Iron-carbon suspended filler, ozone-iron-carbon fluidized bed treatment device and treatment method

Abstract

The invention discloses iron-carbon suspended filler and an ozone-iron-carbon fluidized bed treatment device and method. The iron-carbon suspended filler is prepared from iron, carbon, a catalyst and a pore-forming agent, and the density is 0.9-1.2 g / cm < 3 >. The treatment device comprises a reaction tower, iron-carbon suspended filler, an aeration device and a water inlet / outlet, the reaction tower is filled with iron-carbon suspended filler; the water inlet is positioned at the bottom of the reaction tower; the aeration device is arranged at the bottom of the reaction tower; and the water outlet is positioned on the upper side of the reaction tower. The treatment method comprises the steps of equipment inspection and filler filling; feeding water, and controlling the water feeding flow rate to be 5-40m / h; introducing air, and controlling the introduction amount of ozone to be 5-60mg / L; regularly sampling and analyzing, judging whether the reaction achieves an expected effect or not, and ensuring a continuous water inlet reaction state; and discharging water. The ozone-iron carbon fluidized bed treatment device and the treatment method for degradation-resistant organic wastewater have the advantages of high mass transfer efficiency, high degradation efficiency and flexible operation, and can adapt to different water quality and treatment requirements.

Description

Technical Field

[0001] The present invention belongs to the technical field of wastewater treatment, and relates to a device and method for treating refractory organic wastewater, and in particular to an iron-carbon suspended filler, an ozone-iron-carbon fluidized bed treatment device and method for treating refractory organic wastewater. Background Art

[0002] Due to the complex composition and difficulty in treating refractory organic wastewater, a single treatment technology often fails to achieve the desired treatment effect, so the combined use of multiple treatment technologies has become a trend. A common method is to use oxidation technology in combination with biological treatment technology. Advanced oxidation technology can be used to pre-treat wastewater to improve the biodegradability of wastewater, and then biological treatment technology can be used for deep treatment. The rational use of oxidation technology in the pretreatment stage is a key step in whether wastewater meets the standards after treatment. The current mainstream oxidation technologies mainly use Fenton oxidation, ozone oxidation, wet oxidation, electrochemical oxidation technology, photocatalytic oxidation technology, etc. These technologies all have problems to varying degrees: high treatment costs, high material consumption, low utilization, and may even produce more toxic intermediates.

[0003] Common technologies for treating refractory organic wastewater provided in the prior art include the following.

[0004] (1) Advanced oxidation technology. High processing cost: Some advanced oxidation technologies require the use of expensive oxidants (such as hydrogen peroxide), catalysts or special equipment (such as ultraviolet light generators, etc.), resulting in high processing costs, which to some extent limits their large-scale application.

[0005] Its main disadvantages are high oxidant consumption and high technical requirements. In order to ensure the treatment effect, a large amount of oxidant is often consumed, which increases the operating cost and the difficulty of subsequent treatment. In addition, the reaction process of some advanced oxidation technologies is relatively complicated, and the control requirements for reaction conditions are strict, requiring professional technicians to operate and maintain.

[0006] (2) Electrochemical oxidation technology. The main disadvantages are the high cost of electrode materials and high energy consumption. High-performance electrode materials are expensive and may be contaminated or corroded during the treatment process, requiring regular replacement, which increases operating costs. In order to provide sufficient electrical energy to drive the electrode reaction, a large amount of electrical energy is required, resulting in high operating costs, especially for wastewater with large treatment volumes. In addition, during the electrochemical oxidation process, some by-products may be produced, such as chlorine and oxygen, which may cause secondary pollution to the environment if not handled properly.

[0007] (3) Photocatalytic oxidation technology. The main disadvantages are the high cost of catalyst preparation and low light energy utilization. The preparation process of high-performance photocatalysts is complicated and costly, which limits their large-scale application. Due to the limited penetration of light and the low efficiency of photocatalysts in absorbing light energy, the light energy utilization rate is low, which affects the treatment effect. In addition, during the photocatalytic oxidation process, some intermediates may be produced, which may be more toxic than the original pollutants and require further treatment.

[0008] (4) Membrane separation technology. The main disadvantages are high investment cost, membrane fouling problem and difficulty in treating concentrated liquid. The equipment investment cost of membrane separation technology is relatively high, especially for some high-performance membrane materials, which limits its application in some small and medium-sized enterprises. Pollutants in wastewater are easily deposited on the membrane surface, causing membrane fouling, affecting the separation performance and service life of the membrane. Regular cleaning and replacement are required, increasing operating costs and maintenance workload. The membrane separation process will produce a certain amount of concentrated liquid, which contains high concentrations of pollutants and needs further treatment, otherwise it will pollute the environment.

[0009] (6) Micro-electrolysis ozone reaction technology. The newly developed micro-electrolysis ozone reaction technology can solve the pain points of the existing technology, such as packing compaction and excessive sludge production. However, the existing micro-electrolysis ozone reaction technology still has defects such as low mass transfer efficiency and low degradation efficiency.

[0010] Prior art "Micro-electrolysis ozone reaction integrated device" (patent number: CN201920218428.1): The device includes a can-shaped micro-electrolysis ozone reactor, which is provided with an iron-carbon micro-electrolysis packing layer, and the packing layer includes a plurality of packing strings suspended above the reactor, and each packing string is composed of a plurality of packing units connected one by one by a flexible material. This design enables each packing unit on each packing string to fully contact and react with the wastewater, improves the utilization rate of the micro-electrolysis packing, and avoids the passivation and hardening phenomenon caused by placing the iron-carbon micro-electrolysis packing together in the past, as well as the frequent addition of iron to the packing and the frequent unloading and stirring of the iron-carbon micro-electrolysis packing. The technology has the following main areas for improvement: 1) The filler sintered ball is a solid sphere, and only the surface of the sphere can be used, the contact reaction area is small, and the efficiency needs to be improved; 2) Under the action of airflow, several strings of fillers in the iron-carbon micro-electrolysis filler layer will swing, promoting full contact between the filler unit and the wastewater to promote the micro-electrolysis reaction. At the same time, the metal ions generated by the micro-electrolysis reaction and the activated carbon that falls off from the iron-carbon micro-electrolysis filler can be used as catalysts for the ozone oxidation reaction. In actual operation, due to the oxide film covering the surface of the ball, the disturbance of the airflow may not be able to completely cause the activated carbon to fall off. If the oxide film increases to a certain thickness over time, the passivation effect produced will prevent the reaction from continuing.

[0011] Prior art "An integrated ozone membrane aeration coupled enhanced iron-carbon micro-electrolysis electrochemical device" (patent number: CN202221005926.6): The reactor includes an inlet pipe, an inlet pump, an ozone generator, a microporous ceramic aeration membrane, a reactor shell, a graphite anode, a stainless steel cathode, a DC voltage-regulated power supply, a dust-removal ash-based iron-carbon filler, and a water outlet system. Ozone is generated by an ozone generator and passed into the reactor through a microporous ceramic membrane placed at the bottom of the reactor. The device has the advantages of strong impact resistance, flexibility and easy control, strong anti-toxicity, and small footprint in the process of domestic sewage treatment. In this technology, since the wastewater first enters the overflow buffer zone in the reactor shell, and then flows into the reaction zone from above through the overflow weir between the overflow buffer zone and the electrolysis zone, the disturbance effect of the water flow is poor, and the dust-removal ash iron-carbon particles are easily accumulated at the bottom of the reaction zone, causing the iron-carbon particles to compact and reduce the treatment efficiency. Furthermore, no specific production method and size of the iron-carbon particles are proposed, and the operability is poor in practical applications. Secondly, the actual removal efficiency of this technology needs to be further improved.

[0012] Prior art "An iron-carbon micro-electrolysis process for wastewater treatment with ozone" (patent number: CN201711333950.6): Technical content: The process includes adjusting the pH of the wastewater to 2-9 with an acid solution / alkaline solution, filtering the wastewater after adjusting the pH and transporting it to an iron-carbon micro-electrolysis reactor, introducing ozone therein, and after reacting for 1-3 hours, discharging the wastewater from the iron-carbon micro-electrolysis reactor, and finally transporting the output wastewater to a neutralization sedimentation tank for precipitation. This process improves the treatment capacity of organic matter in wastewater, better overcomes the color reversion phenomenon, broadens the pH range of wastewater entering the iron-carbon micro-electrolysis reactor, reduces the amount of acid and alkali, reduces the amount of neutralization sedimentation sludge, and reduces the comprehensive cost of wastewater treatment. In this technology, the iron filings and carbon particles of the iron-carbon filler layer are simply mixed. Due to the difference in density, the two are easily stratified. The iron filings with high density accumulate at the bottom, causing the filler to compact. Further stratification of the iron-carbon filler may reduce the potential difference generated, thereby affecting the removal efficiency. Summary of the invention

[0013] The technical problem to be solved by the present invention is: to overcome the shortcomings of the prior art, to solve the pain points of the oxidation technology in the treatment process of difficult-to-degrade organic wastewater, such as high treatment cost, large material consumption, low utilization rate, filler compaction, more sludge generation, low mass transfer efficiency, and low degradation efficiency, and to provide an iron-carbon suspended filler, and at the same time to provide an ozone-iron-carbon fluidized bed treatment device and treatment method for difficult-to-degrade organic wastewater with low treatment cost, low material consumption, high utilization rate, high mass transfer efficiency, and high degradation efficiency.

[0014] One of the purposes of the present invention is to provide an iron-carbon suspension filler, which is prepared by the following method:

[0015] (1) Mixing raw materials: sieving sponge iron powder, graphene powder, ionic fixing agent (quaternary ammonium salt type cationic fixing agent, etc.), palladium alloy catalyst (synthetic catalyst such as platinum, cobalt, copper, nickel, etc.), pore-forming agent (ammonium carbonate, ammonium bicarbonate, ammonium chloride, bone meal, polymethacrylate, methyl methacrylate, sawdust, rice husk, cotton and other plant waste) and polymer (polyurethane or polypropylene or high-density polyethylene) respectively, and then mixing sponge iron powder (15-30%), graphene powder (3-10%), ionic fixing agent (5-10%), palladium alloy catalyst (0.5-1.0%), pore-forming agent (5-20%), polyurethane or polypropylene or high-density polyethylene (20-40%) and water (30-40%) in a preset mass ratio, and performing ultrasonic enhancement to promote uniform distribution of each component to obtain an initial raw material a;

[0016] (2) Raw material ball milling: ball milling the initial raw material a to obtain an initial raw material b with a particle size of ≤100 μm;

[0017] (3) Electrostatic spraying: The suspension carrier is pretreated to make it conductive, and then the obtained initial raw material b is coated on the entire suspension carrier skeleton by electrostatic spraying to form an iron-carbon micro-electrolytic coating with a thickness of 0.5 to 1 mm on the surface of the suspension carrier, thus obtaining a formed iron-carbon suspension filler;

[0018] (4) Filler sintering: The formed iron-carbon suspension filler is placed in a tubular furnace for high-temperature sintering (280-320° C.) in an oxygen-free atmosphere, and then naturally cooled to room temperature and then soaked and cleaned with water to obtain the spare iron-carbon suspension filler; the particle size of the iron-carbon suspension filler is 0.2-0.6 cm; the density of the iron-carbon suspension filler is 0.9-1.2 g / cm 3 .

[0019] Furthermore, in the above step (1), the ionic fixing agent is a quaternary ammonium salt type cationic fixing agent or the like; the palladium alloy catalyst is a catalyst synthesized from palladium and one or more of platinum, cobalt, copper, nickel, etc.; the pore-forming agent is ammonium carbonate, ammonium bicarbonate, ammonium chloride, bone meal, polymethacrylate, methyl methacrylate, or plant waste such as sawdust, rice husk, cotton, or one or more of the combinations thereof; the polymer is polyurethane or polypropylene or high-density polyethylene (polyurethane or polypropylene or high-density polyethylene plays a bonding and suspension role)

[0020] Furthermore, in the above step (3), the suspension carrier is a polytetrafluoroethylene porous suspension carrier, which has a porous circular, square or other shape; its particle size is 1.5mm-5.5mm, and its density is 0.9-1.2g / cm 3The suspension carrier is used as a supporting material for the iron-carbon electrolytic material and the catalyst, which increases the contact area between the reactant and the iron-carbon electrolytic material and the catalyst, and improves the reaction efficiency. To make the particle size of the prepared iron-carbon suspension filler range from 0.2 to 0.6 cm, the particle size of the selected suspension carrier is required to range from 1.5 mm to 5.5 mm.

[0021] Furthermore, in the above step (3), the suspension carrier is an organic carrier. It is made conductive by chemical oxidation with hydrogen peroxide, potassium permanganate, potassium dichromate, etc., or by introducing oxygen-containing polar groups such as hydroxyl, carboxyl, carbonyl, etc. on the surface of the suspension carrier (organic carrier) by oxygen plasma, nitrogen plasma, argon plasma, etc., so as to make it conductive.

[0022] The density of the iron-carbon suspension filler prepared by the above method is 0.9-1.2g / cm 3 The filler can be fully fluidized simply by the flow of gas / liquid.

[0023] Another object of the present invention is to provide an ozone-iron-carbon fluidized bed treatment device for refractory organic wastewater, which comprises a reaction tower, an iron-carbon suspension filler, a water inlet, an aeration device and a water outlet; the reaction tower is a fluidized bed reactor; the reaction tower is filled with the iron-carbon suspension filler; the density of the iron-carbon suspension filler is 0.9-1.2 g / cm 3 The particle size of the iron-carbon suspended filler is between 2-6mm; the water inlet is located at the bottom of the reaction tower to ensure that the wastewater enters the reaction zone evenly; the aeration device is arranged at the bottom of the reaction tower to introduce ozone into the wastewater; the water outlet is located on the upper side of the reaction tower; the aeration device comprises an ozone inlet, a water distributor and an aerator connected in sequence; and a plurality of aerators are arranged on the water distributor.

[0024] Furthermore, the reaction tower is a vertical cylindrical tower filled with iron-carbon suspension fillers. The iron-carbon suspension fillers are in a fluidized state under the action of aeration and water flow, so that the iron-carbon is fully in contact with wastewater and ozone.

[0025] Furthermore, an intercepting screen is arranged in the upper part of the reaction tower, and the intercepting screen is fixed on the inner wall of the reaction tower.

[0026] Furthermore, the ozone air inlet is connected to an ozone generator; and the water inlet is connected to a feed pump.

[0027] Furthermore, the tail gas outlet at the top of the reaction tower is connected to the ozone inlet at the bottom of the reaction tower, and the tail gas contains more ozone, which can be recycled.

[0028] Furthermore, the reaction tower is provided with a temperature control system, which includes a temperature sensor, a transmitter and a PLC controller connected in sequence.

[0029] Another object of the present invention is to provide a method for treating organic wastewater using the above-mentioned ozone-iron-carbon fluidized bed treatment device for refractory organic wastewater, which is as follows:

[0030] Step 1: Preparation

[0031] Check whether the equipment of the whole set of equipment including ozone generator, reaction tower (fluidized bed reactor), feeding device (water inlet and feeding pump), discharging device (water outlet and outlet valve), temperature control system (temperature sensor, transmitter and PLC controller), aeration device (ozone inlet, water distributor and aerator), etc. and each component are operating normally.

[0032] The pH range of wastewater to be treated is 1-11. The iron-carbon suspension filler after cleaning and screening is filled into the reaction tower (fluidized bed reactor), ensuring that the particle size of the iron-carbon suspension filler meets the requirement of 2-6mm. The filling amount is generally determined according to the volume of the reaction tower and the amount of water to be treated, and the filling height is 1 / 5 to 1 / 3 of the height of the reaction tower.

[0033] Step 2: Wastewater treatment stage

[0034] The wastewater to be treated is slowly introduced into the reaction tower (fluidized bed reactor) through the feed pump, and the flow rate of the wastewater is controlled to form a stable fluidized state in the reaction tower. The inlet flow rate of the wastewater should be reasonably adjusted according to factors such as the size of the reaction tower, the properties of the filler, and the treatment requirements, and controlled between 5-40m / h.

[0035] Turn on the ozone generator and evenly introduce the generated ozone gas into the reaction tower (fluidized bed reactor) through the water distributor and aerator. The amount of ozone introduced needs to be precisely controlled according to factors such as wastewater quality, treatment objectives, and ozone utilization rate, and should be controlled between 5-60 mg / L.

[0036] During the reaction, pay close attention to the changes in parameters such as temperature (required to be ≥10℃), pressure, pH value, etc. in the reaction tower, and adjust them through the corresponding control system to keep them within the set range. During the reaction, control the temperature to be ≥10℃, pressure to be 0.01-0.08Mpa, and pH value to be 1-11.

[0037] According to the nature of the wastewater and the treatment requirements, the inlet flow rate is adjusted to control the reaction time between 30-240 minutes. The water quality indicators of the wastewater are sampled and analyzed regularly to determine whether the reaction has achieved the expected effect. When the water quality indicators meet the discharge standards or treatment requirements, the inlet flow rate of the wastewater is controlled at a constant value, and fine-tuned according to the outlet indicators in the later stage to ensure the continuous inlet reaction state. The treated wastewater is discharged from the outlet on the side of the top of the reaction tower and enters the subsequent treatment unit or is directly discharged.

[0038] For used iron-carbon suspension fillers, it can be decided whether to regenerate them or replace them with new ones based on their loss conditions and activity recovery degree.

[0039] The degradation mechanism of the ozone-iron-carbon fluidized bed technology of the present invention is as follows: In the ozone-iron-carbon fluidized bed, the ferrous ions (Fe2+) produced by iron-carbon micro-electrolysis can catalyze the decomposition of ozone to produce more hydroxyl radicals (·OH). The redox potential of hydroxyl radicals is as high as 2.80V, which is a stronger oxidant than ozone. Hydroxyl radicals can react rapidly with organic matter in the wastewater indiscriminately, decomposing the difficult-to-degrade organic matter into easily degradable small-molecule organic matter, and then further oxidizing it into carbon dioxide and water.

[0040] The ozone-iron-carbon fluidized bed treatment device provided by the present invention can achieve a COD degradation rate of 50%-70% for wastewater containing refractory organic matter such as pharmaceutical wastewater and printing and dyeing wastewater. At the same time, the removal effect of chromaticity reaches more than 80%-95%, which can effectively improve the appearance of wastewater; the removal rate of ammonia nitrogen is about 30%-50%.

[0041] Beneficial effects of the present invention:

[0042] The ozone-iron-carbon fluidized bed treatment device and treatment method for refractory organic wastewater of the present invention have the following advantages over the prior art:

[0043] (1) Efficient mass transfer: Since the iron-carbon suspension filler is in a fluidized state, the contact area between wastewater, iron-carbon and ozone is greatly increased, and the mass transfer efficiency is high. This allows the reaction to proceed more fully and improves the removal efficiency of organic matter.

[0044] (2) Significant synergistic effect: The synergistic effect of ozone and iron-carbon micro-electrolysis can enhance the degradation ability of organic matter, especially for some difficult-to-degrade organic pollutants, such as complex organic matter in printing and dyeing wastewater, pharmaceutical wastewater, etc., and has a good treatment effect.

[0045] (3) Flexible operation: The reaction process can be controlled by adjusting parameters such as the amount of ozone introduced, the particle size and filling amount of the iron-carbon suspension filler, and the flow rate of the wastewater to adapt to different water quality and treatment requirements.

[0046] The differences between the present invention and the prior art (including the patents disclosed in the background technology section) are mainly reflected in the following aspects:

[0047] (1) Method for preparing iron-carbon suspension filler

[0048] In addition to iron and carbon materials, the iron-carbon suspension filler is supplemented with a catalyst (palladium alloy catalyst) to enhance the degradation of refractory organic matter. In order to ensure a better fluidized state of the suspension filler in the fluidized bed, pore-forming agents and polyurethane (or polypropylene or high-density polyethylene) are added to make the density of the iron-carbon suspension filler between 0.9-1.2g / cm 3 The filler can be fully fluidized simply by the flow of gas / liquid.

[0049] (2) High organic matter removal efficiency, especially the removal rate of difficult-to-degrade organic matter

[0050] As a heterogeneous catalyst, the iron-carbon filler, combined with the synergistic effect of the palladium alloy catalyst, can continuously and efficiently catalyze the decomposition of ozone to produce hydroxyl radicals in a fluidized bed, thereby improving the utilization rate and oxidation capacity of ozone. These highly active hydroxyl radicals have extremely strong oxidizing ability and can non-selectively undergo rapid oxidation reactions with various organic matter in the wastewater, decomposing difficult-to-degrade macromolecular organic matter into small molecular organic matter, and even directly mineralizing into carbon dioxide and water, significantly improving the biodegradability of the wastewater. In iron-carbon micro-electrolysis, the metal electrode potential difference between iron and carbon is about 0.9-1.7V, and the potential difference generated by the iron-carbon micro-electrolysis filler is about 1.2V. The electrode potential of ozone is about 2.08V-2.7V in an acidic environment, and it has strong oxidizing properties. In the ozone-catalyst-iron-carbon fluidized bed system of the present invention, the electrode potential of ozone under neutral conditions can reach 2.8V (the electrode potential or potential difference generated by the entire ozone-catalyst-iron-carbon fluidized bed system is measured by an electrochemical workstation measurement method), and the addition of the catalyst changes the activation energy of the reaction, enhances the electron transfer process, and makes the redox potential of the entire reaction system more conducive to the degradation of organic matter.

[0051] (3) Good fluidization performance

[0052] Through the reasonable design of the reaction tower (fluidized bed reactor) structure and operating conditions, as well as the shape of the iron-carbon suspension filler (optimized to be round or square), particle size (0.2-0.6cm), density (0.9-1.2g / cm 3 ) and other parameters are optimized to ensure that the iron-carbon filler has good fluidization performance in the fluidized bed and can achieve uniform fluidization at a lower fluidization velocity, reducing energy consumption and filler wear. It also avoids short circuits and dead zones caused by uneven fluidization, thereby improving the stability of the reaction tower and the treatment effect.

[0053] (4) Integrated treatment process This technology integrates the functions of multiple wastewater treatment units into one, achieving the synergistic effect of multiple processes such as ozone oxidation, iron-carbon micro-electrolysis, and fluidized bed adsorption. This not only improves the wastewater treatment effect, but also can cope with complex and changeable wastewater quality, complete the removal of multiple pollutants in the same reactor, reduce the complexity of the process flow and the floor space occupied, and reduce investment costs and operational management difficulties.

[0054] (5) Flexibility of operating conditions

[0055] The ozone iron-carbon fluidized bed has a wide range of adaptability to wastewater quality, water volume, temperature and other operating conditions. Under different water quality conditions, the efficient treatment of wastewater can be achieved by adjusting the ozone dosage, the dosage of iron-carbon suspension filler, the reaction time and other parameters. At the same time, the process can be operated at normal temperature and pressure, without the need for special conditions such as high temperature and high pressure, which reduces the requirements for equipment and operating costs.

[0056] (6) Reduce sludge production

[0057] Compared with traditional iron-carbon micro-electrolysis, the present invention produces less sludge during the treatment process. This is because, in addition to the generation of sludge during the iron-carbon micro-electrolysis process, the synergistic effect of ozone and catalyst can also directly oxidize and decompose some organic matter without the need to remove it through sludge precipitation. Compared with traditional iron-carbon micro-electrolysis, the sludge production can be reduced by 1 / 5-1 / 4, reducing the burden and cost of sludge treatment.

[0058] (7) Feasibility of intelligent control

[0059] The operating parameters of the process are relatively easy to monitor and control, such as ozone concentration, flow rate, reaction temperature, pH value, etc., which provides convenient conditions for realizing intelligent control. By installing online monitoring equipment and automatic control systems, the process parameters can be monitored and adjusted in real time to ensure the stable operation and treatment effect of the reactor, and improve the automation and management efficiency of wastewater treatment.

[0060] (8) Environmental friendliness

[0061] The iron-carbon micro-electrolysis process needs to work under pH 2-5 conditions. The present invention does not need to add a large amount of chemical agents to adjust the pH during the wastewater treatment process, reducing the use of chemical agents and the risk of secondary pollution. At the same time, the process of the present invention can efficiently remove difficult-to-degrade organic matter, reduce the toxicity and biological inhibition of wastewater, facilitate subsequent biological treatment or direct discharge, is more environmentally friendly, and meets the requirements of sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1It is a schematic structural diagram of the ozone-iron-carbon fluidized bed treatment device of the present invention.

[0063] In the figure: 1. Water inlet; 2. Sewage outlet; 3. Ozone air inlet; 4. Water distributor; 5. Aerator; 6. Iron-carbon suspension filler; 7. Intercepting screen; 8. Water outlet; 9. Exhaust outlet DETAILED DESCRIPTION

[0064] Now in conjunction with the accompanying drawings and specific embodiments, the present invention will be further described in detail. The accompanying drawings of the present application are all simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, so they only show the formation related to the present invention. These embodiments should be understood to be only used to illustrate the present invention without limiting the scope of protection of the present invention. After reading the content of the present invention, those skilled in the art can make various modifications to the present invention, and these equivalent changes and modifications also fall into the scope of protection limited by the present invention.

[0065] Example 1-Example 3

[0066] The iron-carbon suspension filler provided in this application is prepared by the following method:

[0067] (1) Mixing raw materials: sieve each raw material (50 mesh), and then take each raw material a according to the composition ratio of Table 1, Table 2 and Table 3, add water and mix evenly. Perform ultrasonic enhancement during the mixing process to promote uniform distribution of each component, and obtain the initial raw material a;

[0068] Table 1 Preparation of iron-carbon suspension filler initial raw material a component ratio one

[0069]

[0070]

[0071] Table 2 Preparation of iron-carbon suspension filler initial raw material a component ratio 2

[0072]

[0073] Table 3 Preparation of iron-carbon suspension filler initial raw material a component ratio three

[0074]

[0075]

[0076] (2) Raw material ball milling: ball milling the initial raw material a to obtain an initial raw material b with a particle size of ≤100 μm;

[0077] (3) Electrostatic spraying: The suspension carrier (the suspension carrier is a polytetrafluoroethylene porous suspension carrier, which is in the shape of a porous round or square, with a particle size of 1.5 mm-5.5 mm and a density of 0.9-1.2 g / cm 3 The suspended carrier is used as a supporting material for the iron-carbon electrolytic material and the catalyst, which increases the contact area between the reactant and the iron-carbon electrolytic material and the catalyst, and improves the reaction efficiency) and is pretreated to make it conductive (by chemical oxidation with hydrogen peroxide, potassium permanganate, potassium dichromate, etc., or by introducing oxygen-containing polar groups such as hydroxyl, carboxyl, and carbonyl on the surface of the organic carrier through oxygen plasma, nitrogen plasma, argon plasma, etc., so that it has conductive properties), and then the obtained initial raw material b is coated with the entire suspended carrier skeleton by electrostatic spraying, and an iron-carbon micro-electrolytic coating with a thickness of 0.5 to 1 mm is formed on the surface of the suspended carrier, that is, the formed iron-carbon suspended filler is obtained;

[0078] (4) Filler sintering: The formed iron-carbon suspension filler is placed in a tubular furnace for high-temperature sintering (280-320°C) in an oxygen-free atmosphere. After naturally cooling to room temperature, it is soaked and cleaned with water to obtain a spare iron-carbon suspension filler with a particle size of 2-6 mm.

[0079] The density of the iron-carbon suspension filler prepared by the above method is 0.9-1.2g / cm 3 The filler can be fully fluidized simply by the flow of gas / liquid.

[0080] Example 4

[0081] like Figure 1 As shown, the present invention is an ozone-iron-carbon fluidized bed treatment device for refractory organic wastewater, which mainly includes a reaction tower 10, an iron-carbon suspension filler 6, a water inlet 1, an aeration device and a water outlet 8; the reaction tower 10 is filled with the iron-carbon suspension filler 6; the density of the iron-carbon suspension filler is 0.9-1.2g / cm 3 The particle size of the iron-carbon suspension filler is between 2-6 mm; the water inlet 1 is located at the bottom side of the reaction tower 10 to ensure that the wastewater enters the reaction zone evenly; the water outlet 8 is located at the upper side of the reaction tower 10, and the treated wastewater is discharged from it; the aeration device is arranged at the bottom of the reaction tower 10, which is used to introduce ozone into the wastewater; the aeration device comprises an ozone inlet 3, a water distributor 4 and an aerator 5 connected in sequence. The water distributor 4 is provided with a plurality of aerators 5. The ozone inlet 3 at the front end of the aeration device is connected to the ozone generator. A sewage outlet 2 is provided at the bottom of the reaction tower 10.

[0082] The reaction tower 10 is a vertical cylindrical tower filled with iron-carbon suspension filler 6. The iron-carbon suspension filler 6 is in a fluidized state under the action of aeration and water flow, so that the iron-carbon is fully in contact with wastewater and ozone.

[0083] An intercepting screen 7 is arranged at the upper inner portion of the reaction tower 10 , and the intercepting screen 7 is fixed on the inner wall of the reaction tower 10 .

[0084] The ozone air inlet 3 is connected to the ozone generator; the water inlet 1 is connected to the feed pump; and a water outlet valve is provided at the water outlet 8.

[0085] The tail gas outlet 9 at the top of the reaction tower 10 is connected to the ozone inlet 3 at the bottom of the reaction tower 10 to recycle the ozone contained in the tail gas.

[0086] The reaction tower 10 is provided with a temperature control system, which includes a temperature sensor, a transmitter and a PLC controller connected in sequence.

[0087] Example 5

[0088] A method for treating organic wastewater using the ozone-iron-carbon fluidized bed treatment device for refractory organic wastewater described in Example 1 is as follows:

[0089] Step 1: Preparation

[0090] Check whether the equipment of the whole set of equipment including ozone generator, reaction tower (fluidized bed reactor), feeding device (water inlet and feeding pump), discharging device (water outlet and outlet valve), temperature control system (temperature sensor, transmitter and PLC control system), aeration device (ozone inlet, water distributor and aerator), etc. and each component are operating normally.

[0091] The pH range of the wastewater to be treated is 1-11. The iron-carbon suspension filler after washing and screening is filled into the reaction tower (fluidized bed reactor) to ensure that the particle size of the iron-carbon suspension filler meets the requirement of 2-6mm. The filling amount is generally determined according to the volume of the reaction tower and the amount of water to be treated. The filling height of the iron-carbon suspension filler is 1 / 5 to 1 / 3 of the height of the reaction tower.

[0092] Step 2: Wastewater treatment stage

[0093] The wastewater to be treated is slowly introduced into the reaction tower (fluidized bed reactor) through the feed pump, and the flow rate of the wastewater is controlled to form a stable fluidized state in the reaction tower. The inlet flow rate of the wastewater should be reasonably adjusted according to factors such as the size of the reaction tower, the properties of the filler, and the treatment requirements, and controlled between 5-40m / h.

[0094] Turn on the ozone generator and evenly introduce the generated ozone gas into the reaction tower (fluidized bed reactor) through the water distributor and aerator. The amount of ozone introduced needs to be precisely controlled according to factors such as wastewater quality, treatment objectives, and ozone utilization rate, and should be controlled between 5-60 mg / L.

[0095] During the reaction, pay close attention to the changes in parameters such as temperature (required to be ≥10℃), pressure, pH value, etc. in the reaction tower, and adjust them through the corresponding control system to keep them within the set range. During the reaction, control the temperature to be ≥10℃, pressure to be 0.01-0.08Mpa, and pH value to be 1-11.

[0096] According to the nature of the wastewater and the treatment requirements, the inlet flow rate is adjusted to control the reaction time between 30-240 minutes. The water quality indicators of the wastewater are sampled and analyzed regularly to determine whether the reaction has achieved the expected effect. When the water quality indicators meet the discharge standards or treatment requirements, the inlet flow rate of the wastewater is controlled at a constant value, and fine-tuned according to the outlet indicators in the later stage to ensure the continuous inlet reaction state. The treated wastewater is discharged from the outlet on the side of the top of the reaction tower and enters the subsequent treatment unit or is directly discharged.

[0097] For used iron-carbon suspension fillers, it can be decided whether to regenerate them or replace them with new ones based on their loss conditions and activity recovery degree.

[0098] Example 6 Treatment of wastewater from indigo production

[0099] The wastewater generated by an enterprise in Inner Mongolia that produces indigo products, a special dye for denim, was taken as the treatment object. The main pollutants in the wastewater were difficult-to-degrade organic matter. Influent water quality: CODcr content is about 9000mg / L, ammonia nitrogen content is about 600mg / L, pH 10.5. Reaction conditions: The particle size range of iron-carbon suspended filler is 3-5mm, the filler filling factor is 1 / 4 of the reactor height, the ozone injection amount is 10mg / L, and the inlet flow rate is 10m / h. The experiment was carried out for 120min. At the same time, iron-carbon micro-electrolysis (commercially available, pH 2, filling factor 1 / 4, reaction time 120min) and ozone catalysis experiments (pH 10.5, ozone injection amount 10mg / L, reaction time 120min) were carried out as control groups. The experimental results are as follows:

[0100]

[0101]

[0102] From the experimental results of Example 2, the removal rate of COD and ammonia nitrogen of such wastewater as printing and dyeing wastewater by the wastewater treatment method of the present invention is significantly better than that of iron-carbon micro-electrolysis or ozone catalysis.

[0103] Example 7

[0104] The wastewater generated by a textile printing and dyeing enterprise in Jiangsu Province was taken as the treatment object. The main pollutants in the wastewater were difficult-to-degrade organic matter. Influent water quality: CODcr content was 11430, ammonia nitrogen content was about 350mg / L, pH 9.84. Reaction conditions: The particle size range of iron-carbon suspended filler was 2-4mm, the filler filling factor was 1 / 3 of the reactor height, the ozone injection amount was 15mg / L, and the inlet flow rate was 5m / h for 180min. At the same time, iron-carbon micro-electrolysis (commercially available, pH 2, filling factor 1 / 3, reaction time 180min) and ozone catalysis experiments (pH 9.84, ozone injection amount 15mg / L, reaction time 180min) were carried out as control groups. The experimental results are as follows:

[0105]

[0106] The experimental results of Example 3 also show that the removal rate of COD and ammonia nitrogen of the wastewater treatment method of the present invention for printing and dyeing wastewater and other types of wastewater is significantly better than that of iron-carbon micro-electrolysis or ozone catalysis.

[0107] Example 8

[0108] The wastewater generated by a pharmaceutical intermediate production enterprise in Anhui was taken as the treatment object. Influent water quality: CODcr content is above 97400mg / L, and ammonia nitrogen content is about 400mg / L. Reaction conditions: The particle size range of iron-carbon suspended filler is 3-5mm, the filler filling coefficient is 1 / 3 of the reactor height, the ozone injection amount is 30mg / L, and the inlet flow rate is 10m / h. The experiment was carried out for 240min. After the experiment, the wastewater was allowed to settle, and the upper effluent was treated with the company's patented strain (CGMCC No.17168, CGMCCNo.17167) combined with the activated sludge method for 5-6 days to meet the effluent standards required by the company (CODcr <1000mg / L, ammonia nitrogen <200mg / L). The experimental results are as follows:

[0109]

[0110] Note: The removal rate of step 2 is the cumulative removal rate of step 1 + step 2.

[0111] The experimental results of Example 4 show that the COD removal rate of pharmaceutical wastewater and other wastewater types can reach 99% and the ammonia nitrogen removal rate can reach more than 75% by using the wastewater treatment method of the present invention combined with the patented strain + activated sludge method.

[0112] The above display only describes the main features and inventive points of the present invention. It should be understood by those skilled in the art that the present invention is not limited by the above-mentioned embodiments. Without departing from the present invention and the scope of protection, the present invention may have various changes, and these changes and improvements will fall within the scope of protection claimed by the present invention. The scope of protection claimed by the present invention is limited by the attached claims and their equivalents.

Claims

1. An iron-carbon suspension filler, characterized in that: Made by the following method: (1) Mixing raw materials: 15-30% of sponge iron powder, 3-10% of graphene powder, 5-10% of ionic fixing agent, 0.5-1.0% of palladium alloy catalyst, 5-20% of pore-forming agent and 20-40% of polymer in a mass ratio are sieved separately, and then 30-40% of water is added according to a preset ratio and mixed evenly, and ultrasonic enhancement is performed during the mixing process to obtain an initial raw material a; (2) Raw material ball milling: ball milling the initial raw material a to obtain an initial raw material b with a particle size of ≤100 μm; (3) Electrostatic spraying: The suspension carrier is pretreated to make it conductive, and then the obtained initial raw material b is coated on the entire suspension carrier skeleton by electrostatic spraying to form an iron-carbon micro-electrolytic coating with a thickness of 0.5 to 1 mm on the surface of the suspension carrier, thus obtaining a formed iron-carbon suspension filler; (4) Filler sintering: The formed iron-carbon suspension filler is placed in a tubular furnace and sintered at 280-320° C. in an oxygen-free atmosphere, and then naturally cooled to room temperature and then soaked and cleaned to obtain the spare iron-carbon suspension filler; the density of the iron-carbon suspension filler is 0.9-1.2 g / cm 3 .

2. The iron-carbon suspension filler according to claim 1, characterized in that: In the step (1), the ionic fixing agent is a quaternary ammonium salt type cationic fixing agent or the like; the palladium alloy catalyst is a catalyst synthesized from palladium and one or more of platinum, cobalt, copper, and nickel; the pore-forming agent is ammonium carbonate, ammonium bicarbonate, ammonium chloride, bone meal, polymethacrylate, methyl methacrylate, sawdust, rice husk, cotton, or a combination of one or more of the above; and the polymer is polyurethane, polypropylene, or high-density polyethylene.

3. The iron-carbon suspension filler according to claim 1, characterized in that: In the step (3), the suspension carrier is a polytetrafluoroethylene porous suspension carrier; the suspension carrier is an organic carrier; it is chemically oxidized by hydrogen peroxide, potassium permanganate, or potassium dichromate to make it conductive; or, oxygen-containing polar groups hydroxyl, carboxyl, or carbonyl are introduced onto the surface of the suspension carrier by oxygen plasma, nitrogen plasma, or argon plasma to make it conductive.

4. An ozone-iron-carbon fluidized bed treatment device for refractory organic wastewater using the iron-carbon suspension filler as claimed in claim 1, characterized in that: The device comprises a reaction tower, an iron-carbon suspension filler, a water inlet, an aeration device and a water outlet; the reaction tower is a fluidized bed reactor; the reaction tower is filled with an iron-carbon suspension filler; the density of the iron-carbon suspension filler is 0.9-1.2 g / cm 3 The particle size of the iron-carbon suspension filler is between 2-6 mm; the water inlet is located at the bottom of the reaction tower to ensure that the wastewater enters the reaction zone evenly; the aeration device is located at the bottom of the reaction tower to introduce ozone into the wastewater; The water outlet is located on the upper side of the reaction tower; the aeration device comprises an ozone air inlet, a water distributor and an aerator connected in sequence; and a plurality of aerators are arranged on the water distributor.

5. The ozone-iron-carbon fluidized bed treatment device for refractory organic wastewater according to claim 4, characterized in that: The reaction tower is in a vertical cylindrical shape; the ozone air inlet is connected to the ozone generator; and the water inlet is connected to the feed pump.

6. The ozone-iron-carbon fluidized bed treatment device for refractory organic wastewater according to claim 4, characterized in that: An intercepting screen is arranged at the upper part of the reaction tower, and the intercepting screen is fixed on the inner wall of the reaction tower.

7. The ozone-iron-carbon fluidized bed treatment device for refractory organic wastewater according to claim 4, characterized in that: The tail gas outlet at the top of the reaction tower is connected to the ozone inlet at the bottom of the reaction tower.

8. A method for treating organic wastewater using the ozone-iron-carbon fluidized bed treatment device for refractory organic wastewater as claimed in claim 5, characterized in that: The following steps are involved: (1) Check whether the equipment and components of the whole set of equipment are operating normally; fill the iron-carbon suspension filler after cleaning and screening into the reaction tower, ensure that the particle size of the iron-carbon suspension filler meets the requirement of 2-6mm, and the filling height is 1 / 5 to 1 / 3 of the height of the reaction tower; (2) slowly introducing the wastewater to be treated into the reaction tower through a feed pump, controlling the inlet flow rate of the wastewater to be between 5-40 m / h, so that a stable fluidized state is formed in the reaction tower; (3) Turn on the ozone generator and evenly introduce the generated ozone gas into the reaction tower through the water distributor and the aerator for reaction; the amount of ozone introduced is controlled between 5-60 mg / L; (4) Regularly sample and analyze the wastewater quality indicators to determine whether the reaction has achieved the expected effect; when the water quality indicators meet the discharge standards or treatment requirements, control the wastewater inlet flow rate at a constant value, and make fine adjustments based on the effluent indicators in the later stage to ensure continuous inlet reaction status; (5) The treated wastewater is discharged from the outlet on the top side of the reaction tower and enters the subsequent treatment unit or is directly discharged.

9. The method for treating organic wastewater according to claim 8, characterized in that: In step (3), the reaction time is controlled to be between 30 and 240 minutes; during the reaction, the temperature in the reaction tower is controlled to be ≥10°C, the pressure to be 0.01-0.08Mpa, and the pH value to be 1-11.

10. The method for treating organic wastewater according to claim 8, characterized in that: For used iron-carbon suspension fillers, decide whether to regenerate them or replace them with new ones based on their loss and activity recovery.

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