Biological contact oxidation method and system

Abstract

The invention provides a biological contact oxidation method and a biological contact oxidation system, which are applied to the technical field of water pollution control and treatment, and the method comprises the following steps: introducing sewage into a reaction tank of the biological contact oxidation system, and treating the sewage based on an iron-carbon filler and activated sludge in the reaction tank; wherein microorganisms in the iron-carbon filler and the activated sludge are subjected to a coupling reaction to jointly treat the sewage. According to the biological contact oxidation method and system provided by the invention, an acidic biofilm is formed on the surface of the iron-carbon filler by using microorganisms to provide an acidic environment and promote the generation of micro-electrolysis, decomposed iron ions can enhance the settling performance of activated sludge and enhance the sewage dephosphorization effect, and activated carbon can adsorb pollutants in sewage, so that the sewage treatment effect is improved. The sewage purification effect is improved. The iron-carbon filler has the effect of promoting short-cut nitrification and denitrification of microorganisms, the required aeration rate is low, and energy conservation and consumption reduction are facilitated. The whole process does not need to add an acid-base agent, so that the process is simplified, and the influence on the sewage purification effect is avoided.

Description

Technical Field

[0001] The present disclosure relates to the technical field of water pollution control and treatment, and more specifically, to a biological contact oxidation method and system. Background Art

[0002] Adding various agents or fillers to sewage to reduce the concentration of pollutants in sewage is a common water treatment technology. Common water treatment fillers include ceramsite, soft fillers, semi-soft fillers, elastic three-dimensional fillers, etc., all of which aim to increase the amount of microbial biofilm and improve water treatment efficiency by increasing the amount of microorganisms per unit area.

[0003] Studies have found that iron-carbon can be used for sewage treatment through micro-electrolysis technology, and has a good sewage treatment effect. However, due to the high pH value requirements of the treatment environment, iron-carbon needs to add acid / alkali when using iron-carbon fillers for sewage treatment. The treatment process is relatively complicated and there are certain safety hazards. Therefore, iron-carbon is currently often used in the form of physical and chemical reactors for the pretreatment of high-concentration or high-difficulty wastewater, and has not been used in conventional sewage treatment. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] The present disclosure provides a biological contact oxidation method and system for at least partially solving one of the above-mentioned technical problems.

[0006] (II) Technical solution

[0007] A first aspect of the present disclosure provides a biological contact oxidation method, which includes: introducing sewage into a reaction tank of a biological contact oxidation system, and treating the sewage based on iron-carbon fillers and activated sludge in the reaction tank; wherein the iron-carbon fillers and microorganisms in the activated sludge undergo a coupled reaction to jointly treat the sewage.

[0008] According to an embodiment of the present disclosure, the method further includes: during the sewage treatment process, continuously aerating the reaction tank based on an aerator.

[0009] According to the embodiments of the present disclosure, during the sewage treatment process, microorganisms in the activated sludge attach to the iron-carbon filler, produce acidic intermediate metabolites, and provide an acidic environment for the iron-carbon filler; the iron-carbon filler undergoes micro-electrolysis in the acidic environment, decomposing into iron ions and activated carbon, and the sewage is treated based on the iron ions and activated carbon.

[0010] A second aspect of the present disclosure provides a biological contact oxidation system, which includes: an iron-carbon contact oxidation module and an auxiliary treatment module; wherein the auxiliary treatment module includes activated sludge, and the iron-carbon contact oxidation module treats sewage through the coupling reaction of iron-carbon fillers and microorganisms in the activated sludge; the iron-carbon contact oxidation module includes: at least one iron-carbon filler group; the iron-carbon filler group is composed of a filler grid and iron-carbon fillers, and there are gaps between adjacent iron-carbon filler groups.

[0011] According to an embodiment of the present disclosure, the auxiliary treatment module includes: activated sludge, an inlet pipe, and an outlet pipe; sewage enters the system through the inlet pipe, and is discharged from the system through the outlet pipe after treatment, wherein the sedimentation ratio of the activated sludge is 5% to 15%.

[0012] According to an embodiment of the present disclosure, the system further includes: an aerator for oxygenating and stirring and mixing; the aerator is evenly arranged between the iron-carbon filler groups.

[0013] According to the embodiment of the present disclosure, the specific surface area of ​​the iron-carbon filler is 1.2 m 2 / g, physical strength 800 kg / m 2 , bulk density 1200 g / L, porosity ≥ 65%, iron-carbon ratio 75% ~ 85%, catalyst content 5%; the iron-carbon filler filling height does not exceed 1m, and the iron-carbon filler accounts for 10% ~ 20% of the volume of the reaction system.

[0014] According to an embodiment of the present disclosure, the height difference between the bottom of the iron-carbon filler group and the bottom of the reaction tank is 40-50 cm.

[0015] According to an embodiment of the present disclosure, the gas-water ratio of the iron-carbon contact oxidation module is 2:1 to 12:1, and the dissolved oxygen concentration is 1 to 2 mg / L.

[0016] According to an embodiment of the present disclosure, the iron-carbon contact oxidation module is a split structure, and the number of iron-carbon filler groups and the volume of the iron-carbon fillers in each iron-carbon filler group can be adjusted according to the sewage quality.

[0017] (III) Beneficial effects

[0018] The biological contact oxidation method and system provided by the present disclosure include at least the following beneficial effects:

[0019] 1. The biological contact oxidation method and system provided by the present disclosure form an acidic biofilm on the surface of the iron-carbon filler through the acidic intermediate metabolites naturally metabolized by microorganisms after attachment to the iron-carbon filler, promote the occurrence of micro-electrolysis, and then degrade organic matter. The reaction does not require the addition of acid-base agents to adjust the pH value, avoiding the secondary pollution of sewage and the problem of effluent color reversal. In addition, the iron ions after the decomposition of the iron-carbon filler can enhance the sedimentation performance of the activated sludge and strengthen the phosphorus removal effect of sewage. The iron-carbon filler has the effect of promoting the short-range nitrification and denitrification of microorganisms, reducing the amount of aeration required in the sewage treatment process, and is conducive to energy saving and consumption reduction.

[0020] 2. The biological contact oxidation system provided by the present invention has good sludge settling properties, and the sludge settling rate is 30% to 50% higher than that of conventional biochemical processes, which can significantly reduce the floor space and save construction costs.

[0021] 3. The biological contact oxidation system provided by the present disclosure has a simple structure, is easy to install, and has flexible scale. The iron-carbon filler can meet the process requirements when the volume of the system accounts for less than 20%. The filler is easy to replace and supplement, and can be flexibly adjusted according to actual conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0023] Figure 1 The structure of a biological contact oxidation system according to an embodiment of the present disclosure is schematically shown.

[0024] [Reference Signs]

[0025] 1-water inlet pipe; 2-water outlet pipe; 3-activated sludge; 4-aerator; 5-filler grid; 6-iron-carbon filler; 7-filler grid support beam. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings. Obviously, the described embodiments are 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 ordinary technicians in the field without creative work are within the scope of protection of the present disclosure.

[0027] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0028] In the present disclosure, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be a direct connection, or it can be indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.

[0029] In the description of the present disclosure, it is necessary to understand that the terms "longitudinal", "length", "circumferential", "front", "rear", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the subsystem or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present disclosure.

[0030] Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or configurations will be omitted when they may cause confusion in the understanding of the present disclosure. The shapes, sizes, and positional relationships of the components in the drawings do not reflect the actual size, proportion, and actual positional relationship. In addition, in the claims, any reference symbol between brackets shall not be construed as a limitation to the claims.

[0031] Similarly, in order to simplify the present disclosure and help understand one or more of the various disclosed aspects, in the above description of the exemplary embodiments of the present disclosure, the various features of the present disclosure are sometimes grouped together into a single embodiment, figure, or description thereof. The description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0032] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the feature. In the description of the present disclosure, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0033] The biological contact oxidation method provided by the embodiment of the present disclosure includes: introducing sewage into a reaction tank of the biological contact oxidation system, and treating the sewage based on the iron-carbon filler and activated sludge in the reaction tank; wherein the iron-carbon filler and the microorganisms in the activated sludge undergo a coupled reaction to jointly treat the sewage.

[0034] Specifically, during the sewage treatment process, the reaction tank is continuously aerated based on the aerator. Aeration based on the aerator can provide oxygen to the microorganisms in the activated sludge for their respiratory metabolism. In addition, during the continuous aeration process of the aerator, it will drive the flow of sewage and activated sludge, play a stirring role, keep the microorganisms in the activated sludge in a suspended state, increase the contact area between the microorganisms and sewage, and reduce the dead zone in the sewage, thereby improving the treatment effect.

[0035] During the sewage treatment process, microorganisms in the activated sludge attach to the iron-carbon filler, produce acidic intermediate metabolites, and provide an acidic environment for the iron-carbon filler. The iron-carbon filler undergoes micro-electrolysis in the acidic environment, decomposing into iron ions and activated carbon, and the wastewater to be treated is treated based on the iron ions and activated carbon.

[0036] Specifically, the microorganisms attached to the iron-carbon filler will naturally metabolize anaerobic sulfate-reducing bacteria and aerobic iron-oxidizing bacteria, or acidic intermediate metabolites of other anaerobic bacteria or facultative bacteria, leading to acidification of the extracellular environment, forming an iron-carbon-microorganism coupling effect, effectively treating difficult-to-degrade organic matter, and promoting the biochemical treatment effect of microorganisms.

[0037] During aeration and micro-electrolysis reactions, the iron-carbon filler will release iron ions and activated carbon into the sewage. Among them, iron ions can keep the soluble proteins and carbohydrates produced during the biodegradation process in the activated sludge flocs, thereby reducing the organic matter concentration in the effluent, and can effectively reduce the expansion of filamentous bacteria in the activated sludge, making the activated sludge flocs more compact, enhancing the sedimentation performance of the activated sludge, and also enhancing the phosphorus removal effect of sewage. Activated carbon has physical and chemical properties such as porous structure, rich surface active groups, and contains a variety of mineral salts. It can adsorb pollutants in sewage and improve the sewage purification effect.

[0038] Based on the above biological contact oxidation method, the present disclosure also provides a biological contact oxidation system. Figure 1 The system is described in detail.

[0039] Figure 1 The structure of a biological contact oxidation system according to an embodiment of the present disclosure is schematically shown.

[0040] like Figure 1 As shown, the biological contact oxidation system provided by the present disclosure mainly includes an iron-carbon contact oxidation module, an auxiliary treatment module and an aerator.

[0041] The iron-carbon contact oxidation module includes at least one group of iron-carbon filler groups, which are composed of a filler grid 5 and an iron-carbon filler 6, and there are gaps between adjacent iron-carbon filler groups. The iron-carbon contact oxidation module is a split structure, and the number of iron-carbon filler groups and the volume of iron-carbon filler in each iron-carbon filler group can be adjusted according to the sewage quality.

[0042] The auxiliary treatment module includes an inlet pipe 1, an outlet pipe 2, and activated sludge 3. Specifically, the activated sludge reacts with iron and carbon to jointly treat the sewage.

[0043] The aerators 4 are evenly arranged between the iron-carbon filler groups for oxygenation and stirring. On the one hand, the aerators transfer oxygen from the air to the mixed liquid to meet the breathing needs of microorganisms in the activated sludge. On the other hand, the aerators put the mixed liquid in a violent mixing state, so that the activated sludge, dissolved oxygen and organic matter are fully contacted while preventing sludge deposition.

[0044] The sewage treatment process of the biological contact oxidation system provided in the embodiment of the present disclosure includes: the treated sewage enters the iron-carbon contact oxidation system through the water inlet pipe 1, is aerated through the aerator 4, the iron-carbon filler 6 and the activated sludge 3 work together to degrade organic matter, completing the sewage treatment, and the treated sewage is discharged from the outlet pipe 2.

[0045] In some embodiments, there are gaps between adjacent iron-carbon filler groups, which helps to ensure sufficient contact between sewage and filler and improve sewage treatment efficiency. Setting gaps between adjacent iron-carbon filler groups can ensure that water can flow smoothly through the filler layer, avoid blockage problems, and ensure sewage treatment efficiency.

[0046] In some embodiments, the aerator 4 is a liftable tube aerator, which is connected to the aeration main pipe by a flange. When the aerator needs to be replaced, the aerator to be replaced can be rotated out of the packing area and then taken out from between the packings, which is convenient for maintenance.

[0047] In some embodiments, the surface area of ​​the iron-carbon filler ratio is 1.2 m 2 / g, physical strength is 800 kg / m 2 , bulk density is 1200 g / L, porosity ≥ 65%, iron-carbon ratio is 75% ~ 85%, and catalyst content is 5%.

[0048] In some embodiments, the settling ratio SV30 of the activated sludge 3 is 5% to 15%.

[0049] In some embodiments, the filling height of the iron-carbon filler does not exceed 1 m, and the volume of the iron-carbon filler accounts for 10% to 20% of the volume of the reaction system to avoid clogging of the filler and excessive burden on the filler grid.

[0050] In some embodiments, the iron-carbon filler group is arranged on the filler grid support beam 7, and the height difference between the bottom of the iron-carbon filler group and the bottom of the reaction tank is 40-50 cm. Maintaining a certain height difference can prevent the iron-carbon filler from directly contacting the bottom of the reaction tank, thereby avoiding blockage problems caused by excessive filler particles or excessive bottom sediments, which helps to ensure the smooth flow of sewage and the continuous progress of the sewage treatment process. In addition, the appropriate height difference can ensure more uniform aeration, avoid insufficient aeration pressure or uneven aeration due to excessive accumulation of fillers, thereby improving the sewage treatment effect.

[0051] In some embodiments, the air-water ratio of the iron-carbon contact oxidation module is 2:1~12:1, and the dissolved oxygen concentration is 1~2mg / L. Compared with the traditional contact oxidation method, the iron-carbon filler biofilm used in the embodiment of the present disclosure forms a good anaerobic and anaerobic environment inside, without excessive dissolved oxygen to destroy the reaction environment, and violent aeration can easily cause the biofilm to fall off. At the same time, lower dissolved oxygen is conducive to the accumulation of nitrite bacteria and promotes short-range nitrification and denitrification. Therefore, the aeration volume required for the entire process is lower, which is conducive to energy saving and consumption reduction.

[0052] In the traditional sewage treatment process, the iron-carbon filler has a high correlation with the pH value of the environment. Therefore, it is necessary to adjust the pH value of the treatment environment by adding acid and / or alkali to complete the sewage treatment.

[0053] The disclosed embodiment uses iron-carbon as filler to treat sewage together with microorganisms in activated sludge, thereby effectively improving the efficiency of sewage treatment. After the microorganisms attach to the iron-carbon filler, they will produce acidic intermediate metabolites, forming an acidic biofilm on the surface of the iron-carbon filler, providing an acidic environment for sewage treatment, promoting the occurrence of micro-electrolysis, and then degrading organic matter. In this process, there is no need to add acid-base agents to adjust the pH value, which can avoid secondary pollution of sewage by acid-base agents and the problem of effluent color reversal, and improve the sewage purification effect while simplifying the sewage purification process.

[0054] Compared with traditional iron-carbon treatment, the present invention provides an acidic environment for iron-carbon filler by setting activated sludge in the biological contact oxidation system, avoiding the process of adjustment by industrial acid and industrial alkali in traditional processes, effectively simplifying the steps of iron-carbon filler treatment of sewage, and improving sewage treatment efficiency and safety.

[0055] In addition, the biological contact oxidation system provided by the embodiment of the present disclosure has a simple structure, is easy to install, and has flexible and adjustable scale. Compared with the biological filter process, the reaction system of the present disclosure does not require backwashing, and the iron-carbon filler accounts for less than 20% of the volume in the system to meet the process requirements. The filler is easy to replace and supplement, and can be flexibly adjusted according to the project situation.

[0056] In order to verify that the sewage treatment capacity of the disclosed system is better than that of the traditional filler sewage biochemical reaction system, the disclosed system and the traditional filler sewage biochemical reaction system are used to treat the same batch of sewage to be treated. The sewage enters the two systems in batches, stays in the system for 6 hours, and then exits the two systems. The experiment is repeated for multiple batches to test the treatment stability of the two systems and compare the effluent pollutant concentration and precipitation efficiency under the two systems.

[0057] It should be noted that, except for the different filler materials used, the structures of the system disclosed in the present invention and the traditional filler wastewater biochemical reaction system are the same, the filler particle size is 5-8 mm, and the filling volume proportion of the two fillers is the same, which is 20%.

[0058] Table 1 Pollutant concentrations of the same batch of sewage after treatment by two systems

[0059]

[0060] Table 2 Average sedimentation rate of activated sludge under two systems

[0061]

[0062] As shown in Table 1 and Table 2, the treatment effect of the biological contact oxidation system disclosed in the present invention is stably better than the treatment effect of the traditional filler sewage biochemical reaction system. The present invention provides higher treatment efficiency, shorter sludge settling time, and saves floor space and energy consumption.

[0063] The embodiments of the present disclosure are described above. However, these embodiments are only for illustrative purposes and are not intended to limit the scope of the present disclosure. Although the embodiments are described above separately, this does not mean that the measures in the various embodiments cannot be used in combination to advantage. Without departing from the scope of the present disclosure, those skilled in the art may make a variety of substitutions and modifications, which should all be included in the scope of protection of the present disclosure.

Claims

1. A biological contact oxidation method, characterized in that: The method comprises: The sewage is introduced into a reaction tank of a biological contact oxidation system, and the sewage is treated based on the iron-carbon filler and activated sludge in the reaction tank; The iron-carbon filler and the microorganisms in the activated sludge undergo a coupled reaction to jointly treat the sewage.

2. The biological contact oxidation method according to claim 1, characterized in that: The method further comprises: During the sewage treatment process, the reaction tank is continuously aerated based on the aerator.

3. The biological contact oxidation method according to claim 1, characterized in that: During the sewage treatment process, the microorganisms in the activated sludge attach to the iron-carbon filler, produce acidic intermediate metabolites, and provide an acidic environment for the iron-carbon filler; The iron-carbon filler undergoes micro-electrolysis in an acidic environment to decompose into iron ions and activated carbon, and the sewage is treated based on the iron ions and activated carbon.

4. A biological contact oxidation system for executing the biological contact oxidation method according to any one of claims 1 to 3, characterized in that: The system comprises: Iron-carbon contact oxidation module and auxiliary treatment modules; Wherein, the auxiliary treatment module includes activated sludge, and the iron-carbon contact oxidation module treats sewage through the coupling reaction of iron-carbon filler and microorganisms in the activated sludge; The iron-carbon contact oxidation module comprises: at least one iron-carbon filler group; the iron-carbon filler group is composed of a filler grid and iron-carbon fillers, and there are intervals between adjacent iron-carbon filler groups.

5. The biological contact oxidation system according to claim 4, characterized in that: The auxiliary treatment module includes: activated sludge, a water inlet pipe, and a water outlet pipe; The sewage to be treated enters the system through the water inlet pipe and is discharged from the system through the water outlet pipe after treatment, wherein the settling ratio of the activated sludge is 5% to 15%.

6. The biological contact oxidation system according to claim 4, characterized in that: The system further comprises: The aerator is used for oxygenation and stirring and mixing; the aerator is evenly arranged between the iron-carbon filler groups.

7. The biological contact oxidation system according to claim 4, characterized in that: The specific surface area of ​​the iron-carbon filler is 1.2 m 2 / g, physical strength 800 kg / m 2 , bulk density 1200 g / L, porosity ≥ 65%, iron-carbon ratio 75% ~ 85%, catalyst content 5%; the iron-carbon filler filling height does not exceed 1 m, and the iron-carbon filler accounts for 10% ~ 20% of the volume of the reaction system.

8. The biological contact oxidation system according to claim 4, characterized in that: The height difference between the bottom of the iron-carbon filler group and the bottom of the reaction tank is 40-50 cm.

9. The biological contact oxidation reaction system according to claim 4, characterized in that: The gas-water ratio of the iron-carbon contact oxidation module is 2:1 to 12:1, and the dissolved oxygen concentration is 1 to 2 mg / L.

10. The biological contact oxidation system according to claim 4, characterized in that: The iron-carbon contact oxidation module is a split structure, and the number of iron-carbon filler groups and the volume of the iron-carbon fillers in each iron-carbon filler group can be adjusted according to the quality of the sewage.

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