A device and method for simultaneously removing heavy metals and organic matter in industrial wastewater

Abstract

The application discloses a device and method for synchronously removing heavy metals and organic matters in industrial wastewater, and particularly relates to the technical field of water treatment. The device and method promote the activation of manganese dioxide on the surface of manganese sand to generate high-activity sulfate radical and persulfate radical by using a complexing agent, so as to improve the oxidation degradation efficiency of organic pollutants. Meanwhile, the residual manganese dioxide formed in the reaction process has good heavy metal adsorption performance, and the dynamic fluidization contact of manganese sand particles in the fluidized bed reactor enhances the mass transfer and reaction rate of pollutants. Through the process provided by the application, the efficient removal of various organic pollutants and heavy metal ions in wastewater can be realized under mild conditions, and the problems of low treatment efficiency, complex process flow and secondary pollution existing in traditional methods can be avoided. The application has good application prospect and popularization value, and can effectively cope with the technical challenges of complex composition and difficult treatment of industrial wastewater.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of water treatment, more particularly, the present application relates to a device and method for simultaneously removing heavy metals and organic matters in industrial wastewater. BACKGROUND

[0002] After decades of development, 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 part of sudden pollution events, has become a hot issue of widespread concern by domestic and foreign researchers; the main sources of heavy metal pollution in water bodies include but are not limited to electroplating process, metal smelting, mechanical manufacturing and other industrial activities, as well as illegal and illegal discharge of enterprises, etc. These activities directly or indirectly discharge a large amount of heavy metal elements into the water environment, leading to the increasingly serious problem of heavy metal pollution in water bodies.

[0003] The composition of heavy metals in industrial wastewater is complex, and the main pollutants include various heavy metal ions, organic matter such as mineral processing reagents, and heavy metal organic chelates formed therefrom; with the continuous improvement of industrialization level, the demand for mineral resources continues to increase, and non-ferrous metal industry has become an important pillar industry of national economy; however, the problem of complex wastewater has also become increasingly prominent, such as chelates of metals such as thallium, chromium, and cadmium (e.g. Cd-EDTA) widely exist 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 hazard events such as Japan's bone pain disease (water cadmium pollution), Minamata disease (water mercury pollution), and the Danube River heavy metal pollution accident that shocked the world all originated from heavy metal pollution in industrial wastewater; although traditional processes are relatively mature for the treatment of free heavy metal ions, with the advancement of industrial technology and raw materials, a large amount of heavy metal complexes and organic chelates with complex structures appear in wastewater; such pollutants have high stability and strong biological toxicity, making them extremely difficult to treat; heavy metal organic chelates can enter the body through respiration, drinking water and food chain, and have long-term cumulative effects in the body; some typical chelate pollutants have a long incubation period and can cause long-term or even lifelong health hazards to the human body;

[0005] Currently, the treatment technologies for heavy metal wastewater mainly include flocculation sedimentation, oxidation-reduction, ion exchange, membrane separation, adsorption, etc., and each technology has certain advantages and limitations; for example, flocculation sedimentation has the advantages of low cost and simple operation, and is suitable for high-concentration heavy metal wastewater (such as copper and zinc smelting wastewater), which can simultaneously remove multiple metal ions (such as Cu 2+ , Pb2+ , Zn 2+ ), but there are problems of large amount of sludge, safe landfill or resource treatment; and in the treatment of low concentration heavy metal wastewater (<10 mg / L), the removal rate is low, it is easy to be interfered by complexing agents (such as EDTA), and toxic H2S gas may be generated in the process of sulfide precipitation; ion exchange method has high selectivity, can recover precious metals (such as gold, silver) or high value-added metals (such as nickel), and can ensure stable water quality, which is suitable for low concentration wastewater deep treatment, but the resin is easy to be polluted by high concentration salt (such as Na + , Ca 2+ ), and the regeneration cost is high; and it is not suitable for wastewater with high turbidity or high suspended solids content, and needs additional pretreatment;

[0006] Adsorption method has the characteristics of flexible process and strong adaptability, and can select adsorbent according to specific pollutants, which is suitable for low concentration wastewater (such as trace copper and zinc wastewater) treatment, but the cost of adsorbent is high (such as MOFs material), and the saturated adsorbent needs to be regenerated or replaced frequently; membrane separation technology has high separation efficiency (the removal rate can be more than 95%), the treatment process does not need to add chemical agents, and the environmental protection is good, which is suitable for water resource reuse, but the problems of membrane pollution and scaling exist universally, and the maintenance cost, investment and energy consumption are high, which 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 no sludge is generated, which is environmentally friendly, but it is mainly suitable for high concentration and single metal wastewater treatment, and the pH value and current density need to be strictly controlled to avoid side reactions;

[0007] Biological treatment method has the advantages of low cost and environmental friendliness, and is suitable for low concentration wastewater with good biodegradability (such as zinc-containing wastewater), and has no secondary pollution problem, but microorganisms are easy to be inhibited by heavy metals, and need to be domesticated and cultured for a long time, the treatment period is long (several days to several weeks), and the overall efficiency is lower than that of chemical method; advanced oxidation technology can completely decompose organic pollutants, avoid the interference of complexing agents on subsequent heavy metal precipitation, and improve the biodegradability of wastewater, which is suitable for combination with other processes, but the cost of reagent is high (such as H2O2, O3), and toxic intermediate products may be generated in the reaction process, and there is no direct removal effect on high concentration heavy metal ions, which needs to be combined with other technologies;

[0008] In summary, although the existing technology can detect and treat heavy metal ions in industrial wastewater to some extent, due to the complexity of industrial wastewater, it often contains multiple heavy metals, organic pollutants and stable heavy metal complexes, which brings many challenges to the treatment process, and it is urgent to develop new wastewater treatment technology which is more efficient, environmentally friendly and suitable for complex pollution system. SUMMARY

[0009] In order to overcome the above-mentioned defects of the prior art, embodiments of the present application provide a device and method for synchronously removing heavy metals and organic matters in industrial wastewater, which promotes the activation of manganese dioxide on the surface of manganese sand to generate high-activity free radicals by using a complexing agent, and realizes the efficient synchronous removal of organic matter oxidation and heavy metal ions by combining the dynamic adsorption of manganese sand particles in the fluidized bed reactor, so as to solve the problems of complex pollution components and high treatment difficulty of industrial wastewater proposed in the above background art.

[0010] In order to achieve the above-mentioned purpose, the present application provides the following technical solutions: a device for synchronously removing heavy metals and organic matters in industrial wastewater, comprising a tank body, a pipeline system;

[0011] The top of the tank body is provided with an exhaust valve and a cover plate, the exhaust valve is used for discharging excess gas, and the cover plate is used for sealing the tank body.

[0012] An ORP / pH sensor is arranged on the inner wall of the tank body, a NaOH / H2SO4 dosing pipe is arranged on the side wall of the tank body, the NaOH / H2SO4 dosing pipe is used for adjusting the pH of the industrial wastewater, a biological reaction zone and a manganese sand precipitation zone are sequentially arranged in the tank body from top to bottom, a liquid distributor is arranged below the biological reaction zone, the liquid distributor comprises a perforated plate and an atomizing nozzle, a detachable backwashing filter screen is arranged above the tank body, the manganese sand precipitation zone is connected with the biological reaction zone, the manganese sand precipitation zone has a circular table structure, a sludge discharge valve is arranged at the bottom of the manganese sand precipitation zone to discharge sediments, the diameter of the sludge discharge valve is the same as the diameter of the manganese sand precipitation zone at the bottom as a carrier, and a solid-liquid reaction zone is arranged between the liquid distributor and the backwashing filter screen, and the solid-liquid reaction zone is composed of the biological reaction zone and the manganese sand precipitation zone.

[0013] The pipeline system is arranged on the wall of the tank body, the pipeline system comprises a water outlet pipe, a NaOH / H2SO4 dosing pipe, a water inlet pipe and a manganese sand regeneration liquid dosing pipe which are sequentially arranged on the side wall of the tank body from top to bottom, the water outlet pipe is arranged above the solid-liquid reaction zone, the NaOH / H2SO4 dosing pipe is arranged on the side wall 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 dosing pipe is arranged below the manganese sand precipitation zone, and a complexing agent dosing pipe and a peroxymonosulfate dosing pipe are communicated with the middle part of the water inlet pipe.

[0014] The industrial wastewater to be treated, the complexing agent and the peroxymonosulfate are mixed in the device, and then mixed and reacted with the filled manganese sand particles, so as to realize the removal of heavy metal ions and organic matters.

[0015] In a preferred embodiment, a support is arranged at the bottom of the tank body, the support is a three-leg support, and the support is used for supporting 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 simultaneously removing heavy metal ions and organic pollutants in industrial wastewater:

[0018] The industrial wastewater to be treated is mixed with a complexing agent and a persulfate salt, and then input into a device for simultaneously removing heavy metal ions and organic pollutants in industrial wastewater, which comprises a solid-liquid reaction zone equipped with a liquid distributor, the liquid distributor being composed of a porous plate and an atomizing nozzle for uniformly distributing the mixed solution; the mixed solution is contacted with the filled manganese sand particles in the solid-liquid reaction zone, the complexing agent reacts with the manganese dioxide on the surface of the manganese sand to form a complex, which in turn promotes the autocatalytic oxidation of the persulfate salt to generate SO5· - and SO4· - free radicals;

[0019] The free radicals oxidize and degrade the organic pollutants in the wastewater, and at the same time, the residual MnO2 particles generated in the reaction process adsorb the heavy metal ions in the wastewater; the sediments are discharged through a sludge discharge valve arranged in the manganese sand sedimentation zone, so as to achieve 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 including pyrolusite, hausmannite, hydrohausmannite, rhodochrosite, and the particle size being 0.8-1.2mm;

[0021] The persulfate salt 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 ethylenediaminetetramethylene phosphonic acid (EDTMP), hydroxyethylidene diphosphonic acid (HEDP), amino-tris-methylene phosphonic acid (ATMP), diethylene triamine penta-methylene phosphonic acid (DETPMP) and polyamino polyether tetramethylene phosphonic acid (PAPEMP).

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

[0024] The molar ratio of the heavy metal ions to the persulfate salt 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 the organic matter in the industrial wastewater is 200mg / L to 10000mg / L; and the content of the heavy metal ions in the industrial wastewater is 10mg / L to 1000mg / 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, pharmaceuticals and personal care products, antibiotics, hormones, sunscreens, microplastics, perfluorooctanoic acid, and perfluorooctane sulfonic acid.

[0028] In a preferred embodiment, the hydraulic residence time is 15 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 after the industrial wastewater to be treated is mixed with organophosphates and persulfate in a specific ratio, it enters the fluidized bed reactor through the inlet pipe. A perforated plate and atomizing nozzles are used to ensure the mixture is evenly distributed and in full contact with the manganese sand particles. The complexing agent reacts with manganese dioxide to form a complex, thereby promoting the autocatalytic oxidation of persulfate. During this process, HSO5- is oxidized to SO5. ·- Simultaneously, the Mn(IV)-complexing agent is reduced to form the Mn(III)-complex; HSO5 - It can oxidize Mn(III)-complexing agents to Mn(IV)-complexing agents, while generating SO4. ·- SO5 free radicals generated by persulfate activation ·- SO4 ·- With a high redox potential, it can effectively remove organic pollutants. As the reaction proceeds, MnO2 gradually aggregates into particles, generating residual MnO2 solid. The MnO2 generated in the reaction has a stronger ability to adsorb heavy metal ions and can adsorb heavy metal ions in the soil. Organophosphonate complexing agents can replace the difficult-to-biodegrade complexing agents (such as EDTA) that complex with heavy metal ions in the original industrial wastewater. Organophosphonates have ester bonds and a bio-based framework. After the complexation is completed, they can be decomposed into small molecules by microbial action. The released heavy metal ions can be biologically fixed or converted into low-toxicity forms (such as MnCO3), thereby achieving the simultaneous removal of heavy metal ions and organic pollutants in industrial wastewater.

[0031] The technical effects and advantages of this invention are as follows:

[0032] 1. This invention utilizes 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. It provides a systematic and effective solution to the problems of high treatment difficulty and complex pollutant composition in existing treatment methods.

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

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

[0035] 4. This invention uses a complexing agent to replace stable organic chelated heavy metal complexes in industrial wastewater, thereby disrupting their stable structure, promoting the release of heavy metal ions, and combining with a microbially degradable complexing agent matrix to achieve the biotransformation of heavy metals into low-toxic forms, thus reducing ecological and environmental risks.

[0036] 5. The fluidized bed reaction mode achieves continuous and stable treatment 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 potential for large-scale application and promotion value. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of the device of the present invention.

[0038] The attached diagram is labeled as follows: exhaust valve (1), cover plate (2), water outlet pipe (3), backwash filter (4), tank (5), ORP / pH sensor (6), NaOH / H2SO4 dosing pipe (7), liquid distributor (8), persulfate dosing pipe (9), complexing agent dosing pipe (10), water inlet pipe (11), manganese sand regeneration solution dosing pipe (12), and sludge discharge valve (13). Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

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

[0041] Example 1:

[0042] The embodiment provides a fluidized bed treatment device for synchronously removing heavy metal ions and organic matter pollutants in industrial wastewater; the device comprises a tank body 5, a pipeline 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, the top of the tank body 5 is provided with an exhaust valve 1 and a cover plate 2, the exhaust valve 1 is used for discharging excess gas generated in the device during the reaction process, and the cover plate 2 is used for sealing the tank body 5, so that the device remains in a closed state during the reaction process, and external gas interference is avoided; the bottom of the tank body 5 is provided with a three-leg support 14 for stably supporting the tank body and enhancing the structural strength and overall stability of the device;

[0044] An ORP / pH sensor 6 is arranged on the inner wall of the tank body 5 and is used for monitoring the oxidation reduction potential (ORP) and pH value in the reaction system in real time, so that the reaction process is ensured to be in the set optimal working condition; the side wall of the tank body 5 is sequentially provided with a water outlet pipe 3, a NaOH / H2SO4 adding pipe 7, a water inlet pipe 11 and a manganese sand regeneration liquid adding pipe 12, which are respectively used for water discharge, acid regulator adding, raw water feeding and manganese sand regeneration liquid adding; wherein the middle part of the water inlet pipe 11 is provided with a complexing agent adding pipe 10 and a persulfate adding pipe 9, so that the pre-adding of the reagents can be completed synchronously during the raw water feeding process;

[0045] In the tank body 5, a detachable backwashing filter screen 4, a solid-liquid reaction zone and a manganese sand precipitation zone are sequentially arranged from top to bottom; the liquid distributor 8 is located at the bottom of the solid-liquid reaction zone and is composed of a perforated plate and an atomizing nozzle, so that the raw water and the pretreated mixed liquid can be uniformly distributed, the contact effect of the fluid and the manganese sand particles is enhanced, and a stable fluidized reaction environment is formed; the backwashing filter screen 4 is arranged above the solid-liquid reaction zone and is used for intercepting manganese sand particles and preventing the manganese sand particles from flowing out with the treated water; the solid-liquid reaction zone is located between the liquid distributor 8 and the backwashing filter screen 4 and is responsible for the main oxidation-reduction and adsorption reaction process; the manganese sand precipitation zone below the solid-liquid reaction zone is in a circular table structure and is used for realizing effective separation of manganese sand particles and other solid deposits, and the bottom is provided with a sludge valve 13, through which the accumulated precipitates can be discharged regularly, so that the long-term stable operation of the system is maintained;

[0046] The working process of the fluidized bed wastewater treatment device 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 the peroxymonosulfate are synchronously added into the wastewater through the complexing agent adding pipe 10 and the peroxymonosulfate adding pipe 9, to form a reaction precursor mixed solution; the mixed solution is uniformly distributed to the solid-liquid reaction zone through the porous plate and the atomizing nozzle of the liquid distributor 8, and fully contacts with the manganese sand particles filled in the reaction zone; under the guide action of the liquid upward flow on the inner wall of the tank body 5, the mixed solution forms a fluidized flow spirally rising from bottom to top in the solid-liquid reaction zone, which significantly increases the contact area and mass transfer efficiency of the liquid and the manganese sand particles.

[0047] During the reaction process, the complexing agent reacts with the manganese dioxide on the surface of the manganese sand particles to generate a complex, which promotes the autocatalytic oxidation reaction of the peroxymonosulfate, to generate highly active SO5· - and SO4· - radicals; these radicals can effectively oxidize and degrade the organic pollutants in the wastewater, and at the same time, the residual MnO2 particles formed during the reaction process have excellent adsorption capacity for heavy metal ions in the wastewater, so that the heavy metal ions are efficiently removed; the treated water is filtered through the backwashing filter screen 4, and discharged from the water outlet pipe 3; the excess gas generated during the reaction escapes from the top exhaust valve 1, and the residual particles deposited at the bottom are regularly discharged through the sludge discharge valve 13; the manganese sand precipitation zone can timely add manganese sand regeneration liquid (such as sodium hypochlorite solution) to restore the adsorption activity of the manganese sand, so as 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 is selected as the treatment object; the filled manganese sand particles are selected from natural manganese sand, and the particle size is controlled to be 1 mm; the complexing agent is selected to be hydroxyethylidene diphosphonic acid (HEDP), and the peroxymonosulfate is selected to be sodium persulfate; the reagent ratio is 1:5:10 according to the molar ratio of Cd(II):HEDP:sodium persulfate; the initial pH value of the industrial wastewater is adjusted to 6, and the hydraulic retention time of the reaction system is set to 30 minutes.

[0049] After the treatment is completed, the residual concentration of Cd(II) in the effluent is quantitatively detected by an inductively coupled plasma optical emission spectrometer (ICP-OES), and the residual concentration of phenol in the effluent is quantitatively detected by a high performance liquid chromatograph (HPLC); by comparing with the initial concentration of the influent, the removal rates of Cd(II) and phenol are calculated; the experimental results show that under the above operating conditions, the removal rate of Cd(II) reaches 98.2%, and the removal rate of phenol reaches 90.3%.

[0050] Embodiment 2:

[0051] 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 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 hydraulic retention time of this example was 15 min. The removal rates of Cd(II) and phenol after treatment are shown in Table 1 below.

[0056] Example 5:

[0057] The reaction time after dosing in this example was 45 min. The removal rates of Cd(II) and phenol after treatment are shown in Table 1 below.

[0058] Example 6:

[0059] The complexing agent used in this example was amino-tris-methylene phosphonic acid. The removal rates of Cd(II) and phenol after treatment are shown in Table 1 below.

[0060] Example 7:

[0061] The complexing agent used in this example was ethylene-diamine-tetra-methylene phosphonic acid. The removal rates of Cd(II) and phenol after treatment are shown in Table 1 below.

[0062] Example 8:

[0063] The molar ratio of Cd(II) : complexing agent : sodium persulfate was 1 : 2 : 10. The removal rates of Cd(II) and phenol after treatment are shown in Table 1 below.

[0064] Example 9:

[0065] The molar ratio of Cd(II) : complexing agent : sodium persulfate was 1 : 10 : 10. The removal rates of Cd(II) and phenol after treatment are shown in Table 1 below.

[0066] Example 10:

[0067] The molar ratio of Cd(II) : complexing agent : sodium persulfate was 1 : 5 : 2. The removal rates of Cd(II) and phenol after treatment are shown in Table 1 below.

[0068] Example 11:

[0069] The molar ratio of Cd(II): complexing agent: sodium persulfate was 1:5:5, and the removal rates of Cd(II) and phenol after treatment were shown in Table 1 below.

[0070] Example 12:

[0071] The molar ratio of Cd(II): complexing agent: sodium persulfate was 1:5:20, and the removal rates of Cd(II) and phenol after treatment were shown in Table 1 below.

[0072] Comparative Example 1:

[0073] The molar ratio of Cd(II): complexing agent: sodium persulfate was 1:5:20, and the removal rates of Cd(II) and phenol after treatment were shown in Table 1 below.

[0074] Comparative Example 2:

[0075] The molar ratio of Cd(II): complexing agent: sodium persulfate was 1:5:20, and the removal rates of Cd(II) and phenol after treatment were shown in Table 1 below.

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

[0077]

[0078]

[0079] From Examples 1-3, it can be seen that the pH affects the removal rates of Cd(II) and phenol in the present application, and the removal effect of phenol is better at pH = 6. Lower pH affects the conversion of MnO2 in the reaction system and inhibits the removal of Cd(II). Higher pH affects the formation and stability of active species in the reaction system, thereby affecting the removal effect of phenol. When the pH is 6, the treatment effect is best.

[0080] From Examples 1, 4, and 5, it can be seen that the reaction time after adding the drug affects the removal effect. When the reaction time is 20 min, not only is the removal rate good, but also time cost is saved. If the reaction time is insufficient, the active species cannot effectively remove 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 different organic phosphate complexing agents have little difference in the removal effect of phenol and Cd(II), and each has its own advantages.

[0082] From examples 1, 8-12, it can be seen that the molar ratio of Cd(II), complexing agent, sodium peroxymonosulfate has a certain influence on the removal rate of Cd(II) and phenol; among them, the effect of the molar ratio of Cd(II), complexing agent, sodium peroxymonosulfate is 1:5:10 is the best, the low concentration of complexing agent will lead to the conversion and stability of active intermediates decrease, thus leading to the overall removal rate decrease concentration; the low concentration of sodium peroxymonosulfate is insufficient to generate SO5·-, SO4·-, thus affecting the occurrence of subsequent reaction;

[0083] From examples 1, comparative examples 1-2, it can be seen that without complexing agent, MnO2 cannot effectively activate sodium peroxymonosulfate to generate SO5·-, SO4·-, thus cannot effectively oxidize and decompose organic matter, cannot displace the refractory complexing agent, affects the adsorption of heavy metal ions by manganese sand, also cannot generate MnO2 with stronger metal ion adsorption capacity; without sodium peroxymonosulfate, SO5·-, SO4·- cannot be generated, subsequent reaction cannot be carried out, and the synchronous removal of Cd(II) and organic matter cannot be achieved.

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

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

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

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

[0088] Table 4: Effect of different complexing agents on removal rate of Cd(II) and phenol

[0089] Complexing agent type Cd(II) removal efficiency (%) Phenol removal efficiency (%) Hydroxyethylidene diphosphonic acid (HEDP) 98.2 90.3 Aminotri(methylene phosphonic acid) (ATMP) 98.5 91.1 Ethylenediamine tetra(methylene phosphonic acid) (EDTMP) 99.1 92.3

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

[0091] Molar ratio (Cd(II): complexing agent: peroxymonosulfate) Cd(II) removal efficiency (%) Phenol removal efficiency (%) 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 removal rates of Cd(II) and phenol and other water quality parameters under different treatment conditions

[0093]

[0094]

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

[0096]

[0097] The above merely describes the preferred embodiments of the present application, and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A device for simultaneously removing heavy metals and organic matters in industrial wastewater, comprising a tank body (5) and a pipeline system, characterized in that: the top of the tank body (5) is provided with an exhaust valve (1) for discharging excess gas and a cover plate (2) for sealing the tank body (5); an ORP / pH sensor (6) is arranged on the inner wall of the tank body (5), and a NaOH / H2SO4 dosing pipe (7) is arranged on the side wall of the tank body (5) for adjusting the pH of the 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) comprising a perforated plate and an atomizing nozzle is arranged below the biological reaction zone; a detachable backwashing filter screen (4) is arranged above the tank body (5); the manganese sand precipitation zone is connected with the biological reaction zone and has a circular truncated cone structure; a sludge discharge valve (13) is arranged at the bottom of the manganese sand precipitation zone to discharge the sediment, and the diameter of the sludge discharge valve (13) is the same as that of the bottom of the manganese sand precipitation zone as a carrier; a solid-liquid reaction zone is arranged between the liquid distributor (8) and the backwashing filter screen (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) and comprises a water outlet pipe (3), the NaOH / H2SO4 dosing pipe (7), a water inlet pipe (11) and a manganese sand regeneration liquid dosing pipe (12) sequentially 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, the NaOH / H2SO4 dosing pipe (7) is arranged 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, and the manganese sand regeneration liquid dosing pipe (12) is arranged below the manganese sand precipitation zone; a complexing agent dosing pipe (10) and a persulfate dosing pipe (9) are connected to the middle part of the water inlet pipe (11); the industrial wastewater to be treated is mixed with the complexing agent and the persulfate in the device, and then is mixed and reacted with the filled manganese sand particles to remove the heavy metal ions and the organic matters. A support is arranged at the bottom of the tank body (5), and the support is a three-leg support for supporting the tank body (5); a water inlet pump, a valve and a flowmeter are sequentially arranged on the water inlet pipe (11).

3. A method for simultaneously removing heavy metals and organic matters in industrial wastewater, comprising the use of the device for simultaneously removing heavy metals and organic matters in industrial wastewater according to claim 2, characterized in that: the free radicals oxidize and degrade the organic pollutants in the wastewater, and the residual MnO2 particles generated in the reaction process adsorb the heavy metal ions in the wastewater; the sediment is discharged through the sludge discharge valve (13) arranged in the manganese sand precipitation zone to simultaneously remove the heavy metal ions and the organic pollutants in the industrial wastewater. ​ ​ 2. The device for simultaneously removing heavy metals and organic matters in industrial wastewater according to claim 1, characterized in that: ​ ​ ​ The industrial wastewater to be treated is mixed with a complexing agent and a peroxymonosulfate, and then input into a device for simultaneously removing heavy metals and organic matters in industrial wastewater, which comprises a solid-liquid reaction zone equipped with a liquid distributor (8) composed of a porous plate and an atomizing nozzle for uniformly distributing the mixed solution; the mixed solution is contacted with the filled manganese sand particles in the solid-liquid reaction zone, the complexing agent reacts with the manganese dioxide on the surface of the manganese sand to form a complex, which further promotes the autocatalytic oxidation of the peroxymonosulfate to generate SO5· - and SO4· - radicals; ​ 4. The method for simultaneously removing heavy metals and organic matters 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 material, the natural manganese sand including pyrolusite, hausmannite, rhodochrosite, and rhodanite, and the particle size is 0.8-1.2mm; The persulfate salt is selected from one or more of ammonium persulfate, potassium persulfate, sodium persulfate; The complexing agent is selected from one or more of ethylenediaminetetramethylene phosphonic acid (EDTMP), hydroxyethylidene diphosphonic acid (HEDP), amino trimethylene phosphonic acid (ATMP), diethylene triamine pentamethylene phosphonic acid (DETPMP), polyamino polyether tetramethylene phosphonic acid (PAPEMP).

5. The method of claim 4, wherein the method is characterized by: 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 persulfate salt is 1:2 to 1:

20.

6. The method for simultaneously removing heavy metals and organic matters 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 of claim 6, wherein the method is characterized by: The content of the organic matter in the industrial wastewater is 200mg / L to 10000mg / L; the content of the heavy metal ion in the industrial wastewater is 10mg / L to 1000mg / L.

8. The method of claim 7, wherein the method is characterized by: The organic matter includes one or more of persistent organic pollutants, polychlorinated biphenyls, dioxins, DDT, endocrine disruptors, bisphenol A, nonylphenol, estradiol, pharmaceuticals and personal care products, antibiotics, hormones, sunscreens, microplastics, perfluorooctanoic acid, perfluorooctane sulfonic acid.

9. The method of claim 8, wherein the method is characterized by: The hydraulic retention time is 15 minutes to 45 minutes.

10. The method of claim 9, wherein the method is characterized by: The heavy metal ion includes one or more of Ti(I), Pb(II), Cd(II), As(III), Sb(III).

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