Industrial wastewater treatment system

Abstract

The utility model discloses an industrial wastewater treatment system which comprises a first aeration tank, a sewage treatment tank, a second aeration tank, an air floatation tank and a clean water tank, wherein a water inlet of the first aeration tank is communicated with the industrial wastewater concentration tank, and a water outlet of the first aeration tank is communicated with the sewage treatment tank; a water outlet of the sewage treatment tank is communicated with the second aeration tank through a pipeline with a first water pump; a water outlet of the second aeration tank is sequentially communicated with the air floatation tank and the clean water tank; the bottoms of the sewage treatment tank and the second aeration tank are communicated with a sludge tank through pipelines, and the sludge tank is communicated with a filter press. According to the utility model, ferrous sulfate in wastewater is effectively removed through two-stage aeration treatment; the ferrous sulfate-containing wastewater treatment device is high in wastewater treatment efficiency, a large batch of wastewater can be effectively purified in time, the treated clear water is environment-friendly and pollution-free, and pollution-free discharge of the ferrous sulfate-containing wastewater is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of industrial wastewater treatment, in particular to an industrial wastewater treatment system containing ferrous sulfate. Background Art

[0002] The wastewater generated by steel washing in steel mills usually contains a certain amount of impurities such as ferrous sulfate and particulate matter. If it is not treated, it will have adverse effects on the environment after discharge, especially the ferrous sulfate component, which will pollute the water body and affect the respiratory and digestive systems of organisms.

[0003] Chinese patent CN1590304A discloses a method for comprehensive utilization of ferrous sulfate wastewater and scrap iron, which achieves the purpose of wastewater treatment and reuse of iron elements by adding scrap iron to react with ferrous sulfate in the wastewater to generate black iron oxide, red iron oxide and ammonium sulfate.

[0004] However, in the process of realizing the technical solutions of the inventions and creations in the embodiments of the present application, the inventors of the present application found that the above-mentioned technology has at least the following technical problems: the steel washing wastewater has the characteristics of huge wastewater volume, but low ferrous sulfate content therein. The above-mentioned patented technology adopts a treatment method for converting, purifying and reusing iron elements, which has the problems of high treatment cost and low wastewater treatment efficiency. It cannot timely and effectively purify industrial wastewater with large production volume, and has poor feasibility and economy. Utility Model Content

[0005] The utility model provides an industrial wastewater treatment system, which can timely and efficiently treat wastewater containing ferrous sulfate generated by washing steel in a steel rolling mill, achieve zero discharge of wastewater, and solve the above problems existing in the prior art.

[0006] In order to solve the above technical problems, the utility model provides an industrial wastewater treatment system, comprising a first aeration tank, a sewage treatment tank, a second aeration tank, a flotation tank and a clean water tank; wherein the water inlet of the first aeration tank is connected to the industrial wastewater concentration tank, and the water outlet thereof is connected to the sewage treatment tank; the water outlet of the sewage treatment tank is connected to the second aeration tank through a pipeline with a first water pump; the water outlet of the second aeration tank is connected to the flotation tank and the clean water tank in turn; the bottoms of the sewage treatment tank and the second aeration tank are connected to a sludge tank through a pipeline, and the sludge tank is connected to a filter press.

[0007] In a preferred embodiment of the utility model, the system further comprises a first sedimentation tank and a second sedimentation tank, wherein the bottom of the second aeration tank is first connected to the first sedimentation tank through a pipeline, and the second sedimentation tank is connected to the sludge tank.

[0008] In a preferred embodiment of the utility model, a flushing water pipe is connected to the second aeration tank.

[0009] In a preferred embodiment of the utility model, the second aeration tank is higher than the first aeration tank; the water levels of the industrial wastewater concentration tank, the first aeration tank and the sewage treatment tank are gradually reduced; and the water levels of the flotation tank and the clean water tank are gradually reduced.

[0010] In a preferred embodiment of the utility model, aeration pipes are laid in both the first aeration tank and the second aeration tank, and the aeration pipes have aeration holes opened downward.

[0011] In a preferred embodiment of the present invention, the water outlet of the flotation pool is located at the lower middle portion of the side wall of the flotation pool.

[0012] In a preferred embodiment of the utility model, the clean water tank includes a first clean water tank and a second clean water tank, the first clean water tank is connected to the water outlet of the flotation tank, and a water outlet pipe is arranged at the rear end of the second clean water tank.

[0013] In a preferred embodiment of the present utility model, the second clean water tank is also connected to the flushing water pipe, and a second water pump is installed on the flushing water pipe.

[0014] In a preferred embodiment of the present invention, a filter is further installed on the pipeline between the sewage treatment tank and the second aeration tank, and the filter is located before the sewage treatment tank and the first water pump.

[0015] In a preferred embodiment of the present invention, the filtrate outlet of the filter press is connected to the first aeration tank through a pipeline.

[0016] The beneficial effects of the utility model are as follows: the utility model is an industrial wastewater treatment system, which effectively removes ferrous sulfate in wastewater through the design of a first aeration tank, a sewage treatment tank, a second aeration tank, a flotation tank, a clean water tank and a sludge tank, and through two-stage aeration treatment; the utility model has high wastewater treatment efficiency, can timely and effectively purify and treat large quantities of wastewater, and the treated clean water is environmentally friendly and pollution-free, thereby achieving pollution-free discharge of wastewater containing ferrous sulfate. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of a preferred embodiment of an industrial wastewater treatment system of the utility model;

[0018] The markings of the components in the accompanying drawings are as follows:

[0019] 100. Industrial wastewater concentration pool;

[0020] 10. The first aeration tank, 20. The sewage treatment tank, 30. The second aeration tank, 31. The flushing water pipe, 40. The flotation tank, 50. The clean water tank, 51. The first clean water tank, 52. The second clean water tank, 521. The outlet pipe, 61. The first water pump, 62. The second water pump, 70. The filter, 80. The sludge tank, 91. The first sedimentation tank, 92. The second sedimentation tank, 93. The filter press. DETAILED DESCRIPTION

[0021] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0022] Example 1

[0023] like Figure 1 As shown, the utility model discloses an industrial wastewater treatment system for treating industrial wastewater containing ferrous sulfate. The system comprises a first aeration tank 10, a sewage treatment tank 20, a second aeration tank 30, an air flotation tank 40 and a clean water tank 50 connected in sequence; wherein the water inlet of the first aeration tank 10 is connected to the industrial wastewater concentration tank 100, and the wastewater to be treated collected in the industrial wastewater concentration tank 100 first enters the first aeration tank 10, and then flows into the subsequent tanks step by step for treatment.

[0024] Specifically, the first aeration tank 10 is a low-level aeration tank, which is used to perform preliminary aeration treatment on the wastewater in preparation for the subsequent wastewater purification process. The outlet of the first aeration tank 10 is connected to the sewage treatment tank 20. The water levels of the industrial wastewater concentration tank 100, the first aeration tank 10 and the sewage treatment tank 20 are lowered one by one. Through the design of lowering the water level one by one, the wastewater in the industrial wastewater concentration tank 100 can flow through the first aeration tank 10 by utilizing the water level difference after the valve is opened, and then enter the sewage treatment tank 20 for treatment, thereby saving the energy consumption of wastewater transportation and reducing the operating cost of wastewater treatment.

[0025] Lime water and aluminum salt agents, such as aluminum chloride, are added to the sewage treatment pool 20. Under the action of lime water, agents and dissolved oxygen, ferrous sulfate in the wastewater is converted into trivalent iron, and precipitation is generated under alkaline conditions and settles to the bottom of the pool. In addition, granular impurities, sludge, etc. will also settle to the bottom of the pool, so that the wastewater is purified.

[0026] The second aeration tank 30 is a high-position aeration tank, and the water outlet of the sewage treatment tank 20 is connected to the second aeration tank 30 through a pipe with a first water pump 61. The middle and lower parts of the first aeration tank 10 and the second aeration tank 30 are both arranged with a plurality of aeration pipes (not shown), and downward aeration holes are provided on the aeration pipes. The design of the aeration holes opening downward can prevent sludge and the like in the wastewater from entering the aeration holes, and can prevent the aeration holes from being blocked. The wastewater treated by the sewage treatment tank 20 is treated by aeration again in the second aeration tank 30, so that the remaining ferrous sulfate is further transformed and precipitated under the action of dissolved oxygen and residual agents in the wastewater. The removal rate of ferrous sulfate is improved by two-stage conversion and sedimentation treatment.

[0027] A filter 70 is also installed on the pipeline between the sewage treatment tank 20 and the second aeration tank 30. The filter 70 is located in front of the first water pump 61 (i.e., between the sewage treatment tank and the first water pump) and is used to intercept larger particles with a particle size greater than or equal to 2 mm to prevent the water pump from being blocked or causing equipment failure due to the particles.

[0028] The water outlet of the second aeration tank 30 is connected to the air flotation tank 40 through a pipeline. The water outlet of the air flotation tank 40 is connected to the clean water tank 50 through a pipeline. The liquid levels in the second aeration tank 30, the air flotation tank 40 and the clean water tank 50 are reduced one by one. By designing the second aeration tank 30 as a high-level aeration tank and then utilizing the design of the water level difference, it plays a role in saving wastewater transportation energy consumption and reducing the operating cost of wastewater treatment.

[0029] Purifiers and polymer agents, such as sodium polyacrylate, are added into the flotation tank 40 to perform flotation treatment on the wastewater after the ferrous sulfate is removed, thereby further improving the purification effect of the wastewater.

[0030] The clean water tank 50 includes a first clean water tank 51 and a second clean water tank 52. The first clean water tank 51 is connected to the water outlet at the middle and lower part of the side wall of the flotation tank 40 through a pipeline, and the clean water at the middle and lower part of the flotation tank 40 flows into the clean water tank 51. A water outlet pipe 521 is arranged at the rear end of the second clean water tank 52. The clean water discharged through the water outlet pipe 521 can be directly discharged or reused.

[0031] The bottom of the sewage treatment pool 20 is connected to the sludge pool 80 through a pipeline, and the sludge deposited therein flows into the sludge pool 80 .

[0032] The bottom of the second aeration tank 30 is connected to the first sedimentation tank 91, the second sedimentation tank 92 and the sludge tank 80 in sequence through pipes. The top of the second aeration tank 30 is also connected to a flushing water pipe 31, and the flushing water pipe 31 is connected to the second clean water tank 52 through a pipe with a second water pump 62. Part of the clean water in the second clean water tank 52 is pumped into the flushing water pipe 31 by the second water pump 62 to flush the second aeration tank 30, thereby realizing wastewater reuse, improving water resource utilization, and saving water resources. Through the arrangement of the flushing water pipe 31, the first sedimentation tank 91 and the second sedimentation tank 92, the sludge at the bottom of the second aeration tank 30 is effectively transferred to the sludge tank for unified treatment, thereby improving the subsequent wastewater aeration treatment effect.

[0033] Compared with the sewage treatment tank 20, the amount of sludge deposited in the second aeration tank 30 is small. After being rinsed with clean water, the sludge is precipitated in the first sedimentation tank 91 and the second sedimentation tank 92, and finally enters the sludge tank 80 to be mixed with the sludge flowing in from the sewage treatment tank 20. The sludge tank 80 is connected to the filter press 93, and the sludge collected in the sludge tank 80 is filtered by the filter press to recover the filter cake, and the filtered wastewater is then passed into the first aeration tank 10, so as to achieve effective purification and pollution-free discharge of process wastewater.

[0034] The utility model provides an industrial wastewater treatment system, which has the following advantages:

[0035] 1. The wastewater treatment efficiency is high and large quantities of wastewater can be purified and treated in a timely and effective manner.

[0036] 2. By utilizing the design of the high-position second aeration tank and lowering the water levels of the industrial wastewater concentration tank, the first aeration tank and the sewage treatment tank one by one before the second aeration tank, and lowering the water levels of the flotation tank and the clear water tank one by one after the second aeration tank, the energy consumption required for wastewater transportation in the system is effectively reduced, thereby reducing the wastewater operation cost.

[0037] 3. Through two-stage aeration, ferrous sulfate in wastewater is effectively removed. The treated clean water is environmentally friendly and pollution-free, achieving pollution-free discharge of ferrous sulfate-containing wastewater.

[0038] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An industrial wastewater treatment system, characterized in that: It comprises a first aeration tank, a sewage treatment tank, a second aeration tank, an air flotation tank and a clean water tank; wherein the water inlet of the first aeration tank is connected with an industrial wastewater concentration tank, and the water outlet thereof is connected with the sewage treatment tank; the water outlet of the sewage treatment tank is connected with the second aeration tank through a pipeline with a first water pump; the water outlet of the second aeration tank is connected with the air flotation tank and the clean water tank in sequence; the bottoms of the sewage treatment tank and the second aeration tank are connected with a sludge tank through a pipeline, and the sludge tank is connected with a filter press.

2. An industrial wastewater treatment system according to claim 1, characterized in that: The system further comprises a first sedimentation tank and a second sedimentation tank, wherein the bottom of the second aeration tank is firstly connected with the first sedimentation tank through a pipeline, and the second sedimentation tank is connected with the sludge tank.

3. An industrial wastewater treatment system according to claim 2, characterized in that: The second aeration tank is connected with a flushing water pipe.

4. An industrial wastewater treatment system according to claim 1, characterized in that: The second aeration tank is higher than the first aeration tank; the water levels of the industrial wastewater concentration tank, the first aeration tank and the sewage treatment tank are gradually reduced; and the water levels of the flotation tank and the clean water tank are gradually reduced.

5. An industrial wastewater treatment system according to claim 1 or 4, characterized in that: Aeration pipes are laid in the first aeration tank and the second aeration tank, and the aeration pipes are provided with aeration holes opened downwards.

6. An industrial wastewater treatment system according to claim 3, characterized in that: The water outlet of the air flotation pool is located at the lower middle part of the side wall of the air flotation pool.

7. An industrial wastewater treatment system according to claim 6, characterized in that: The clean water tank comprises a first clean water tank and a second clean water tank, the first clean water tank is connected to the water outlet of the flotation tank, and a water outlet pipe is arranged at the rear end of the second clean water tank.

8. An industrial wastewater treatment system according to claim 7, characterized in that: The second clear water tank is also connected to the flushing water pipe, and a second water pump is installed on the flushing water pipe.

9. An industrial wastewater treatment system according to claim 1, characterized in that: A filter is also installed on the pipeline between the sewage treatment tank and the second aeration tank, and the filter is located before the sewage treatment tank and the first water pump.

10. An industrial wastewater treatment system according to claim 1, characterized in that: The filtrate outlet of the filter press is connected to the first aeration tank through a pipeline.

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