029] Accurately measure 500 mL of electroplating wastewater with a COD content of 200 mg / L, and simultaneously weigh a certain mass of regularized iron-carbon micro-electrolysis filler to treat the wastewater. A large number of research experiments show that when the regularized iron-carbon filler dosage is 8 g / L and the reaction time is 90 min, the COD removal efficiency is 92.5%, and the effect is good.

[0030] pH COD Before wastewater treatment (mg / L) 3.2 200 After wastewater treatment (mg / L) 4.5 15 Removal rate / 92.5%

[0031] The above describes in detail the preparation method and application of an iron-straw biochar micro-electrolysis filler provided in the examples of this application. The description of the above examples is only intended to help understand the method and core concept of this application; at the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of this application. In summary, the contents of this specification should not be construed as limiting this application.

[0032] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different nouns to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. For example, "including" and "comprising" mentioned throughout the specification and claims are open-ended terms, so they should be interpreted as "including / including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve the technical problems within the preset error range and basically achieve the technical effects. The subsequent description in the specification is a preferred embodiment of the present application, but the description is for the purpose of illustrating the general principles of the present application, and is not used to limit the scope of the present application. The scope of protection of the present application shall be as defined in the attached claims.

[0033] It should also be noted that the terms "include," "comprises," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a product or system comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such product or system. In the absence of further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the product or system comprising the element.

[0034] It should be understood that the term "and / or" as used herein is merely a description of the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0035] The above description shows and describes several preferred embodiments of the present application. However, as previously mentioned, it should be understood that the present application is not limited to the form disclosed herein and should not be construed as excluding other embodiments. Instead, the present application is applicable to various other combinations, modifications, and environments and can be modified within the scope of the application concept described herein through the above teachings or the technology or knowledge in the relevant field. Modifications and changes made by those skilled in the art without departing from the spirit and scope of the present application shall be protected by the claims appended hereto.

Claims

1. A method for preparing an iron-straw biochar micro-electrolysis filler, characterized in that, The preparation method uses sponge iron and straw as carbon raw materials, further adds a binder and a catalyst, mixes uniformly, performs high-temperature roasting without oxygen after granulation, forms regular iron-carbon micro-electrolysis filler after sintering and granulation, and has a porosity of not less than 65%; The sponge iron is 30-65 parts by weight, the porous bio-carbon prepared from straw is 35-60 parts by weight, the binder is 15-20 parts by weight, and the catalyst is 2-8 parts by weight; The binder is sodium silicate or bentonite, and the catalyst is zinc powder. The high-temperature roasting without oxygen is performed in an inert atmosphere at a sintering temperature of 400-800 DEG C.

2. The production method according to claim 1, characterized by, The particle size of the sponge iron is 110-170 mesh; The particle size of the porous bio-carbon prepared from straw is 110-140 mesh; The particle size of the sodium carbonate or bentonite is 90-110 mesh; The particle size of the zinc powder is 110-170 mesh.

3. The preparation method according to claim 1, characterized in that The preparation process of the porous carbon material prepared from straw is as follows: the straw is cut and crushed, placed in a quartz boat, roasted in a tube furnace under a nitrogen atmosphere at 200-700 DEG C for 2.5-4 hours, naturally cooled to room temperature under a nitrogen atmosphere after roasting, taken out, ground in a mortar and passed through a 100-150 mesh screen, and the porous bio-carbon is obtained.

4. The iron-carbon micro-electrolysis filler prepared by the preparation method of any one of claims 1-3 is applied to treatment of electroplating wastewater with high COD.