CN211813997U

CN211813997U - Printing and dyeing wastewater recovery device

Info

Publication number: CN211813997U
Application number: CN201922391778.0U
Authority: CN
Inventors: 胡长鑫; 胡晓宇; 吴瑞军
Original assignee: Tianjin Motimo Membrane Technology Co Ltd
Current assignee: Tianjin Motimo Membrane Technology Co Ltd
Priority date: 2019-12-26
Filing date: 2019-12-26
Publication date: 2020-10-30
Anticipated expiration: 2029-12-26

Abstract

The utility model belongs to the field of sewage treatment, in particular to a recovery device for printing and dyeing wastewater discharge, which comprises a grid, an air floatation tank, a hydrolysis acidification tank, an anaerobic tank, an aerobic tank, an MBR tank, an RO membrane tank, an NF membrane tank, a Fenton tank and an active carbon MBR tank which are connected in sequence; the concentrated water outlet of the RO membrane pool is connected with the raw water inlet of the NF membrane pool; a concentrated water outlet of the NF membrane tank is connected with the Fenton tank; the water production ends of the RO membrane pool and the NF membrane pool are connected with the water production pool. The device can use at most printing and dyeing trade organic pollutant COD content high, can effectual reduction aquatic organic pollutant's content, through the reverse osmosis membrane pond, reaches the purpose of minimizing and the effect of desalination, makes quality of water obtain promotion by a wide margin, and the requirement of the reuse water of satisfying can effectively reduce the emission and the water consumption of enterprise's waste water to reach the purpose that reduces the pollution of printing and dyeing waste water.

Description

Printing and dyeing wastewater recovery device

Technical Field

The utility model belongs to the sewage treatment field, concretely relates to printing and dyeing discharge wastewater recovery device.

Background

In China, the printing and dyeing industry occupies an important position in national economic development, printing and dyeing wastewater is a main source of pollution of textile industry, the treatment of the printing and dyeing wastewater is a difficult problem before the development of environmental protection, and the printing and dyeing wastewater has large amount and complex components, contains various dyes, printing and dyeing auxiliaries, acid, alkali and inorganic salt, is difficult to degrade and decolor, has high operation cost and the like, and is very difficult to treat.

The incomplete statistics of the discharged wastewater per year in the national printing and dyeing industry is about 0.6 × 109m3, the number is conservative, and most of the wastewater in the wastewater cannot achieve stable standard discharge, namely the wastewater is not recycled. However, with the destruction of the domestic environment, the improvement of the domestic environmental protection requirement, the enhancement of the treatment of the printing and dyeing wastewater and the reduction of the harm are urgent problems, corresponding measures are taken for printing and dyeing enterprises, the recycling and standard discharge of the discharged wastewater are too good, and the method is not only the requirement of sustainable development, but also the key for improving the economic benefit of the enterprises.

Aiming at the difficulty of treatment of the printing and dyeing wastewater, a very ideal treatment method and a corresponding treatment device have not been found so far, so that the development of a relatively complete treatment device is of great significance.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a printing and dyeing discharges waste water recovery unit.

The utility model discloses a realize above-mentioned purpose, adopt following technical scheme:

a device for recovering printing and dyeing discharged wastewater comprises a grid, an air floatation tank, a hydrolysis acidification tank, an anaerobic tank, an aerobic tank, an MBR tank, an RO membrane tank, an NF membrane tank, a Fenton tank and an active carbon MBR tank which are connected in sequence; the concentrated water outlet of the RO membrane pool is connected with the raw water inlet of the NF membrane pool; a concentrated water outlet of the NF membrane tank is connected with the Fenton tank; and the water production ends of the RO membrane pool and the NF membrane pool are connected with the water production pool.

The grids comprise 1-2 coarse grids with clear distance of 5mm-8mm and 2-3 fine grids with clear distance of 1-2 mm.

The sludge discharging port of the MBR tank is connected with a plate-and-frame filter press, and the outlet of sludge water is connected with the aerobic tank.

The application also includes a process for using the device for recovering wastewater discharged by printing and dyeing, which comprises

1) The pretreatment part comprises that printing and dyeing wastewater sequentially passes through a grating, an air floatation tank, a hydrolysis acidification tank, an anaerobic tank, an aerobic tank and an MBR tank;

2) the reduction part comprises a RO membrane pool and an NF membrane pool through which the pre-treated water passes in sequence;

3) and in the advanced treatment part, the reduced water passes through a Fenton tank and an active carbon MBR stage tank.

Adding liquid caustic soda into the air floatation tank in the step 1) to adjust the pH value to be 6.5-7, adding 1000ppm of PAC flocculant and 5-10ppm of cation PAM to perform filter pressing and desliming, wherein the water content of sludge is 60%, and the COD removal rate of raw water is more than 60%.

The dissolved oxygen in the anaerobic tank is less than 0.2mg/L, and the dissolved oxygen in the aerobic tank is controlled to be 5-8 mg/L; through the anaerobic stage and the aerobic stage, the removal rate of COD content is more than 85 percent. And 3, MBR (membrane bioreactor) membrane produced water SDI is less than 3, so that the water inlet requirement of a subsequent RO process is met.

In the RO membrane pool in the step 2), the set recovery rate of the reverse osmosis membrane is 70 percent; and (3) enabling a concentrated water outlet of the RO reverse osmosis membrane to enter a NF nanofiltration membrane stage, and setting the recovery rate of the nanofiltration membrane in the NF membrane pool to be 40%.

Compared with the prior art, the beneficial effects of the utility model are that:

effectively comprehensively applies the water treatment technology to achieve the aim of recycling the printing and dyeing wastewater. The process adopts a double-membrane method (RO and NF double membranes) to treat the printing and dyeing wastewater, because different substances are separated or intercepted in the operation process of the membrane separation technology, the membrane separation process is a pure physical process, has no phase change and chemical reaction, and realizes the recovery of water resources under the condition of no secondary pollution; and the high-efficient separation of membrane, it is stable to go out water, has guaranteed that the product water of membrane can satisfy the water supply requirement. And the membrane equipment device has small occupied area, high automation degree and simple and convenient operation and maintenance.

The device can use at most printing and dyeing trade organic pollutant COD content high, and traditional technology is handled and is not reached emission standard, through the preliminary treatment technology, can effectual reduction aquatic organic pollutant's content, through reverse osmosis process, reaches the purpose of minimizing and the effect of desalination, makes quality of water obtain promotion by a wide margin, and the requirement of the reuse water of satisfying can effectively reduce the emission and the water consumption of enterprise's waste water to reach the purpose that reduces the pollution of printing and dyeing waste water.

Drawings

FIG. 1 is a schematic view of the waste water recovery device for printing and dyeing wastewater of the present invention;

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the present invention will be further described in detail with reference to the accompanying drawings and preferred embodiments.

FIG. 1 shows a recovery device of printing and dyeing wastewater, comprising a grid 1, an air flotation tank 2, a hydrolysis acidification tank 3, an anaerobic tank 4, an aerobic tank 5, an MBR tank 6, an RO membrane tank 7, an NF membrane tank 8, a Fenton tank 9 and an active carbon MBR tank 10 which are connected in sequence; the concentrated water outlet of the RO membrane pool is connected with the raw water inlet of the NF membrane pool; a concentrated water outlet of the NF membrane tank is connected with the Fenton tank 9; and the water production ends of the RO membrane pool and the NF membrane pool are connected with a water production pool 11. The grids comprise 1-2 coarse grids with clear distance of 5mm-8mm and 2-3 fine grids with clear distance of 1-2 mm. The sludge discharge port of the MBR tank is connected with the plate-and-frame filter press 12, and the outlet of the sludge water is connected with the aerobic tank.

The process of using the device for recovering the printing and dyeing discharged wastewater takes a certain project in Jiangsu as an example, the whole set of system is operated after being installed, the system is designed to treat 4 ten thousand tons of water per day, the COD content of raw water is between 1200 and 1500mg/L, the pH value is between 3 and 5, and the process is applied to the water quality.

Three rotary grating machines are used for pre-treating the grating, wherein one coarse grating with a clear distance of 5mm and two fine gratings with a clear distance of 1mm intercept floating objects and larger particle suspended matters in the wastewater.

Effluent passes through 2 shallow air flotation water purifiers in an air flotation tank, the diameter of each shallow air flotation water purifier is 14m, the treated water amount is 2 ten thousand tons/day, the pH of the incoming water is acidic, after air flotation, water quality is combined, liquid caustic soda with the concentration of 30% is added into a hydrolysis acidification tank, the pH is adjusted to be 6.5-7, PAC1000ppm with the concentration of 10% and cation PAM 5-10ppm are added in the air flotation process for filter pressing and desliming, sludge is treated by a plate and frame filter press, the treated sludge is pulled out of a factory for treatment, and after filter pressing, the water content of sludge cakes is about 60%. Through the air floatation process, the COD content of raw water can be reduced from 1500mg/L to below 600mg/L, and the removal rate can reach more than 60 percent. The air floatation process is the beginning of pretreatment, the load and design of the subsequent process are directly influenced by the treatment effect, the water quality of inlet water needs to be continuously detected every day, and particularly, the indexes COD and pH of treatment in the process section are continuously detected, so that the adding amount of a medicament is determined. The pH value of the effluent of the process section is adjusted to 6.5-7 to meet the conditions of subsequent hydrolytic acidification and biochemical reaction. Measuring COD of raw water and effluent, and determining the removal effect of the process on organic pollutants in water and the incoming water condition of the subsequent process.

Air-float effluent passes through a hydrolytic acidification tank, macromolecular substances which are difficult to biodegrade are degraded into micromolecular substances which are easy to biodegrade through hydrolytic acidification, the full load retention time of the hydrolytic acidification tank is designed to be 5.3h, sewage enters an anaerobic tank after passing through the hydrolytic acidification tank, organic substances are hydrolyzed, acidified and methanated through the action of anaerobic bacteria to remove the organic substances in the wastewater, so that the sewage has better biochemical property, the full load retention time of the stage is designed to be 8.6h, the dissolved oxygen of the anaerobic tank is controlled within 0.2mg/L, the effluent of the anaerobic tank enters an aerobic tank, the dissolved oxygen of the aerobic tank is controlled to be between 5 and 8mg/L, the organic substances are decomposed into inorganic substances through the aerobic respiration of activated sludge, so that the content of the water is reduced, the full load retention time of the stage is designed to be 19h according to the quality of the incoming water, and the treatment of the whole biochemical process is carried out, COD's clearance can reach more than 85%, and COD's content can reduce to within 90mg/L, and biochemical process goes out water, and after MBR membrane technology handles, COD's content can further reduce to within 70mg/L, or lower, and MBR membrane product water SDI <3 satisfies the requirement of intaking of follow-up RO technology.

The set recovery rate of the RO membrane in the RO membrane pool is 70 percent, namely, the RO membrane pool is concentrated by 3.3 times, the indexes of hardness, salt content, ion content and the like in water are greatly removed by the RO membrane pool, and the RO membrane pool also has a remarkable decoloring function, and the produced high-quality water meets the requirement of printing and dyeing water and is directly recycled. The concentrated water of the RO membrane pool enters the NF membrane pool, a large amount of organic matters which are difficult to degrade are contained in the RO concentrated water, COD reaches about 200mg/L, the NF system is processed, the NF recovery rate is designed to be 40%, the organic matters in the water are further concentrated, the content of COD can reach about 320mg/L, the treatment is convenient, the treatment water volume is further reduced, the treatment capacity of subsequent processes is reduced, the NF produced water and the RO produced water are recycled together, the NF concentrated water is processed through a Fenton process, the COD can be reduced to within 100mg/L, the removal rate of the Fenton pool to the COD can reach over 70%, the water after the Fenton treatment reduces the content of the COD to within 60mg/L through the treatment of the active carbon MBR pool, and the removal rate of the COD by the process reaches over 40%. So that the produced water can reach the discharge standard.

The above description is only for the preferred embodiment of the present invention, and for those skilled in the art, there are variations on the detailed description and the application scope according to the idea of the present invention, and the content of the description should not be construed as a limitation to the present invention.

Claims

1. A device for recovering printing and dyeing discharged wastewater is characterized by comprising a grating, an air flotation tank, a hydrolysis acidification tank, an anaerobic tank, an aerobic tank, an MBR tank, an RO membrane tank, an NF membrane tank, a Fenton tank and an active carbon MBR tank which are connected in sequence; the concentrated water outlet of the RO membrane pool is connected with the raw water inlet of the NF membrane pool; a concentrated water outlet of the NF membrane tank is connected with the Fenton tank; and the water production ends of the RO membrane pool and the NF membrane pool are connected with the water production pool.

2. The recycling device for wastewater discharged from textile printing according to claim 1, wherein the grids comprise 1-2 coarse grids spaced 5mm-8mm apart and 2-3 fine grids spaced 1-2mm apart.

3. The recycling device for the printing and dyeing wastewater according to claim 1, characterized in that the sludge outlet of the MBR tank is connected with a plate-and-frame filter press, and the sludge water outlet is connected with the aerobic tank.