Industrial wastewater treatment and recycling system

Abstract

The utility model belongs to the technical field of industrial wastewater treatment, and particularly relates to an industrial wastewater treatment and recycling system. The industrial wastewater treatment and recycling system comprises an open buffer tank, an inclined plate sedimentation tank, a clear water buffer tank, a carbon dioxide analysis hardness removal unit, an automatic water purification unit, a membrane device and a recycling storage unit which are sequentially connected, and backwashing water outlets of the automatic water purification unit and the membrane device are connected with the input end of a backwashing water treatment unit; the output end of the backwashing water treatment unit is connected with the recycling storage unit, and sludge discharge ports of the inclined plate sedimentation tank and the backwashing water treatment unit are connected with the sludge tank. According to the industrial wastewater treatment and recycling system disclosed by the utility model, the settling and flocculating devices are designed in stages to treat industrial wastewater, so that the stable operation of the system is realized, and the water quality is ensured; meanwhile, the backwashing water treatment unit is designed, so that the stability of system operation is ensured, the frequency of device maintenance is reduced, and the production efficiency is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of industrial wastewater treatment, and particularly relates to an industrial wastewater treatment, recycling and utilization system. Background Technique

[0002] Circulating cooling water, cleaning wastewater from each workshop, and collected rainwater, as common industrial wastewater in industrial production, need to consume a large amount of resources for treatment before they can be discharged. However, directly discharging the treated sewage after meeting the discharge standards will cause a large amount of water resource waste; in addition, in actual production, the circulating cooling water will undergo multiple heat exchanges with multiple devices, resulting in an increase in the turbidity of the water, and the concentrations of F - , Ca 2+ , Mg 2+ , Cl - rise. The increase in turbidity and ion concentration will cause the process devices to be corroded, affecting production.

[0003] CN212102481U discloses an industrial wastewater treatment system. The wastewater is successively treated by a wastewater tank, a preliminary sedimentation tank group, a primary filter tank, a first fiber ball filter tank, an anaerobic tank, a biochemical tank, and a second fiber ball filter tank, and then flows into a recovery water tank for recycling or is discharged through a discharge tank; the output ends of the biochemical tank, the primary filter tank, and the first fiber ball filter tank are connected to a sludge treatment system; the system has remarkable effects. The fiber ball filter tank can remove heavy metals to avoid poisoning microorganisms, recover sludge impurities through the sludge treatment system, and use the recovery water tank to recover the treated water, reducing production costs and avoiding waste of resources; however, it only adds medicine once at the primary filter tank stage, has limited treatment capacity for wastewater, and does not have a regular backwashing design at the fiber ball filter tank, making it extremely easy to have problems of fiber ball blockage, and thus the system operation stability is limited.

[0004] Therefore, it is necessary to design an industrial wastewater treatment system in actual production to realize the recycling of industrial wastewater, improve water quality, meet environmental protection requirements, reduce the frequency of device maintenance, and improve production efficiency. Content of the Utility Model

[0005] The purpose of the utility model is to overcome the defects existing in the prior art, and provide an industrial wastewater treatment, recycling and utilization system. By designing sedimentation and flocculation devices in stages to treat industrial wastewater, the stable operation of the system is realized and the water quality is guaranteed; at the same time, a backwash water treatment unit is designed to ensure the stability of the system operation, reduce the frequency of device maintenance, and improve production efficiency.

[0006] The industrial wastewater treatment, recycling and utilization system described in this utility model includes an open buffer tank, an inclined plate sedimentation tank, a clear water buffer tank, a carbon dioxide stripping and hardness removal unit, an automatic water purification unit, a membrane device and a recycling storage unit, which are connected in sequence; the open buffer tank is used to collect industrial wastewater generated during production; the clear water buffer tank is provided with a sodium hydroxide feeding port for adjusting the pH of the wastewater input into the inclined plate sedimentation tank; the backwash water outlets of the automatic water purification unit and the membrane device are connected to the input end of the backwash water treatment unit, and the output end of the backwash water treatment unit is connected to the recycling storage unit for collecting the treated clear water in the backwash water treatment unit; the sludge discharge outlets of the inclined plate sedimentation tank and the backwash water treatment unit are both connected to the sludge tank for transporting the sedimented sludge, the sludge tank is connected to a plate and frame filter press for sludge dewatering, and a pipeline for returning to the inclined plate sedimentation tank is provided at the filtrate outlet of the plate and frame filter press.

[0007] Preferably, an inclined plate baffle trough and an inclined plate sedimentation trough are arranged in the inclined plate sedimentation tank. The inclined plate baffle trough is used to divert the input wastewater to the inclined plate sedimentation trough; polyaluminum chloride (PAC), polyacrylamide (PAM) and defluorination agents are transported in the inclined plate sedimentation trough for primary flocculation and separation of the wastewater to obtain clear water and sludge.

[0008] Preferably, the carbon dioxide stripping and hardness removal unit includes a carbon dioxide stripping reaction tank and a carbon dioxide stripping sedimentation tank connected in sequence, and the carbon dioxide stripping reaction tank is connected to a gas-phase carbon dioxide pipeline.

[0009] Preferably, the backwash water treatment unit includes a PAC tank, a PAM tank and a sedimentation tank connected in sequence. The recycling storage unit includes a pure water tank, a medium water tank and a clear water tank. The pure water tank and the clear water tank are both connected to the medium water tank, and the medium water tank is provided with a recycling pipeline for realizing the recycling use of clear water.

[0010] Preferably, the clear water discharge outlet of the sedimentation tank is connected to the clear water tank, and the sludge discharge outlet of the sedimentation tank is connected to the sludge tank.

[0011] Preferably, the automatic water purification unit includes a sand filter inclined plate trough and a sand filter water production tank connected in sequence. The sand filter inclined plate trough and the membrane device are both provided with a backwash water inlet and a backwash water outlet. The backwash water outlets are both connected to the input end of the PAC tank, and the backwash water inlets are both connected to the outlet of the medium water tank for transporting backwash water to backwash the membrane device and the sand filter inclined plate trough; a pipeline connecting the outlet of the membrane device to the input end of the pure water tank is provided.

[0012] Preferably, the sand filter inclined plate trough is connected to a hydrochloric acid pipeline.

[0013] Specifically, the working process of the industrial wastewater treatment, recycling and utilization system is as follows:

[0014] (1)Circulating cooling water, cleaning wastewater from each workshop, and collected rainwater are transported to an open buffer tank for storage. After reaching the specified process liquid level, the centrifugal pump is automatically started to transport the industrial wastewater to the inclined plate sedimentation tank;

[0015] (2)After the industrial wastewater flows into the inclined plate sedimentation tank, a certain proportion of PAC, PAM, and defluorination agents (a mixture of chelating agent, flocculant, and hydroxyapatite) are added according to the amount of industrial wastewater, and the pH is adjusted to 6 - 6.5. After primary flocculation and separation, clear water and sludge are obtained, and the sludge is transported to the sludge tank for temporary storage;

[0016] (3)The clear water after turbidity removal and defluorination treatment in the inclined plate sedimentation tank enters the clear water buffer tank by overflow. There is a sodium hydroxide feeding port on the clear water buffer tank for adjusting the pH of the wastewater input from the inclined plate sedimentation tank to 11.5 - 12.5;

[0017] (4)The liquid in the clear water buffer tank is transported to the carbon dioxide stripping and hardness removal unit. The carbon dioxide stripping and hardness removal unit includes a carbon dioxide stripping reaction tank and a carbon dioxide stripping sedimentation tank connected in sequence. The carbon dioxide stripping reaction tank is connected to the gas-phase carbon dioxide pipeline, and the pH is adjusted to 10 - 10.5 by adjusting the carbon dioxide input amount;

[0018] (5)The carbon dioxide stripping and hardness removal unit is connected to the automatic water purification unit. The automatic water purification unit includes a sand filtration inclined plate tank and a sand filtration product water tank connected in sequence. The sand filtration inclined plate tank is connected to the hydrochloric acid pipeline, and the pH is adjusted to neutral by adjusting the hydrochloric acid addition amount. The sand filtration product water tank is connected to the membrane device to remove suspended particles and Na + and Cl - in the water. The produced pure water enters the intermediate water tank for reuse after passing through the pure water tank; among them, the internal structures of the sand filtration inclined plate tank and the membrane device are prone to blockage and need to be cleaned regularly. The cleaning frequency is 4 - 6 h / time. The backwash water from the intermediate water tank flushes the sand filtration inclined plate tank and the membrane device and then enters the backwash water treatment unit, passing through the PAC tank, PAM tank, and sedimentation tank in sequence to obtain clear water and sludge. The sludge enters the sludge tank, and the clear water is transported to the intermediate water tank through the clear water tank for continuous reuse. The sludge in the sludge tank enters the plate and frame filter press for dehydration and is treated as hazardous waste. The filter press water generated by the plate and frame filter press can be returned to the inclined plate sedimentation tank for continuous treatment and reuse.

[0019] Compared with the prior art, the beneficial effects of the present utility model are:

[0020] The industrial wastewater treatment, recycling and utilization system of the present utility model stages the treatment of industrial wastewater through the design of an inclined plate sedimentation tank, a clear water buffer tank, a carbon dioxide stripping and hardness removal unit, an automatic water purification unit, a membrane device and a recycling storage unit, achieving stable operation of the system and ensuring water quality. At the same time, a backwash water treatment unit is designed at the automatic water purification unit and the membrane device, ensuring the stability of the system operation, reducing the frequency of equipment maintenance and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 FIG. 1 is a process flow diagram of the industrial wastewater treatment, recycling and utilization system provided by the present utility model.

[0022] In the figure: 1, open buffer tank; 2, inclined plate sedimentation tank; 3, clear water buffer tank; 4, carbon dioxide stripping and hardness removal unit; 41, carbon dioxide stripping reaction tank; 42, carbon dioxide stripping sedimentation tank; 5, automatic water purification unit; 51, sand filter inclined plate tank; 52, sand filter product water tank; 6, membrane device; 7, recycling storage unit; 71, pure water tank; 72, intermediate water tank; 73, clear water tank; 8, backwash water treatment unit; 81, PAC tank; 82, PAM tank; 83, sedimentation tank; 9, sludge tank; 10, plate and frame filter press; 11, gas-phase carbon dioxide pipeline; 12, hydrochloric acid pipeline. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The following further describes the specific technical solutions of the present utility model with reference to the drawings.

[0024] As Figure 1 shown, the industrial wastewater treatment, recycling and utilization system includes an open buffer tank 1, an inclined plate sedimentation tank 2, a clear water buffer tank 3, a carbon dioxide stripping and hardness removal unit 4, an automatic water purification unit 5, a membrane device 6 and a recycling storage unit 7 connected in sequence. The backwash water outlets of the automatic water purification unit 5 and the membrane device 6 are connected to the input end of the backwash water treatment unit 8, the output end of the backwash water treatment unit 8 is connected to the recycling storage unit 7, and the sludge discharge outlets of the inclined plate sedimentation tank 2 and the backwash water treatment unit 8 are both connected to the sludge tank 9 for transporting the sedimented sludge; the sludge tank 9 is connected to a plate and frame filter press 10 for sludge dewatering, and a pipeline for returning the filtrate of the plate and frame filter press 10 to the inclined plate sedimentation tank 2 is provided at the filtrate outlet; a sodium hydroxide feeding port is provided on the clear water buffer tank 3.

[0025] An inclined plate baffle tank and an inclined plate sedimentation tank are arranged in the inclined plate sedimentation tank 2.

[0026] The carbon dioxide stripping and hardness removal unit 4 includes a carbon dioxide stripping reaction tank 41 and a carbon dioxide stripping sedimentation tank 42 connected in sequence, and the carbon dioxide stripping reaction tank 41 is connected to the gas-phase carbon dioxide pipeline 11.

[0027] The described backwash water treatment unit 8 includes a PAC tank 81, a PAM tank 82, and a sedimentation tank 83 connected in sequence.

[0028] The described reuse storage unit 7 includes a pure water tank 71, a medium water tank 72, and a clear water tank 73. The pure water tank 71 and the clear water tank 73 are both connected to the medium water tank 72, and the medium water tank 72 is provided with a reuse pipeline.

[0029] The clear water discharge port of the sedimentation tank 83 is connected to the clear water tank 73, and the sludge discharge port of the sedimentation tank 83 is connected to the sludge tank 9.

[0030] The described automatic water purification unit 5 includes a sand filter inclined plate tank 51 and a sand filter product water tank 52 connected in sequence. Both the sand filter inclined plate tank 51 and the membrane device 6 are provided with a backwash water inlet and a backwash water outlet. The backwash water outlets are both connected to the input end of the PAC tank 81, and the backwash water inlets are both connected to the outlet of the medium water tank 72. A pipeline connecting the outlet of the membrane device 6 to the input end of the pure water tank 71 is provided.

[0031] The sand filter inclined plate tank 51 is connected to the hydrochloric acid delivery pipeline 12.

[0032] The described industrial wastewater treatment and recycling system has the following working process:

[0033] (1) Circulating cooling water, cleaning wastewater from each workshop, and collected rainwater are transported to the open buffer tank 1 for storage. After reaching the specified process liquid level, the centrifugal pump is automatically started to transport the industrial wastewater to the inclined plate sedimentation tank 2;

[0034] (2) After the industrial wastewater flows into the inclined plate sedimentation tank 2, a certain proportion of PAC, PAM, and defluorination agents (a mixture of chelating agents, flocculants, and hydroxyapatite) are transported according to the amount of industrial wastewater, and the pH value is adjusted to 6 - 6.5. After primary flocculation and separation, clear water and sludge are obtained, and the sludge is transported to the sludge tank 9 for temporary storage;

[0035] (3) The clear water after turbidity removal and defluorination treatment in the inclined plate sedimentation tank 2 enters the clear water buffer tank 3 by overflow. The clear water buffer tank 3 is provided with a sodium hydroxide feeding port for adjusting the pH of the wastewater input from the inclined plate sedimentation tank 2 to 11.5 - 12.5;

[0036] (4) The liquid in the clear water buffer tank 3 is transported to the carbon dioxide stripping and hardness removal unit 4. The carbon dioxide stripping and hardness removal unit 4 includes a carbon dioxide stripping reaction tank 41 and a carbon dioxide stripping sedimentation tank 42 connected in sequence. The carbon dioxide stripping reaction tank 41 is connected to the gas-phase carbon dioxide delivery pipeline 11, and the pH is adjusted to 10 - 10.5 by adjusting the carbon dioxide input amount;

[0037] (5)The carbon dioxide stripping and hardness removal unit 4 is connected to the automatic water purification unit 5. The automatic water purification unit 5 includes a sand filtration inclined plate tank 51 and a sand filtration product water tank 52 connected in sequence. The sand filtration inclined plate tank 51 is connected to the hydrochloric acid delivery pipeline 12, and the pH value is adjusted to neutral by adjusting the amount of hydrochloric acid added. The sand filtration product water tank 52 is connected to the membrane device 6 to remove suspended particles and Na + and Cl - in the water. The produced pure water enters the intermediate water tank 72 for reuse after passing through the pure water tank 71. Among them, the internal structures of the sand filtration inclined plate tank 51 and the membrane device 6 are prone to blockage and need to be cleaned regularly. The cleaning frequency is 4 - 6 h / time. The backwash water from the intermediate water tank 72 flushes the sand filtration inclined plate tank 51 and the membrane device 6 and then enters the backwash water treatment unit 8, passing through the PAC tank 81, the PAM tank 82, and the sedimentation tank 83 in sequence to obtain clear water and sludge. The sludge enters the sludge tank 9, and the clear water is transported to the intermediate water tank 72 through the clear water tank 73 for continuous reuse. The sludge in the sludge tank 9 enters the plate and frame filter press 10 for dehydration and is treated as hazardous waste. The filter press water generated by the plate and frame filter press 10 can be returned to the inclined plate sedimentation tank 2 for further treatment and reuse.

[0038] Taking the in-plant circulating wastewater as the treatment object, the wastewater treatment effect is shown in Table 1.

[0039] Table 1 Comparison of wastewater treatment data before and after

[0040]

[0041] It can be seen from Table 1 that the industrial wastewater treatment and recycling system described in the present utility model can effectively treat industrial wastewater. After treatment, the concentrations of F - , Ca 2+ and Mg 2+ are low, the water quality is stable, and it will not cause further corrosion to subsequent devices during use, meeting the environmental protection requirements.

Claims

1. An industrial wastewater treatment, recycling and utilization system, characterized in that, It includes an open buffer tank (1), an inclined plate sedimentation tank (2), a clear water buffer tank (3), a carbon dioxide stripping and hardness removal unit (4), an automatic water purification unit (5), a membrane device (6) and a reuse storage unit (7) connected in sequence. The backwash water outlets of the automatic water purification unit (5) and the membrane device (6) are connected to the input end of a backwash water treatment unit (8), the output end of the backwash water treatment unit (8) is connected to the reuse storage unit (7), and the sludge discharge outlets of the inclined plate sedimentation tank (2) and the backwash water treatment unit (8) are both connected to a sludge tank (9).

2. The industrial wastewater treatment, recycling and utilization system according to claim 1, wherein An inclined plate baffle tank and an inclined plate sedimentation tank are arranged in the inclined plate sedimentation tank (2).

3. The industrial wastewater treatment, recycling and utilization system according to claim 1, wherein The carbon dioxide stripping and hardness removal unit (4) includes a carbon dioxide stripping reaction tank (41) and a carbon dioxide stripping sedimentation tank (42) connected in sequence, and the carbon dioxide stripping reaction tank (41) is connected to a gas-phase carbon dioxide delivery pipeline (11).

4. The industrial wastewater treatment, recycling and utilization system according to claim 1, wherein The backwash water treatment unit (8) includes a PAC tank (81), a PAM tank (82) and a sedimentation tank (83) connected in sequence.

5. The industrial wastewater treatment, recycling and utilization system according to claim 4, wherein, The reuse storage unit (7) includes a pure water tank (71), a medium water tank (72) and a clear water tank (73). The pure water tank (71) and the clear water tank (73) are both connected to the medium water tank (72), and a reuse pipeline is arranged on the medium water tank (72).

6. The industrial wastewater treatment and recycling system according to claim 5, characterized in that, The clear water discharge outlet of the sedimentation tank (83) is connected to the clear water tank (73), and the sludge discharge outlet of the sedimentation tank (83) is connected to the sludge tank (9).

7. The industrial wastewater treatment, recycling and utilization system according to claim 5, characterized in that, The automatic water purification unit (5) includes a sand filter inclined plate tank (51) and a sand filter product water tank (52) connected in sequence. Both the sand filter inclined plate tank (51) and the membrane device (6) are provided with a backwash water inlet and a backwash water outlet, and the backwash water outlets are both connected to the input end of the PAC tank (81), and the backwash water inlets are both connected to the outlet of the medium water tank (72); a pipeline connected to the input end of the pure water tank (71) is arranged at the outlet of the membrane device (6).

8. The industrial wastewater treatment, recycling and utilization system according to claim 7, characterized in that, The sand filter inclined plate tank (51) is connected to a hydrochloric acid delivery pipeline (12).

9. The industrial wastewater treatment, recycling and utilization system according to claim 1, characterized in that, The sludge tank (9) is connected to a plate and frame filter press (10), and a pipeline for returning to the inclined plate sedimentation tank (2) is arranged at the filtrate outlet of the plate and frame filter press (10).

10. The industrial wastewater treatment, recycling and utilization system according to claim 1, characterized in that, A sodium hydroxide feeding port is arranged on the clear water buffer tank (3).

Images