Device and method for synchronously removing heavy metals and organic matters in industrial wastewater

Abstract

The invention discloses a device and a method for synchronously removing heavy metals and organic matters in industrial wastewater, and particularly relates to the technical field of water treatment.A complexing agent is used for promoting manganese dioxide on the surface of manganese sand to activate peroxymonosulfate to generate high-activity sulfate free radicals and persulfate free radicals, so that the oxidative degradation efficiency of organic pollutants is improved; meanwhile, residual manganese dioxide formed in the reaction process has good heavy metal adsorption performance, and the mass transfer and reaction rate of pollutants is enhanced by combining the dynamic fluidized contact effect of manganese sand particles in the fluidized bed reactor. According to the process provided by the invention, various organic pollutants and heavy metal ions in the wastewater can be synchronously and efficiently removed under a mild condition, the problems of low treatment efficiency, complex process flow, secondary pollution and the like in a traditional method are avoided, and the process has a good application prospect and popularization value; the technical challenges of complex components and high treatment difficulty of industrial wastewater can be effectively handled.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and more particularly to a device and method for synchronously removing heavy metals and organic matter from industrial wastewater. Background Art

[0002] After decades of development, along with the rapid expansion of the global population and the rapid advancement of industrialization, the frequency of sudden environmental pollution accidents has increased significantly. Heavy metal pollution in water bodies, as an important component of sudden pollution incidents, has become a hot topic of widespread concern among researchers at home and abroad. The main sources of heavy metal pollution in water bodies include but are not limited to industrial activities such as electroplating, metal smelting, and machinery manufacturing, as well as human activities such as illegal discharge and leakage by enterprises. These activities directly or indirectly release large amounts of heavy metal elements into the water environment, resulting in the increasingly serious problem of heavy metal pollution in water bodies.

[0003] The heavy metal composition of industrial wastewater is complex, with major pollutants including various heavy metal ions, organic matter such as mineral processing agents, and the heavy metal organic chelates they form. With the continuous improvement of industrialization and the increasing demand for mineral resources, the non-ferrous metal industry has become a key pillar of the national economy. However, the resulting complex wastewater problems are also becoming increasingly prominent. For example, chelates of metals such as thallium, chromium, and cadmium (such as Cd-EDTA) are widely present in heavy metal wastewater. If such wastewater is directly discharged into water bodies without proper treatment, it will pose a serious threat to the sustainable development of the ecological environment and human life and health.

[0004] Historical experience shows that the prevention and control of industrial wastewater pollution is directly related to human health and public safety. Typical public health incidents such as Japan's osteomalacia (cadmium pollution in water bodies), Minamata disease (mercury pollution in water bodies), and the world-shaking Danube heavy metal pollution accident all stem from heavy metal pollution in industrial wastewater. Although traditional processes are relatively mature for treating free heavy metal ions, with the advancement of industrial technology and raw materials, a large number of complex heavy metal complexes and organic chelates have appeared in wastewater. These pollutants are highly stable and highly biotoxic, making them extremely difficult to treat. Heavy metal organic chelates can enter organisms through respiration, drinking water, and the food chain, and have long-term cumulative effects in organisms. Some typical chelated pollutants have a long incubation period and may cause long-term or even lifelong health hazards to humans.

[0005] At present, the treatment technologies for heavy metal wastewater mainly include flocculation and sedimentation, oxidation-reduction method, ion exchange method, membrane separation method, adsorption method, etc. Each technology has certain advantages and limitations. For example, flocculation and sedimentation method has the advantages of low cost and simple operation. It is suitable for high-concentration heavy metal wastewater (such as copper and zinc smelting wastewater) and can remove multiple metal ions (such as Cu, 2+ , Pb2+ 、Zn 2+ ), but there are problems such as large amount of sludge, which needs to be safely landfilled or recycled; and when treating low-concentration heavy metal wastewater (<10mg / L), the removal rate is low, and it is easily interfered by complexing agents (such as EDTA), and toxic H2S gas may be produced during the sulfide precipitation process; the ion exchange method has high selectivity and can recover precious metals (such as gold and silver) or high value-added metals (such as nickel), and can ensure the stability of the effluent water quality. It is suitable for deep treatment of low-concentration wastewater, but the resin is easily affected by high concentration salts (such as Na + , Ca 2+ ) pollution, high regeneration cost; and is not suitable for wastewater with high turbidity or high suspended solids content, requiring additional pretreatment;

[0006] The adsorption method has the characteristics of flexible process and strong adaptability. Adsorbents can be selected according to specific pollutants. It is suitable for the treatment of low-concentration wastewater (such as trace copper and zinc wastewater), but the adsorbent cost is relatively high (such as MOFs materials), and the adsorbent needs to be frequently regenerated or replaced after saturation; membrane separation technology has high separation efficiency (removal rate can reach more than 95%), and the treatment process does not require the addition of chemical agents, which is environmentally friendly and suitable for water resource reuse, but membrane pollution and scaling problems are common, and the maintenance cost is high, and the investment and energy consumption are large. It is suitable for large enterprises with sufficient funds; electrolysis method can directly recover metal resources, has good economic benefits (such as copper electrolysis recovery rate >90%), and does not produce sludge, which is environmentally friendly, but it is mainly suitable for the treatment of high-concentration, single metal wastewater, and the pH value and current density must be strictly controlled to avoid side reactions;

[0007] Biological treatment methods have the advantages of low cost and environmental friendliness. They are suitable for low-concentration wastewater with good biodegradability (such as zinc-containing wastewater) and do not pose secondary pollution problems. However, microorganisms are easily inhibited by heavy metal toxicity and require long-term acclimatization and cultivation. The treatment cycle is longer (several days to several weeks), and the overall efficiency is lower than that of chemical methods. Advanced oxidation technology can completely decompose organic pollutants, avoid the interference of chelating agents with subsequent heavy metal precipitation, and improve the biodegradability of wastewater. It is suitable for combination with other processes, but the cost of reagents is high (such as H2O2 and O3), and toxic intermediates may be generated during the reaction. It has no direct removal effect on high-concentration heavy metal ions and needs to be used in conjunction with other technologies.

[0008] In summary, although existing technologies can detect and treat heavy metal ions in industrial wastewater to a certain extent, due to the complex composition of industrial wastewater, it often contains multiple heavy metals, organic pollutants and their stable heavy metal complexes, which makes the treatment process face many challenges. There is an urgent need to develop new wastewater treatment technologies that are more efficient, environmentally friendly and suitable for complex pollution systems. Summary of the Invention

[0009] In order to overcome the above-mentioned defects of the prior art, an embodiment of the present invention provides a device and method for the simultaneous removal of heavy metals and organic matter in industrial wastewater. By utilizing a chelating agent to promote manganese dioxide on the surface of manganese sand to activate peroxymonosulfate to generate highly active free radicals, combined with the dynamic adsorption effect of manganese sand particles in a fluidized bed reactor, the oxidative degradation of organic matter and the efficient simultaneous removal of heavy metal ions are achieved, thereby solving the problems of complex industrial wastewater pollution components and difficulty in treatment raised in the above-mentioned background technology.

[0010] To achieve the above-mentioned object, the present invention provides the following technical solutions: a device for simultaneously removing heavy metals and organic matter from industrial wastewater, comprising a tank body and a piping system;

[0011] The top of the tank body is provided with an exhaust valve and a cover plate, wherein the exhaust valve is used to discharge excess gas; the cover plate is used to seal the tank body;

[0012] An ORP / pH sensor is provided on the inner wall of the tank body, and a NaOH / H2SO4 injection pipe is provided on the side wall of the tank body, and the NaOH / H2SO4 injection pipe is used to adjust the pH of industrial wastewater; a biological reaction zone and a manganese sand precipitation zone are arranged in sequence from top to bottom in the tank body; a liquid distributor is provided below the biological reaction zone, and the liquid distributor includes a porous plate and an atomizing nozzle, and a removable backwash filter is provided above the tank body; the manganese sand precipitation zone is connected to the biological reaction zone, and the manganese sand precipitation zone has a truncated cone structure. A mud discharge valve is provided at the bottom of the manganese sand precipitation zone to discharge sediment, and the diameter of the mud discharge valve is the same as the diameter of the bottom of the manganese sand precipitation zone serving as a carrier; a solid-liquid reaction zone is provided between the liquid distributor and the backwash filter, and the solid-liquid reaction zone is composed of the biological reaction zone and the manganese sand precipitation zone;

[0013] The piping system is arranged on the wall of the tank body; the piping system includes a water outlet pipe, a NaOH / H2SO4 injection pipe, a water inlet pipe, and a manganese sand regeneration liquid injection pipe arranged in sequence from top to bottom on the side wall of the tank body; the water outlet pipe is arranged above the solid-liquid reaction zone, and the NaOH / H2SO4 injection pipe is located on the side walls of the biological reaction zone and the manganese sand precipitation zone; the water inlet pipe is arranged below the biological reaction zone and the manganese sand precipitation zone; the manganese sand regeneration liquid injection pipe is arranged below the manganese sand precipitation zone; the middle part of the water inlet pipe is connected to the complexing agent injection pipe and the peroxymonosulfate injection pipe;

[0014] In the device, the industrial wastewater to be treated is mixed with a complexing agent and peroxymonosulfate, and then mixed with filled manganese sand particles for reaction, thereby achieving the removal of heavy metal ions and organic matter.

[0015] In a preferred embodiment, a bracket is provided at the bottom of the tank body, and the bracket is a three-legged bracket, and the bracket is used to support the tank body;

[0016] The water inlet pipe is sequentially provided with a water inlet pump, a valve and a flow meter.

[0017] A method for simultaneous removal of heavy metals and organic matter from industrial wastewater:

[0018] The industrial wastewater to be treated is mixed with a complexing agent and peroxymonosulfate, and then fed into a device for simultaneously removing heavy metals and organic matter from the industrial wastewater. The device includes a solid-liquid reaction zone equipped with a liquid distributor. The liquid distributor comprises a porous plate and an atomizing nozzle for evenly distributing the mixed liquid. The mixed liquid contacts manganese sand particles in the solid-liquid reaction zone, and the complexing agent reacts with manganese dioxide on the surface of the manganese sand to form a complex, thereby promoting the autocatalytic oxidation of the peroxymonosulfate to generate SO5· - and SO4· - Free radicals;

[0019] The free radicals oxidize and degrade the organic pollutants in the wastewater, and the residual MnO2 particles generated during the reaction adsorb the heavy metal ions in the wastewater; the sediment is discharged through the mud discharge valve set in the manganese sand precipitation area, thereby realizing the simultaneous removal of heavy metal ions and organic pollutants in industrial wastewater.

[0020] In a preferred embodiment, the manganese sand particles are selected from one or more of natural manganese sand, modified manganese sand or synthetic manganese materials, the natural manganese sand includes pyrolusite, psilomelane, manganese ore and rhodochrosite, and the particle size is 0.8-1.2 mm;

[0021] The peroxymonosulfate is selected from one or more of ammonium persulfate, potassium persulfate, and sodium persulfate;

[0022] The complexing agent is selected from one or more of ethylenediaminetetramethylenephosphonic acid (EDTMP), hydroxyethylidenediphosphonic acid (HEDP), aminotrimethylenephosphonic acid (ATMP), diethylenetriaminepentamethylenephosphonic acid (DETPMP), and polyaminopolyethertetramethylenephosphonic acid (PAPEMP).

[0023] In a preferred embodiment, the molar ratio of the heavy metal ion to the complexing agent is 1:2 to 1:10;

[0024] The molar ratio of the heavy metal ion to the peroxymonosulfate is 1:2 to 1:20.

[0025] In a preferred embodiment, the pH value of the industrial wastewater is controlled at 5 to 7.

[0026] In a preferred embodiment, the content of organic matter in the industrial wastewater is 200 mg / L to 10,000 mg / L; the content of heavy metal ions in the industrial wastewater is 10 mg / L to 1,000 mg / L.

[0027] In a preferred embodiment, the organic matter includes one or more of persistent organic pollutants, polychlorinated biphenyls, dioxins, DDT, endocrine disruptors, bisphenol A, nonylphenol, estradiol, medicines and personal care products, antibiotics, hormones, sunscreens, microplastics, perfluorooctanoic acid, and perfluorooctane sulfonic acid.

[0028] In a preferred embodiment, the hydraulic retention time is 15 minutes to 45 minutes.

[0029] In a preferred embodiment, the heavy metal ions include one or more of Ti(I), Pb(II), Cd(II), As(III), and Sb(III).

[0030] It should be further explained that the industrial wastewater to be treated is mixed with organic phosphate and peroxymonosulfate in a specific ratio and then enters the fluidized bed reactor through the water inlet pipe. A porous plate and atomizing nozzle are used to evenly distribute the mixed liquid and fully contact it with the manganese sand particles. The chelating agent reacts with manganese dioxide to form a complex, thereby promoting the autocatalytic oxidation of peroxymonosulfate. In this process, HSO5- is oxidized to SO5 ·- At the same time, the Mn(IV)-complexing agent is reduced to form a Mn(III)-complex; HSO5 - Able to oxidize Mn(III)-complexing agent to Mn(IV)-complexing agent, while producing SO4 ·- ; Free radical SO5 generated by peroxymonosulfate activation ·- 、SO4 ·- It has a high redox potential and can effectively remove organic pollutants. As the reaction proceeds, MnO2 gradually aggregates into particles to generate residual MnO2 solid. The MnO2 generated by the reaction has a stronger ability to adsorb heavy metal ions and can adsorb heavy metal ions in the soil. Organic phosphonate chelating agents can replace the difficult-to-biodegrade chelating agents (such as EDTA) that are chelated with heavy metal ions in the original industrial wastewater. Organic phosphonates have ester bonds and bio-based skeletons. After completing the chelation, they can be decomposed into small molecules by microbial action. The released heavy metal ions can be fixed by organisms or converted into low-toxic forms (such as MnCO3), thereby achieving the simultaneous removal of heavy metal ions and organic pollutants in industrial wastewater.

[0031] Technical effects and advantages of the present invention:

[0032] 1. The present invention uses a complexing agent to synergistically activate manganese dioxide to generate highly active free radicals, combined with the fluidized adsorption mechanism of manganese sand, to simultaneously and efficiently remove complex heavy metal ions and organic pollutants from industrial wastewater. This provides a systematic and effective solution to the problems of existing treatment difficulties and complex pollutant components.

[0033] 2. By promoting the autocatalytic reaction of peroxymonosulfate to generate sulfate radicals and persulfate radicals, the deep breakage and degradation of the molecular structure of organic matter is achieved, the biodegradability of wastewater is improved, and the interference of organic residues on subsequent treatment units is avoided;

[0034] 3. Through the dynamic fluidization contact process of manganese sand particles in the fluidized bed reactor, the mass transfer rate and reaction efficiency are significantly improved, so that heavy metal ions are quickly combined with the manganese dioxide particles generated by the reaction, thereby enhancing the fixation and removal of heavy metals in wastewater;

[0035] 4. The present invention uses a complexing agent to replace the stable organic chelated heavy metal complex in industrial wastewater, destroying its stable structure, promoting the release of heavy metal ions, and combining with a microbial degradable complexing agent matrix to achieve biological transformation of heavy metals into low-toxic forms, thereby reducing ecological and environmental risks;

[0036] 5. Through the fluidized bed reaction mode, continuous and stable treatment can be achieved under mild operating conditions, avoiding the secondary pollution problems caused by strong oxidation or precipitation processes in traditional methods. The process flow is simple and has good large-scale application potential and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Schematic diagram of the structure of the device of the present invention.

[0038] The accompanying drawings are marked as follows: exhaust valve (1), cover plate (2), water outlet pipe (3), backwash filter (4), tank body (5), ORP / pH sensor (6), NaOH / H2SO4 addition pipe (7), liquid distributor (8), peroxymonosulfate addition pipe (9), complexing agent addition pipe (10), water inlet pipe (11), manganese sand regeneration liquid addition pipe (12), mud discharge valve (13). DETAILED DESCRIPTION

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0040] Refer to the instruction manual Figure 1 , an apparatus and method for simultaneously removing heavy metals and organic matter from industrial wastewater according to an embodiment of the present invention;

[0041] Example 1:

[0042] This embodiment provides a fluidized bed treatment device for simultaneously removing heavy metal ions and organic pollutants from industrial wastewater; the device includes: a tank body 5, a piping system, a solid-liquid reaction zone, a manganese sand precipitation zone and a support structure;

[0043] The tank body 5 is a vertically arranged cylindrical structure. An exhaust valve 1 and a cover plate 2 are provided on the top of the tank body 5. The exhaust valve 1 is used to discharge excess gas generated inside the device during the reaction process. The cover plate 2 is used to seal the tank body 5 to ensure that the device remains sealed during the reaction process and prevent external gas from interfering with the reaction environment. A tripod 14 is installed at the bottom of the tank body 5 to stably support the tank body and enhance the structural strength and overall stability of the device.

[0044] An ORP / pH sensor 6 is provided on the inner wall of the tank body 5 for real-time monitoring of the oxidation-reduction potential (ORP) and pH value in the reaction system to ensure that the reaction process is in the set optimal operating conditions; an outlet pipe 3, a NaOH / H2SO4 dosing pipe 7, a water inlet pipe 11, and a manganese sand regeneration liquid dosing pipe 12 are sequentially provided on the side wall of the tank body 5, which are respectively used for effluent discharge, acidity regulator dosing, raw water feeding, and manganese sand regeneration liquid dosing operations; wherein, a complexing agent dosing pipe 10 and a peroxymonosulfate dosing pipe 9 are provided in the middle of the water inlet pipe 11 to facilitate the simultaneous completion of the pre-dosing of the reagents during the raw water feeding process;

[0045] Inside the tank body 5, a detachable backwash filter 4, a solid-liquid reaction zone and a manganese sand precipitation zone are arranged in sequence from top to bottom; the liquid distributor 8 is located at the bottom of the solid-liquid reaction zone, and is composed of a porous plate and an atomizing nozzle combination, which can achieve uniform distribution of raw water and pre-treated mixed liquid, enhance the contact effect between the fluid and the manganese sand particles, and form a stable fluidized reaction environment; a backwash filter 4 is provided above the solid-liquid reaction zone for intercepting manganese sand particles and preventing them from being lost with the treated water; between the liquid distributor 8 and the backwash filter 4 is the solid-liquid reaction zone, which is responsible for the main redox and adsorption reaction processes; below the solid-liquid reaction zone is the manganese sand precipitation zone, which has a truncated cone structure for effectively separating manganese sand particles from other solid sediments, and a mud discharge valve 13 is provided at the bottom, through which accumulated sediment can be regularly discharged to maintain long-term stable operation of the system;

[0046] The working process of the fluidized bed wastewater treatment device described in this embodiment is as follows: first, the industrial wastewater to be treated is input into the tank body 5 through the water inlet pipe 11; during the water inlet process, the complexing agent and peroxymonosulfate are synchronously added to the wastewater through the complexing agent feeding pipe 10 and the peroxymonosulfate feeding pipe 9 to form a reaction precursor mixed liquid; the mixed liquid is evenly distributed to the solid-liquid reaction zone through the porous plate and atomizing nozzle of the liquid distributor 8, and is fully contacted with the manganese sand particles filled in the reaction zone; due to the guiding effect of the liquid rising on the inner wall of the tank body 5, the mixed liquid forms a fluidized flow that spirals upward from bottom to top in the solid-liquid reaction zone, significantly increasing the contact area between the liquid and the manganese sand particles and the mass transfer efficiency;

[0047] During the reaction, the complexing agent reacts with the manganese dioxide on the surface of the manganese sand particles to form a complex, which promotes the autocatalytic oxidation reaction of peroxymonosulfate to generate highly active SO5· - and SO4· - Free radicals; these free radicals can effectively oxidize and degrade organic pollutants in wastewater. At the same time, the residual MnO2 particles formed in the reaction process have excellent adsorption capacity for heavy metal ions in wastewater, realizing efficient removal of heavy metal ions. The treated water is filtered through the backwash filter 4 and discharged from the outlet pipe 3. The excess gas generated by the reaction escapes from the top exhaust valve 1, and the residual particles deposited at the bottom are regularly discharged through the mud discharge valve 13. The manganese sand precipitation area can be timely added with manganese sand regeneration liquid (such as sodium hypochlorite solution) to restore the adsorption activity of manganese sand to ensure the continuous and stable operation of the device.

[0048] In this embodiment, simulated industrial wastewater with an initial Cd(II) concentration of 100 mg / L and a phenol concentration of 1500 mg / L was selected as the treatment object; the manganese sand particles filled were selected from natural manganese sand, and the particle size was controlled to be 1 mm; the complexing agent was hydroxyethylidene diphosphonic acid (HEDP), and the peroxymonosulfate was sodium persulfate, and the reagents were proportioned according to the molar ratio of Cd(II):HEDP:sodium persulfate of 1:5:10; the initial pH value of the industrial wastewater was adjusted to 6, and the hydraulic retention time of the reaction system was set to 30 minutes;

[0049] After treatment, the residual concentration of Cd(II) in the water was quantitatively detected using an inductively coupled plasma optical emission spectrometer (ICP-OES), and the residual concentration of phenol in the water was quantitatively detected using a high-performance liquid chromatography (HPLC). The removal rates of Cd(II) and phenol were calculated by comparing them with the initial influent concentrations. Experimental results showed that under the above operating conditions, the Cd(II) removal rate reached 98.2%, and the phenol removal rate reached 90.3%.

[0050] Example 2:

[0051] The difference from Example 1 is that the pH of the industrial wastewater was adjusted to pH = 5. The removal rates of Cd(II) and phenol after treatment are shown in Table 1 below.

[0052] Example 3:

[0053] The difference from Example 1 is that the pH of the industrial wastewater was adjusted to pH = 7. The removal rates of Cd(II) and phenol after treatment are shown in Table 1 below.

[0054] Example 4:

[0055] The difference from Example 1 is that the hydraulic retention time in this example is 15 minutes. The removal rates of Cd(II) and phenol after treatment are shown in Table 1 below.

[0056] Example 5:

[0057] The difference from Example 1 is that the reaction time after adding the drug in this example is 45 minutes. The removal rates of Cd(II) and phenol after treatment are shown in Table 1 below.

[0058] Example 6:

[0059] Different from Example 1, in this example, aminotri(methylenephosphonic acid) is used as the complexing agent. The removal rates of Cd(II) and phenol after treatment are shown in Table 1 below.

[0060] Example 7:

[0061] Different from Example 1, ethylenediaminetetramethylenephosphonic acid was used as the complexing agent in this example. The removal rates of Cd(II) and phenol after treatment are shown in Table 1 below.

[0062] Example 8:

[0063] Different from Example 1, the molar ratio of Cd(II): complexing agent: sodium permonosulfate is 1:2:10. The removal rates of Cd(II) and phenol after treatment are shown in Table 1 below.

[0064] Example 9:

[0065] Different from Example 1, the molar ratio of Cd(II): complexing agent: sodium permonosulfate is 1:10:10. The removal rates of Cd(II) and phenol after treatment are shown in Table 1 below.

[0066] Example 10:

[0067] Different from Example 1, the molar ratio of Cd(II): complexing agent: sodium permonosulfate is 1:5:2. The removal rates of Cd(II) and phenol after treatment are shown in Table 1 below.

[0068] Example 11:

[0069] The difference from Example 1 is that the molar ratio of Cd(II): complexing agent: sodium permonosulfate is 1:5:5. The removal rates of Cd(II) and phenol after treatment are shown in Table 1 below.

[0070] Example 12:

[0071] The difference from Example 1 is that the molar ratio of Cd(II): complexing agent: sodium permonosulfate is 1:5:20. The removal rates of Cd(II) and phenol after treatment are shown in Table 1 below.

[0072] Comparative Example 1:

[0073] Different from Example 1, no complexing agent was added in this comparative example. The removal rates of Cd(II) and phenol after treatment are shown in Table 1 below.

[0074] Comparative Example 2:

[0075] Different from Example 1, sodium permonosulfate was not added in this comparative example. The removal rates of Cd(II) and phenol after treatment are shown in Table 1 below.

[0076] Table 1: Test results of different examples and comparative examples in terms of Cd(II) and phenol removal rates

[0077]

[0078]

[0079] As can be seen from Examples 1-3, pH affects the removal rate of Cd(II) and phenol in the present invention. The present invention has a better removal effect on phenol at pH = 6. A lower pH will affect the conversion of MnO2 in the reaction system and inhibit the removal of Cd(II). A higher pH will affect the formation and stability of active species in the reaction system, resulting in poor removal of phenol. The treatment effect is best when pH = 6.

[0080] It can be seen from Examples 1, 4, and 5 that the reaction time after adding the drug affects the removal effect. When the reaction time is 20 min, not only a better removal rate is achieved, but also time cost can be saved. If the reaction time is insufficient, the active species cannot effectively remove the organic pollutants, and the conversion rate of MnO2 is low, and the adsorption capacity for Cd(II) is also insufficient.

[0081] From Examples 1, 6, and 7, it can be seen that the removal effects of different organophosphate complexing agents on phenol and Cd(II) are similar, and each of the three has its own advantages;

[0082] From Examples 1, 8-12, it can be seen that the molar ratio of Cd(II), complexing agent, and sodium permonosulfate has a certain influence on the removal rate of Cd(II) and phenol; among them, the molar ratio of Cd(II), complexing agent, and sodium permonosulfate of 1:5:10 has the best effect. A low concentration of the complexing agent will lead to a decrease in the conversion and stability of the active intermediate, thereby reducing the overall removal rate; a low concentration of sodium permonosulfate will result in insufficient SO5·- and SO4·-, thereby affecting the occurrence of subsequent reactions;

[0083] It can be seen from Example 1 and Comparative Examples 1-2 that in the absence of a chelating agent, MnO2 cannot effectively activate sodium permonosulfate to generate SO5·- and SO4·-, thereby failing to effectively oxidize and decompose organic matter, failing to replace the difficult-to-degrade chelating agent, affecting the adsorption of heavy metal ions by manganese sand, and failing to generate MnO2 with stronger metal ion adsorption capacity; in the absence of sodium permonosulfate, SO5·- and SO4·- cannot be generated, subsequent reactions cannot proceed, and the simultaneous removal of Cd(II) and organic matter cannot be achieved.

[0084] Table 2: Effect of reaction time on Cd(II) and phenol removal efficiency

[0085] Reaction time (min) Cd(II) removal rate (%) Phenol removal rate (%) 15 80.9 75.1 30 98.2 90.3 45 99.4 94.6

[0086] Table 3: Effect of pH on Cd(II) and phenol removal rates

[0087] pH Cd(II) removal rate (%) Phenol removal rate (%) 5 90.6 86.1 6 98.2 90.3 7 92.4 58.7

[0088] Table 4: Effects of different complexing agents on the removal efficiency of Cd(II) and phenol

[0089] Complexing agent type Cd(II) removal rate (%) Phenol removal rate (%) Hydroxyethylidene diphosphonic acid (HEDP) 98.2 90.3 Aminotrimethylphosphonic acid (ATMP) 98.5 91.1 Ethylenediaminetetramethylenephosphonic acid (EDTMP) 99.1 92.3

[0090] Table 5: Effect of peroxymonosulfate molar ratio on Cd(II) and phenol removal efficiency (complexing agent)

[0091] Molar ratio (Cd(II): complexing agent: peroxymonosulfate) Cd(II) removal rate (%) Phenol removal rate (%) 1:2:10 91.4 85.2 1:5:10 98.2 90.3 1:10:10 99.6 93.2 1:5:2 77.8 70.4 1:5:5 81.5 79.8 1:5:20 73.1 62.6

[0092] Table 6: Comparison of Cd(II) and phenol removal rates and other water quality parameters under different treatment conditions

[0093]

[0094]

[0095] Table 7: Test results of effluent water quality and mineralization characteristics

[0096]

[0097] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A device for simultaneously removing heavy metals and organic matter from industrial wastewater, comprising a tank (5) and a piping system, characterized in that: The top of the tank body (5) is provided with an exhaust valve (1) and a cover plate (2), wherein the exhaust valve (1) is used to exhaust excess gas; and the cover plate (2) is used to seal the tank body (5); An ORP / pH sensor (6) is provided on the inner wall of the tank body (5), and a NaOH / H2SO4 dosing pipe (7) is provided on the side wall of the tank body (5), and the NaOH / H2SO4 dosing pipe (7) is used to adjust the pH of industrial wastewater; a biological reaction zone and a manganese sand precipitation zone are sequentially arranged in the tank body (5) from top to bottom; a liquid distributor (8) is provided below the biological reaction zone, and the liquid distributor (8) includes a porous plate and an atomizing nozzle, and a detachable backwash filter (4) is provided above the tank body (5); the manganese sand precipitation zone is connected to the biological reaction zone, and the manganese sand precipitation zone is a truncated cone structure. A mud discharge valve (13) is provided at the bottom of the manganese sand precipitation zone to discharge sediment, and the diameter of the mud discharge valve (13) is the same as the diameter of the bottom of the manganese sand precipitation zone serving as a carrier; a solid-liquid reaction zone is provided between the liquid distributor (8) and the backwash filter (4), and the solid-liquid reaction zone is composed of the biological reaction zone and the manganese sand precipitation zone; The pipeline system is arranged on the wall of the tank body (5); the pipeline system includes a water outlet pipe (3), a NaOH / H2SO4 dosing pipe (7), a water inlet pipe (11) and a manganese sand regeneration liquid dosing pipe (12) arranged on the side wall of the tank body (5) from top to bottom; the water outlet pipe (3) is arranged above the solid-liquid reaction zone, and the NaOH / H2SO4 dosing pipe (7) is located on the side wall of the biological reaction zone and the manganese sand precipitation zone; the water inlet pipe (11) is arranged below the biological reaction zone and the manganese sand precipitation zone; the manganese sand regeneration liquid dosing pipe (12) is arranged below the manganese sand precipitation zone; the middle part of the water inlet pipe (11) is connected to the complexing agent dosing pipe (10) and the peroxymonosulfate dosing pipe (9); In the device, the industrial wastewater to be treated is mixed with a complexing agent and peroxymonosulfate, and then mixed with filled manganese sand particles for reaction, thereby achieving the removal of heavy metal ions and organic matter.

2. The device for simultaneously removing heavy metals and organic matter from industrial wastewater according to claim 1, characterized in that: A bracket is provided at the bottom of the tank body (5), wherein the bracket is a three-legged bracket and is used to support the tank body (5); The water inlet pipe (11) is provided with a water inlet pump, a valve and a flow meter in sequence.

3. A method for simultaneously removing heavy metals and organic matter from industrial wastewater, comprising applying the device for simultaneously removing heavy metals and organic matter from industrial wastewater according to claim 2, characterized in that: The industrial wastewater to be treated is mixed with a complexing agent and peroxymonosulfate, and then fed into a device for simultaneously removing heavy metals and organic matter from the industrial wastewater. The device comprises a solid-liquid reaction zone equipped with a liquid distributor (8), wherein the liquid distributor (8) is composed of a porous plate and an atomizing nozzle and is used to evenly distribute the mixed liquid. The mixed liquid contacts the manganese sand particles filled in the solid-liquid reaction zone, and the complexing agent reacts with the manganese dioxide on the surface of the manganese sand to form a complex, thereby promoting the autocatalytic oxidation of the peroxymonosulfate to generate SO5· - and SO4· - Free radicals; The free radicals oxidize and degrade the organic pollutants in the wastewater, and the residual MnO2 particles generated during the reaction adsorb the heavy metal ions in the wastewater; the sediment is discharged through the mud discharge valve (13) provided in the manganese sand precipitation area, thereby achieving the simultaneous removal of heavy metal ions and organic pollutants in the industrial wastewater.

4. The method for simultaneously removing heavy metals and organic matter from industrial wastewater according to claim 3, characterized in that: The manganese sand particles are selected from one or more of natural manganese sand, modified manganese sand or synthetic manganese materials, the natural manganese sand includes pyrolusite, psilomelane, manganite and rhodochrosite, and the particle size is 0.8-1.2 mm; The peroxymonosulfate is selected from one or more of ammonium persulfate, potassium persulfate, and sodium persulfate; The complexing agent is selected from one or more of ethylenediaminetetramethylenephosphonic acid (EDTMP), hydroxyethylidenediphosphonic acid (HEDP), aminotrimethylenephosphonic acid (ATMP), diethylenetriaminepentamethylenephosphonic acid (DETPMP), and polyaminopolyethertetramethylenephosphonic acid (PAPEMP).

5. The method for simultaneously removing heavy metals and organic matter from industrial wastewater according to claim 4, characterized in that: The molar ratio of the heavy metal ion to the complexing agent is 1:2 to 1:10; The molar ratio of the heavy metal ion to the peroxymonosulfate is 1:2 to 1:

20.

6. The method for simultaneously removing heavy metals and organic matter from industrial wastewater according to claim 5, characterized in that: The pH value of the industrial wastewater is controlled at 5 to 7.

7. The method for simultaneously removing heavy metals and organic matter from industrial wastewater according to claim 6, characterized in that: The content of organic matter in the industrial wastewater is 200 mg / L to 10,000 mg / L; the content of heavy metal ions in the industrial wastewater is 10 mg / L to 1,000 mg / L.

8. The method for simultaneously removing heavy metals and organic matter from industrial wastewater according to claim 7, characterized in that: The organic matter includes one or more of persistent organic pollutants, polychlorinated biphenyls, dioxins, DDT, endocrine disruptors, bisphenol A, nonylphenol, estradiol, medicines and personal care products, antibiotics, hormones, sunscreens, microplastics, perfluorooctanoic acid, and perfluorooctane sulfonic acid.

9. The method for simultaneously removing heavy metals and organic matter from industrial wastewater according to claim 8, characterized in that: The hydraulic retention time is 15 to 45 minutes.

10. The method for simultaneously removing heavy metals and organic matter from industrial wastewater according to claim 9, characterized in that: The heavy metal ions include one or more of Ti(I), Pb(II), Cd(II), As(III), and Sb(III).

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