Perchlorate sewage treatment device, sewage treatment system and sewage treatment method

Abstract

The present disclosure provides a perchlorate sewage treatment device, a sewage treatment system and a sewage treatment method, wherein the sewage treatment device comprises: an adsorption part, the adsorption part is used to adsorb perchlorate ions in sewage; a support part, the support part is installed on the top of the adsorption part and is connected to the adsorption part; a plant absorption part, the support part is used to support the plant absorption part; the plant absorption part passes through the support part and is connected to the adsorption part, and is used to absorb perchlorate ions in the adsorption part; wherein the plant absorption part comprises a first plant and a second plant; the first plant is selected from North American sweetgum and / or North American black willow, and the second plant is selected from sea salicornia and / or nettle. The sewage treatment device of the present disclosure realizes efficient removal of perchlorate ions by precise absorption and enrichment through the plant absorption part; at the same time, the shielding of the plant absorption part also plays a role in preventing the loss of the adsorption layer.

Description

Technical Field

[0001] The present disclosure relates to the technical field of sewage treatment, and in particular to a perchlorate sewage treatment device, a sewage treatment system and a sewage treatment method. Background Art

[0002] Perchlorate (ClO 4- ) is one of the main inorganic pollutants in the environment and is widely present in surface water, groundwater and soil. At present, perchlorate is widely used in fireworks, gunpowder, mining, printing and dyeing and other industries, which also causes high concentrations of perchlorate in wastewater. As an endocrine disruptor, perchlorate will interfere with the thyroid gland's use of iodine when it enters the human body, affecting human health.

[0003] Taking fireworks wastewater as an example, perchlorate in fireworks wastewater has the characteristics of non-volatility, high solubility and kinetic stability, and its concentration is extremely high. Since perchlorate is stable and difficult to complex, it is difficult to remove perchlorate in wastewater through conventional water treatment processes such as coagulation, sedimentation and filtration.

[0004] At present, the most widely used and effective methods are ion exchange and biodegradation. Although the ion exchange method can effectively enrich the anions in the wastewater through the strongly charged functional groups of the anion exchange resin, this process only enriches and concentrates the perchlorate ions, and does not fundamentally remove the perchlorate ions. In addition, the desorption process produces a very high concentration of salt solution, which poses a risk of secondary pollution.

[0005] Therefore, how to effectively remove perchlorate from wastewater is a problem that needs to be solved urgently. Summary of the invention

[0006] The purpose of the present disclosure is to provide a perchlorate sewage treatment device, a sewage treatment system and a sewage treatment method, which have solved the above-mentioned technical problems.

[0007] The present disclosure is implemented as follows:

[0008] In a first aspect, the present disclosure provides a perchlorate sewage treatment device, the sewage treatment device comprising:

[0009] An adsorption part, wherein the adsorption part is used to adsorb perchlorate ions in sewage;

[0010] A support portion, the support portion is installed on the top of the adsorption portion and is communicated with the adsorption portion;

[0011] The plant absorption part, the support part is used to support the plant absorption part; the plant absorption part passes through the support part and is connected with the adsorption part, and is used to absorb the perchlorate ions in the adsorption part;

[0012] Wherein, the plant absorption part comprises a first plant and a second plant; the first plant is selected from Liquidambar formosana and / or Willow nigra, and the second plant is selected from Salicornia herba and / or Urtica dioica.

[0013] As an embodiment, the adsorption part includes:

[0014] a holding box filled with an anion exchange resin;

[0015] The containing box is in an inverted cone shape, and a water inlet is provided at the bottom of the containing box; the supporting part is installed at the top of the containing box.

[0016] As an embodiment, the support portion includes:

[0017] A fixing assembly, the fixing assembly is installed on the top of the containing box and is in communication with the containing box;

[0018] The matrix is ​​placed in the fixing assembly and is used to support the plant absorption part; the plant absorption part passes through the fixing assembly and is connected with the anion exchange resin.

[0019] As an embodiment, the fixing assembly includes:

[0020] A containing frame; the containing frame is installed on the top of the containing box;

[0021] The wire mesh is installed at the bottom of the containing frame; the plant absorption part passes through the wire mesh and is connected with the anion exchange resin.

[0022] As an embodiment, the substrate is expanded clay; the particle size of the expanded clay is 3-9 mm.

[0023] As an embodiment, the planting density of the first plant is 2-7 plants / m 2 The planting density of the second plant is 15-30 plants / m 2 .

[0024] As an implementation mode, there is a gap between the support part and the adsorption part; the distance of the gap is 0.5-1m.

[0025] In a second aspect, the present disclosure provides a sewage treatment system, the sewage treatment system comprising:

[0026] A collection tank for collecting sewage containing perchlorate ions;

[0027] Filtration tank, used to filter particulate impurities in sewage;

[0028] Membrane bioreactors, used to remove organic matter and suspended solids from wastewater;

[0029] Perchlorate sewage treatment plant, used to remove perchlorate ions from sewage;

[0030] Wherein, the perchlorate wastewater treatment device is the perchlorate wastewater treatment device described in the first aspect;

[0031] The water collection tank, the filtering tank, the membrane bioreactor and the perchlorate sewage treatment device are arranged in sequence.

[0032] In a third aspect, the present disclosure provides a sewage treatment method, using the perchlorate sewage treatment device described in the first aspect, the sewage treatment method comprising:

[0033] Passing the wastewater containing chlorate ions into a perchlorate wastewater treatment plant;

[0034] The hydraulic retention time of sewage in the perchlorate sewage treatment plant is 7-14 days;

[0035] Salvage the plant absorption part and take out the ceramsite in the support part;

[0036] After cleaning, the ceramsite is backfilled into the support part;

[0037] Plant the plant absorber back into the support.

[0038] As an implementation method, the sewage immersion depth does not exceed 2 / 3 of the height of the support portion.

[0039] The present disclosure has at least the following beneficial effects:

[0040] The sewage treatment device disclosed in the present invention arranges a plant absorption part on the top of the adsorption layer. The absorption part can absorb perchlorate ions in the sewage and accurately absorb and enrich them through the plant absorption part, thereby achieving efficient removal of perchlorate ions; at the same time, the shielding of the plant absorption part also plays a role in preventing the loss of the adsorption layer.

[0041] Additional aspects and advantages of the present disclosure will be given in part in the following description, which will become obvious from the following description, or will be learned through practice of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The drawings described herein are used to provide a further understanding of the present disclosure, constitute a part of the present disclosure, and do not constitute an improper limitation of the present disclosure. In the drawings:

[0043] Figure 1 A schematic diagram of the flow of a sewage treatment system in an embodiment;

[0044] Figure 2 Schematic diagram of the structure of the perchlorate wastewater treatment device in this embodiment;

[0045] Figure 3 Schematic diagram of the structure of the fixing assembly in this embodiment.

[0046] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0047] 1. Adsorption part; 11. Receiving box; 12. Anion exchange resin; 2. Support part; 21. Fixing assembly; 211. Receiving frame; 212. Wire mesh; 22. Matrix; 3. Plant absorption part; 4. Water inlet pipe; 5. Control valve; 6. Support column; 7. Water outlet pipe; 8. Water distributor. DETAILED DESCRIPTION

[0048] In order to more fully understand the technical content of the present disclosure, the present disclosure will be further introduced and explained in conjunction with the accompanying drawings and specific embodiments. It should be noted that the terms "upper", "lower", "front", "back", "inside", "outside", etc. indicate directions or positional relationships that are not given the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, it cannot be understood as a limitation on the present disclosure. In addition, the terms "first", "second", etc. are used to distinguish different components, etc., and do not represent a sequence, nor do they limit "first" and "second" to be different types.

[0049] The technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all of the embodiments; based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without making any creative work shall fall within the scope of protection of the present disclosure.

[0050] The present disclosure is further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present disclosure and are not used to limit the scope of the present disclosure.

[0051] In the following examples, the materials, reagents and instruments used can be purchased from commercial sources unless otherwise specified.

[0052] The perchlorate sewage treatment device, sewage treatment system and sewage treatment method in the embodiments of the present disclosure will be described in detail below.

[0053] First, the perchlorate wastewater treatment device according to the first aspect of this embodiment is described.

[0054] Perchlorate wastewater treatment plant

[0055] See also Figure 2 and Figure 3This embodiment provides a perchlorate sewage treatment device, wherein, an adsorption part 1, the adsorption part 1 is used to adsorb perchlorate ions in sewage; a support part 2, the support part 2 is installed on the top of the adsorption part 1 and is connected to the adsorption part 1; a plant absorption part 3, the support part 2 is used to support the plant absorption part 3; the plant absorption part 3 passes through the support part 2 and is connected to the adsorption part 1, and is used to absorb perchlorate ions in the adsorption part 1; wherein the plant absorption part 3 includes a first plant and a second plant; the first plant is selected from North American liquidambar and / or North American black willow, and the second plant is selected from sea salicornia and / or nettle.

[0056] It can be understood that the perchlorate sewage treatment device of this embodiment is used to remove perchlorate ions in sewage; wherein the plant absorption part 3, the support part 2 and the adsorption part 1 are arranged in sequence along the vertical direction.

[0057] During actual use, the adsorption part 1 contacts the sewage and adsorbs the perchlorate ions in the sewage; the plant absorption part 3 is stably placed (planted) by the support part 2, and the support part 2 has a plurality of through holes and a receiving cavity opening upward. The roots of the plant absorption part 3 pass through the through holes of the support part 2 and are connected with the adsorption part 1, so as to absorb the perchlorate ions in the adsorption part 1 to reduce the concentration of the perchlorate ions.

[0058] Specifically, the plant absorption part 3 of this embodiment contains both the first plant (Liquid gum and / or Willow nigra) and the second plant (Salicornia salsa and / or Urtica dioica). This embodiment has been verified to find that the combination of the first plant and the second plant can better reduce the concentration of perchlorate ions and delay the death of the plant absorption part 3 compared with the single use of the first plant and the second plant.

[0059] As a preferred implementation of this embodiment, the planting density of the first plant is 2-7 plants / m 2 , more preferably 3-5 plants / m 2 ; For example: 2 plants / m 2 , 3 plants / m 2 , 4 plants / m 2 , 5 plants / m 2 , 6 plants / m 2 , 7 plants / m 2 .

[0060] The planting density of the second plant is 15-30 plants / m 2 , preferably 20-25 plants / m 2 ; For example: 15 plants / m 2 , 16 plants / m 2 , 17 plants / m 2 , 18 plants / m 2 , 19 plants / m 2 , 20 plants / m 2, 21 plants / m 2 , 22 plants / m 2 , 23 plants / m 2 , 24 plants / m 2 , 25 plants / m 2 , 26 plants / m 2 , 27 plants / m 2 , 28 plants / m 2 , 29 plants / m 2 , 30 plants / m 2 .

[0061] The plant absorption part 3 of this embodiment also has a shielding effect, which can effectively prevent the adsorption layer from being lost.

[0062] Therefore, in the sewage treatment device of this embodiment, by setting the plant absorption part 3 on the top of the adsorption layer, the adsorption part 1 can absorb the perchlorate ions in the sewage, and accurately absorb and enrich them through the plant absorption part 3, thereby realizing efficient removal of perchlorate ions (reducing the concentration of perchlorate ions).

[0063] At the same time, the present embodiment has concluded through relevant experiments that in water bodies with high perchlorate concentrations (e.g., 1.2-1.5 mg / kg), although the growth of the plant absorption part 3 is inhibited, the perchlorate enrichment rate in the plant absorption part 3 is increased instead, which can achieve the purpose of quickly reducing the perchlorate concentration in the water body. It is speculated that the principle may be that the high concentration of perchlorate ions enhances the permeability of the root cells of the plant absorption part 3, thereby promoting the absorption of perchlorate ions.

[0064] Hereinafter, the adsorption part 1 and the support part 2 of this embodiment will be described in further detail.

[0065] The adsorption part 1 of this embodiment includes a containing box 11, and the containing box 11 is filled with an anion exchange resin 12; wherein the containing box 11 is in an inverted cone shape, and the bottom of the containing box 11 has a water inlet; the support part 2 is installed on the top of the containing box 11;

[0066] It can be understood that the containing box 11 has a cavity which opens upward and is used to contain an anion exchange resin 12, and the anion exchange resin 12 can absorb perchlorate ions in sewage; the cavity of the containing box 11 is connected to the supporting part 2, and the roots of the plant absorption part 3 can contact the anion exchange resin 12 in the containing box 11 after passing through the through holes of the supporting part 2, thereby absorbing the perchlorate ions enriched in the anion exchange resin 12.

[0067] The present embodiment does not specifically limit the anion exchange resin 12, and the anion exchange resin 12 known for adsorbing perchlorate ions may be used, such as Seplite LSI-107 anion exchange resin.

[0068] The containing box 11 is in an inverted cone shape; the supporting portion 2 is installed on the top of the containing box 11 .

[0069] It is understandable that the cross-sectional area of ​​the inverted cone-shaped container 11 decreases from top to bottom, which can be used to fill the resin, prevent the resin from escaping, and ensure the adsorption effect. At the same time, the bottom of the container 11 has a water inlet, that is, the sewage enters the container 11 from bottom to top, which helps to improve the utilization rate and treatment efficiency of the resin; because the water flow can pass through the resin bed more evenly, reducing the short-circuit phenomenon of the water flow, thereby improving the adsorption effect. In addition, it can also reduce the ditch effect that may occur in the resin layer, ensuring that the entire resin layer can participate in the adsorption process.

[0070] As an implementation manner, support columns 6 are installed on both sides of the receiving box 11 , and the support columns 6 can provide stable support for the receiving box 11 , so that the receiving box 11 can be stably placed.

[0071] As an implementation method, a water inlet pipe 4 is installed at the bottom of the water inlet, and the receiving box 11 is installed with a water distributor 8 connected to the water inlet pipe 4. The sewage flows into the water distributor 8 through the water inlet pipe 4, thereby achieving uniform water distribution in the receiving box 11.

[0072] Wherein, a control valve 5 is installed on the water inlet pipe 4 to realize the opening and closing of the water inlet pipe 4.

[0073] Please continue reading Figure 2 and Figure 3 The support part 2 of this embodiment includes: a fixing component 21, which is installed on the top of the containing box 11; a substrate 22, which is placed in the fixing component 21 and is used to support the plant absorption part 3; the plant absorption part 3 passes through the fixing component 21 and is connected to the anion exchange resin 12.

[0074] Please continue reading Figure 3 The fixing component 21 has a receiving cavity (opening upward) for placing the substrate 22, and supports the plant absorption part 3 through the substrate 22. At the same time, the fixing component 21 has a plurality of through holes, and the root of the plant absorption part 3 passes through the through holes and communicates with the anion exchange resin 12, so as to absorb the perchlorate ions in the anion exchange resin 12 to reduce the concentration of the perchlorate ions.

[0075] As an embodiment, the substrate 22 is ceramsite, wherein the particle size of the ceramsite is 3-9 mm. The ceramsite selected in this embodiment can reduce the generation of biofilm and prevent the microbial action from affecting the absorption and enrichment of perchlorate by the top plant absorption part 3.

[0076] For example, the ceramsite used in this embodiment can be purchased from Henan Xingan Environmental Protection Technology Co., Ltd. for sewage treatment ceramsite, with a specification of 3-9 mm.

[0077] Specifically, the fixing assembly 21 comprises: a containing frame 211 ; the containing frame 211 is installed on the top of the containing box 11 ; a wire mesh 212 ; the wire mesh 212 is installed on the bottom of the containing frame 211 ; the plant absorption part 3 passes through the wire mesh and is connected to the anion exchange resin 12 .

[0078] It can be understood that the receiving frame 211 has a channel in the vertical direction, and the wire mesh 212 is installed at the bottom of the receiving frame 211 so that the receiving frame 211 forms a receiving cavity (opening upward) for placing the substrate 22; and the wire mesh 212 itself has a plurality of through holes, which facilitates the roots of the plant absorption part 3 to pass through the through holes and connect with the anion exchange resin 12.

[0079] The wire mesh 212 of this embodiment can be a stainless steel wire mesh or an iron wire mesh known in the art.

[0080] The bottom of the container 11 is provided with a water outlet, and a water outlet pipe 7 is usually installed on the water outlet to discharge the sewage. When the concentration of perchlorate drops to a suitable concentration, it can be directly discharged from the bottom of the container 11.

[0081] Specifically, a control valve 5 or a sealing plug is installed on the water outlet pipe 7 to realize opening and closing of the water outlet pipe 7 .

[0082] As an embodiment, there is a gap between the support part 2 and the adsorption part 1, and the distance of the gap is 0.5-1m. Specifically, there is a gap between the bottom of the containing frame 211 and the anion exchange resin 12, and the distance of the gap is 0.5-1m, preferably 0.6m.

[0083] Next, the sewage treatment system according to the second aspect of this embodiment will be described in detail.

[0084] Sewage treatment system

[0085] This embodiment also provides a sewage treatment system. Figure 1 , the sewage treatment system includes:

[0086] A collection tank for collecting sewage containing perchlorate ions;

[0087] Filtration tank, used to filter particulate impurities in sewage;

[0088] Membrane bioreactors, used to remove organic matter and suspended solids from wastewater;

[0089] Perchlorate sewage treatment plant, used to remove perchlorate ions from sewage;

[0090] The above-mentioned water collection tank, filtration tank, membrane bioreactor and perchlorate wastewater treatment device are arranged in sequence.

[0091] It can be understood that the sewage treatment system of this embodiment is suitable for sewage containing perchlorate ions, such as fireworks wastewater.

[0092] The membrane bioreactor used in this embodiment is a known membrane bioreactor, such as a membrane bioreactor of model KJDF4090A purchased from Hangzhou Kaijie Membrane Separation Technology Co., Ltd.

[0093] Next, fireworks wastewater will be taken as an example to explain the sewage treatment system of this embodiment.

[0094] The sewage treatment system comprises a water collection tank, a filtering tank, a membrane bioreactor and a perchlorate sewage treatment device which are arranged in sequence and communicated with each other.

[0095] Among them, the water collection tank (volume 10m 3 ) is used to collect fireworks wastewater, which contains only pollutants such as paper scraps, organic matter, suspended matter and perchlorate ions; the water outlet of the collection pool is connected to the water inlet of the filter pool, and the filter pool (volume 15m 3 ) is equipped with a filter screen at the water outlet to filter particulate impurities (such as paper scraps) in the fireworks wastewater; usually, the fireworks wastewater will stay in the filter tank for 1-2 hours, and the particulate impurities in the fireworks wastewater will settle to the bottom of the filter tank. After filtering the particulate impurities in the fireworks wastewater in the filter tank, the filtered fireworks wastewater is passed into the membrane bioreactor, which intercepts the activated sludge and suspended matter in the fireworks wastewater, realizes the solid-liquid separation of the purified water and the activated sludge, strengthens the biochemical reaction, and improves the sewage treatment effect and the effluent water quality; the sewage treated by the membrane bioreactor is passed into the containing chamber through the water inlet at the bottom of the containing box 11, thereby removing the perchlorate ions in the sewage.

[0096] Since perchlorate ions are highly water-soluble and chemically stable in water, the present embodiment further adopts the above-mentioned perchlorate wastewater treatment device to remove perchlorate ions from fireworks wastewater. As mentioned above, the wastewater treatment device of the present embodiment, by setting the plant absorption part 3 on the top of the adsorption layer, the absorption part can absorb the perchlorate ions in the sewage, and accurately absorb and enrich them through the plant absorption part 3, thereby realizing efficient removal of perchlorate ions (reducing the concentration of perchlorate ions).

[0097] Next, the sewage treatment method according to the third aspect of this embodiment will be described in detail.

[0098] Wastewater treatment methods

[0099] The sewage treatment method of this embodiment comprises the following steps:

[0100] (1) passing the sewage containing chlorate ions into a perchlorate sewage treatment device;

[0101] (2) The hydraulic retention time of sewage in the perchlorate sewage treatment plant is 7-14 days;

[0102] (3) fishing out the plant absorption part 3 and taking out the ceramsite in the support part 2;

[0103] (4) After cleaning, the ceramsite is backfilled into the support portion 2;

[0104] (5) Plant the plant absorbing part 3 back into the supporting part 2.

[0105] The retention time in this example is the hydraulic retention time (HRT).

[0106] Among them, if the sewage retention time in the perchlorate sewage treatment device is long, a large number of plant absorption parts 3 will fall over. After the dead plant absorption parts 3 rot in the water body, the enriched perchlorate ions therein will be released into the water body again, causing the water quality to deteriorate.

[0107] At the same time, since the support part 2 is in direct contact with sewage, the matrix 22 (ceramsite) in the support part 2 will be attached with biofilm, which will affect the growth of the roots of the plant absorption part 3 and the absorption of perchlorate ions; therefore, in this example, it is necessary to salvage the plant absorption part 3 and take out the ceramsite in the support part 2 on time (such as every 5-10 days), replace it with new ceramsite, or wash the ceramsite, sterilize it at high temperature to remove the biofilm in the ceramsite, and then fill the ceramsite back into the support part 2. In this way, it can effectively avoid that the biofilm on the ceramsite will affect the growth of the roots of the plant absorption part 3 and the absorption of perchlorate ions, so as to better reduce the concentration of perchlorate ions.

[0108] Among them, the high-temperature disinfection method is: put the salvaged expanded clay into hot water, heat it to 90 degrees, keep it for 3 minutes, and then dry it.

[0109] The plants that have been salvaged and not replanted can be cleaned, dried, crushed, sintered, and mixed with bentonite (50 parts of plants, 70 parts of bentonite, and 8 parts of gypsum are sintered at a sintering temperature of 900°C, and granulated to obtain ceramsite. The density of the ceramsite obtained by firing is 550-6005kg / m 3 , with a particle size of 3-9 mm, can be used as a backfill matrix 22.

[0110] As an implementation method, in the process of passing sewage containing chlorate ions into a perchlorate sewage treatment device, usually, the immersion depth of the sewage does not exceed 2 / 3 of the height of the middle support part 2, which can effectively avoid the lack of oxygen and rot of the roots of the plant absorption part 3 and accelerate the death of the plant absorption part 3.

[0111] The present disclosure will be further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present disclosure and are not used to limit the scope of the present disclosure.

[0112] In the following examples, the materials, reagents and instruments used can be purchased from commercial sources unless otherwise specified.

[0113] It should be noted that in the following examples or comparative examples, young plants with a stem length of 0.7 m±0.1 m (about 1.5 cm in diameter) were selected for Liquidambar formosana and Willow of North America, and young plants with a stem length of 0.2 m±0.05 m were selected for Salicornia herba and Urtica dioica.

[0114] Example 1

[0115] In this embodiment, the support part has a height of 0.6 m, the bottom adsorption part has a thickness of 3 m, is filled with Seplite LSI-107 anion exchange resin, and the distance between the bottom adsorption part and the support part is 0.6 m.

[0116] The top plant absorption part is mixed with Liquidambar formosana, nettle and samphire. The planting density of Liquidambar formosana is 3 plants / m 2 The planting density of Salicornia and Urtica dioica is 20 plants / m 2 The support part is composed of a rectangular containing frame 211 (2m long, 0.5m wide, 0.6m high), a double-layer wire mesh 212 and a base body, and the double-layer wire mesh is installed at the bottom of the containing frame; the base body is filled with a thickness of 0.5m and is composed of ceramsite, which is purchased from Henan Xingan Environmental Protection Technology Co., Ltd. for sewage treatment, and has a particle size of 3-9mm.

[0117] The pre-treated effluent is introduced into the containing box 11 from the water inlet, the sewage immersion depth is 1 / 3 of the support height, and the hydraulic retention time is 10 days.

[0118] The water was monitored on the 0th, 15th and 30th days, and the perchlorate concentration was 1.2-1.5 mg / kg.

[0119] After 15 days, the plants in the top plant absorption part and the ceramsite in the support part were salvaged, and new ceramsite was replaced. The salvaged plants were immediately planted back to the support part. The perchlorate concentration on the 15th day was taken as the initial concentration, and the perchlorate concentration on the last day was taken as the final concentration, and the perchlorate removal rate after salvage was calculated.

[0120] The calculation formula of perchlorate removal rate is: CL = (C0-C1) / C0×100%;

[0121] In the above formula, C0 is the initial concentration and C1 is the final concentration.

[0122] Among them, the salvaged expanded clay is cleaned and sterilized at high temperature, and can be used again after the biofilm in the expanded clay is removed; the high-temperature sterilization method is: put the expanded clay in hot water, heat it to 90°C, keep it for 3 minutes, and then dry it.

[0123] Example 2

[0124] The basic content of this embodiment is the same as that of embodiment 1, except that: Liquidambar formosana is planted in the top plant absorption part, and the planting density of Liquidambar formosana is 8 plants / m 2 .

[0125] Example 3

[0126] The basic content of this embodiment is the same as that of embodiment 1, except that: the top plant absorption part is mixed with nettle and samphire, and the planting density of samphire and nettle is 20 plants / m 2 .

[0127] Example 4

[0128] The basic content of this embodiment is the same as that of embodiment 1, except that the hydraulic retention time is 7 days.

[0129] Example 5

[0130] The basic content of this embodiment is the same as that of embodiment 1, except that the hydraulic retention time is 14 days.

[0131] Example 6

[0132] The basic content of this embodiment is the same as that of Embodiment 1, except that the height of the support portion is 0.45 m.

[0133] Example 7

[0134] The basic content of this embodiment is the same as that of Embodiment 1, except that the height of the support portion is 0.7 m.

[0135] Example 8

[0136] The basic content of this embodiment is the same as that of embodiment 1, except that: the top plant absorption part is mixed with black willow, nettle and samphire, and the planting density of black willow is 3 plants / m 2 The planting density of Salicornia and Urtica dioica is 20 plants / m 2 .

[0137] Comparative Examples 1-6

[0138] The differences between Comparative Examples 1-6 and the embodiments are shown in Table 1 below.

[0139] Table 1:

[0140]

[0141]

[0142] The perchlorate effluent from the above system was collected 6 times, the perchlorate removal rate was tested, and the average perchlorate removal rate was calculated and the results are shown in Table 2 below.

[0143] Table 2:

[0144]

[0145]

[0146] Combined with the test results in Table 2, Liquidambar styraciflua, Salix nigra, Allenrolfea occidentalis, and Urtica fissa E. Pritz have extremely strong enrichment capabilities for perchlorate; at the same time, in water bodies with high perchlorate concentrations, although the growth of plants is inhibited, the perchlorate enrichment rate in the plants increases instead, achieving the purpose of quickly reducing the perchlorate concentration in the water body. It is speculated that this may be because the permeability of the root cells of the plant absorption part is enhanced due to the high-concentration perchlorate stress.

[0147] As can be seen from Examples 1-3 and 8, the removal effect of mixed plants is better than that of only planting one or two types of plants, and some plants died when only planting American sweetgum. As can be seen from Examples 4-5, the hydraulic retention time is kept at 10d for the best. Although the removal effect of Examples 6 and 7 is close to that of Example 1, the American sweetgum in Example 6 partially fell over during the middle and late growth process, and the substrate did not play a good fixing role, and the excessive amount of substrate used in Example 7 increased the cost.

[0148] In Comparative Example 1, the substrate was not replaced, and the Liquidambar formosana showed lodging, and the Urtica dioica and Salicornia herba died one after another after the rapid growth period, which not only led to a decrease in the perchlorate absorption rate, but also after the dead plants rotted in the water body, the perchlorate or chloride ions enriched in the plants were re-released into the water body, resulting in a decrease in the effluent quality.

[0149] The water hyacinth in Comparative Example 2 did not effectively remove perchlorate, and under the stress of this concentration, some of the plants died on the 20th day.

[0150] The plants in Comparative Example 3 grew too fast after 15 days, and the North American liquidambar formosana showed lodging. The nettles and samphires began to die one after another after the rapid growth period. After the dead plants rotted in the water body, the enriched perchlorates or chloride ions were released back into the water body, resulting in a decrease in the effluent quality.

[0151] In Comparative Example 4, due to the low perchlorate concentration in the middle supporting layer water body, plant growth was not effectively inhibited, resulting in a faster plant growth rate. After 30 days, the pollutant removal effect was only 80.5%, and the North American liquidambar formosana lodging phenomenon occurred.

[0152] In Comparative Examples 5 and 6, the plants of Comparative Example 5 fell down on the 24th day due to the excessive growth of Liquidambar formosana, while a large area of ​​plants died on the 26th day in Comparative Example 6.

[0153] In summary, the sewage treatment device of this embodiment, by setting the plant absorption part on the top of the adsorption layer, the absorption part can absorb the perchlorate ions in the sewage, and accurately absorb and enrich them through the plant absorption part, thereby realizing efficient removal of the perchlorate ions.

[0154] The technical solutions provided by the embodiments of the present disclosure are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the embodiments of the present disclosure. The description of the above embodiments is only applicable to help understand the principles of the embodiments of the present disclosure. At the same time, for those skilled in the art, according to the embodiments of the present disclosure, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present disclosure.

Claims

1. A perchlorate wastewater treatment device, characterized in that: The sewage treatment device comprises: An adsorption part (1), wherein the adsorption part (1) is used to adsorb perchlorate ions in sewage; A support portion (2), wherein the support portion (2) is mounted on the top of the adsorption portion (1) and is in communication with the adsorption portion (1); The plant absorption part (3) is used for supporting the plant absorption part (3); the plant absorption part (3) passes through the support part (2) and is connected with the adsorption part (1) to absorb the perchlorate ions in the adsorption part (1); Wherein, the plant absorption part (3) comprises a first plant and a second plant; the first plant is selected from Liquidambar formosana and / or Willow nigra, and the second plant is selected from Salicornia herba and / or Urtica dioica.

2. The perchlorate wastewater treatment device according to claim 1, characterized in that: The adsorption part (1) comprises: A containing box (11), wherein the containing box (11) is filled with an anion exchange resin (12); The containing box (11) is in an inverted cone shape, and the bottom of the containing box (11) is provided with a water inlet; the supporting portion (2) is installed on the top of the containing box (11).

3. The perchlorate wastewater treatment device according to claim 2, characterized in that: The support portion (2) comprises: A fixing assembly (21), wherein the fixing assembly (21) is installed on the top of the containing box (11) and is in communication with the containing box (11); A matrix (22) is placed in the fixing component (21) and is used to support the plant absorption part (3); the plant absorption part (3) passes through the fixing component (21) and is connected to the anion exchange resin (12).

4. The perchlorate wastewater treatment device according to claim 3, characterized in that: The fixing assembly (21) comprises: A containing frame (211); the containing frame (211) is installed on the top of the containing box (11); The wire mesh (212) is installed at the bottom of the containing frame (211); the plant absorption part (3) passes through the wire mesh (212) and is connected to the anion exchange resin (12).

5. The perchlorate wastewater treatment device according to claim 3, characterized in that: The substrate (22) is ceramsite; the particle size of the ceramsite is 3-9 mm.

6. The perchlorate wastewater treatment device according to any one of claims 1 to 4, characterized in that: The planting density of the first plant is 2-7 plants / m 2 The planting density of the second plant is 15-30 plants / m 2 .

7. The perchlorate wastewater treatment device according to claim 1, characterized in that: There is a gap between the support part (2) and the adsorption part (1); the distance of the gap is 0.5-1m.

8. A sewage treatment system, characterized in that: The sewage treatment system comprises: A collection tank for collecting sewage containing perchlorate ions; Filtration tank, used to filter particulate impurities in sewage; Membrane bioreactors, used to remove organic matter and suspended solids from wastewater; Perchlorate sewage treatment plant, used to remove perchlorate ions from sewage; Wherein, the perchlorate wastewater treatment device is the perchlorate wastewater treatment device according to any one of claims 1 to 7; The water collection tank, the filtering tank, the membrane bioreactor and the perchlorate sewage treatment device are arranged in sequence.

9. A method for treating sewage, characterized in that: Using the perchlorate wastewater treatment device according to any one of claims 1 to 7, the wastewater treatment method comprises: Passing the wastewater containing chlorate ions into a perchlorate wastewater treatment plant; The hydraulic retention time of sewage in the perchlorate sewage treatment plant is 7-14 days; Salvaging out the plant absorption part (3) and taking out the ceramsite in the support part (2); After cleaning, the ceramsite is backfilled into the support part (2); The plant absorbing part (3) is planted back into the supporting part (2).

10. The sewage treatment method according to claim 9, characterized in that: The immersion depth of the sewage does not exceed 2 / 3 of the height of the support part (2).

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