Multi-physicochemical-biochemical coupled semi-coke wastewater treatment system and application thereof

Abstract

The invention relates to a multiple physicochemical-biochemical coupled semi-coke wastewater treatment system and application thereof. The treatment system comprises an oil removal module, a phenol ammonia treatment module, a biochemical treatment module and a deep treatment module, the oil removal module comprises a gravity oil removal unit and an air flotation oil removal unit; the phenol-ammonia treatment module comprises one or more of a single-tower ammonia distillation deacidification unit, an extraction dephenolization unit and a resin adsorption dephenolization unit; the biochemical treatment module comprises one or more hydrolytic acidification units, one or more biological thickening units, one or more iron-carbon micro-electrolysis units and one or more A / O units; the deep treatment module comprises one or more ozone floatation units. According to the embodiment of the invention, the sequence of each unit in the combined module can be flexibly adjusted according to the water quality condition, the recycling and high-efficiency treatment of the high-phenol-ammonia semi-coke wastewater are realized, and the treated semi-coke wastewater can stably meet the emission standard.

Description

Technical Field

[0001] The present disclosure relates to the technical field of industrial wastewater treatment, and in particular to a multiple physicochemical-biochemical coupled blue charcoal wastewater treatment system and its application. Background Art

[0002] Semi-coke is a carbon material with broad application prospects. In recent years, its industry has been developing rapidly. However, the wastewater generated during the production of semi-coke contains a large amount of organic matter, phenolic compounds, volatile substances and other harmful substances, causing serious pollution to the environment.

[0003] The characteristics of semi-coke wastewater mainly include the following aspects: 1. Complex pollutant composition: Semi-coke wastewater contains a large number of organic substances, phenolic compounds, volatile substances and other harmful substances, making the pollutant composition of the wastewater more complex than that of coking wastewater. 2. High concentration of pollutants: Compared with coking wastewater, the concentration of organic substances, phenolic compounds and volatile substances in semi-coke wastewater is higher, making the treatment process more difficult. 3. Variable water quality conditions: The water quality of semi-coke wastewater fluctuates greatly and is affected by the production process and raw materials. The treatment process needs to be flexibly adjusted to cope with different water quality conditions.

[0004] Due to the special properties of lignite wastewater, traditional coking wastewater treatment processes are often unable to adapt to the treatment needs of lignite wastewater. Traditional treatment processes have the following problems: 1. Low treatment efficiency: Existing treatment methods are often unable to efficiently degrade organic matter and phenolic compounds in lignite wastewater, resulting in treatment effects that cannot meet environmental emission standards. 2. Unstable treatment effects: Traditional biological treatment methods are sensitive to water quality fluctuations. When water quality changes, the treatment effect is difficult to maintain stability. 3. High cost and waste generation: Existing physical and chemical treatment methods often require a large amount of chemical input and waste generation, which increases the cost of wastewater treatment and produces secondary pollution. Summary of the invention

[0005] In order to solve at least one of the above technical problems, the present disclosure provides a multiple physicochemical-biochemical coupled blue charcoal wastewater treatment system and its application.

[0006] As one aspect, the present disclosure provides a multiple physical, chemical and biochemical coupled lignite wastewater treatment system, the lignite wastewater treatment system comprising an oil removal module, a phenol-ammonia treatment module, a biochemical treatment module and a deep treatment module; the oil removal module comprises a gravity oil removal unit and a flotation oil removal unit; the phenol-ammonia treatment module comprises one or more of a single-tower ammonia evaporation deacidification unit, an extraction dephenolization unit, and a resin adsorption dephenolization unit; the biochemical treatment module comprises one or more hydrolysis acidification units, one or more biological thickening units, one or more iron-carbon micro-electrolysis units, and one or more A / O units; wherein the combination mode between different units of the biochemical treatment module can be flexibly adjusted; the deep treatment module comprises one or more ozone flotation units; wherein, in the ozone flotation unit, ozone, coagulation, and flotation act simultaneously in the same system to form a multi-coupled system.

[0007] As one aspect, the present disclosure provides a method for treating lignite wastewater, which is carried out using the above-mentioned multiple physicochemical-biochemical coupled lignite wastewater treatment system; the treatment method comprises the following steps: pre-treating the lignite wastewater through an oil removal module; removing ammonia nitrogen and phenolic pollutants from the lignite wastewater through a phenol-ammonia treatment module, wherein the phenol-ammonia treatment module comprises at least two of a single-tower ammonia evaporation deacidification unit, an extraction dephenolization unit and a resin adsorption dephenolization unit; removing residual emulsified oil from the lignite wastewater through an oil removal module; removing residual toxic substances and ammonia nitrogen from the lignite wastewater through a biochemical treatment module, wherein the biochemical treatment module comprises one or more hydrolysis acidification units, one or more biological thickening units, one or more iron-carbon micro-electrolysis units, and one or more A / O units; treating the lignite wastewater through a deep treatment module in a multi-coupled system in which ozone, coagulation and flotation act simultaneously.

[0008] As yet another aspect, the present disclosure provides an application of the above-mentioned lignite wastewater treatment system or the above-mentioned lignite wastewater treatment method in treating lignite wastewater.

[0009] The technical solution of the embodiment of the present disclosure has the following advantages:

[0010] (1) High-efficiency treatment capability: The lignite wastewater treatment system and its application of the disclosed embodiments combine physicochemical methods with biochemical methods, utilize physicochemical reactions to perform preliminary treatment in wastewater, remove most organic matter and phenolic compounds, and then further degrade the organic matter in the wastewater through biochemical reactions, thereby significantly improving the treatment efficiency and being able to efficiently remove harmful substances in lignite wastewater.

[0011] (2) Flexible adjustment and stable treatment effect: The lignite wastewater treatment system and its application of the disclosed embodiment can be flexibly adjusted according to the characteristics of the lignite wastewater and water quality fluctuations through adjustable process flow and parameters to achieve the best treatment effect, and can stably treat the lignite wastewater and meet the emission standards.

[0012] (3) Reducing treatment costs: The lignite wastewater treatment system and its application of the disclosed embodiment utilize the complementary characteristics of physicochemical methods and biochemical methods, reduce the demand for chemicals, reduce treatment costs, and reduce waste generation, which is beneficial to reducing secondary pollution to the environment.

[0013] (4) Environmental friendliness: The lignite wastewater treatment system and its application according to the disclosed embodiment can completely degrade harmful substances in the lignite wastewater, so that the discharge of the treated lignite wastewater meets environmental requirements and reduces the negative impact on water resources and the ecological environment.

[0014] (5) Wide applicability: The lignite wastewater treatment system and its application according to the disclosed embodiment can not only efficiently purify lignite wastewater and help the lignite industry achieve green transformation and sustainable development, but its advanced technology and design concept can also be flexibly applied to similar industrial wastewater treatment scenarios, providing solutions for wastewater management in multiple fields such as chemical industry, metallurgy, and energy.

[0015] In summary, the lignite wastewater treatment system and its application of the disclosed embodiments provide the lignite industry with an efficient, stable, environmentally friendly and economically practical lignite wastewater treatment method. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0017] 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.

[0018] Figure 1 A schematic diagram of a blue carbon wastewater treatment system according to an embodiment of the present disclosure;

[0019] Figure 2 This is a schematic diagram of the operation flow of an embodiment of the combination method I between the various units of the biochemical treatment module in the method for treating lignite wastewater of Example 3 of the present disclosure.

[0020] Reference numerals:

[0021] 1- Gravity oil removal unit; 2- Single tower ammonia distillation deacidification unit; 3- Extraction dephenolization unit; 4- Resin adsorption dephenolization unit; 5- Flotation oil removal unit; 6- Hydrolysis acidification unit; 7- Biothickening unit; 8- Iron-carbon micro-electrolysis unit; 9- A / O unit, 10- Ozone flotation unit. DETAILED DESCRIPTION

[0022] In order to more clearly understand the above-mentioned objectives, features and advantages of the present disclosure, the scheme of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0023] In the following description, many specific details are set forth to facilitate a full understanding of the present disclosure, but the present disclosure 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 disclosure, rather than all of the embodiments.

[0024] According to an embodiment of one aspect of the present disclosure, a multiple physicochemical-biochemical coupled semi-coke wastewater treatment system is provided, the semi-coke wastewater treatment system comprising an oil removal module, a phenol-ammonia treatment module, a biochemical treatment module and a deep treatment module; the oil removal module comprises a gravity oil removal unit and a flotation oil removal unit; the phenol-ammonia treatment module comprises one or more of a single-tower ammonia evaporation deacidification unit, an extraction dephenolization unit, and a resin adsorption dephenolization unit; the biochemical treatment module comprises one or more hydrolysis acidification units, one or more biological thickening units, one or more iron-carbon micro-electrolysis units, and one or more A / O units; wherein the combination mode between different units of the biochemical treatment module can be flexibly adjusted; the deep treatment module comprises one or more ozone flotation units; wherein, in the ozone flotation unit, ozone, coagulation, and flotation act simultaneously in the same system to form a multi-coupled system.

[0025] In the lignite wastewater treatment system of the disclosed embodiment, different modules are used to treat different pollutants, and the combination of the treatment units can be flexibly adjusted. The advantages of the physicochemical method and the biological method can be fully utilized to effectively solve the problems existing in the lignite wastewater treatment process, improve the treatment efficiency and stability, and reduce the wastewater treatment cost and the generation of secondary pollution, thereby achieving efficient treatment of lignite wastewater containing pollutants such as organic matter, nitrogen, and phosphorus, and promoting the healthy, green, and sustainable development of the lignite industry; this is of great significance to the sustainable development of the lignite industry.

[0026] In some embodiments of the present disclosure, the oil removal module includes at least one of a gravity oil removal unit and a flotation oil removal unit. The oil removal module is mainly used to remove heavy oil mainly composed of condensed aromatic hydrocarbons, light oil mainly composed of straight-chain hydrocarbons, and emulsified oil in lignite wastewater.

[0027] In some embodiments of the present disclosure, the gravity oil removal unit in the oil removal module is used for pretreatment of raw water, and the flotation oil removal unit uses air flotation to further remove the residual emulsified oil in the lignite wastewater obtained after the phenol-ammonia treatment module's evaporation of phenol and amine.

[0028] In some embodiments of the present disclosure, the phenol-ammonia treatment module includes at least one of a single-tower ammonia evaporation and deacidification unit, an extraction dephenolization unit, and a resin adsorption dephenolization unit. The phenol-ammonia treatment module is mainly used to remove ammonia nitrogen and phenol pollutants in lignite wastewater.

[0029] In some embodiments of the present disclosure, ammonia is removed from the phenol-ammonia treatment module using a single-tower ammonia evaporation and deacidification unit, and after deamination, phenolic pollutants are removed using one or both of an extraction dephenolization unit and a resin adsorption dephenolization unit.

[0030] In some embodiments of the present disclosure, the resin used in the resin adsorption dephenolization unit is LS-106, with a water content of 50-60%, a phenol adsorption capacity of ≥100 g / L, an average pore size of 3.9-4.5 nm, and a pore volume of 1.0-1.3 cm 3 / g, specific surface area ≥1200m 2 / g, wet true density 1.01~1.08g / mL, wet apparent density 0.65~0.75g / mL.

[0031] In some embodiments of the present disclosure, the biochemical treatment module includes one or more hydrolysis acidification units, one or more biological thickening units, one or more iron-carbon micro-electrolysis units, and one or more A / O units. The biochemical treatment module is mainly used to remove residual phenol-amine and cyanide pollutants, polycyclic aromatic hydrocarbons, and toxic substances such as heterocyclic compounds containing nitrogen, oxygen, and sulfur in the lignite wastewater.

[0032] In some embodiments of the present disclosure, the biothickening unit is made to have more outstanding physical properties and biocompatibility by adding high-efficiency denitrification biological materials, wherein the amount of microbial attachment is increased by 2.1 times, functional bacteria enrichment is achieved, carbon sources are saved, and energy consumption is reduced.

[0033] In some embodiments of the present disclosure, denitrification biological material is added to the biothickening unit, wherein the denitrification biological material is a granular composite biological carrier synthesized from one or more of polyvinyl alcohol, phytic acid, and iron.

[0034] In some embodiments of the present disclosure, in the iron-carbon micro-electrolysis unit, the pH is adjusted by adding sulfuric acid.

[0035] In some embodiments of the present disclosure, in the biochemical treatment module, first, through a variety of pretreatment methods combined between different units such as flotation oil removal units and iron-carbon micro-electrolysis units, the toxicity of lignite wastewater is reduced, and the chroma and chemical oxygen demand (COD) of the lignite wastewater are greatly reduced; then, through the "multiple hydrolysis acidification units + biological thickening units" process, the insoluble organic matter and toxic organic matter in the lignite wastewater are hydrolyzed into small molecular organic matter that is easy to biodegrade, thereby further improving the biodegradability of the lignite wastewater. The lignite wastewater after the above combined pretreatment is then subjected to the biochemical treatment of "multiple A / O units (anoxic denitrification + aerobic nitrification units)".

[0036] In some embodiments of the present disclosure, the A / O unit includes an A unit and an O unit. The A / O unit is an anoxic denitrification + aerobic nitrification unit, the A unit is an anoxic denitrification unit, and the O unit is an aerobic nitrification unit.

[0037] In some embodiments of the present disclosure, at least one sedimentation tank is set after the biological thickening unit; and / or, at least one sedimentation tank and at least one secondary sedimentation tank are set after the biological thickening unit; and / or, at least one sedimentation tank is set after the A / O unit; and / or, at least one sedimentation tank and at least one secondary sedimentation tank are set after the A / O unit.

[0038] In some embodiments of the present disclosure, a sedimentation tank and / or a secondary sedimentation tank may be provided after the biological thickening unit and the A / O unit. The specific judgment is based on the actual situation. The present disclosure does not make too many limitations, and only the following exemplary examples are given:

[0039] In some embodiments of the present disclosure, a sedimentation tank and multiple secondary sedimentation tanks are provided after the biological thickening unit; multiple sedimentation tanks and one secondary sedimentation tank are provided after the biological thickening unit; multiple sedimentation tanks and multiple secondary sedimentation tanks are provided after the biological thickening unit.

[0040] In some embodiments of the present disclosure, a sedimentation tank and multiple secondary sedimentation tanks are provided after the A / O unit; multiple sedimentation tanks and one secondary sedimentation tank are provided after the A / O unit; multiple sedimentation tanks and multiple secondary sedimentation tanks are provided after the A / O unit.

[0041] In some embodiments of the present disclosure, the deep treatment module includes an ozone flotation unit, which is formed by coupling ozone catalytic oxidation and coagulation. The deep treatment module is mainly used to remove high-chroma stubborn pollutants in blue carbon wastewater.

[0042] In some embodiments of the present disclosure, the deep treatment module uses a multi-coupled integrated ozone flotation technology that combines ozone catalytic oxidation with a coagulation process to further remove biochemical effluent and ensure the harmlessness of the final treated effluent.

[0043] In some embodiments of the present disclosure, the multi-coupled integrated ozone flotation technology refers to the simultaneous action of ozone, coagulation, and flotation in the same system to form a multi-coupled system; compared with traditional technologies, the multi-coupled integrated ozone flotation technology has a processing efficiency that is increased by 2 times, energy consumption is reduced by 25%, operating costs are reduced by 40%, residence time is shortened by 25%, and the footprint is reduced by 75%.

[0044] In some embodiments of the present disclosure, in the multi-coupled integrated ozone flotation technology, the agent added for coagulation is one or more of polyaluminium chloride (PAC) and polyacrylamide (PAM); preferably, polyaluminium chloride (PAC).

[0045] According to an embodiment of the present disclosure, a method for treating lignite wastewater is provided, and the treatment method is carried out by using the above-mentioned multiple physicochemical-biochemical coupled lignite wastewater treatment system; the treatment method comprises the following steps: the lignite wastewater is pretreated by an oil removal module; the lignite wastewater is passed through a phenol-ammonia treatment module to remove ammonia nitrogen and phenolic pollutants in the lignite wastewater, wherein the phenol-ammonia treatment module comprises a single-tower ammonia evaporation deacidification unit, an extraction dephenolization unit and a resin adsorption dephenolization unit connected in sequence; the lignite wastewater is passed through an oil removal module to remove residual emulsified oil in the lignite wastewater; the lignite wastewater is passed through a biochemical treatment module to remove residual toxic substances and ammonia nitrogen in the lignite wastewater, wherein the biochemical treatment module comprises one or more hydrolysis acidification units, one or more biological thickening units, one or more iron-carbon micro-electrolysis units, and one or more A / O units; the lignite wastewater is treated through a deep treatment module in a multi-coupled system in which ozone, coagulation and flotation act simultaneously.

[0046] In some embodiments of the present disclosure, a method for treating lignite wastewater includes the following steps: the lignite wastewater is pretreated by a gravity oil removal unit; the pretreated lignite wastewater enters a phenol-ammonia treatment module, and sequentially passes through one or more single-tower ammonia distillation and deacidification units, one or more extraction dephenolization units, and one or more resin adsorption dephenolization units in the phenol-ammonia treatment module to remove ammonia nitrogen and phenolic pollutants in the lignite wastewater; the lignite wastewater treated by the phenol-ammonia treatment module enters an air flotation oil removal unit in an oil removal module to remove residual emulsified oil in the lignite wastewater after passing through the phenol-ammonia treatment module; the lignite wastewater is sequentially passed through one or more hydrolysis acidification units, one or more biological thickening units, one or more iron-carbon micro-electrolysis units, and one or more A / O units in a bio-treatment module to remove toxic substances in the lignite wastewater; the lignite wastewater passes through an ozone flotation unit in a deep treatment module to remove high-chroma stubborn pollutants in the lignite wastewater.

[0047] In some embodiments of the present disclosure, in a method for treating lignite wastewater as mentioned above, during the process of pre-treatment of lignite wastewater by steaming aminophenol and extracting phenol through a phenol-ammonia treatment module, after the lignite wastewater passes through a single-tower steaming aminophenol deacidification unit, the outlet water temperature of the lignite wastewater is generally around 60-90°C, and before entering the extraction dephenolization unit and / or the resin adsorption dephenolization unit, the temperature of the lignite wastewater needs to be cooled to between 20 and 40°C, for example, it can be 21.6°C, 24.3°C, 27.9°C, 29.3°C, 32.6°C, 37.6°C, 39.8°C, etc. When the temperature is in the range of 20 to 40°C, it can provide better dephenolization effect and operational stability, the physical properties and chemical reaction effects of the solvent or adsorbent and the substance to be dephenolized are better, and the dephenolization efficiency can be increased. For example, the temperature of the semi-carbon wastewater entering the extraction dephenolization unit and / or the resin adsorption dephenolization unit is selected from any one of 21°C, 23°C, 26°C, 29°C, 31°C, 36°C, and 39°C.

[0048] In some embodiments of the present disclosure, in a method for treating lignite wastewater as described above, during the process of pre-treatment of lignite wastewater by steaming amino acids and extracting phenols through a phenol-ammonia treatment module, the following situations are included: (1) when the water quality is stable, the phenol-ammonia treatment module includes a single-tower steaming amino acid removal unit and an extraction dephenolization unit connected in sequence; (2) when the water quality exceeds the standard, the phenol-ammonia treatment module includes a single-tower steaming amino acid removal unit, an extraction dephenolization unit and a resin adsorption dephenolization unit connected in sequence.

[0049] In some embodiments of the present disclosure, in the above-mentioned method for treating blue carbon wastewater, the treatment of blue carbon wastewater adopts a method combining "oil removal pretreatment (carried out by oil removal module) + evaporation of aminophenol pretreatment (carried out by phenol-ammonia treatment module) + biochemical treatment (carried out by biochemical treatment module)". After the blue carbon wastewater "oil removal pretreatment + evaporation of aminophenol pretreatment", the COD, phenol, NH3-N and petroleum pollution index contents in the effluent of blue carbon wastewater are up to 5000mg / L, 600mg / L, 300mg / L and 50mg / L respectively, and biochemical treatment cannot be directly carried out. It is also necessary to carry out multiple pretreatment methods such as treatment by oil removal module, treatment by hydrolysis acidification unit and pretreatment by iron-carbon micro-electrolysis unit to further improve the biodegradability of blue carbon wastewater.

[0050] In some embodiments of the present disclosure, in the above-mentioned blue carbon wastewater treatment method, the combination mode between the various units of the biochemical treatment module can be adjusted. Therefore, the oil removal module (i.e., pre-detoxification process), the biochemical treatment module (i.e., biochemical treatment process), and the deep treatment module (i.e., deep treatment process) before the biochemical treatment module can be flexibly combined and adjusted, that is, the combination mode between the various units of the oil removal module, the biochemical treatment module, and the deep treatment module can be changed and flexibly adjusted.

[0051] In some embodiments of the present invention, the combination of the various units is selected according to the on-site conditions such as the water quality and water quantity of the lignite wastewater; wherein the combination of the various units refers to the order in which the lignite wastewater passes through the oil removal module, the biochemical treatment module and the deep treatment module.

[0052] In some embodiments of the present disclosure, the semi-coke wastewater passes through an oil removal module (wherein the oil removal module is a dissolved air flotation oil removal unit), a biochemical treatment module and a deep treatment module (wherein the deep treatment module is an ozone flotation unit), and the combination of the various units passed through is selected from one or more of the following methods:

[0053] Combination method I-1: dissolved air flotation oil removal unit → first stage hydrolysis acidification unit → second stage hydrolysis acidification unit → biological thickening unit → first stage iron-carbon micro-electrolysis unit → first stage A / O unit → second stage A / O unit → second stage iron-carbon micro-electrolysis unit → ozone flotation unit;

[0054] Combination II-1: dissolved air flotation oil removal unit → primary iron-carbon micro-electrolysis unit → secondary iron-carbon micro-electrolysis unit → primary hydrolysis acidification unit → secondary hydrolysis acidification unit → biological thickening unit → primary A / O unit → secondary A / O unit → ozone flotation unit;

[0055] Combination III-1: dissolved air flotation oil removal unit → first stage hydrolysis acidification unit → second stage hydrolysis acidification unit → biological thickening unit → first stage A / O unit → second stage A / O unit → first stage iron-carbon micro-electrolysis unit → second stage iron-carbon micro-electrolysis unit → ozone flotation unit.

[0056] In some embodiments of the present disclosure, at least one sedimentation tank and / or at least one secondary sedimentation tank is arranged after the biological thickening unit; at least one sedimentation tank and / or at least one secondary sedimentation tank is arranged after the secondary A / O unit; the residual sludge produced in the sedimentation tank and / or the secondary sedimentation tank and the sludge and scum produced in the iron-carbon micro-electrolysis tank and the ozone flotation treatment process are all transported to the sludge tank and reach the screw dewatering machine through the lifting pump, and the generated leachate is returned to the biochemical water inlet regulating tank.

[0057] In some embodiments of the present disclosure, part of the effluent of the lignite wastewater from the biological thickening unit is returned to the first hydrolysis acidification unit; part of the effluent of the lignite wastewater from the secondary sedimentation tank is returned to the first hydrolysis acidification unit after passing through the intermediate water tank; part of the effluent of the lignite wastewater from the sedimentation tank is returned to the first hydrolysis acidification unit and the biological thickening tank.

[0058] In some embodiments of the present disclosure, the residence times of the first-stage hydrolysis acidification unit, the second-stage hydrolysis acidification unit, the biological thickening unit, the first-stage iron-carbon micro-electrolysis unit, the second-stage iron-carbon micro-electrolysis unit, the first-stage A / O unit, the second-stage A / O unit and the ozone flotation unit are 12 h, 12 h, 24 h, 2 h, 2 h, 12 h, 12 h and 2 h, respectively.

[0059] In some embodiments of the present disclosure, the COD volumetric loading rates of the first hydrolysis acidification unit, the second hydrolysis acidification unit, the biothickening unit, the first A / O unit, and the second A / O unit are 1.2 kg / (m 3 ·d)、1.0kg / (m 3 ·d)、1.3kg / (m 3 ·d)、0.7kg / (m 3 ·d)、0.6kg / (m 3 ·d).

[0060] In some embodiments of the present disclosure, a regulating tank is provided in front of the biochemical treatment module, and a demulsifier is added into the regulating tank to remove residual emulsified oil pollutants in the lignite wastewater after treatment by the front-end oil removal module, wherein the dosage of the demulsifier is 300 mg / L and the dissolved air ratio is 30%.

[0061] In some embodiments of the present disclosure, considering that the raw water quality may be lower than the designed water quality during actual operation, some processes may exceed the operating capacity and may be discharged directly without going through the deep treatment module.

[0062] In some embodiments of the present disclosure, when the above-mentioned lignite wastewater treatment system or lignite wastewater treatment method is used, the treated lignite wastewater is tested, and the changes in water quality in each monomer structure are detected in real time through an automated monitoring system. The process is flexibly adjusted according to the water quality, thereby achieving efficient, stable and low-cost treatment of lignite wastewater. The final effluent water quality meets the emission standard requirements of the national standard "Pollutant Emission Standard for Coking Chemical Industry" (GB16171-2012), and the specific parameters are shown in Table 1.

[0063] Table 1 GB16171-2012 Discharge Standards for Semi-coal Wastewater

[0064]

[0065] The scheme of the present disclosure is further illustrated by the following examples.

[0066] Example 1

[0067] A treatment system for blue carbon wastewater

[0068] This embodiment provides a blue carbon wastewater treatment system coupled with multiple physicochemical and biochemical reactions. The schematic diagram of the blue carbon wastewater treatment system is as follows: Figure 1 As shown. The semi-coke wastewater treatment system includes a gravity oil removal unit 1, a phenol-ammonia treatment module, a flotation oil removal unit 5, a biochemical treatment module and a deep treatment module which are connected in sequence. Among them, the phenol-ammonia treatment module includes a single-tower ammonia evaporation deacidification unit 2, an extraction dephenolization unit 3 and a resin adsorption dephenolization unit 4. The biochemical treatment module includes a hydrolysis acidification unit 6, a biological thickening unit 7, an iron-carbon micro-electrolysis unit 8 and two A / O units (9). The deep treatment module includes an ozone flotation unit 10.

[0069] Example 2

[0070] A method for treating blue carbon wastewater using a blue carbon wastewater treatment system

[0071] This embodiment provides a method for treating blue carbon wastewater using the above-mentioned treatment system, comprising the steps of:

[0072] S1: The semi-coke wastewater is pre-treated by the gravity oil removal unit 1 in the oil removal module;

[0073] S2: The pretreated blue carbon wastewater obtained in step S1 is sequentially processed by a single-tower ammonia distillation deacidification unit 2, an extraction dephenolization unit 3, and a resin adsorption dephenolization unit 4 in the phenol-ammonia treatment module to remove ammonia nitrogen and phenolic pollutants in the blue carbon wastewater;

[0074] S3: the semi-coke wastewater obtained in step S2 enters the flotation oil removal unit 5 in the oil removal module to remove the residual emulsified oil in the semi-coke wastewater after the phenol-ammonia treatment module evaporates the phenol;

[0075] S4: The semi-carbon wastewater obtained in step S3 is processed by the hydrolysis acidification unit 6, the biological thickening unit 7, the iron-carbon micro-electrolysis unit 8, and the two A / O units 9 in the biochemical treatment module in turn to remove toxic substances in the semi-carbon wastewater; wherein, the biological thickening unit 7 adds a high-efficiency denitrification biological material (the denitrification biological material is a composite biological carrier synthesized from one or more of polyvinyl alcohol, phytic acid, and iron; wherein the composite biological carrier is in the shape of spherical particles), and the iron-carbon micro-electrolysis unit 8 adjusts the pH of the primary iron-carbon micro-electrolysis unit to 4-4.5 by adding sulfuric acid, and the pH of the secondary iron-carbon micro-electrolysis unit to 4.5-5;

[0076] S5: The semi-coke wastewater obtained in step S4 is treated by the ozone flotation unit 10 in the deep treatment module to remove high-chroma stubborn pollutants in the semi-coke wastewater; the added reagents in the ozone flotation unit 10 are polyaluminium chloride (PAC) and polyacrylamide (PAM).

[0077] S6: Determine the pollutant content of the semi-coke wastewater obtained in step S4.

[0078] Example 3

[0079] This embodiment provides a process for treating a certain semi-coal wastewater using the treatment method provided in Example 2, wherein the semi-coal wastewater passes through the oil removal module, the biochemical treatment module and the deep treatment module, and the combination mode between the various units is combination mode I; the specific treatment process is as follows Figure 2 shown.

[0080] like Figure 2 As shown, the semi-coke wastewater is pretreated by the oil removal module and the phenol-ammonia treatment module. The effluent of the semi-coke wastewater after the phenol-ammonia treatment module's evaporation and phenol extraction action enters the regulating tank, and enters the dissolved air flotation device (i.e., the flotation oil removal unit in the oil removal module) through the lifting pump to remove residual oil pollutants. The effluent of the semi-coke wastewater of the dissolved air flotation device (i.e., the flotation oil removal unit in the oil removal module) enters the first hydrolysis acidification tank (i.e., the first hydrolysis acidification unit), the second hydrolysis acidification tank (i.e., the second hydrolysis acidification unit), the biological thickening tank (i.e., the biological thickening unit), and the sedimentation tank in turn. The sedimentation tank is provided with a reflux pipe to the first hydrolysis acidification tank and the biological thickening tank respectively. The sedimentation tank The effluent of the lignite wastewater in the pool enters the primary iron-carbon micro-electrolysis pool (i.e., iron-carbon micro-electrolysis unit), the primary A / O pool (i.e., A / O unit), the secondary A / O pool (i.e., A / O unit), and the secondary sedimentation tank in sequence through a lifting pump. A reflux pipe is provided in the secondary sedimentation tank to flow back to the primary A pool (i.e., A unit). A reflux pipe is provided in the A / O pool (i.e., A / O unit) to flow the O pool (i.e., O unit) back to the A pool (i.e., A unit). The effluent of the lignite wastewater in the secondary sedimentation tank enters the secondary iron-carbon micro-electrolysis pool (i.e., iron-carbon micro-electrolysis unit) and the ozone flotation unit (i.e., enters the deep treatment module for ozone catalytic oxidation) in sequence through a lifting pump, and finally meets the emission standards. Among them, the pH of the iron-carbon micro-electrolysis unit is adjusted by a sulfuric acid dosing device, and the pH of the effluent of the semi-carbon wastewater of the iron-carbon micro-electrolysis unit is adjusted by an alkali dosing device (30% sodium hydroxide) to ensure the normal operation of the treatment process of the subsequent biochemical treatment module; the sludge produced in the iron-carbon micro-electrolysis cell (i.e.: iron-carbon micro-electrolysis unit) and the ozone flotation unit (i.e.: deep treatment module) is transported to the sludge pool through the sludge and slag discharge pipe, and enters the screw press dehydrator for further dehydration through the lifting pump. Among them, the treatment time of the first hydrolysis acidification tank, the second hydrolysis acidification tank, the biological thickening tank, the first iron-carbon micro-electrolysis cell, the second iron-carbon micro-electrolysis cell, the first A / O cell, the second A / O cell and the ozone flotation unit of the deep treatment module are 12h, 12h, 24h, 2h, 2h, 12h, 12h and 2h respectively.

[0081] The water quality of the blue carbon wastewater before and after the blue carbon wastewater is treated by the blue carbon wastewater treatment system of Example 1 is shown in Table 2. It can be seen that after being treated by the blue carbon wastewater treatment system of physicochemical reaction-biochemical reaction-deep treatment, all kinds of pollutants in the blue carbon wastewater are efficiently removed, and the treatment results meet the limits in Table 1.

[0082] Table 2 Results of blue carbon wastewater after system treatment in Example 3

[0083]

[0084] The disclosed embodiments provide a multiple physicochemical-biochemical coupled lignite wastewater treatment system and its application, wherein the lignite wastewater treatment system comprises a treatment system including an oil removal module, a phenol-ammonia treatment module, a biochemical treatment module and a deep treatment module; different modules treat different pollutants, and the process flow of each treatment unit can be flexibly adjusted, so as to fully utilize the advantages of physicochemical and biological treatment methods, effectively solve the problems existing in the lignite wastewater treatment process, improve treatment efficiency and stability, and reduce wastewater treatment costs and the generation of secondary pollution.

[0085] The multiple physical, chemical and biochemical coupled lignite wastewater treatment system and its application of the disclosed embodiments can flexibly adjust the process sequence according to the treated water quality to solve the defects in the treatment process caused by water quality fluctuations, ensure the efficient removal of pollutants such as oils, phenols, ammonia nitrogen, etc., and realize the resource utilization and harmless treatment of lignite wastewater. It has the advantages of low cost, high efficiency and energy saving, environmental sustainability, and stable treatment effect. It effectively solves the problems existing in the treatment of lignite wastewater, and provides the lignite industry with an efficient, stable, environmentally friendly and economically practical wastewater treatment method.

[0086] 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.

[0087] The above description is only a specific embodiment of the present disclosure, so that those skilled in the art can understand or implement the present disclosure. 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 disclosure. Therefore, the present disclosure will not be limited to the embodiments described herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A multiple physical-chemical-biochemical coupled blue carbon wastewater treatment system, characterized in that: The blue carbon wastewater treatment system includes an oil removal module, a phenol-ammonia treatment module, a biochemical treatment module and a deep treatment module; The oil removal module includes a gravity oil removal unit and an air flotation oil removal unit; The phenol-ammonia treatment module includes one or more of a single-tower ammonia distillation and deacidification unit, an extraction dephenolization unit, and a resin adsorption dephenolization unit; The biochemical treatment module includes one or more hydrolysis acidification units, one or more biothickening units, one or more iron-carbon micro-electrolysis units, and one or more A / O units; Wherein, the combination mode between different units of the biochemical treatment module can be flexibly adjusted; The deep processing module includes one or more ozone flotation units; Wherein, in the ozone flotation unit, ozone, coagulation and flotation act simultaneously in the same system to form a multi-element coupling system.

2. The multiple physical-chemical-biochemical coupled blue carbon wastewater treatment system according to claim 1 is characterized in that: The oil removal module is used to remove heavy oil, light oil and emulsified oil from the semi-coke wastewater; And / or, the oil removal module includes one or more of a gravity oil removal unit and an air flotation oil removal unit.

3. The multiple physical-chemical-biochemical coupled blue carbon wastewater treatment system according to claim 1 or 2, characterized in that: The phenol-ammonia treatment module is used to remove ammonia nitrogen and phenol pollutants in the blue carbon wastewater; And / or, the biochemical treatment module is used to remove residual toxic substances in the blue carbon wastewater, and the toxic substances include one or more of phenol-amine and cyanide pollutants, polycyclic aromatic hydrocarbons and heterocyclic compounds containing nitrogen, oxygen and sulfur.

4. The multiple physical-chemical-biochemical coupled blue carbon wastewater treatment system according to any one of claims 1 to 3, characterized in that: The deep treatment module is mainly used to remove stubborn pollutants in the blue carbon wastewater.

5. The multiple physical-chemical-biochemical coupled blue carbon wastewater treatment system according to any one of claims 1 to 4, characterized in that: At least one sedimentation tank is arranged after the biothickening unit; and / or, at least one sedimentation tank and at least one secondary sedimentation tank are arranged after the biothickening unit; And / or, at least one sedimentation tank is arranged after the A / O unit; And / or, at least one sedimentation tank and at least one secondary sedimentation tank are arranged after the A / O unit.

6. The multiple physical-chemical-biochemical coupled blue carbon wastewater treatment system according to any one of claims 1 to 5, characterized in that: The combination of the various units of the biochemical treatment module includes: Combination method I: one or more hydrolysis acidification units, one or more biothickening units, one or more iron-carbon micro-electrolysis units, one or more A / O units, and one or more iron-carbon micro-electrolysis units connected in sequence; and / or, combination II: one or more iron-carbon micro-electrolysis units, one or more hydrolysis acidification units, one or more biothickening units, and one or more A / O units connected in sequence; And / or, combination III: one or more hydrolysis acidification units, one or more biothickening units, one or more A / O units, and one or more iron-carbon micro-electrolysis units connected in sequence.

7. A method for treating blue carbon wastewater, characterized in that: The treatment method is carried out using the multiple physical-chemical-biochemical coupled blue carbon wastewater treatment system according to any one of claims 1 to 6; The processing method comprises the steps of: The semi-coal wastewater is pre-treated through the oil removal module; The semi-coke wastewater is passed through a phenol-ammonia treatment module to remove ammonia nitrogen and phenolic pollutants in the semi-coke wastewater, wherein the phenol-ammonia treatment module includes at least two of a single-tower ammonia evaporation deacidification unit, an extraction dephenolization unit, and a resin adsorption dephenolization unit; The semi-coke wastewater passes through the oil removal module to remove the residual emulsified oil in the semi-coke wastewater; The semi-carbon wastewater is passed through a biochemical treatment module to remove residual toxic substances and ammonia nitrogen in the semi-carbon wastewater, wherein the biochemical treatment module includes one or more hydrolysis acidification units, one or more biological thickening units, one or more iron-carbon micro-electrolysis units, and one or more A / O units; The semi-coke wastewater is treated through a deep treatment module in a multi-coupled system where ozone, coagulation and flotation act simultaneously.

8. The method for treating blue carbon wastewater according to claim 7, characterized in that: The filling material in the resin adsorption dephenolization unit is resin, wherein the water content of the resin is 50-60%, the phenol adsorption capacity is ≥100g / L, the average pore diameter is 3.9-4.5nm, and the pore volume is 1.0-1.3cm 3 / g, specific surface area ≥1200m 2 / g, wet true density 1.01~1.08g / mL, wet apparent density 0.65~0.75g / mL.

9. The method for treating blue carbon wastewater according to claim 7 or 8, characterized in that: Adding denitrification biological material in the biological thickening unit, wherein the denitrification biological material is a granular composite biological carrier synthesized from one or more of polyvinyl alcohol, phytic acid, and iron; and / or, the pH of the iron-carbon micro-electrolysis unit is adjusted using an acid, preferably sulfuric acid; And / or, a reagent is added to the ozone flotation unit, and the reagent includes one or more of polyaluminium chloride (PAC) and polyacrylamide (PAM).

10. Use of the semi-coke wastewater treatment system according to any one of claims 1 to 6 or the semi-coke wastewater treatment method according to any one of claims 7 to 9 in treating semi-coke wastewater.

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