Water treatment process for removing antimony heavy metal

Abstract

The invention relates to a water treatment process for removing heavy metal antimony, which belongs to a water treatment technology, and is realized by the following steps: adding polymerized ferrous sulfate and polyacrylamide on a raw water pipeline, feeding into an inclined plate sedimentation tank, stirring, and discharging suspended matters, particulate matters, colloids and high-concentration antimony in water from a bottom drain outlet; a supernatant outlet of the inclined plate sedimentation tank enters a quartz sand filter through a pipeline b, a chelating agent is added into the pipeline b to convert most of antimony in an ionic state into antimony in a chelating state, and the chelated antimony is intercepted and removed by the quartz sand filter; a water outlet of the quartz sand filter enters the DMI65 filter through a water outlet pipeline, meanwhile, pressurized gas is introduced into the tank body to stir a DMI65 filter material, and a purified water outlet pipeline is arranged at the bottom end of the DMI65 filter. According to the process, the efficiency of removing the antimony heavy metal is high, the removal rate reaches 99% or above, the concentration of the heavy metal antimony in effluent is 0.005 ppm or below, and DMI65 is low in operation cost for filtering and removing harmful substances such as antimony and the like, simple to operate and maintain and long in filter material replacement period.

Description

TECHNICAL FIELD

[0001] The present application belongs to water treatment technology, and particularly relates to a water treatment process for removing antimony heavy metal. BACKGROUND

[0002] Antimony exists naturally in the earth's crust and can be released into water bodies through natural processes such as rock weathering and volcanic activity. The geological structure of some areas has a high content of antimony (such as antimony-rich areas in Hunan and Guizhou, China), resulting in natural antimony exceeding the standard in surface water and groundwater. Antimony and antimony compounds are widely used in industries such as metallurgy (such as lead-antimony alloy), chemical industry (flame retardant, catalyst), electronics, ceramics, glass, etc. If the wastewater and waste residue generated during the production process are not properly treated, antimony may be leaked into water bodies. Antimony mining and smelting are the main human sources of antimony pollution. The antimony concentration in mining wastewater and tailings leachate can be as high as several thousand mg / L. In addition, the use of antimony-containing pesticides in agricultural production, leachate from household waste, and waste gas emitted by coal-fired power plants after being washed by rainwater can also release antimony into water bodies.

[0003] Long-term contact or ingestion of water containing antimony can cause gastrointestinal diseases, liver and kidney function damage, and even cancer. Antimony can accumulate in the food chain and inhibit the growth and reproduction of aquatic organisms (such as fish and algae), disrupting the balance of aquatic ecosystems. Therefore, it is necessary to treat wastewater containing antimony. Early water treatment technologies for heavy metals (such as chemical precipitation, adsorption, ion exchange, etc.) have certain limitations when treating antimony: Chemical precipitation method: iron salts, aluminum salts, and other flocculants need to be added, which is effective for removing trivalent antimony but has low removal efficiency for pentavalent antimony and produces a large amount of sludge; Traditional adsorption method: conventional adsorbents such as activated carbon have low adsorption capacity and poor selectivity for antimony, making it difficult to meet the treatment requirements of low-concentration antimony wastewater; Membrane separation method: membrane technologies such as reverse osmosis can effectively remove antimony, but are costly and prone to clogging, making them unsuitable for large-scale wastewater treatment; Therefore, it is necessary to develop an efficient, economical, and targeted antimony removal process. SUMMARY

[0004] The present application aims to overcome the shortcomings of the prior art and provides a water treatment process for removing antimony heavy metal.

[0005] The water treatment process for removing antimony heavy metal according to the present application is achieved by the following steps: a. Pretreatment: A polymeric ferrous sulfate dosing tank and a polyacrylamide dosing tank are provided on the raw water pipeline a. After dosing, the raw water is pumped into the inclined plate sedimentation tank and stirred, and the suspended solids, particulate matter, colloids, and high-concentration antimony in the water sink through the bottom blowdown port; b, quartz sand filter: the supernatant outlet of the inclined plate sedimentation tank is connected with the quartz sand filter through pipeline b, the quartz sand filter removes small particulate matter, and provides water conditions for subsequent DMI filtration; a filter water inlet pump and a chelating agent dosing device are arranged on pipeline b; after the chelating agent dosing device is added on the water inlet pipeline of the quartz sand filter, most of the ionic antimony in the water is converted into chelated antimony, and then the chelated antimony is removed by the quartz sand filter; c, DMI65 filter: the water outlet of the quartz sand filter is connected with the DMI65 filter through the water outlet pipeline c, and at the same time, the tank body is connected with a gas under pressure to stir the DMI65 filter material; a clean water outlet pipeline d is arranged at the bottom end of the DMI65 filter; the heavy metals in the water are removed in the form of hydroxide particles by adsorption and separation of the mineral filter material DMI65; a water inlet pump and an oxidant dosing device I are arranged on pipeline c; The DMI65 adsorbent is a porous sea sand particle, with a porosity of 46.5%, a particle size of 0.4-0.6 mm, a particle density of 2.69, and a volume density of 1.46, and can efficiently adsorb antimony heavy metals; The DMI65 filter is a vertical tank body, which is composed of a shell body and upper and lower heads fixed on both ends of the shell body; the upper head is provided with a water inlet A and an air outlet B, and the lower head is provided with a water outlet C; a manhole D is arranged on the side wall of the shell body; an upper water distributor and a lower water distributor are fixed on the connection between the shell body and the upper head and the lower head; the upper water distributor is composed of water-permeable holes arranged on a partition plate; superior arc-shaped transverse partition plates are fixed in the shell body from top to bottom; vertical net plates are fixed between the chord of the superior arc-shaped transverse partition plate and the lower layer superior arc-shaped transverse partition plate; the vertical net plates are fixed between the chord of the lowermost superior arc-shaped transverse partition plate and the lower water distributor; water-permeable holes are arranged on the side partition plate corresponding to the lowermost superior arc-shaped transverse partition plate; the superior arc-shaped transverse partition plates and the vertical net plates divide the shell body into a plurality of adsorption chambers; the DMI65 filter material is filled in the adsorption chambers; the raw water enters the tank body through the water inlet on the top of the tank body; the superior arc-shaped transverse partition plates in the shell body are water-proof; the vertical net plates can intercept the filter material and allow water to pass through; the water enters the tank body and forms an S-shaped route in the tank body, so that the water and the filter material have both horizontal contact and vertical contact, and the contact area and the contact time are increased; more than one air inlet is arranged on the side wall of each adsorption chamber; the air pump continuously fills the tank body with air under pressure, and the air flow continuously stirs the DMI65 filter material, so that the DMI65 filter material does not harden after long-term use.

[0006] As a further improvement of the present application, when the raw water is industrial wastewater, it needs to be pretreated, and the steps are as follows: the raw water is filtered by a grating filter to remove mechanical impurities, and then is subjected to coagulation and sedimentation pretreatment.

[0007] As a further improvement of the present invention, a backwashing line e is connected to the purified water outlet pipe d at the bottom of the DMI65 filter. A backwashing oxidant dosing device is installed on the backwashing line e, and a backwashing water pump is connected to the backwashing line e. The backwashing line e is connected to the bottom pipes of the quartz sand filter and the DMI65 filter respectively. The top of the quartz sand filter and the DMI65 filter is connected to the backwashing water discharge pipe f. The backwashing oxidant is sodium hypochlorite, chlorine dioxide, or hydrogen peroxide, and the dosing concentration is 1-200 ppm.

[0008] As a further improvement of the present invention, the concentration of the added polyferrous sulfate is 1-200 mg / L, and the concentration of the added polyacrylamide is 1-50 mg / L.

[0009] As a further improvement of the present invention, the oxidant dosing device I is a dosing device for soluble inorganic compounds of ferric iron, and the concentration of the added amount is 1-200 mg / L.

[0010] As a further improvement of the present invention, the soluble inorganic compound of ferric iron is ferric chloride.

[0011] As a further improvement of the present invention, the chelating agent is one of ethylenediaminetetraacetic acid, dithiocarbamate, or chitosan derivative, and its addition amount is 10-100 mg / L.

[0012] This invention has the following advantages: 1. This process has high efficiency in removing antimony heavy metals, with a removal rate of over 99%, and the concentration of antimony heavy metals in the effluent is below 0.005 ppm, exceeding the current domestic emission requirements; 2. The DMI65 filter removes harmful substances such as antimony with low operating costs, simple maintenance, and long filter media replacement cycle; 3. Water treatment equipment designed according to this process has a low total investment and does not require a large amount of civil engineering, only related ground foundations; 4. The DMI65 filter has a low density, requiring less energy for backwashing and saving power; the concentrated water produced during backwashing is minimal, only 1% of the water volume it treats. 5. DMI65 filtration can remove some trivalent antimony. In some environments, if trivalent antimony cannot be oxidized to pentavalent antimony, but it is necessary to reduce the antimony in the water, this process can effectively reduce trivalent antimony in the water. 6. It can reduce most of the TDS in water, and water with high conductivity can also be treated directly without the equipment caking; 7. DMI65 filter media does not require chemical regeneration, only periodic automatic backwashing, and has a service life of 6-8 years. Its operating cost is lower than that of quartz sand and manganese sand, which also require backwashing, but have a service life of less than 3 years. Attached Figure Description

[0013] Figure 1 This is a process flow diagram of the present invention; Figure 2 This is a schematic diagram of the DMI65 filter. Detailed Implementation

[0014] The water treatment process for removing antimony heavy metals according to the present invention is achieved through the following steps: a. Pretreatment: A polyferrous sulfate dosing tank 1 and a polyacrylamide dosing tank 2 are installed on the raw water pipeline a. The ideal conditions for the raw water are: pH range of 6-9, temperature of 5-45℃, and antimony content of less than 5mg / L. After the raw water is dosed, it enters the inclined plate sedimentation tank 4 through the coagulation inlet pump 3 and is stirred. Suspended solids, particulate matter, colloids, and high concentrations of antimony in the water settle and are discharged through the bottom drain. The flow rate of the inlet pump 4 is 5-15 m / h. The concentration of polyferrous sulfate added is 1-200mg / L, that is, 1-200mg of polyferrous sulfate is added per liter of the liquid to be treated. The concentration of polyacrylamide added is 1-50mg / L, that is, 1-50mg of polyacrylamide is added per liter of the liquid to be treated. b. Quartz Sand Filtration: The supernatant outlet of the inclined plate sedimentation tank 4 enters the quartz sand filter 5 through pipe b. The quartz sand filter 5 is filled with granular quartz sand and can remove fine particulate matter, providing inlet water conditions for the subsequent DMI65 filtration. A filter inlet pump 6 and a chelating agent dosing device 7 are installed in pipe b. The chelating agent is one of ethylenediaminetetraacetic acid (EDTA), dithiocarbamate, or chitosan derivative, and its addition amount is 10-100 mg / L, that is, 10-100 mg of chelating agent is added per liter of the liquid to be treated. The specific amount needs to be adjusted according to the concentration of antimony ions in the water and the water quality characteristics. By adding the chelating agent dosing device 7 to the inlet pipe of the quartz sand filter 5, most of the ionic antimony in the water is converted into chelated antimony, and the chelated antimony is intercepted and removed by the quartz sand filter 5. The remaining small amount of low-concentration ionic antimony is removed by the subsequent DMI65 filter, including the matching oxidant dosing device I10. c. DMI65 Filtration: The water outlet of the quartz sand filter 5 enters the DMI65 filter 8 through the outlet pipe c. At the same time, pressurized gas is introduced into the tank to agitate the DMI65 filter media. A clean water outlet pipe d is provided at the bottom of the DMI65 filter 8. Through adsorption and separation by the mineral filter media DMI65, heavy metals in the water are adsorbed and removed in the form of hydroxide particles, with a heavy metal removal rate of over 99.8% and a reduction in water hardness of over 30%. An inlet pump 9 and an oxidant dosing device I10 are provided on pipe c. The oxidant dosing device I10 contains ferric chloride, and the concentration added is 1-200 mg / L, that is, 1-200 mg of ferric soluble inorganic compound is added per liter of the liquid to be treated. The DMI65 filter media is a porous sea sand particle with a porosity of 46%, a particle size of 0.1-0.5 mm, a particle density of 2.69, and a bulk density of 1.56, which can efficiently adsorb antimony heavy metals. During the DMI65 filtration process, adding a low concentration (1~3 ppm) of ferric chloride or chlorine dioxide serves not only as a reactant for DMI65 but also as a water disinfectant. For removing antimony from water, due to the small molecular size of antimony compounds, adding trace amounts of iron-based compound reagents causes the small antimony compounds to be adsorbed onto the iron-based reagent body, where they are intercepted by DMI65 and undergo a chemical reaction to form water-insoluble antimony compounds.

[0015] The water treatment process for removing antimony heavy metals according to the present invention involves equipment including a ferrous sulfate dosing tank 1, a polyacrylamide dosing tank 2, a coagulation inlet pump 3, an inclined plate sedimentation tank 4, a quartz sand filter 5, a filter inlet pump 6, a chelating agent dosing device 7, a DMI65 filter 8, an inlet pump 9, an oxidant dosing device I 10, a backwash water pump 11, and a backwash oxidant dosing device 12. A polyferrous sulfate dosing tank 1 and a polyacrylamide dosing tank 2 are installed on the raw water pipeline a. After the raw water is dosed, it enters the inclined plate sedimentation tank 4 through the coagulation inlet pump 3. The supernatant outlet of the inclined plate sedimentation tank 4 is connected to the quartz sand filter 5 through pipeline b. A filter inlet pump 6 and a chelating agent dosing device 7 are installed on pipeline b. The outlet of the quartz sand filter 5 is connected to the inlet of the DMI65 filter 8 through the outlet pipeline c. A clean water outlet pipeline d is installed at the bottom of the DMI65 filter 8. An inlet pump 9 and an oxidant dosing device I10 are installed on pipeline c. A backwash pipeline e is connected to the clean water outlet pipeline d. A backwash oxidant dosing device 12 is installed on the backwash pipeline e. A backwash water pump 11 is connected to the backwash pipeline e. The backwash pipeline e is connected to the bottom pipelines of the quartz sand filter 5 and the DMI65 filter 8 respectively. The top of the quartz sand filter 5 and the DMI65 filter 8 is connected to the backwash water discharge pipe f.

[0016] The DMI65 filter 8 is a vertical tank, consisting of end caps fixed at the upper and lower ends of a shell 13. The upper end cap has an inlet A and an outlet B, and the lower end cap has an outlet C. A manhole D is located on the side wall of the shell 13. An upper water distributor 14 and a lower water distributor 15 are fixed to the inner circumference of the shell at the connection between the shell 13 and the upper and lower end caps. The upper water distributor 14 is formed by evenly distributing water-permeable holes on a partition plate. Inside, there are interlaced arc-shaped horizontal partitions 16 fixed from top to bottom. A vertical mesh plate 17 is fixed between the chord edge of the arc-shaped horizontal partition 16 and the lower arc-shaped horizontal partition. A vertical mesh plate 17 is fixed between the chord edge of the lowest arc-shaped horizontal partition 16 and the lower water distributor 15. On the lower water distributor 15, a water-permeable hole 20 is opened on one side of the vertical mesh plate 17 and the side of the partition corresponding to the lowest arc-shaped horizontal partition 16. The other side 21 of the vertical mesh plate 17 has no water-permeable hole and is impermeable. The upper water distributor 14, lower water distributor 15, arc-shaped horizontal partition 16, and vertical mesh plate 17 divide the interior of the housing 13 into multiple adsorption chambers 18. Each adsorption chamber 18 is filled with DMI65 filter media, which is porous sea sand particles with a porosity of 46.5%, a particle size of 0.4-0.6 mm, a particle density of 2.69, and a bulk density of 1.46. It can efficiently adsorb antimony heavy metals. Due to the partitioned moving structure design, the DMI65 filter media is filled... Inside the entire shell, raw water enters the tank through the inlet at the top. Due to the arc-shaped horizontal baffle 16 inside the shell, which is impermeable, and the vertical mesh plate 17, which intercepts the filter media and is permeable, the water enters the tank and its path inside the tank is S-shaped. This allows the water to have both lateral and vertical contact with the filter media, increasing the contact area and contact time. This fundamentally solves the problems of incomplete water filtration, incomplete contact between wastewater and filter media, and insufficient reaction time in existing filters.

[0017] This DMI65 filter can be used for filtering liquids with high turbidity and high suspended solids without premature clogging. Due to the special internal structure of the tank, it also solves the problem of filter media caking when treating high-salt wastewater.

[0018] The DMI65 filter 8 features a vertical structure, allowing the liquid to be filtered to flow laterally through the filter media layer. This structural change improves the filter's effluent accuracy, increases the single-unit processing capacity, and broadens the range of influent turbidity indicators, thus significantly enhancing the performance, application scope, and range of applications of the DMI65 filter 8.

[0019] The DMI65 filter 8 of this invention has a vertical structure and a unique internal partitioned vortex separation design, which can continuously remove the trapped substances on the surface of the medium. Each adsorption chamber 18 has one or more air inlets 19 on its side wall, and an air stirring device is used to continuously fill the tank with pressurized air through an air pump. The air flow continuously stirs the DMI65 filter material, so that the DMI65 filter material does not caking during long-term use.

[0020] A backwash line e is connected to the clean water outlet pipe d at the bottom of the DMI65 filter 8. A backwash oxidant dosing device 12 is installed on the backwash line e. A backwash water pump 11 is connected to the top, and the backwash pipeline e is connected to the bottom pipeline of the quartz sand filter 5 and the DMI65 filter 8 respectively for backwashing the filters. During backwashing, the purified water produced by this system is injected in the reverse direction into the adsorption bed, the flushing pressure is 0.2Mpa-0.3Mpa, the water flow rate is 25-40m3 / m2·H, and the flushing is carried out at room temperature until the effluent is visually clear, transparent and free of pollutants. The two adsorption beds are then activated and put into operation. The top of the quartz sand filter 5 and the DMI65 filter 8 are connected to the backwash water discharge pipe f. The backwash oxidant is sodium hypochlorite, chlorine dioxide or hydrogen peroxide, and the amount added is in a mathematical proportion to the concentration of heavy metal ions. The chemical is continuously added to the flushing pipeline by the chemical dosing pump, and the concentration is 1-200ppm, that is, 1-200mg of sodium hypochlorite, chlorine dioxide or hydrogen peroxide is added to each liter of backwash water.

[0021] The DMI65 filter 8 boasts superior backwashing performance. Compared to traditional filters, the DMI65 filter 8 performs layered cleaning of the filter media, resulting in faster and more thorough backwashing and desorption. Independent tests show that the DMI65 filter 8 can complete backwashing in 3 minutes at a backwash flow rate of 45 m / h, while traditional filters require backwashing at 55 m / h or higher, and the backwashing process can last for more than 8 minutes to achieve the same backwashing effect. The water consumption of traditional filters is 400% of that of the DMI65 filter 8; in actual backwashing, the power consumption for pumping is also 400%, and the power consumption for replenishing backwash water for post-treatment is also 400%.

[0022] The following benefits will be obtained from using this technology to treat wastewater: (1) The circulating water system does not discharge sewage and no longer generates wastewater. Therefore, it saves the investment in wastewater equipment and wastewater treatment costs, as well as the consumption of water resources and the cost of water resources. (2) The circulating water system uses clean water as supplementary water, which saves investment in wastewater equipment and wastewater treatment costs, and realizes the reuse of wastewater resources, thereby reducing the amount of fresh water used in the circulating water system and saving water resource costs.

[0023] The antimony removal process of this invention does not require large amounts of oxidants and does not generate secondary pollution. It only involves simple coagulation and sedimentation pretreatment to remove most suspended solids and large particles such as particulate matter from the raw water, followed by DMI 65 filtration for antimony removal. The effluent meets relevant reuse or discharge standards. The process is simple, has low operating costs, and is easy to operate and maintain. This process can be used in most operating conditions in all production industries, including printing and dyeing, mining, and electroplating, and can also be used for groundwater treatment, offering significant environmental and economic benefits.

[0024] When the raw water to be treated is industrial wastewater, this device requires pretreatment. The steps are as follows: filter the raw water with a bar screen to remove mechanical impurities, and then perform coagulation and sedimentation pretreatment.

[0025] The process of this invention involves adding a chelating agent dosing device to the inlet pipe of a quartz sand filter. This converts most of the ionic antimony in the water into chelated antimony, which is then removed by the quartz sand filter. The remaining small amount of low-concentration ionic antimony is removed by a subsequent DMI65 filter 8, which includes a matching ferric chloride dosing system.

[0026] The removal of antimony (Sb) from water using chelating agents relies on the multidentate coordination ability of these agents to form stable, water-insoluble chelates with antimony ions in the water. These chelates are then separated and removed from the water through precipitation, adsorption, or filtration. The form of antimony in water is influenced by environmental conditions such as pH and redox potential (ORP), and it mainly exists as inorganic ions, with a small amount existing as organic antimony (which is present in low concentrations in the environment; industrial wastewater primarily contains inorganic antimony). Trivalent antimony ( Under acidic or reducing conditions (such as industrial wastewater and anaerobic water bodies), it mainly exists in the free state. Or hydrolyzed state (e.g.) It contains [a substance] and is highly toxic; Pentavalent antimony ( Under neutral or oxidizing conditions (such as in natural water bodies), it mainly exists in the form of oxygen-containing anions (e.g. (It has relatively low toxicity, but is more soluble in water and is difficult to remove by conventional precipitation methods;) Therefore, chelating agents need to target the structural characteristics of antimony in different valence states, breaking its stable water-soluble state through coordination. The core logic of the chelating agent in this application for removing antimony from water is: utilizing the coordination ability of multidentate ligands to form stable cyclic chelates with antimony ions, converting water-soluble antimony into an insoluble solid, which then enters a quartz sand filter for separation and removal through precipitation and adsorption. The advantages of this method are its strong targeting and high removal efficiency, but it requires selecting a suitable chelating agent based on the antimony's valence state and the water matrix, and controlling the reaction conditions to avoid interference.

[0027] Antimony-containing wastewater filtered by a quartz sand filter enters a DMI65 filter. The principle of further antimony removal is as follows: ferric chloride is added to the inlet pipe of the DMI65 filter to create an oxidizing environment in the water. When the wastewater containing ferric chloride enters the DMI65 filtration system, the DMI65 filter media, with the participation of ferric chloride, forms ionic antimony hydroxide precipitate [Sb(OH)3] in the water. Antimony hydroxide is an insoluble particulate solid, which is further trapped and adsorbed by the DMI65 filter media.

[0028] The effects of the present invention will be further explained below: 1. This process achieves high efficiency in removing antimony heavy metals, with a removal rate exceeding 99%. The antimony concentration in the effluent is below 0.005 ppm, exceeding current domestic discharge requirements. The table below shows the antimony content in the effluent after treatment with this process for wastewater with different antimony contents:

[0029] 2. The DMI65 filter has low operating costs for removing harmful substances such as antimony, with a total operating cost of 0.5-1.0 yuan per ton of water. The filter media replacement cycle is 6-8 years. Based on a 6-year replacement cycle, the cost is equivalent to 0.21 yuan per ton of water. For example: A project uses 7 tons of quartz sand filter media. The replacement cycle for quartz sand is 1-1.5 years, calculated as 1 year. Each replacement requires 7 tons of quartz sand filter media. At a cost of 1000 yuan per ton of quartz sand, the cost per ton of water for replacing the quartz sand is: Cost per ton of water = 1000 * 7 / 216000 = 0.03 yuan / ton of water; With 7 tons of DMI65 filter media, meaning that after the replacement cycle is reached, 7 tons of DMI65 filter media need to be replaced each time. At a cost of 32,630 yuan per ton of filter media, the cost per ton of water for replacing DMI65 filter media is: Cost per ton of water = 32630 * 7 / 216000 / 6 = 0.18 yuan / ton of water; The cost per ton of water is 0.03 + 0.18 = 0.21 yuan / ton.

Claims

1. A water treatment process for removing antimony heavy metal, characterized in that... This is achieved through the following steps: a. Pretreatment: A polyferrous sulfate dosing tank (1) and a polyacrylamide dosing tank (2) are installed on the raw water pipeline a. After the raw water is dosed, it enters the inclined plate sedimentation tank (4) through the coagulation inlet pump (3) and is stirred. The suspended solids, particulate matter, colloids and high concentrations of antimony in the water settle down and are discharged through the bottom drain. b. Quartz sand filtration: The supernatant outlet of the inclined plate sedimentation tank (4) enters the quartz sand filter (5) through pipeline b. The quartz sand filter (5) removes fine particulate matter and provides inlet water conditions for subsequent DMI filtration. A filter inlet pump (6) and a chelating agent dosing device (7) are installed in pipeline b. By adding the chelating agent dosing device (7) to the inlet pipe of the quartz sand filter (5), most of the ionic antimony in the water is converted into chelated antimony, and the chelated antimony is intercepted and removed by the quartz sand filter (5). c. DMI65 filtration: The water outlet of the quartz sand filter (5) enters the DMI65 filter (8) through the water outlet pipe c. At the same time, pressurized gas is introduced into the tank to agitate the DMI65 filter media. A clean water outlet pipe d is provided at the bottom of the DMI65 filter (8). Through adsorption and separation by the mineral filter media DMI65, heavy metals in the water are adsorbed and removed in the form of hydroxide particles. A water inlet pump (9) and an oxidant dosing device I (10) are provided on the pipe c. The DMI65 filter media is a porous sea sand particle with a porosity of 46.5%, a particle size of 0.4-0.6 mm, a particle density of 2.69, and a bulk density of 1.46, which can efficiently adsorb antimony heavy metals. The DMI65 filter (8) is a vertical tank, consisting of caps fixed at the upper and lower ends of the shell (13). The upper cap has an inlet A and an outlet B, and the lower cap has an outlet C. A manhole D is located on the side wall of the shell (13). An upper water distributor (14) and a lower water distributor (15) are fixed to the inner circumference of the shell at the connection between the shell (13) and the upper and lower caps. (14) is composed of water-permeable holes evenly distributed on a partition plate; inside the shell (13), there are arc-shaped horizontal partition plates (16) fixed from top to bottom in an alternating manner, and a vertical mesh plate (17) is fixed between the chord edge of the arc-shaped horizontal partition plate (16) and the lower arc-shaped horizontal partition plate, and a vertical mesh plate (17) is fixed between the chord edge of the lowest arc-shaped horizontal partition plate (16) and the lower water distributor (15), and the lower water distributor (15) and the lowest arc-shaped horizontal partition plate ( 16) A water-permeable hole (20) is provided on the corresponding side partition; the arc-shaped horizontal partition (16) and the vertical mesh plate (17) divide the interior of the shell (13) into multiple adsorption chambers (18). DMI65 filter material is filled in the adsorption chamber (18). The DMI65 filter material is filled in the entire shell. The raw water enters the tank through the water inlet at the top of the tank. The arc-shaped horizontal partition (16) inside the shell is impermeable to water, while the vertical mesh plate (17) intercepts the filter material that can be permeable to water. After the water enters the tank, the route inside the tank is S-shaped, so that the water and the filter material have both horizontal and vertical contact, and the contact area and contact time are increased. Each adsorption chamber (18) has one or more air inlets (19) on its side wall. Pressurized air is continuously injected into the tank through an air pump. The air flow continuously agitates the DMI65 filter material, so that the DMI65 filter material does not clump during long-term use.

2. The water treatment process for removing antimony heavy metals as described in claim 1, characterized in that... When the raw water is industrial wastewater, it needs to be pretreated. The steps are as follows: filter the raw water with a bar screen to remove mechanical impurities, and then carry out coagulation and sedimentation pretreatment.

3. The water treatment process for removing antimony heavy metals as described in claim 1, characterized in that: A backwash line e is connected to the clean water outlet pipe d at the bottom of the DMI65 filter (8). A backwash oxidant dosing device (12) is installed on the backwash line e. A backwash water pump (11) is connected to the backwash line e. The backwash line e is connected to the bottom pipes of the quartz sand filter (5) and the DMI65 filter (8). The top of the quartz sand filter (5) and the DMI65 filter (8) is connected to the backwash water discharge pipe f. The backwash oxidant is sodium hypochlorite, chlorine dioxide, or hydrogen peroxide, and the dosing concentration is 1-200 ppm.

4. The water treatment process for removing antimony heavy metals as described in claim 1, characterized in that... The concentration of the polyferrous sulfate added is 1-200 mg / L, and the concentration of the polyacrylamide added is 1-50 mg / L.

5. The water treatment process for removing antimony heavy metals as described in claim 1, characterized in that... The oxidant dosing device I (10) is a dosing device for soluble inorganic compounds of ferric iron, with a dosing concentration of 1-200 mg / L.

6. The water treatment process for removing antimony heavy metals as described in claim 5, characterized in that... The soluble inorganic compound of ferric iron mentioned is ferric chloride.

7. The water treatment process for removing antimony heavy metals as described in claim 1, characterized in that... The chelating agent is one of ethylenediaminetetraacetic acid, dithiocarbamate, or chitosan derivative, and its addition amount is 10-100 mg / L.

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