Short-process wastewater zero discharge treatment process

Abstract

This invention discloses a short-process zero-discharge wastewater treatment technology, relating to the field of wastewater treatment technology. The process of this invention dynamically monitors the sludge sedimentation amount in a high-density clarifier and adjusts the corresponding chemical dosage based on the monitoring results. This ensures reasonable monitoring of the high-density clarifier and maintains stable effluent quality. By analyzing the reasonable sedimentation value, the process promptly interrupts wastewater from entering subsequent processes, avoiding the risk of fouling the primary reverse osmosis (RO1) and secondary reverse osmosis (RO2) stages. Sufficient sedimentation of wastewater is achieved within the high-density clarifier, effectively reducing subsequent treatment steps and optimizing the wastewater treatment process.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and more specifically, to a short-process wastewater zero-discharge treatment technology. Background Technology

[0002] Currently, the conventional process for a two-stage reverse osmosis concentration system with zero wastewater discharge is as follows: equalization tank → primary high-density clarifier → clear water tank (pH adjusted by adding acid) → V-type filter 1 (or multi-media filtration) → ultrafiltration UF1 → primary reverse osmosis concentration → primary reverse osmosis RO1 (recovery rate 70%-75%) → RO1 tank → secondary high-density clarifier → V-type filter 2 (or multi-media filtration) → ultrafiltration UF2 → clear water tank (pH adjusted by adding acid) → weak acid resin IX1 → weak acid resin IX2 → decarbonizer → RO2 (recovery rate 70%-75%).

[0003] This process has the following problems:

[0004] 1. The dosage of chemicals in the primary high-density clarifier is greatly affected by water volume and quality, making it difficult to control and resulting in poor effluent quality stability. 2. Poor effluent quality stability in the primary high-density clarifier leads to a high risk of fouling in the primary reverse osmosis (RO1) tank, low recovery rate, frequent cleaning, and poor operational stability. This further makes it difficult to control the dosage in the secondary high-density clarifier, resulting in poor effluent quality stability. 3. Poor effluent quality stability in the secondary high-density clarifier leads to a high risk of fouling in the secondary reverse osmosis (RO2) tank, low recovery rate, frequent cleaning, and poor operational stability. 4. The system has a long process route, with each treatment unit discharging a certain amount of wastewater during operation, resulting in a relatively large total wastewater discharge. This wastewater re-enters the equalization tank or RO1 tank, increasing the equipment size of each unit and raising the system's investment cost. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a short-process wastewater zero-discharge treatment process.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A short-process wastewater zero-discharge treatment technology includes the following steps:

[0008] S1. Wastewater and the self-drainage from the equipment within the system enter the wastewater equalization tank, and are then lifted into the high-density clarification tank. The high-density clarification tank clarifies the wastewater, dynamically adjusts the dosage of chemicals, and determines whether the clarified wastewater can enter the filter. If it is determined that the clarified wastewater can enter the filter, it enters the filter, then enters the intermediate water tank, is lifted into the ultrafiltration tank, then enters the ultrafiltration permeate tank, is lifted into the biochemical treatment unit, and is then lifted by a high-pressure pump into the first-stage reverse osmosis (RO1). The reverse osmosis permeate enters the reclaimed water tank, and the concentrate enters the RO1 concentrate tank.

[0009] S2. The concentrate from the first-stage reverse osmosis RO1 is boosted into the second-stage reverse osmosis RO2 concentration, the permeate enters the reclaimed water tank, and the concentrate enters the subsequent treatment unit;

[0010] S3. After the wastewater from ultrafiltration, primary reverse osmosis RO1 and secondary reverse osmosis RO2 chemical cleaning is discharged, it is pumped to the regenerated liquid treatment system. After treatment, the permeate enters the wastewater equalization tank and the settled sludge enters the sludge tank.

[0011] S4. The sludge tank collects sludge from the high-density clarifier and the regenerated liquor treatment system. The sludge is lifted by a lift pump and doped with chemicals before entering the sludge dewatering machine. The filtrate is returned to the wastewater equalization tank, and the sludge cake is sent to the sludge field or transported off-site.

[0012] S5. The backwash wastewater from the filter and ultrafiltration is collected and discharged into the wastewater equalization tank;

[0013] S6. When the scaling index of the secondary reverse osmosis RO2 concentrate reaches the limit, the regenerated liquid treatment system is used to treat the easily scaling substances in the RO1 concentrate to improve the recovery rate and operational stability of the secondary reverse osmosis RO2.

[0014] S7. The sludge generated by the high-density clarifier and regenerated liquid treatment system enters the sludge tank. After being treated by the sludge dewatering machine, the filtrate enters the wastewater equalization tank, and the sludge cake is sent to the sludge field or transported off-site.

[0015] Furthermore, the high-density clarifier clarifies the wastewater, and the dosage is dynamically adjusted. Specifically, after the wastewater enters the high-density clarifier, the amount of sludge settled is collected every t of time. A high and low sludge settling threshold are set, where the high threshold is greater than the low threshold. When the sludge settling amount is between the high and low thresholds, the current dosage is maintained. When the sludge settling amount is greater than the high threshold, the current dosage is reduced. When the sludge settling amount is less than the low threshold, the current dosage is increased. An abnormal sedimentation record is generated, and the ratio of the sludge settling amount to the low threshold is calculated to obtain a detection index, which is labeled as SM. This is based on t... SM Collect the amount of sludge settled in the high-density clarifier in the next step.

[0016] Furthermore, the sedimentation anomaly record includes the time of the sedimentation anomaly and the amount of sludge settled.

[0017] Further, to determine whether the clarified wastewater can enter the filter tank, the following steps are taken: Obtain all sedimentation anomaly records from the high-density clarifier within n time periods prior to the current system time, label the total number of sedimentation anomaly records as ES, sum the sedimentation amounts of all sludge sediments and take the average to obtain the average sludge sedimentation amount, labeling it as HY, obtain the average sedimentation anomaly interval KS, and use the formula... The reasonable sedimentation value CD of the high-density clarifier is obtained, where a1 is the coefficient of the total number of sedimentation anomaly records, a2 is the coefficient of the average sludge sedimentation amount, and a3 is the coefficient of the average sedimentation anomaly interval. A reasonable sedimentation threshold is set. When the reasonable sedimentation value of the high-density clarifier is greater than or equal to the reasonable sedimentation threshold, no corresponding treatment is taken. When the reasonable sedimentation value of the high-density clarifier is less than the reasonable sedimentation threshold, wastewater is prevented from entering the filter.

[0018] Furthermore, the average precipitation anomaly interval is obtained as follows: all precipitation anomaly records are sorted in chronological order of precipitation anomaly time; the time difference between the precipitation anomaly times of two adjacent precipitation anomaly records after sorting is calculated to obtain the precipitation anomaly interval; all precipitation anomaly intervals are summed and averaged to obtain the average precipitation anomaly interval, which is marked as KS.

[0019] Furthermore, the regenerated liquid treatment system consists of reaction precipitation and filtration.

[0020] Furthermore, the biochemical treatment unit introduces hydrolysis acidification technology, which promotes the hydrolysis reaction of organic matter by adding acidifying agents to generate easily degradable intermediate products. Then, it uses physicochemical methods such as activated carbon adsorption and ozone oxidation to further remove pollutants such as organic matter and heavy metals from the wastewater.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The process of this invention dynamically monitors the sludge sedimentation amount in the high-density clarifier and adjusts the corresponding chemical dosage based on the monitoring results. This ensures reasonable monitoring of the high-density clarifier and maintains stable effluent quality. By analyzing the reasonable sedimentation value, the process promptly interrupts the flow of wastewater into subsequent processes, avoiding the risk of fouling the primary reverse osmosis (RO1) and secondary reverse osmosis (RO2) stages. Sufficient sedimentation of wastewater is achieved within the high-density clarifier, effectively reducing the number of processing steps in subsequent stages and optimizing the wastewater treatment process. Attached Figure Description

[0023] Figure 1 This is a flowchart of a short-process wastewater zero-discharge treatment process according to the present invention. Detailed Implementation

[0024] Reference Figure 1 A short-process wastewater zero-discharge treatment technology includes the following steps:

[0025] S1. Wastewater and the self-drainage from the equipment within the system enter the wastewater equalization tank, and are then lifted into the high-density clarification tank. The high-density clarification tank clarifies the wastewater, dynamically adjusts the dosage of chemicals, and determines whether the clarified wastewater can enter the filter. If it is determined that the clarified wastewater can enter the filter, it enters the filter, then enters the intermediate water tank, is lifted into the ultrafiltration tank, then enters the ultrafiltration permeate tank, is lifted into the biochemical treatment unit, and is then lifted by a high-pressure pump into the first-stage reverse osmosis (RO1). The reverse osmosis permeate enters the reclaimed water tank, and the concentrate enters the RO1 concentrate tank.

[0026] S2. The concentrate from the first-stage reverse osmosis RO1 is boosted into the second-stage reverse osmosis RO2 concentration, the permeate enters the reclaimed water tank, and the concentrate enters the subsequent treatment unit;

[0027] S3. After the wastewater from ultrafiltration, primary reverse osmosis RO1 and secondary reverse osmosis RO2 chemical cleaning is discharged, it is pumped to the regenerated liquid treatment system. After treatment, the permeate enters the wastewater equalization tank and the settled sludge enters the sludge tank.

[0028] S4. The sludge tank collects sludge from the high-density clarifier and the regenerated liquor treatment system. The sludge is lifted by a lift pump and doped with chemicals before entering the sludge dewatering machine. The filtrate is returned to the wastewater equalization tank, and the sludge cake is sent to the sludge field or transported off-site.

[0029] S5. The backwash wastewater from the filter and ultrafiltration is collected and discharged into the wastewater equalization tank;

[0030] S6. When the scaling index of the secondary reverse osmosis RO2 concentrate reaches the limit, the regenerated liquid treatment system is used to treat the easily scaling substances in the RO1 concentrate to improve the recovery rate and operational stability of the secondary reverse osmosis RO2.

[0031] S7. The sludge generated by the high-density clarifier and regenerated liquid treatment system enters the sludge tank. After being treated by the sludge dewatering machine, the filtrate enters the wastewater equalization tank, and the sludge cake is sent to the sludge field or transported off-site.

[0032] A high-density clarifier is used to clarify wastewater. Specifically, after wastewater enters the high-density clarifier, the amount of sludge settled is collected every t (ton) of time. A high and low sludge settling threshold are set, with the high threshold being greater than the low threshold. Both thresholds are preset system values ​​and can be modified according to actual needs. When the sludge settling amount is between the high and low thresholds, the current dosage is maintained. When the sludge settling amount is greater than the high threshold, the current dosage is reduced. When the sludge settling amount is less than the low threshold, the current dosage is increased. An abnormal sedimentation record is generated, including the abnormal sedimentation time (i.e., the time when the dosage was increased) and the sludge settling amount. The ratio of the sludge settling amount to the low threshold is calculated to obtain a detection index, labeled SM, based on t (tons).SM Collect the sludge sedimentation volume of the high-density clarifier for the next cycle. Obtain all sedimentation anomaly records from the high-density clarifier within n hours prior to the current system time. Mark the total number of sedimentation anomaly records as ES. Sum the sludge sedimentation volumes of all records and take the average to obtain the average sludge sedimentation volume, marked as HY. Sort all sedimentation anomaly records according to the chronological order of the anomaly times. Calculate the time difference between the anomaly times of two adjacent records after sorting to obtain the sedimentation anomaly interval. Sum all sedimentation anomaly intervals and take the average to obtain the average sedimentation anomaly interval, marked as KS. Use the formula... The reasonable sedimentation value CD of the high-density clarifier is obtained, where a1 is the coefficient of the total number of sedimentation anomaly records, a2 is the coefficient of the average sludge sedimentation amount, and a3 is the coefficient of the average sedimentation anomaly interval. The values ​​of a1, a2, and a3 are 0.81, 0.52, and 0.69, respectively. A reasonable sedimentation threshold is set. The reasonable sedimentation threshold is a system-set threshold that can be modified according to actual needs. When the reasonable sedimentation value of the high-density clarifier is greater than or equal to the reasonable sedimentation threshold, no corresponding action is taken. When the reasonable sedimentation value of the high-density clarifier is less than the reasonable sedimentation threshold, wastewater is prevented from entering the filter.

[0033] The regenerated liquid treatment system consists of reaction precipitation and filtration.

[0034] The biochemical treatment unit introduces hydrolysis acidification technology, which promotes the hydrolysis reaction of organic matter by adding acidifying agents to generate easily degradable intermediate products. Then, it uses physicochemical methods such as activated carbon adsorption and ozone oxidation to further remove pollutants such as organic matter and heavy metals from the wastewater.

[0035] The process of this invention dynamically monitors the sludge sedimentation amount in the high-density clarifier and adjusts the corresponding dosage based on the monitoring results. This ensures reasonable monitoring of the high-density clarifier and maintains stable effluent quality. By analyzing the reasonable sedimentation value, the process promptly interrupts the flow of wastewater into subsequent processes, avoiding the risk of fouling the primary reverse osmosis (RO1) and secondary reverse osmosis (RO2) stages. Sufficient sedimentation of wastewater is achieved within the high-density clarifier, effectively reducing the number of subsequent treatment steps and optimizing the wastewater treatment process.

[0036] The above formulas are all dimensionless calculations. The formulas are derived from software simulations based on a large amount of collected data to obtain the most recent real-world results. The preset parameters in the formulas are set by those skilled in the art according to the actual situation.

[0037] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more sets of available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium. A semiconductor medium can be a solid-state drive.

[0038] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0039] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0040] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0041] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0042] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0043] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A short-process wastewater zero-discharge treatment technology, characterized in that, Includes the following steps: S1. Wastewater and the self-drainage from equipment within the system enter the wastewater equalization tank, and are then pumped into the high-density clarification tank. The high-density clarification tank clarifies the wastewater, dynamically adjusts the dosage of chemicals, and determines whether the clarified wastewater can enter the filter. If it is determined that the clarified wastewater can enter the filter, it enters the filter, then enters the intermediate water tank, is pumped into the ultrafiltration tank, then into the ultrafiltration permeate tank, is pumped into the biological treatment unit, and is then pumped by a high-pressure pump into the first-stage reverse osmosis (RO1). The reverse osmosis permeate enters the reclaimed water tank, and the concentrate enters the RO1 concentrate tank. S2. The concentrate from the first-stage reverse osmosis RO1 is boosted into the second-stage reverse osmosis RO2 concentration, the permeate enters the reclaimed water tank, and the concentrate enters the subsequent treatment unit; S3. After the wastewater from ultrafiltration, primary reverse osmosis RO1 and secondary reverse osmosis RO2 chemical cleaning is discharged, it is pumped to the regenerated liquid treatment system. After treatment, the permeate enters the wastewater equalization tank and the settled sludge enters the sludge tank. S4. The sludge tank collects sludge from the high-density clarifier and the regenerated liquor treatment system. The sludge is lifted by a lift pump and doped with chemicals before entering the sludge dewatering machine. The filtrate is returned to the wastewater equalization tank, and the sludge cake is sent to the sludge field or transported off-site. S5. The backwash wastewater from the filter and ultrafiltration is collected and discharged into the wastewater equalization tank; S6. The regenerated liquid treatment system is used to treat easily scale-forming substances in the RO1 concentrate when the scaling index of the secondary reverse osmosis RO2 concentrate reaches the limit, so as to improve the recovery rate and operational stability of the secondary reverse osmosis RO2. A high-density clarifier is used to clarify wastewater, and the dosage is dynamically adjusted. Specifically, after the wastewater enters the high-density clarifier, the amount of sludge settled is collected every ton of time. A high and low sludge settling threshold are set, where the high threshold is greater than the low threshold. When the sludge settling amount is between these two thresholds, the current dosage is maintained. When the sludge settling amount is greater than the high threshold, the dosage is reduced. When the sludge settling amount is less than the low threshold, the dosage is increased. Anomaly records are generated, and the ratio of the sludge settling amount to the low threshold is calculated to obtain a detection index, which is labeled SM. Collect the sludge sedimentation volume of the high-density clarifier for the next sedimentation cycle; sedimentation anomaly records include sedimentation anomaly time and sludge sedimentation volume; determine whether the clarified wastewater can enter the filter tank, specifically: obtain all sedimentation anomaly records of the high-density clarifier within n hours before the current system time, mark the total number of sedimentation anomaly records as ES, sum all sludge sedimentation volumes and take the average to obtain the average sludge sedimentation volume, and mark it as HY; sort all sedimentation anomaly records according to the chronological order of sedimentation anomaly time, calculate the time difference between the sedimentation anomaly times of two adjacent sedimentation anomaly records after sorting to obtain the sedimentation anomaly interval, sum all sedimentation anomaly intervals and take the average to obtain the average sedimentation anomaly interval, and mark it as KS; use the formula The reasonable sedimentation value CD of the high-density clarifier is obtained, where a1 is the coefficient of the total number of sedimentation anomaly records, a2 is the coefficient of the average sludge sedimentation amount, and a3 is the coefficient of the average sedimentation anomaly interval. A reasonable sedimentation threshold is set. When the reasonable sedimentation value of the high-density clarifier is greater than or equal to the reasonable sedimentation threshold, no corresponding treatment is taken. When the reasonable sedimentation value of the high-density clarifier is less than the reasonable sedimentation threshold, wastewater is prevented from entering the filter.

2. The short-process wastewater zero-discharge treatment process according to claim 1, characterized in that, The regenerated liquid treatment system consists of reaction precipitation and filtration.

3. The short-process wastewater zero-discharge treatment process according to claim 2, characterized in that, The biochemical treatment unit introduces hydrolysis acidification technology, which promotes the hydrolysis reaction of organic matter by adding acidifying agents to generate easily degradable intermediate products. The organic matter and heavy metal pollutants in the wastewater are further removed by physicochemical methods such as activated carbon adsorption and ozone oxidation.

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