PVA wastewater treatment system and process

Abstract

The invention discloses a PVA (polyvinyl alcohol) wastewater treatment system and a PVA wastewater treatment process. Comprising a wastewater collection system, a pretreatment system connected with the wastewater collection system through a first connecting pipe, a UASB system connected with the pretreatment system through a second connecting pipe, a strong aeration system connected with the top of the UASB system through a third connecting pipe, an air flotation system connected with the top of the strong aeration system through a fourth connecting pipe, and a water supply system connected with the UASB system through a third connecting pipe. The strong aeration system and the air floatation system are respectively connected with a sludge treatment system through a first sludge discharge pipe, a second sludge discharge pipe, a third sludge discharge pipe and a fourth sludge discharge pipe, and dosing mechanisms are arranged in the strong aeration system and the air floatation system. The PVA wastewater is treated by adopting a combined process of the UASB system, the strong aeration system and the air flotation system, and the PVA wastewater treatment device has the advantages of good treatment effect, stable effluent, strong applicability, economy, feasibility and simple process. The PVA wastewater is removed to the maximum extent, so that the COD (Chemical Oxygen Demand) is reduced from 45000 mg / l to below 5500 mg / l, and the treatment requirement of a comprehensive wastewater system is met.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, and in particular to a PVA wastewater treatment system and process. Background Art

[0002] PVA is a water-soluble polymer with excellent film properties, adhesion, wear resistance and compatibility with other sizing agents. It is also inexpensive and is a synthetic sizing agent with a wide range of applications and excellent sizing process performance. At present, my country's textile printing and dyeing enterprises mostly use a mixture of PVA and starch in the sizing process of textile warp yarns to make up for each other's shortcomings and obtain a good sizing effect. Therefore, the desizing wastewater mainly contains PVA and starch. PVA is a highly biodegradable organic matter with extremely poor biodegradability. Direct discharge into the sewage treatment system will lead to increased foam in the water body, increased viscosity, and inhibit or even destroy the activity of microorganisms in the water, thereby increasing the difficulty of treating textile printing and dyeing wastewater. Therefore, it is necessary to treat the desizing wastewater separately and recycle the PVA in it to reduce the difficulty of treating the comprehensive wastewater of the enterprise, while reducing the raw material consumption and product costs of the enterprise, and improving the enthusiasm and initiative of the enterprise in pollution control.

[0003] At present, the treatment methods of PVA desizing wastewater mainly include biochemical method and physicochemical method. The biochemical method mainly includes anaerobic method, activated sludge method, etc. This type of technology has the defects of poor treatment effect stability, low PVA removal efficiency, and difficulty in forming a specific PVA dominant bacterial community. The physicochemical method mainly includes salting out method, membrane separation method, ozone catalytic oxidation method, photocatalytic oxidation and other technologies.

[0004] Therefore, a PVA wastewater treatment system and process are provided to solve the above-mentioned technical problems. Summary of the invention

[0005] The purpose of the present invention is to provide a PVA wastewater treatment system and process. The present invention adopts biochemical and physical chemical processes to treat PVA wastewater, and the effluent is mixed with comprehensive wastewater for re-treatment. The present invention has the advantages of good treatment effect, stable effluent, strong applicability, economic feasibility and simple process. PVA wastewater is removed to the maximum extent. Thus, COD is reduced from 45000 mg / l to below 5500 mg / l to meet the treatment requirements of the comprehensive wastewater system.

[0006] The object of the present invention is achieved in that:

[0007] A PVA wastewater treatment system comprises a wastewater collection system, a pretreatment system connected to the wastewater collection system through a first connecting pipe, a UASB system connected to the pretreatment system through a second connecting pipe, a strong aeration system connected to the top of the UASB system through a third connecting pipe, an air flotation system connected to the top of the strong aeration system through a fourth connecting pipe, and a sludge disposal system connected to the UASB system, the strong aeration system and the air flotation system through a first mud discharge pipe, a second mud discharge pipe, a third mud discharge pipe and a fourth mud discharge pipe, respectively, wherein a dosing mechanism is provided in the strong aeration system and the air flotation system.

[0008] The flotation system includes a flotation tank, a guide plate for dividing the flotation tank into a first holding tank and a second holding tank, a flotation pump and a stirring body located in the first holding tank, and an air dissolving component located in the second holding tank. The inlet end of the flotation pump is connected to the top of the strong aeration system through a fourth connecting pipe, and the drainage pipe is connected to the interior of the second holding tank.

[0009] The fourth mud discharge pipe is located at the bottom of the first containing tank, and the third mud discharge pipe is located at the lower part of the second containing tank.

[0010] The medicine adding mechanism comprises a box body, a medicine feeding pipe located at the lower part of the box body, a second water inlet located at the bottom of the box body, a second water outlet located at the upper part of the box body, and a plurality of baffles located inside the box body.

[0011] The baffles are arranged in sequence from top to bottom in the box, and are located on the left and right sides of the inner surface of the box. The baffles make the water entering the box arrive at the second water outlet in a wave shape.

[0012] The air dissolving component comprises a containing chamber, a first water inlet located at the lower part of the containing chamber, a first water outlet located at the upper part of the containing chamber, and an air inlet located at the lower part of the containing chamber.

[0013] The wastewater collection system comprises a collection tank, a first grille located in the collection tank, a lifting pump located in the collection tank, and a water inlet pipe located on the collection tank. The water inlet pipe and the lifting pump are located on the left and right sides of the first grille.

[0014] The pretreatment system comprises a treatment tank and a second grid located in the treatment tank.

[0015] A PVA wastewater treatment process comprises the following steps:

[0016] S1, after the wastewater is collected by the wastewater collection system, it enters the pretreatment system through the lifting pump and the first connecting pipe for pretreatment to obtain pretreated wastewater;

[0017] S2, the wastewater pretreated in S1 enters the UASB system through the second connecting pipe, the wastewater is anaerobically treated in the UASB system, anaerobic reaction is carried out to promote the hydrolysis and acidification of the wastewater, and anaerobically treated wastewater is obtained; S3, the wastewater anaerobically treated in S2 enters the strong aeration system through the third connecting pipe to obtain aerated wastewater; the strong aeration system increases the dissolved oxygen content in the water by introducing oxygen into the wastewater to promote the degradation of organic matter;

[0018] S4, the wastewater after aeration treatment in S3 enters the flotation system through the fourth pipeline for treatment, and the treated wastewater is discharged through the drain pipe;

[0019] The bottom of S5, UASB system, strong aeration system and flotation system are connected to the sludge disposal system through a sludge discharge pipe to collect the sludge and carry out centralized treatment.

[0020] The beneficial effects of the present invention are as follows: the present invention adopts a combined process of UASB system, strong aeration system and air flotation system to treat PVA wastewater, which has the advantages of good treatment effect, stable effluent, strong applicability, economic feasibility and simple process. PVA wastewater is removed to the maximum extent, thereby reducing COD from 45000mg / l to below 5500mg / l, meeting the treatment requirements of the comprehensive wastewater system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the present invention;

[0022] Figure 2 It is a structural schematic diagram of the air flotation system of the present invention;

[0023] Figure 3 It is a structural schematic diagram of the medicine adding mechanism of the present invention;

[0024] Figure 4 It is a structural schematic diagram of the gas dissolving component of the present invention;

[0025] In the figure: wastewater collection system 1, pretreatment system 2, UASB system 3, strong aeration system 4, air flotation system 5, sludge disposal system 6, dosing mechanism 7, first connecting pipe 8, second connecting pipe 9, third connecting pipe 10, fourth connecting pipe 11, first mud discharge pipe 12, second mud discharge pipe 13, third mud discharge pipe 14, drainage pipe 15, fourth mud discharge pipe 16, collection tank 101, water inlet pipe 102, first grille 103, lifting pump 104, treatment tank 201, second grid 202, flotation tank 501, flotation pump 502, stirring body 503, guide plate 504, dissolved air component 505, accommodating chamber 5051, first water inlet 5052, first water outlet 5053, air inlet 5054, first accommodating tank 506, second accommodating tank 507, box body 701, drug inlet pipe 702, second water inlet 703, second water outlet 704, baffle 705. DETAILED DESCRIPTION

[0026] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0027] Embodiment 1:

[0028] like Figure 1 As shown, a PVA wastewater treatment system comprises a wastewater collection system 1, a pretreatment system 2 connected to the wastewater collection system 1 through a first connecting pipe 8, a UASB system 3 connected to the pretreatment system 2 through a second connecting pipe 9, a strong aeration system 4 connected to the top of the UASB system 3 through a third connecting pipe 10, a flotation system 5 connected to the top of the strong aeration system 4 through a fourth connecting pipe 11, and a sludge disposal system 6 connected to the UASB system 3, the strong aeration system 4 and the flotation system 5 through a first mud discharge pipe 12, a second mud discharge pipe 13, a third mud discharge pipe 14 and a fourth mud discharge pipe 15, respectively, and a dosing mechanism 7 is provided in the strong aeration system 4 and the flotation system 5. The present invention adopts a combined process of a UASB system, a strong aeration system and a flotation system to treat PVA wastewater, and has the advantages of good treatment effect, stable effluent, strong applicability, economic feasibility and simple process. The PVA wastewater is removed to the maximum extent, thereby reducing the COD from 45000mg / l to below 5500mg / l, meeting the treatment requirements of the comprehensive wastewater system.

[0029] like Figure 2As shown, the flotation system 5 includes a flotation tank 501, a guide plate 504 for dividing the flotation tank 501 into a first receiving tank 506 and a second receiving tank 507, a flotation pump 502 and a stirring body 503 located in the first receiving tank 506, and an air dissolving component 505 located in the second receiving tank 507. The inlet end of the flotation pump 502 is connected to the top of the strong aeration system 4 through a fourth connecting pipe 11, so as to facilitate the wastewater treated by the strong aeration system 4 to be pumped into the flotation system 5. The drain pipe 15 is connected to the inside of the second receiving tank 507 to discharge the treated wastewater through the drain pipe 15. The fourth mud discharge pipe 11 is located at the bottom of the first receiving tank 506, and the third mud discharge pipe 10 is located at the lower part of the second receiving tank 507. The wastewater is subjected to flotation treatment in the flotation tank 501 to remove suspended matter in the wastewater.

[0030] like Figure 3 As shown, the medicine adding mechanism 7 comprises a box 701, a medicine feeding pipe 702 located at the lower part of the box 701, a second water inlet 703 located at the bottom of the box 702, a second water outlet 704 located at the upper part of the box 701, and a plurality of baffles 705 located inside the box 701. The plurality of baffles 705 are sequentially arranged from top to bottom in the box 701, and the baffles 705 are located on the left and right sides of the inner surface of the box 701. The baffles 705 located on the left side of the box 701 and the baffles located on the right side of the box 701 are alternately arranged in the vertical direction. The plurality of baffles 705 make the water flow entering the box 701 arrive at the second water outlet 704 in a wave shape, thereby increasing the time for the water to pass through the box 701, and facilitating the uniform mixing of the medicine in the water.

[0031] like Figure 4 As shown, the gas dissolving component 505 includes a accommodating chamber 5051, a first water inlet 5052 located at the lower part of the accommodating chamber 5051, a first water outlet 5053 located at the upper part of the accommodating chamber 5051, and an air inlet 5054 located at the lower part of the accommodating chamber 5051. Gas enters the accommodating chamber 5051 from the air inlet 5054, and then water enters from the first water inlet 5052 and is mixed with the gas and then discharged from the first water outlet 5053. The gas introduced into the wastewater floats on the upper surface against the suspended matter in the water, which is convenient for removing the suspended matter in the wastewater.

[0032] The wastewater collection system 1 includes a collection tank 101, a first grid 103 located in the collection tank 101, a lifting pump 104 located in the collection tank 101, and an inlet pipe 102 located on the collection tank 101. The inlet pipe 102 and the lifting pump 104 are located on the left and right sides of the first grid 103. The setting of the first grid 103 facilitates the preliminary filtration of the wastewater entering the collection tank 101 to filter out large impurities.

[0033] The pretreatment system 2 includes a treatment tank 201 and a second grid 202 located in the treatment tank 201 . The second grid 202 filters the wastewater entering the treatment tank 201 .

[0034] The sludge treatment system 6 includes a sludge tank, a sludge concentration tank and a sludge dewatering device which are connected in sequence. The sludge is processed by the sludge treatment system to form a dry mud cake for external transportation.

[0035] Example 2

[0036] A PVA wastewater treatment process comprises the following steps:

[0037] S1. After the wastewater is collected by the wastewater collection system 1, it enters the pretreatment system 2 through the lifting pump 104 and the first connecting pipe 8 for pretreatment to obtain pretreated wastewater.

[0038] S2. The wastewater pretreated in S1 enters the UASB system through the second connecting pipe 9. The wastewater is anaerobically treated in the UASB system 3 to undergo anaerobic reaction to promote hydrolysis and acidification of the wastewater, thereby obtaining anaerobic treated wastewater.

[0039] S3, the anaerobic treated wastewater in S2 enters the strong aeration system 4 through the third connecting pipe 10 to obtain aerated wastewater; the strong aeration system 4 increases the dissolved oxygen content in the water by introducing oxygen into the wastewater to promote the degradation of organic matter.

[0040] S4, the wastewater after aeration treatment in S3 enters the flotation system 5 through the fourth pipe 11 for treatment, and the treated wastewater is discharged through the drain pipe 15. The wastewater is subjected to flotation treatment in the flotation tank 501 to remove suspended solids in the wastewater.

[0041] The bottoms of S5, UASB system, strong aeration system 4 and flotation system 5 are connected to sludge disposal system 6 through sludge discharge pipes to collect sludge and carry out centralized treatment.

Claims

1. A PVA wastewater treatment system, characterized in that: The invention comprises a wastewater collection system, a pretreatment system connected to the wastewater collection system through a first connecting pipe, a UASB system connected to the pretreatment system through a second connecting pipe, a strong aeration system connected to the top of the UASB system through a third connecting pipe, a flotation system connected to the top of the strong aeration system through a fourth connecting pipe, and a sludge disposal system connected to the UASB system, the strong aeration system and the flotation system through a first mud discharge pipe, a second mud discharge pipe, a third mud discharge pipe and a fourth mud discharge pipe, respectively, wherein both the strong aeration system and the flotation system are provided with a dosing mechanism.

2. The PVA wastewater treatment system according to claim 1, characterized in that: The flotation system includes a flotation tank, a guide plate for dividing the flotation tank into a first holding tank and a second holding tank, a flotation pump and a stirring body located in the first holding tank, and an air dissolving component located in the second holding tank. The inlet end of the flotation pump is connected to the top of the strong aeration system through a fourth connecting pipe, and the drainage pipe is connected to the interior of the second holding tank.

3. The PVA wastewater treatment system according to claim 2, characterized in that: The fourth mud discharge pipe is located at the bottom of the first containing tank, and the third mud discharge pipe is located at the lower part of the second containing tank.

4. The PVA wastewater treatment system according to claim 1, characterized in that: The medicine adding mechanism comprises a box body, a medicine feeding pipe located at the lower part of the box body, a second water inlet located at the bottom of the box body, a second water outlet located at the upper part of the box body, and a plurality of baffles located inside the box body.

5. The PVA wastewater treatment system according to claim 4, characterized in that: The baffles are arranged in sequence from top to bottom in the box, and are located on the left and right sides of the inner surface of the box. The baffles make the water entering the box arrive at the second water outlet in a wave shape.

6. The PVA wastewater treatment system according to claim 2, characterized in that: The air dissolving component comprises a containing chamber, a first water inlet located at the lower part of the containing chamber, a first water outlet located at the upper part of the containing chamber, and an air inlet located at the lower part of the containing chamber.

7. The PVA wastewater treatment system according to claim 1, characterized in that: The wastewater collection system comprises a collection tank, a first grille located in the collection tank, a lifting pump located in the collection tank, and a water inlet pipe located on the collection tank. The water inlet pipe and the lifting pump are located on the left and right sides of the first grille.

8. The PVA wastewater treatment system according to claim 1, characterized in that: The pretreatment system comprises a treatment tank and a second grid located in the treatment tank.

9. A PVA wastewater treatment process, characterized in that: The following steps are involved: S1, after the wastewater is collected by the wastewater collection system, it enters the pretreatment system through the lifting pump and the first connecting pipe for pretreatment to obtain pretreated wastewater; S2, the wastewater pretreated in S1 enters the UASB system through the second connecting pipe, and the wastewater is anaerobically treated in the UASB system to perform anaerobic reaction to promote hydrolysis and acidification of the wastewater to obtain anaerobic treated wastewater; S3, the anaerobic wastewater in S2 enters the strong aeration system through the third connecting pipe to obtain aerated wastewater; the strong aeration system increases the dissolved oxygen content in the water by introducing oxygen into the wastewater to promote the degradation of organic matter; S4, the wastewater after aeration treatment in S3 enters the flotation system through the fourth pipeline for treatment, and the treated wastewater is discharged through the drain pipe; The bottom of S5, UASB system, strong aeration system and flotation system are connected to the sludge disposal system through a sludge discharge pipe to collect the sludge and carry out centralized treatment.

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