Papermaking wastewater treatment system

Abstract

The utility model provides a papermaking wastewater treatment system which comprises a storage pool used for storing and monitoring zeta potential of papermaking wastewater; the pH regulating tank is used for regulating the pH value of the wastewater; the coagulating sedimentation subsystem is used for removing colloidal impurities and suspended solids in the wastewater; the anaerobic reaction subsystem is used for carrying out anaerobic hydrolysis reaction; the anoxic reaction tank is used for carrying out denitrification reaction; the aerobic reaction subsystem is used for carrying out oxygenolysis reaction; the sludge treatment tank is used for storing sludge and compressing and dehydrating the sludge; the storage tank is respectively connected with the pH regulating tank and the coagulating sedimentation subsystem through pipelines, and the pH regulating tank, the coagulating sedimentation subsystem, the anaerobic reaction subsystem, the anoxic reaction tank and the aerobic reaction subsystem are sequentially connected through pipelines. According to the papermaking wastewater treatment system provided by the utility model, the treatment process in the existing sewage plant is modified, so that the organic matter removal performance is improved, the treatment cost is reduced, and the practicability is high.

Description

Technical Field

[0001] This utility model belongs to the field of papermaking wastewater treatment technology, and specifically relates to a papermaking wastewater treatment system. Background Technology

[0002] Traditional papermaking wastewater treatment methods include both physiochemical and biological processes. Commonly used physiochemical methods include coagulation, Fenton oxidation, and ozone oxidation, but these suffer from problems such as high reagent consumption, low reaction efficiency, and high treatment costs. Biological technology involves adding microorganisms to the water body, utilizing their biochemical processes to decompose organic matter in the wastewater. This is an environmentally friendly, low-energy-consumption, and highly efficient wastewater treatment method. However, papermaking wastewater itself is complex and has poor biodegradability. Even after pre-biological treatment by papermaking industrial parks, the wastewater discharged to centralized wastewater treatment plants, while having a low COD concentration, contains a significantly increased proportion of recalcitrant organic matter such as humic acid and polycyclic aromatic hydrocarbons. Traditional biological degradation processes suffer from low degradation efficiency, making it difficult for effluent to meet standards. Furthermore, in actual operation, even with low effluent COD, factors such as water temperature, pH, water quality, and the effectiveness of the tank capping can cause the anaerobic reactor to struggle to maintain an anaerobic environment, resulting in DO levels exceeding 0 mg / L and impacting the anaerobic treatment effect. Therefore, developing a low-cost and efficient deep treatment technology for papermaking wastewater is of great significance for improving the economic benefits of enterprises and protecting the ecological environment. Utility Model Content

[0003] In order to overcome the shortcomings of the existing technology, the purpose of this utility model is to provide a papermaking wastewater treatment system, which aims to solve the problems of low reaction efficiency, high treatment cost and difficulty in meeting the standards of effluent when treating papermaking wastewater.

[0004] This utility model provides a papermaking wastewater treatment system, comprising:

[0005] A storage tank is used to store and monitor the zeta potential of papermaking wastewater;

[0006] pH adjustment tank is used to adjust the pH value of wastewater;

[0007] The coagulation and sedimentation subsystem is used to remove colloidal impurities and suspended solids from wastewater;

[0008] The anaerobic reaction subsystem is used to carry out anaerobic hydrolysis reactions;

[0009] Anoxic reaction tank, used for denitrification reaction;

[0010] The aerobic reaction subsystem is used for oxidative decomposition reactions;

[0011] Sludge treatment tanks are used for storing sludge and for sludge compression and dewatering.

[0012] The storage tank is connected to the pH adjustment tank and the coagulation sedimentation subsystem via pipelines, and the pH adjustment tank, coagulation sedimentation subsystem, anaerobic reaction subsystem, anoxic reaction tank, and aerobic reaction subsystem are connected in sequence via pipelines.

[0013] To optimize the above technical solutions, specific measures taken also include:

[0014] Furthermore, the storage tank, pH adjustment tank, and coagulation sedimentation subsystem constitute a first working mode, and the storage tank and coagulation sedimentation subsystem constitute a second working mode, with the first and second working modes operating alternately.

[0015] Furthermore, based on the zeta potential of the papermaking wastewater monitored in the storage tank, when the zeta potential is equal to zero, the second working mode is selected; when the zeta potential is not equal to zero, the first working mode is selected.

[0016] Furthermore, the coagulation and sedimentation subsystem includes a coagulation tank and a flocculation tank connected in sequence by pipelines. The coagulation tank is connected to a pH adjustment tank and a storage tank by pipelines, and the flocculation tank is connected to an anaerobic reaction subsystem by pipelines.

[0017] Furthermore, the coagulation tank is equipped with a coagulant, which includes polyferric sulfate (PFS) and polyferric chloride (PAC). A paddle agitator is installed at the bottom of the coagulation tank. The paddle agitator operates intermittently, and the stirring time of a single paddle agitator is not less than 30 minutes.

[0018] Furthermore, the flocculation tank is provided with a flocculant, which is anionic polyacrylamide (PAM). A frame agitator is provided at the bottom of the flocculation tank. The frame agitator operates intermittently, and the stirring time of a single frame agitator is not less than 15 minutes.

[0019] Furthermore, the anaerobic reaction subsystem includes an anaerobic reaction tank and an anaerobic sedimentation tank that form a loop, and the anaerobic reaction tank is connected to the flocculation tank by pipeline.

[0020] Furthermore, it also includes an iron powder box, which is connected to the anaerobic tank pipeline. An electromagnetic pump is installed between the iron powder box and the anaerobic reaction tank. A dissolved oxygen (DO) detector and an oxidation-reduction potential (ORP) monitor are installed on the pipeline between the anaerobic reaction tank and the anaerobic sedimentation tank. Both the dissolved oxygen (DO) detector and the oxidation-reduction potential (ORP) monitor are electrically connected to the electromagnetic pump.

[0021] Furthermore, the aerobic reaction subsystem includes a micro-aerobic reaction tank and a micro-aerobic sedimentation tank connected in sequence by pipelines. The micro-aerobic reaction tank is connected to the anoxic reaction tank by pipelines. The micro-aerobic reaction tank is equipped with compound bacterial agents and activated carbon. The nitrate nitrogen generated by microbial nitrification in the micro-aerobic reaction tank is transported to the anoxic reaction tank along with the sludge mixture through an internal return pipeline, and denitrification is completed through denitrification. The effluent of the micro-aerobic reaction tank is equipped with a dissolved oxygen (DO) detector and a pH monitor.

[0022] Furthermore, the anoxic reaction tank, the microaerobic reaction tank, and the microaerobic sedimentation tank constitute a circulation loop.

[0023] The beneficial effects of this utility model are:

[0024] Compared with existing technologies, the papermaking wastewater treatment system of this invention, compared with conventional papermaking wastewater treatment processes, adds a pH adjustment tank to the coagulation reaction, which improves coagulation efficiency and reduces the amount of coagulant added.

[0025] The amount of iron powder added was adjusted by using a dissolved oxygen (DO) detector and an online oxidation-reduction potential (ORP) monitor, which enhanced the anaerobic environment and improved the treatment efficiency of the anaerobic reactor.

[0026] The activity of the sludge is monitored using data from dissolved oxygen (DO) meters, pH meters, effective viable bacteria counts, effluent COD, and suspended solids (SS) concentrations. When sludge activity is low, the dosage of compound microbial agent and activated carbon is calculated based on the relevant data and added to the micro-aerobic reactor. On the one hand, the compound microbial agent can quickly replenish the number of dominant bacterial colonies in the activated sludge. On the other hand, activated carbon can provide a carrier for microorganisms, preventing sludge loss. Furthermore, activated carbon can adsorb non-biodegradable organic matter and various metabolic substances produced during the growth and reproduction of microorganisms, ensuring that the effluent meets standards.

[0027] The papermaking wastewater treatment system provided by this utility model improves the organic matter removal performance and reduces the treatment cost by modifying the treatment process in existing sewage treatment plants, and is highly practical. Attached Figure Description

[0028] Figure 1 This is a process flow diagram of the papermaking wastewater treatment system of this utility model.

[0029] The attached diagram is labeled as follows: Storage tank 1, pH adjustment tank 2, coagulation tank 3, flocculation tank 4, anaerobic reaction tank 5, anaerobic sedimentation tank 6, anoxic reaction tank 7, microaerobic reaction tank 8, microaerobic sedimentation tank 9, sludge treatment tank 10. Detailed Implementation

[0030] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0031] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0032] A papermaking wastewater treatment system includes: a storage tank 1 for storing and monitoring the zeta potential of papermaking wastewater; a pH adjustment tank 2 for adjusting the pH value of the wastewater; a coagulation and sedimentation subsystem for removing colloidal impurities and suspended solids from the wastewater; an anaerobic reaction subsystem for carrying out anaerobic hydrolysis; an anoxic reaction tank 7 for carrying out denitrification; an aerobic reaction subsystem for carrying out oxidative decomposition; and a sludge treatment tank 10 for storing sludge and for sludge concentration and dewatering. The storage tank 1 is connected to the pH adjustment tank 2 and the coagulation and sedimentation subsystem via pipelines, and the pH adjustment tank 2, the coagulation and sedimentation subsystem, the anaerobic reaction subsystem, the anoxic reaction tank 7, and the aerobic reaction subsystem are connected sequentially via pipelines.

[0033] First, storage tank 1 is used to regulate water quality, balance water volume, and buffer wastewater to prevent excessive wastewater flow from impacting subsequent treatment processes. Second, storage tank 1, pH adjustment tank 2, and the coagulation and sedimentation subsystem constitute the first operating mode. Storage tank 1 and the coagulation and sedimentation subsystem constitute the second operating mode. The first and second operating modes operate alternately, with the switching principle being: based on the zeta potential of the papermaking wastewater monitored in storage tank 1, the second operating mode is selected when the zeta potential is zero, and the first operating mode is selected when the zeta potential is not zero. This can be understood as follows: wastewater transported through the wastewater pipeline first enters and is temporarily stored in storage tank 1, then the zeta potential value of the wastewater is monitored, and the first or second operating mode is selected based on the different zeta potential values. To achieve the switching between the first and second operating modes, a two-way solenoid valve is installed on the pipeline between storage tank 1, pH adjustment tank 2, and the coagulation and sedimentation subsystem. Switching the two-way solenoid valve achieves the switching between the first and second operating modes. When the first working mode is selected, the pH value of the wastewater is adjusted by pH adjustment tank 2. According to the initial pH value range, acid or alkali is selected for neutralization reaction so that the zeta potential of the papermaking wastewater is equal to zero.

[0034] The papermaking wastewater with adjusted zeta potential is transported to the coagulation and sedimentation subsystem, which includes a coagulation tank 3 and a flocculation tank 4 connected in sequence by pipelines. The coagulation tank 3 is connected to the pH adjustment tank 2 and the storage tank 1 by pipelines, and the flocculation tank 4 is connected to the anaerobic reaction subsystem by pipelines.

[0035] A coagulant, including polyferric sulfate (PFS) and polyferric chloride (PAC), is placed in coagulation tank 3. A paddle agitator is installed at the bottom of coagulation tank 3, operating intermittently with a single agitation time of no less than 30 minutes. The coagulant dosage is 0.5-2 g / L. A flocculant, an anionic polyacrylamide (PAM), is placed in flocculation tank 4, with a flocculant dosage of 1-2 mg / L. A frame agitator is installed at the bottom of flocculation tank 4, operating intermittently with a single agitation time of no less than 15 minutes. The flocculant, in conjunction with the coagulant, accelerates the aggregation of fine suspended particles in the water into flocs, thus speeding up the sedimentation of pollutants. Both the coagulant and flocculant are added using conventional dosing devices.

[0036] The anaerobic reaction subsystem includes an anaerobic reaction tank 5 and an anaerobic sedimentation tank 6 that form a loop. The anaerobic reaction tank 5 is connected to the flocculation tank 4 by pipeline.

[0037] To maintain the anaerobic biochemical effect of anaerobic reactor 5, the anaerobic reaction subsystem also includes an iron powder tank. The iron powder tank is connected to the anaerobic tank via piping, and an electromagnetic pump is installed between the iron powder tank and anaerobic reactor 5. A dissolved oxygen (DO) detector and an oxidation-reduction potential (ORP) monitor are installed on the piping between anaerobic reactor 5 and anaerobic sedimentation tank 6. Both the DO detector and the ORP monitor are electrically connected to the electromagnetic pump. Based on the microbial growth environment, threshold ranges are set for dissolved oxygen (DO) and ORP in anaerobic reactor 5. When the DO detector or ORP monitor detects that the corresponding indicator exceeds the threshold range, the electromagnetic pump is activated to add iron powder. In this scheme, the iron powder addition ratio is 5-6 g / L, the ORP threshold range is above -100 mV, and the dissolved oxygen (DO) threshold range is above 0 mg / L.

[0038] After the papermaking wastewater settles in the anaerobic sedimentation tank 6, the supernatant is transported to the anoxic reaction tank 7, part of the lower layer of activated sludge is transported to the anaerobic reaction tank 5, and the remaining lower layer of activated sludge is transported to the sludge storage and treatment tank 10.

[0039] The aerobic reaction subsystem includes a micro-aerobic reaction tank 8 and a micro-aerobic sedimentation tank 9 connected sequentially by pipelines. The micro-aerobic reaction tank 8 is connected to the anoxic reaction tank 7 by pipelines. The micro-aerobic reaction tank 8 contains a compound microbial agent and activated carbon. The compound microbial agent includes one or more components selected from Bacillus, fungi, enzymes, and nutrients. A dissolved oxygen (DO) meter and a pH meter are installed at the effluent outlet of the micro-aerobic reaction tank 8 to maintain a suitable pH value and dissolved oxygen concentration for microbial growth. Nitrate nitrogen produced by microbial nitrification in the micro-aerobic reaction tank 8 is transported to the anoxic reaction tank 7 along with the sludge mixture through an internal return pipeline, where denitrification is completed. An internal return pump is also installed on the return pipeline to improve transport efficiency.

[0040] The anoxic reaction tank 7, the micro-aerobic reaction tank 8, and the micro-aerobic sedimentation tank 9 form a circulation loop, in which part of the activated sludge produced in the micro-aerobic sedimentation tank 9 is returned to the anoxic reaction tank 7 to maintain the total amount of activated sludge inside the anoxic reaction tank 7 and improve the biochemical treatment effect.

[0041] The sludge treatment tank 10 is connected by pipelines to the micro-aerobic sedimentation tank 9, the anaerobic sedimentation tank 6, and the flocculation tank 6, and is used to collect and store the sludge formed in each tank.

[0042] The above descriptions are merely embodiments of the present invention. Common knowledge such as specific structures and characteristics known in the solutions are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the technical field to which the invention pertains before the application date or priority date, are able to obtain all prior art in the field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can improve and implement the solution based on the inspiration given in this application and their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application.

[0043] It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of this utility model, and these should also be considered within the scope of protection of this utility model. These modifications and improvements will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application shall be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A papermaking wastewater treatment system, characterized in that: include, A storage tank is used to store and monitor the zeta potential of papermaking wastewater; pH adjustment tank is used to adjust the pH value of wastewater; The coagulation and sedimentation subsystem is used to remove colloidal impurities and suspended solids from wastewater; The anaerobic reaction subsystem is used to carry out anaerobic hydrolysis reactions; Anoxic reaction tank, used for denitrification reaction; The aerobic reaction subsystem is used for oxidative decomposition reactions; Sludge treatment tanks are used for storing sludge and for sludge compression and dewatering. The storage tank is connected to the pH adjustment tank and the coagulation sedimentation subsystem via pipelines, and the pH adjustment tank, coagulation sedimentation subsystem, anaerobic reaction subsystem, anoxic reaction tank, and aerobic reaction subsystem are connected in sequence via pipelines.

2. The papermaking wastewater treatment system according to claim 1, characterized in that: The storage tank, pH adjustment tank, and coagulation sedimentation subsystem constitute the first working mode, and the storage tank and coagulation sedimentation subsystem constitute the second working mode. The first working mode and the second working mode operate alternately.

3. The papermaking wastewater treatment system according to claim 2, characterized in that: Based on the zeta potential of the papermaking wastewater monitored in the storage tank, when the zeta potential is equal to zero, the second working mode is selected; when the zeta potential is not equal to zero, the first working mode is selected.

4. The papermaking wastewater treatment system according to claim 2, characterized in that: The coagulation and sedimentation subsystem includes a coagulation tank and a flocculation tank connected in sequence by pipelines. The coagulation tank is connected to a pH adjustment tank and a storage tank by pipelines, and the flocculation tank is connected to an anaerobic reaction subsystem by pipelines.

5. The papermaking wastewater treatment system according to claim 4, characterized in that: The coagulation tank is equipped with a coagulant, which includes polyferric sulfate (PFS) and polyferric chloride (PAC). A paddle agitator is installed at the bottom of the coagulation tank. The paddle agitator operates intermittently, and the stirring time of a single paddle agitator is not less than 30 minutes.

6. The papermaking wastewater treatment system according to claim 4, characterized in that: The flocculation tank contains a flocculant, which is anionic polyacrylamide (PAM). A frame agitator is installed at the bottom of the flocculation tank. The frame agitator operates intermittently, and the stirring time of a single frame agitator is not less than 15 minutes.

7. The papermaking wastewater treatment system according to claim 6, characterized in that: The anaerobic reaction subsystem includes an anaerobic reaction tank and an anaerobic sedimentation tank that form a loop, and the anaerobic reaction tank is connected to the flocculation tank by pipeline.

8. The papermaking wastewater treatment system according to claim 7, characterized in that: It also includes an iron powder box, which is connected to the anaerobic tank pipeline. An electromagnetic pump is installed between the iron powder box and the anaerobic reaction tank. A dissolved oxygen (DO) detector and an oxidation-reduction potential (ORP) monitor are installed on the pipeline between the anaerobic reaction tank and the anaerobic sedimentation tank. Both the dissolved oxygen (DO) detector and the oxidation-reduction potential (ORP) monitor are electrically connected to the electromagnetic pump.

9. A papermaking wastewater treatment system according to claim 8, characterized in that: The aerobic reaction subsystem includes a micro-aerobic reaction tank and a micro-aerobic sedimentation tank connected in sequence by pipelines. The micro-aerobic reaction tank is connected to the anoxic reaction tank by pipelines. The micro-aerobic reaction tank is equipped with compound bacterial agents and activated carbon. The nitrate nitrogen produced by microbial nitrification in the micro-aerobic reaction tank is transported to the anoxic reaction tank along with the sludge mixture through an internal return pipeline, and denitrification is completed through denitrification. A dissolved oxygen (DO) detector and a pH monitor are installed at the effluent position of the micro-aerobic reaction tank.

10. A papermaking wastewater treatment system according to claim 9, characterized in that: The anoxic reaction tank, the microaerobic reaction tank, and the microaerobic sedimentation tank form a circulation loop.

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