Wastewater treatment process and device

Abstract

The invention relates to the technical field of wastewater treatment, in particular to a wastewater treatment process and device. The wastewater treatment process comprises the following steps: wastewater sequentially flows through a crystallization zone, an oxidation zone and a granulation zone to be treated, and purified water is obtained; wherein the wastewater contains metal ions and organic matters; ion crystallization is carried out in the crystallization area to form ion crystals, organic matter oxidation modification is carried out in the oxidation area, the modified organic matter and the ion crystals are coordinated and complexed to form a polymer, and the polymer forms a granulated body in the granulation area. According to the wastewater treatment process provided by the invention, metal ions and organic matters in the wastewater can be effectively removed, the treatment effect is enhanced, the solid-liquid separation efficiency is improved, the process flow is shortened, no chemical sludge is generated, the occupied area of the device is small, and the wastewater treatment process has important significance in the field of wastewater treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of wastewater treatment, and in particular to a wastewater treatment process and device. Background Art

[0002] With the development of industrialization, more and more complex organic wastewater is generated in the industrial production process. If these organic wastewaters are not effectively treated, a large amount of organic pollutants will pollute the water body, destroy the balance of aquatic ecosystems, and cause adverse effects such as cytotoxicity and genotoxicity. Organic pollution has always been an important threat to environmental protection and public health. Traditional methods of organic control include physical adsorption, chemical oxidation, biodegradation, etc., which can remove some organic pollutants to a certain extent, but still face some limitations and challenges. For example, chemical oxidation methods may use strong oxidants, such as permanganate, hydrogen peroxide, etc., which are high in cost, dangerous and complex to operate. In addition, the biodegradation method is not efficient in degrading certain organic pollutants, and requires long-term treatment and occupies a large area. Physical adsorption methods usually require a large amount of adsorbents, and the subsequent regeneration and treatment process may cause secondary pollution.

[0003] In addition, there are often a large number of soluble ions in wastewater, such as calcium, magnesium, silicon and other ions, which will deposit and form scale in industrial equipment, causing equipment wear, blockage and failure, and increasing maintenance and operating costs. In some industrial production processes, water hardness will have an important impact on product quality. Therefore, the effective removal of scale-causing ions is also of great significance to industrial production. Commonly used ion control methods include chemical precipitation, ion exchange, etc. Chemical precipitation will produce a large amount of chemical sludge, while ion exchange is expensive, and the generated regenerated concentrated water cannot be treated either.

[0004] Therefore, it is of great significance to provide a treatment process and device that can effectively remove organic matter and metal ions in wastewater. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a wastewater treatment process and device. The wastewater treatment process provided by the present invention can effectively remove metal ions and organic matter in wastewater, enhance the treatment effect, improve the solid-liquid separation efficiency, shorten the process flow, and does not produce chemical sludge. The device occupies a small area and is of great significance in the field of wastewater treatment.

[0006] In a first aspect, the present invention provides a wastewater treatment process, comprising the following steps: passing wastewater through a crystallization zone, an oxidation zone, and a granulation zone in sequence for treatment to obtain purified water;

[0007] Wherein, the wastewater contains metal ions and organic matter;

[0008] The crystallization zone performs ion crystallization to form ionic crystals, the oxidation zone performs oxidation modification of organic matter, the modified organic matter coordinates and complexes with the ionic crystals to form polymers, and the granulation zone forms granules from the polymers.

[0009] The wastewater treatment process provided by the present invention can achieve effective removal of metal ions and organic matter in wastewater, enhance the treatment effect, improve the solid-liquid separation efficiency, shorten the process flow, and no chemical sludge is generated.

[0010] As a preferred technical solution of the present invention, the wastewater enters the crystallization zone from the bottom, overflows from the top of the crystallization zone to the oxidation zone, and flows into the granulation zone from the bottom of the oxidation zone.

[0011] The present invention sets the wastewater flow direction as described above, which can enhance the wastewater treatment effect on the one hand, and effectively reduce the footprint of the device on the other hand.

[0012] As a preferred technical solution of the present invention, the crystallization zone is provided with an ionic crystallization inducer, and the presence of the ionic crystallization inducer can induce the crystallization of metal ions.

[0013] As a preferred technical solution of the present invention, the molar ratio of the ionic crystallization inducer to the metal ion is 0.8-1.5:1, for example, 0.8:1, 1.0:1, 1.2:1, 1.4:1, 1.5:1, etc.

[0014] As a preferred technical solution of the present invention, the metal ion inducer is selected from inorganic salts, such as carbonates, sulfates, silicates, etc., which can produce insoluble precipitates with metal ions.

[0015] As a preferred technical solution of the present invention, the oxidation zone is exposed to ozone gas, and the organic matter in the wastewater can be oxidatively modified under the oxidation of the ozone gas, and then the modified organic matter can coordinate and complex with ionic crystals to form polymers.

[0016] As a preferred technical solution of the present invention, the exposure amount of the ozone gas is 0.1-2 mg / (mgCOD), for example 0.1 mg / (mg COD), 0.5 mg / (mg COD), 1 mg / (mgCOD), 1.5 mg / (mg COD), 2 mg / (mg COD).

[0017] As a preferred technical solution of the present invention, the granulation zone is provided with glass beads, which can induce the polymer to form a dense granulation body.

[0018] As a preferred technical solution of the present invention, the particle size of the glass beads is 1-5 mm, for example, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, etc.

[0019] As a preferred technical solution of the present invention, the filling height of the glass beads is 5-20% of the total height of the granulation zone, such as 5%, 10%, 15%, 20%, etc.

[0020] As a preferred technical solution of the present invention, the hydraulic retention time of the crystallization zone is 2-5 min, for example, 2 min, 3 min, 4 min, 5 min, etc.

[0021] As a preferred technical solution of the present invention, the hydraulic retention time of the oxidation zone is 10-60 min, for example, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, etc.

[0022] As a preferred technical solution of the present invention, the hydraulic retention time of the granulation zone is 5-40 min, for example, 5 min, 10 min, 20 min, 30 min, 40 min, etc.

[0023] When the hydraulic retention time of the crystallization zone, the oxidation zone and the granulation zone is within the above range, the reaction of each step can be made more complete, thereby achieving effective removal of metal ions and organic matter.

[0024] As a preferred technical solution of the present invention, the rising flow rate in the granulation zone is 10-100 m / h, such as 10 m / h, 20 m / h, 40 m / h, 60 m / h, 80 m / h, 100 m / h, etc. When the flow rate is within this range, the collision probability between polymer particles can be effectively increased, thereby completing the densification of the granulation body under the action of hydraulic pressure.

[0025] As a preferred technical solution of the present invention, the metal ions include any one or more of calcium ions, magnesium ions, silicon ions, fluorine ions, lithium ions, manganese ions, lead ions, cobalt ions, and nickel ions.

[0026] As a preferred technical solution of the present invention, the organic matter includes natural organic matter and / or artificially synthesized organic matter.

[0027] The wastewater treatment process provided by the present invention first passes the wastewater into a crystallization zone to use an ion crystallization inducer to induce metal ions in the water to form crystals, then enters an oxidation zone to modify organic matter in combination with the oxidizing effect of ozone, and then the ion crystals capture the modified organic matter to form a crystalline aggregate, and then enters a granulation zone to form granules under the control of hydraulic action, and completes the removal of metal ions and organic pollutants through efficient solid-liquid separation.

[0028] In a second aspect, the present invention provides a wastewater treatment device, comprising a crystallization zone, at least one oxidation zone and at least one granulation zone, wherein the top of the oxidation zone is connected to the top of the crystallization zone, and the bottom of the oxidation zone is connected to the bottom of the granulation zone.

[0029] As a preferred technical solution of the present invention, the bottom of the crystallization zone is provided with an opening for introducing waste water.

[0030] As a preferred technical solution of the present invention, the top of the granulation zone is provided with an opening for discharging clean water, and the bottom of the granulation zone is provided with an opening for discharging granules.

[0031] As a preferred technical solution of the present invention, aeration holes are provided at the bottom of the oxidation zone to expose ozone gas.

[0032] As a preferred technical solution of the present invention, the crystallization zone is provided with an ionic crystallization inducer.

[0033] As a preferred technical solution of the present invention, glass beads are arranged at the bottom of the granulation zone.

[0034] As a preferred technical solution of the present invention, the granulation zone is provided with a reflux device to control the rising flow velocity in the granulation zone, improve the flow state inside the granulation zone, promote the aggregation and coagulation of particles, and enhance the homogeneous granulation of crystals.

[0035] The wastewater treatment device provided by the present invention is characterized in that wastewater is quickly and evenly mixed in a crystallization zone to form ion crystals, and then overflows from the top of the crystallization zone to the oxidation zone where organic matter is oxidized and modified, and the modified organic matter coordinates and complexes with the crystals to form aggregates, and finally flows into the granulation zone from the bottom of the oxidation zone. The aggregates form dense granules under the control of hydraulic action, and the purified water is discharged from the upper end of the device, and the granules are discharged from the bottom. The wastewater treatment device provided by the present invention can effectively remove metal ions and organic matter in water.

[0036] The technical solution provided by the embodiment of the present invention has the following advantages compared with the prior art:

[0037] The wastewater treatment process provided by the present invention can effectively remove metal ions and organic matter in wastewater, enhance the treatment effect, improve the solid-liquid separation efficiency, shorten the process flow, does not produce chemical sludge, and has a small footprint, which is of great significance in the field of wastewater treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0040] Figure 1 This is a schematic diagram of the structure of the wastewater treatment device described in Example 1 of the present invention;

[0041] Among them, 1-crystallization zone, 2-oxidation zone, 3-granulation zone. DETAILED DESCRIPTION

[0042] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0043] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all of the embodiments.

[0044] Example 1

[0045] The present embodiment provides a wastewater treatment device, comprising a crystallization zone 1, an oxidation zone 2 and a granulation zone 3, wherein the top of the oxidation zone 2 is connected to the top of the crystallization zone 1, and the bottom of the oxidation zone 2 is connected to the bottom of the granulation zone 3; the bottom of the crystallization zone 1 is provided with an opening for introducing wastewater, the top of the granulation zone 3 is provided with an opening for discharging clean water, and the bottom of the granulation zone 3 is provided with an opening for discharging granules; the bottom of the oxidation zone 2 is provided with an aeration hole for introducing ozone gas, the crystallization zone 1 is provided with a calcium ion crystallization inducer, and the bottom of the granulation zone 3 is provided with glass beads. The specific structural schematic diagram is shown as follows: Figure 1 shown.

[0046] The present embodiment also provides a wastewater treatment process, which is implemented by the above-mentioned wastewater treatment device, wherein the calcium ion concentration in the wastewater is 500 mg / L and the humic acid content is 20 mg / L; the process comprises the following steps: the wastewater is passed into the crystallization zone 1, the calcium ions in the wastewater react with the inducer to generate primary crystalline particles, and then overflows from the top of the crystallization zone 1 to the oxidation zone 2, under the action of ozone, the humic acid in the water adsorbs and complexes with the crystalline particles to form a crystalline aggregate, and then flows from the bottom of the oxidation zone 2 to the granulation zone 3, the granulation zone is provided with a reflux to adjust the rising flow rate, increase the collision probability between the particles, and complete the densification of the granulation body under the action of hydraulic pressure, the purified water body is discharged from the top discharge device of the granulation zone, and the granulation body is discharged from the bottom of the granulation zone. Among them, the ionic crystallization inducer in the crystallization zone is sodium carbonate, and the molar ratio of the ionic crystallization inducer to calcium ions is 1:1; the flow rate of ozone gas exposed to the oxidation zone is 1 mg / (mgCOD); the particle size of the glass beads in the granulation zone is 1-5 mm, and the filling height is 20% of the total height of the granulation zone device; the hydraulic retention time in the crystallization zone is 4 minutes, the hydraulic retention time in the oxidation zone is 30 minutes, the hydraulic retention time in the granulation zone is 20 minutes, and the rising flow rate is 50 m / h, to obtain purified water, and the calcium ion concentration in the purified water is 20 mg / L, and the humic acid content is 5 mg / L.

[0047] Example 2

[0048] This embodiment provides a wastewater treatment process and device, the device is the same as that in Example 1, the calcium ion concentration in the wastewater is 500 mg / L, and the humic acid content is 20 mg / L;

[0049] The wastewater treatment process includes the following steps: the wastewater is passed into the crystallization zone 1, the calcium ions in the wastewater react with the inducer to form primary crystalline particles, and then overflows from the top of the crystallization zone 1 to the oxidation zone 2. Under the action of ozone, the humic acid in the water adsorbs and complexes with the crystalline particles to form crystalline aggregates, and then flows from the bottom of the oxidation zone 2 to the granulation zone 3. The granulation zone is provided with a reflux to adjust the rising flow rate, increase the collision probability between the particles, and complete the densification of the granulation body under the action of hydraulic pressure. The purified water body is discharged from the top discharge device of the granulation zone, and the granulation body is discharged from the bottom of the granulation zone. Among them, the ionic crystallization inducer in the crystallization zone is sodium carbonate, and the molar ratio of the ionic crystallization inducer to the metal ion is 0.8:1; the flow rate of ozone gas exposed to the oxidation zone is 2 mg / (mgCOD); the particle size of the glass beads in the granulation zone is 1-5 mm, and the filling height is 10% of the total height of the granulation zone device; the hydraulic retention time in the crystallization zone is 5 min, the hydraulic retention time in the oxidation zone is 10 min, the hydraulic retention time in the granulation zone is 5 min, and the rising flow rate is 100 m / h, to obtain purified water, and the calcium ion concentration in the purified water is 30 mg / L, and the humic acid content is 6 mg / L.

[0050] Example 3

[0051] This embodiment provides a wastewater treatment process and device, the device is the same as that in Example 1, the calcium ion concentration in the wastewater is 500 mg / L, and the humic acid content is 20 mg / L;

[0052] The wastewater treatment process includes the following steps: the wastewater is passed into the crystallization zone 1, the calcium ions in the wastewater react with the inducer to form primary crystalline particles, and then overflows from the top of the crystallization zone 1 to the oxidation zone 2. Under the action of ozone, the humic acid in the water adsorbs and complexes with the crystalline particles to form crystalline aggregates, and then flows from the bottom of the oxidation zone 2 to the granulation zone 3. The granulation zone is provided with a reflux to adjust the rising flow rate, increase the collision probability between the particles, and complete the densification of the granulation body under the action of hydraulic pressure. The purified water body is discharged from the top discharge device of the granulation zone, and the granulation body is discharged from the bottom of the granulation zone. Among them, the ionic crystallization inducer in the crystallization zone is sodium carbonate, and the molar ratio of the ionic crystallization inducer to the metal ion is 1.5:1; the flow rate of ozone gas exposed to the oxidation zone is 0.1 mg / (mgCOD); the particle size of the glass beads in the granulation zone is 1-5 mm, and the filling height is 5% of the total height of the granulation zone device; the hydraulic retention time in the crystallization zone is 2 min, the hydraulic retention time in the oxidation zone is 60 min, the hydraulic retention time in the granulation zone is 40 min, and the rising flow rate is 10 m / h, to obtain purified water, and the calcium ion concentration in the purified water is 8 mg / L, and the humic acid content is 12 mg / L.

[0053] From Examples 1-3, it can be found that the wastewater treatment process and device provided by the present invention can effectively remove metal ions and organic matter in wastewater, enhance the treatment effect, improve the solid-liquid separation efficiency, shorten the process flow, no chemical sludge is generated, and the device occupies a small area.

[0054] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0055] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments described herein, but should conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A wastewater treatment process, characterized in that: The method comprises the following steps: passing the wastewater through a crystallization zone, an oxidation zone and a granulation zone in sequence for treatment to obtain purified water; Wherein, the wastewater contains metal ions and organic matter; The crystallization zone performs ion crystallization to form ionic crystals, the oxidation zone performs oxidation modification of organic matter, the modified organic matter coordinates and complexes with the ionic crystals to form polymers, and the granulation zone forms granules from the polymers.

2. The wastewater treatment process according to claim 1, characterized in that: The wastewater enters from the bottom of the crystallization zone, overflows from the top of the crystallization zone to the oxidation zone, and flows into the granulation zone from the bottom of the oxidation zone.

3. The wastewater treatment process according to claim 1 or 2, characterized in that: The crystallization zone is provided with an ionic crystallization inducing agent; Preferably, the molar ratio of the ionic crystallization inducer to the metal ion is 0.8-1.5:1; Preferably, the ionic crystallization inducing agent is selected from inorganic salts.

4. The wastewater treatment process according to any one of claims 1 to 3, characterized in that: The oxidation zone is exposed to ozone gas, and preferably the exposure amount of the ozone gas is 0.1-2 mg / (mgCOD).

5. The wastewater treatment process according to any one of claims 1 to 4, characterized in that: The granulation zone is provided with glass beads; Preferably, the particle size of the glass beads is 1-5 mm; Preferably, the filling height of the glass beads is 5-20% of the total height of the granulation zone.

6. The wastewater treatment process according to any one of claims 1 to 5, characterized in that: The hydraulic retention time of the crystallization zone is 2-5 min; And / or, the hydraulic retention time of the oxidation zone is 10-60 min; And / or, the hydraulic retention time of the granulation zone is 5-40 min.

7. The wastewater treatment process according to any one of claims 1 to 6, characterized in that: The rising flow rate in the granulation zone is 10-100m / h; And / or, the metal ions include any one or more of calcium ions, magnesium ions, silicon ions, fluorine ions, lithium ions, manganese ions, lead ions, cobalt ions, and nickel ions; And / or, the organic matter includes natural organic matter and / or artificially synthesized organic matter.

8. A wastewater treatment device, characterized in that: The invention comprises a crystallization zone, at least one oxidation zone and at least one granulation zone, wherein the top of the oxidation zone is connected with the top of the crystallization zone, and the bottom of the oxidation zone is connected with the bottom of the granulation zone.

9. The wastewater treatment device according to claim 8, characterized in that: The bottom of the crystallization zone is provided with an opening for admitting waste water; And / or, the top of the granulation zone is provided with an opening for discharging clean water, and the bottom of the granulation zone is provided with an opening for discharging granules.

10. The wastewater treatment device according to claim 8 or 9, characterized in that: Aeration holes are provided at the bottom of the oxidation zone; and / or, the crystallization region is provided with an ionic crystallization inducer; And / or, glass beads are arranged at the bottom of the granulation zone.

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