A method for treating acid organic wastewater using steel slag

Abstract

The present application relates to a kind of method for treating acid organic wastewater with steel slag, solve the problem of low utilization rate of steel slag, arbitrary stacking, while solving the problem of acid organic wastewater treatment.The method of the present application is to pass into acid organic wastewater to electrocatalytic steel slag reaction tank, is handled by steel slag reaction tank, i.e.acid organic wastewater can be realized treatment.The structure of the electrocatalytic steel slag reaction tank is innovated in the present application, the treatment effect of electrocatalysis is effectively improved by filling steel slag in three-dimensional hollow cathode and anode, organic matter in wastewater can be first adsorbed by steel slag, and then electrocatalytic oxidation is carried out.The organic matter and organic acid in wastewater are adsorbed by steel slag in the present application, and then electrocatalytic oxidation is carried out, the selectivity of electrocatalytic oxidation is improved, and the power consumption is also reduced.Steel slag treatment and wastewater treatment are combined together, wastewater can be treated on a large scale, and steel slag treatment is also realized, and the treated steel slag is finally used as cement, without any residual pollutants.

Description

TECHNICAL FIELD

[0001] The present application relates to the treatment technology of organic wastewater, in particular to a method for treating acid organic wastewater by using steel slag. BACKGROUND

[0002] Steel slag is an industrial waste residue produced in the process of steelmaking. As a large steel producer, China produces about 50% of the world's total steel output every year. The amount of steel slag discharged is enormous. According to statistics, 0.15-0.2 tons of waste slag will be produced for every ton of crude steel. The accumulated steel slag cannot be utilized and is randomly piled up on vacant land. At present, the annual output of steel slag is about 100 million tons, and the cumulative storage is 1 billion tons, with a comprehensive utilization rate of only 30%. The output of steel slag in China increased from 103 million tons in 2011 to 160 million tons in 2020, and it is expected to reach 169 million tons in 2023. The output and storage of steel slag are increasing year by year, and its reduction and resource utilization conform to the national policy orientation. Due to different chemical compositions and cooling conditions, the appearance and color of steel slag vary greatly. Steel slag with low alkalinity is black and gray, and steel slag with high alkalinity is brown and gray. Steel slag is hard and has a density of 1700-2000 kg·m -3 The main chemical components of steel slag are CaO, MgO, FeO, MnO, Al2O3, Fe2O3, P2O5 and f-CaO.

[0003] Acidic organic wastewater from coal chemical industry, synthetic pharmaceutical industry, printing and dyeing industry, grain processing industry and coking industry has complex composition, high organic matter concentration, multiple types of pollutants, extreme pH value, and often contains various organic matters with biological toxicity or three-teratogenic properties, which is difficult to treat by conventional methods. The conventional treatment method needs to add alkali to the wastewater for neutralization of the acidity of the wastewater, which will increase the salinity of the water, increase the difficulty of biochemical treatment, and also cause a large amount of salt waste. Steel slag contains a large amount of alkaline substances and has a large specific surface area, which can be used for the treatment of acidic organic wastewater. At the same time, it can also solve the problem of direct piling up of steel slag, which causes a large amount of resource waste and occupies a large amount of land.

[0004] Patent No. CN 105502673 A is a device for simultaneous power generation and sewage purification using steel slag as anode. The steel slag electrode is buried in the anode of a microbial fuel cell and is coupled with a composite vertical flow constructed wetland. It can only be used for wastewater with low organic matter content and suitable for plant growth. Patent No. CN 106800332 A is a water treatment method using steel slag to catalyze ozone, which uses steel slag as an ozone catalyst to improve the utilization rate of ozone.

[0005] Patent CN 101353201 A a new method for wastewater treatment, first carbonation of steel slag and then used as filler for microorganisms to increase the attachment area, these patents do not mention the large-scale treatment of steel slag, and how to reuse the steel slag after use. SUMMARY

[0006] The present application aims to provide a treatment method for acid organic wastewater, that is, a treatment method for treating acid organic wastewater by using steel slag. For treating acid organic wastewater, the treatment of acid organic wastewater does not require additional addition of alkali for neutralization, and both the treatment of wastewater and the full use of steel slag can be achieved at the same time, achieving the purpose of turning waste into treasure.

[0007] The present application is a treatment method for treating acid organic wastewater by using steel slag, which comprises the following steps:

[0008] A method for treating acid organic wastewater by using steel slag, comprising the following steps:

[0009] (1) The acid organic wastewater enters the aeration tank for aeration treatment;

[0010] (2) After treatment in the aeration tank, the acid organic wastewater enters the buffer tank;

[0011] (3) The acid organic wastewater from the buffer tank enters the electro-catalytic steel slag reaction tank;

[0012] (4) The effluent from the electro-catalytic steel slag reaction tank meets the standards and enters the next process.

[0013] As a preferred technical solution of the present application, the volume of the aeration tank is 10 m 3 , the control water inflow rate is 0.5-10 m 3 / h, a microporous diffusion aeration device is installed at the bottom of the aeration tank, the control pore size is 200-300 um, the air bubbles of the aeration tank are provided by a nanometer micro-bubble pump, and 10 nm-100 μm ultra-micro bubbles are provided by the nanometer micro-bubble pump, which is more conducive to the removal effect of the aeration tank. The aeration tank is mainly used to remove suspended solids and oils in wastewater, including algae, plant residues, fine colloidal particles and fibers. By releasing highly dispersed small bubbles into the aeration tank, the small bubbles adhere to the fine lightweight solids or oils in the wastewater, so that the density of the small particles is reduced and then floats to the water surface, and then the scraped plate is used for collection and treatment to realize physical separation.

[0014] As a preferred technical solution of the present application, the main purpose of the adjusting tank is to adjust the water volume, and the volume of the adjusting tank is 10 m 3 , and the flow rate is controlled at 0.5-10 m 3 / h. After the system monitors that the COD of the effluent of the steel slag reaction tank is higher than the set value, the control system controls the inflow of the steel slag reaction tank, increases the current density of the composite electrode plate in the electro-catalytic steel slag reaction tank, and reduces the inflow and outflow of the aeration tank, and part of the wastewater in the aeration tank enters the buffer tank.

[0015] As a preferred technical scheme of the present application, the volume of the electro-catalytic steel slag reaction tank is 10 m 3 , the control wastewater flow rate is 0.5-10 m 3 / h, the current density in the electro-catalytic steel slag reaction tank is 0.1-20 A / m 2 , the effective treatment area of the anode and cathode is 1 m 2 , the inflow pH value is 1-6, and the effluent pH value is 7-8.

[0016] As a preferred technical scheme of the present application, the anode of the steel slag reaction tank is a hollow multi-layer three-dimensional titanium-coated ruthenium metal mesh (as shown in Figure 3 ), the pore size of the metal mesh is 10-100 um, and the alkaline steel slag is filled in the three-dimensional titanium-coated ruthenium mesh, and the particle size of the steel slag is greater than 500 um. The cathode of the steel slag reaction tank is a hollow multi-layer three-dimensional titanium metal mesh, the pore size of the metal mesh is 10-100 um, and the alkaline steel slag is filled in the three-dimensional titanium mesh, and the particle size of the steel slag is greater than 500 um. According to the different water quality of the inflow, the cathode of the steel slag reaction tank can also be replaced with other cathode materials such as graphite.

[0017] As a preferred technical scheme of the present application, in the electro-catalytic steel slag reaction tank (as shown in Figure 2 ), the acid organic wastewater adopts a zigzag flow mode in the electro-catalytic steel slag reaction tank, which maximizes the residence time of the acid organic wastewater in the steel slag reaction tank, and the organic matter in the wastewater can be maximally adsorbed on the steel slag through the zigzag flow mode, and then subjected to electro-catalytic oxidation under the action of electro-catalysis.

[0018] As a preferred technical scheme of the present application, the steel slag reaction tank detects the COD and pH value of the outlet of the aeration tank through a detection system, sets the values according to the water quality of the outlet of the aeration tank and the water quality requirements of the outlet of the steel slag reaction tank, and adjusts the flow rate of the steel slag reaction tank and the current density of the anode and cathode plate in real time. After the acid organic wastewater enters the steel slag reaction tank, it flows through the electrode plate of the steel slag reaction tank in a zigzag flow mode. The anode and cathode plate of the steel slag reaction tank is filled with multi-layer alkaline steel slag, and the alkaline substances in the steel slag can effectively neutralize the acid wastewater. Since the steel slag is a porous material, it can adsorb organic matter in the wastewater, and then be subjected to electro-catalytic oxidation and decomposition.

[0019] As a preferred technical scheme of the present application, the anode and cathode of the electro-catalytic steel slag reaction tank are arranged in a staggered multi-layer three-dimensional network structure, the gaps in the middle are used to fill the waste alkaline steel slag, the pH value of the acidic wastewater is adjusted by the alkalinity of the steel slag, and the porous structure of the steel slag can effectively adsorb the organic matter in the wastewater.

[0020] In the present application, different types of steel slag are replaced according to the change of water quality in the electro-catalytic steel slag reaction tank, so as to meet the water outlet requirements.

[0021] In the present application, the steel slag filled in the three-dimensional hollow anode and cathode in the steel slag reaction tank can be used as a cement filler after adsorption saturation, and after high-temperature calcination, the part of the adsorbed organic matter that is not subjected to advanced oxidation is discharged in full compliance with the standards, thereby truly realizing green and efficient utilization.

[0022] As a preferred technical scheme of the present application, the inlet and outlet flow rates of the aeration tank, the buffer tank and the electro-catalytic steel slag reaction tank are controlled by a control system, the control system can receive the flow rate changes of each unit in real time, and the inlet and outlet water flow rates of each unit are controlled by the control system;

[0023] The inlets and outlets of the aeration tank, the buffer tank and the electro-catalytic steel slag reaction tank are each provided with an online COD detector and a pH detector, the online detector is connected to the control system, and the control system can control the outlet parameter changes of each unit in real time;

[0024] The control system can monitor the water quality changes of each unit in real time, dynamically adjust the operation of each unit in real time, and ensure that the water outlet indicators are normal;

[0025] The control system can adjust the inlet and outlet water flow rates of the aeration tank, the buffer tank and the electro-catalytic steel slag reaction tank according to the COD and pH value of the inlet water quality;

[0026] The control system can also adjust the current density of electro-catalysis according to the COD and pH value of the inlet water quality.

[0027] The control system is mainly provided with an online COD detector and a pH detector at the inlets and outlets of the aeration tank, the buffer tank and the electro-catalytic steel slag reaction tank, the online detector is connected to the control system, the control system can control the outlet parameter changes of each unit in real time, the control system can adjust the flow rate, current density and reaction time according to the outlet set indicators of each treatment unit, and the water outlet indicators are ensured to be qualified.

[0028] The acidic organic wastewater of the present application can effectively treat the organic matter in the wastewater after passing through the aeration tank, the buffer tank and the electro-catalytic steel slag reaction tank.

[0029] Compared with other methods for treating acidic organic wastewater, the steel slag reaction tank described in this invention offers several advantages. Steel slag itself is a waste product requiring immediate treatment. Using steel slag for acidic organic wastewater treatment is cost-effective, simple to operate, and transforms waste into a valuable resource. In contrast, other advanced oxidation methods, such as ozone oxidation, require the addition of alkali to adjust the wastewater's pH. Most advanced oxidation processes require an alkaline environment to catalyze the generation of more hydroxyl radicals. The oxidation potential of hydroxyl radicals (HO▪) reaches 2.8V, second only to the strongest oxidant, fluorine (3.06V), and 1.35 times that of ozone. Due to the pollution caused by fluorine, advanced oxidation technology using hydroxyl radicals as oxidants is theoretically and practically the most suitable. It not only has strong oxidizing power and a fast reaction rate (chain reaction) but is also pollution-free, making it the best green oxidant or green oxidation technology, thus ensuring the effectiveness of advanced oxidation. To maintain an alkaline environment, most advanced oxidation processes require the addition of alkali.

[0030] The electrocatalytic steel slag reaction tank of this invention innovates the structure of the electrocatalytic steel slag reaction tank. By filling the three-dimensional hollow anode and cathode with steel slag, the treatment effect of electrocatalysis is effectively improved. Organic matter in wastewater can be adsorbed by the steel slag first (e.g., ...). Figure 4 (As shown), and then electrocatalytic oxidation is performed. Under electrocatalytic oxidation, the adsorbed organic matter in the steel slag is rapidly oxidized, promoting the adsorption of organic matter (such as...) by the steel slag. Figure 4 As shown, the equilibrium shifts to the right. In contrast to conventional electrocatalysis, where the anode oxidizes all substances in the water that come into contact with the anode plate, resulting in some energy loss, this invention improves the selectivity of electrocatalytic oxidation and reduces energy loss by adsorbing organic matter and organic acids in wastewater with steel slag followed by electrocatalytic oxidation.

[0031] The method of this invention has the following unique advantages for acidic organic wastewater:

[0032] 1. This invention changes the previous method where steel slag was only used to adsorb organic matter and heavy metals in wastewater, and after adsorption, the steel slag remained a pollutant that could not be treated. After the adsorption effect of steel slag decreased, the steel slag was mixed into cement and calcined, and the organic matter was completely treated. All the steel slag was then used for cement production, without any pollution.

[0033] 2. An innovative electrocatalytic oxidation structure was developed, utilizing the porous structure of waste steel slag to effectively adsorb organic matter in acidic organic wastewater, providing multiple catalytic active sites for the three-dimensional anode plate. Instead of reacting directly on the electrocatalytic plate, the acidic organic wastewater is first adsorbed onto the steel slag before catalysis, significantly improving the electrocatalytic effect.

[0034] 3. The method changes the simple mode of adding steel slag to the reaction tank, and combines the steel slag treatment with the wastewater treatment, so as to solve the problem of steel slag treatment and realize the treatment of acidic organic wastewater.

[0035] 4. After electrochemical oxidation, the macromolecular organic matter can be degraded into small molecular organic matter, which is suitable for the subsequent deep removal of organic matter and desalination treatment device, and obviously improves the treatment efficiency of the subsequent process.

[0036] 5. The method is carried out at normal temperature and pressure without adjusting pH; the steel slag is used to treat acidic organic wastewater without additional alkali, and at the same time, the pH of the effluent is ensured to be suitable, so as to not affect the subsequent treatment process.

[0037] 6. No additional soluble salt such as sodium chloride and sodium sulfate is added; the tail gas generated in the electrochemical reaction is effectively absorbed, and no secondary pollution is generated;

[0038] 7. The process flow is short, the treatment effect is stable, and the operation is convenient; all units can be automatically operated under the control of the control system, and the control system can dynamically adjust the inlet and outlet flow of each unit and the current density of electrocatalysis in real time according to the change of the inlet water quality. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 The flow chart for treating acidic organic wastewater by using steel slag.

[0040] Figure 2 The schematic diagram of the electrocatalytic steel slag reaction tank.

[0041] Figure 3 The schematic diagram of the local enlargement of the anode and cathode plates of the electrocatalytic steel slag reaction tank.

[0042] Figure 4 The schematic diagram of the steel slag adsorbing organic matter. DETAILED DESCRIPTION

[0043] The technical solutions of the present application will be described below in combination with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0044] Example 1

[0045] The method for treating acidic organic dye wastewater by using steel slag is as follows:

[0046] (1) The organic dye wastewater is pumped from the dye wastewater tank into the aeration tank, and the inlet flow rate of the aeration tank is 1 m3 / h, the gas is injected into the aeration tank by a nanometer micro-bubble pump, the ultra-micro-bubbles with a bubble diameter of 10 nm-100 μm are controlled, the removal rate of light suspended solids such as algae, plant residues, fine colloidal particles and fibers and oils in the acidic organic wastewater is more than 95% by the aeration tank treatment. The light suspended solids such as algae, plant residues, fine colloidal particles and fibers and oils floated are scraped by a scraper. After the aeration tank treatment, the acidic organic wastewater enters a buffer tank.

[0047] (2) The acidic organic wastewater enters a steel slag reaction tank from the buffer tank, the on-line detection system detects that the influent pH value is 3 and the influent COD is 5000 mg / L, the influent flow rate is controlled to be 1 m 3 / h. The anode is a multilayer titanium coated ruthenium three-dimensional network hollow structure, the anode network pore size is 20 um, the inside is filled with alkaline steel slag, and the alkaline steel slag particle size is controlled to be 600 um. The cathode is a multilayer titanium three-dimensional network hollow structure, the cathode network pore size is 20 um, the inside is filled with alkaline steel slag, and the alkaline steel slag particle size is controlled to be 600 um. The three-dimensional electrode plate spacing is 5-10 cm, there are 50 groups of anode plates and cathode plates respectively, and the current density is 5 A / m 2 After the steel slag reaction tank treatment, the effluent COD is 1500 mg / L and the pH value is 7.2.

[0048] Example 2

[0049] The method for treating the acidic electroplating wastewater by using the steel slag is as follows:

[0050] (1) The organic wastewater enters an aeration tank from the electroplating wastewater tank by a pump, the aeration tank influent flow rate is 2 m 3 / h, the gas is injected into the aeration tank by a nanometer micro-bubble pump, the ultra-micro-bubbles with a bubble diameter of 50 nm-100 μm are controlled, the removal rate of light suspended solids and oils in the acidic organic wastewater is more than 96% by the aeration tank treatment. The light suspended solids and oils floated are scraped by a scraper. After the aeration tank treatment, the acidic organic wastewater enters a buffer tank.

[0051] (2) The acidic organic wastewater enters a steel slag reaction tank from the buffer tank, the on-line detection system detects that the influent pH value is 1 and the influent COD is 4000 mg / L, the influent flow rate is controlled to be 1.5 m 3 / h. The effluent COD is set to be 1200 mg / L and the pH value is set to be 7.5. The anode is a multilayer titanium coated ruthenium three-dimensional network hollow structure, the anode network pore size is 30 um, the inside is filled with alkaline steel slag, and the alkaline steel slag particle size is controlled to be more than 700 um. The cathode is a multilayer titanium three-dimensional network hollow structure, the cathode network pore size is 30 um, the inside is filled with alkaline steel slag, and the alkaline steel slag particle size is controlled to be more than 700 um. The three-dimensional electrode plate spacing is 15-25 cm, there are 50 groups of anode plates and cathode plates respectively, and the current density is 10 A / m2 After the steel slag reaction tank treatment, the COD of the effluent detected by the detection system near the effluent outlet was 1500 mg / L, and the pH value was 6.8, which was higher than the set value of COD 1200 mg / L and pH 7.5. The control system adjusted by self-feedback, closed the inlet and outlet of the steel slag reaction tank, started the internal circulating pump of the steel slag reaction tank, adjusted 15A / m 2 , improved the electro-catalytic treatment effect, and the acidic organic wastewater was subjected to cyclic electro-catalysis in the steel slag reaction tank until the effluent reached COD 1200 mg / L and pH 7.5. The control system opened the inlet and outlet of the steel slag reaction tank and continued to treat the acidic organic wastewater.

[0052] Example 3

[0053] The method for treating acidic metallurgical organic wastewater by steel slag is as follows:

[0054] (1) The acidic metallurgical organic wastewater is pumped from the metallurgical wastewater tank into the aeration tank, the water inlet flow rate of the aeration tank is 0.6m 3 / h, the gas is injected into the aeration tank by a nano-bubble pump, the ultra-micro-bubble with a bubble diameter of 60 nm-100 μm is controlled, and the removal rate of suspended solids and oil in the acidic organic wastewater treated by the aeration tank reaches more than 97%. The suspended solids and oil that float up are scraped off by a scraper. After the treatment by the aeration tank, the acidic organic wastewater enters the buffer tank.

[0055] (2) The acidic organic wastewater is pumped from the buffer tank into the steel slag reaction tank, the online detection system detects that the inlet pH value is 5 and the inlet COD is 8000 mg / L, and the inlet flow rate is controlled at 0.6m 3 / h. The anode is a multi-layer titanium coated ruthenium three-dimensional network hollow structure, the anode network aperture is 40 um, the inside is filled with alkaline steel slag, and the particle size of the alkaline steel slag is controlled to be more than 800 um. The cathode is a multi-layer titanium three-dimensional network hollow structure, the cathode network aperture is 40 um, the inside is filled with alkaline steel slag, and the particle size of the alkaline steel slag is controlled to be more than 800 um. The distance between the three-dimensional electrodes is 10-20 cm, and each of the anode and cathode plates has 60 groups. The current density is 18A / m 2 , after the treatment by the steel slag reaction tank, the effluent COD is 1000 mg / L and the pH value is 7.4.

[0056] Comparative Example 1

[0057] The steel slag + electro-catalytic oxidation is used to treat acidic organic dye wastewater.

[0058] The dye wastewater is treated by directly adding steel slag to adjust the pH value in the steel slag reaction tank. The conventional titanium coated ruthenium electrode plate is used as the anode and the titanium electrode plate is used as the cathode in the steel slag reaction tank for comparison test, which is as follows:

[0059] The organic dye wastewater is pumped from the dye wastewater pool into the aeration tank, the water inflow rate of the aeration tank is 1 m 3 / h, the gas is injected into the aeration tank by the nano-micro bubble pump, the ultra-micro bubble with a bubble diameter of 10 nm-100 μm is controlled, the removal rate of the light suspended solids such as algae, plant residues, fine colloidal particles and fibers and oils in the acid organic wastewater treated by the aeration tank reaches 95% or more. The light suspended solids such as algae, plant residues, fine colloidal particles and fibers and oils floated are scraped by the scraper. After the treatment by the aeration tank, the acid organic wastewater enters the buffer tank.

[0060] The acid organic wastewater enters the steel slag reaction tank from the buffer tank, the on-line detection system detects that the inflow pH value is 3 and the inflow COD is 5000 mg / L, the inflow flow rate is controlled to be 1 m 3 / h. The anode titanium coating ruthenium plate and the cathode titanium plate are used, the same amount of steel slag as that in Example 1 is added in the reaction tank. The plate spacing is 5-10 cm, there are 50 groups of anode and cathode plates respectively, the current density is 5 A / m 2 After the treatment by the steel slag reaction tank, the effluent COD is 4500 mg / L and the pH value is 5.

[0061] It is found by comparison that the COD and pH value treatment effect of Comparative Example 1 is far lower than that of Example 1, because the steel slag in Comparative Example 1 only plays an adsorption role, the organic matters adsorbed on the steel slag cannot be oxidized in time, resulting in a small amount of adsorption and a slow adsorption rate. In Example 1, the structure of the electro-catalytic plate is innovated, the steel slag is filled in the three-dimensional hollow plate, the organic matters and acid-containing organic matters in the wastewater can be adsorbed on the steel slag at the same time, and the adsorbed organic matters and acid-containing organic matters can be rapidly oxidized due to the electro-catalytic effect, which promotes the dynamic balance of the adsorption of the organic matters by the steel slag, so the effect of Example 1 is better than that of Comparative Example 1.

[0062] The application provides a method for treating acid organic wastewater by using steel slag, which can directly introduce a large amount of acid organic wastewater into the system without adjusting the pH value in advance, thereby avoiding the generation of more waste salt. The application has the following advantages: 1. The acid organic wastewater treatment is effectively combined with the steel slag treatment, without the need to build a separate steel slag treatment device, thereby greatly simplifying the steel slag treatment cost and realizing the treatment of acid wastewater; 2. The organic matter in the wastewater is completely removed instead of being adsorbed and transferred, thereby leaving pollutants; 3. The adding mode of the steel slag is changed, the steel slag originally added directly into the wastewater is fixed in the hollow three-dimensional network structure, thereby avoiding the steel slag from entering the subsequent treatment process; 4. The steel slag is used to treat the acid organic wastewater, and the adsorption of the steel slag provides catalytic active sites for electro-catalytic oxidation; 5. The alkalinity of the steel slag can neutralize the acidity in the wastewater, and the steel slag itself has alkaline catalytic active sites, which can provide more alkaline active sites for electro-catalysis, thereby catalyzing more hydroxyl radicals; 6. The organic matter in the steel slag that cannot be electro-catalytically oxidized can be replaced quickly after the treatment effect is reduced, and the replaced steel slag can be mixed into cement, and after high-temperature roasting, the organic matter in the steel slag that cannot be electro-catalytically oxidized is completely burned, thereby realizing complete treatment; 7. The steel slag can be used only after being treated by common methods such as hot pouring, disc pouring, hot stewing, water quenching, air quenching, mechanical force, and slag disposal. The steel slag treatment and wastewater treatment can be combined by the application, thereby realizing large-scale wastewater treatment and steel slag treatment, and the treated steel slag is finally used as cement without any residual pollutants.

[0063] The above shows and describes the basic principles and main features of the application and the advantages of the application. It should be understood by those skilled in the art that the application is not limited by the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the application. Without departing from the spirit and scope of the application, various changes and improvements can be made to the application, and these changes and improvements all fall within the scope of the claimed application. The scope of protection of the application is defined by the appended claims and their equivalents.

Claims

1. A method for treating acidic organic wastewater using steel slag, characterized by It comprises the following steps: (1) the acid organic wastewater enters the aeration tank for aeration treatment; (2) after the treatment of the aeration tank, the acid organic wastewater enters the buffer tank; (3) the acid organic wastewater enters the electro-catalytic steel slag reaction tank from the buffer tank; (4) the water discharged from the electro-catalytic steel slag reaction tank meets the standards and enters the next process; The volume of the electro-catalytic steel slag reaction pool is 10 m 3 , the control wastewater flow rate is 0.5-10 m 3 / h, the current density in the electro-catalytic steel slag reaction pool is 0.1-20 A / m 2 , the effective treatment area of the anode and cathode is 1 m 2 , the pH value of the inlet water is 1-6, and the pH value of the outlet water is 7-8; The anode of the electro-catalytic steel slag reaction tank is a hollow multi-layer three-dimensional titanium coated ruthenium metal mesh, the pore size of the metal mesh is 10-100 um, and the alkaline steel slag is filled in the three-dimensional titanium coated ruthenium mesh, the particle size of the steel slag is greater than 500 um, and the cathode of the electro-catalytic steel slag reaction tank is a hollow multi-layer three-dimensional titanium metal mesh, the pore size of the metal mesh is 10-100 um, and the alkaline steel slag is filled in the three-dimensional titanium mesh, the particle size of the steel slag is greater than 500 um; In the electro-catalytic steel slag reaction tank, the acid organic wastewater adopts a zigzag mode, which maximizes the residence time of the acid organic wastewater in the steel slag reaction tank, and the organic matter in the wastewater can be maximally adsorbed on the steel slag through the zigzag mode, and then subjected to electro-catalytic oxidation under the action of electro-catalysis; After the steel slag filled in the three-dimensional hollow anode and cathode of the electro-catalytic steel slag reaction tank is saturated, it is used as a cement filler, and after high-temperature calcination, the organic matter in the steel slag that is not subjected to electro-catalytic oxidation is completely burned, and the steel slag is used as a cement filler, thereby realizing complete treatment.

2. The method for treating acid organic wastewater using steel slag according to claim 1, characterized in that: The aeration tank volume is 10 m 3 , the control water inflow rate is 0.5-10 m 3 / h, a microporous diffusion aeration device is installed at the bottom of the aeration tank, the control pore size is 200-300 um, the bubbles of the aeration tank are provided by a nanometer micro-bubble pump, and 10 nm-100 μm of ultra-micro bubbles are provided by the nanometer micro-bubble pump, which is more beneficial to the removal effect of the aeration tank.

3. The method for treating acid organic wastewater using steel slag according to claim 1, characterized in that: The buffer tank is used for adjusting the water quantity.

4. The method for treating acid organic wastewater using steel slag according to claim 1, characterized in that: The anode and cathode of the electro-catalytic steel slag reaction tank are arranged in a staggered multi-layer three-dimensional mesh structure, the space in the middle is used for filling waste alkaline steel slag, the pH value of the acid wastewater is adjusted by the alkalinity of the steel slag, and the porous structure of the steel slag can effectively adsorb the organic matter in the wastewater.

5. The method for treating acid organic wastewater using steel slag according to claim 1, characterized in that: In the electro-catalytic steel slag reaction tank, different types of steel slag are replaced according to the change of water quality, thereby meeting the water discharge requirements.

6. The method for treating acid organic wastewater with steel slag according to any one of claims 1-5, characterized in that: The inlet and outlet flow rates of the aeration tank, the buffer tank and the electro-catalytic steel slag reaction tank are controlled by a control system, the control system can receive the flow rate changes of each unit in real time, and the inlet and outlet water flow rates of each unit are controlled by the control system; The inlets and outlets of the aeration tank, the buffer tank and the electro-catalytic steel slag reaction tank are each provided with an on-line COD detector and a pH detector, the on-line detector is connected with the control system, and the control system can control the outlet parameter changes of each unit in real time; The control system can monitor the water quality changes of each unit in real time, dynamically adjust the operation of each unit in real time, and ensure that the water discharge indicators are normal; The control system can adjust the inlet and outlet water flow rates of the aeration tank, the buffer tank and the electro-catalytic steel slag reaction tank according to the COD and pH value of the inlet water quality; The control system can also adjust the current density of electro-catalysis according to the COD and pH value of the inlet water quality.

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