CN216191789U

CN216191789U - RO concentrated water treatment system of chemical industry sewage treatment plant

Info

Publication number: CN216191789U
Application number: CN202122746799.7U
Authority: CN
Inventors: 崔海云; 王敏
Original assignee: Shandong Qilu Petrochemical Engineering Co ltd
Current assignee: Shandong Qilu Petrochemical Engineering Co ltd
Priority date: 2021-11-10
Filing date: 2021-11-10
Publication date: 2022-04-05
Anticipated expiration: 2031-11-10

Abstract

The utility model belongs to the technical field of reverse osmosis sewage treatment, and particularly relates to an RO concentrated water treatment system of a sewage treatment plant in the chemical industry. The device comprises a homogenization tank, wherein the homogenization tank is sequentially connected with a high-efficiency sedimentation tank, a denitrification filter tank, an ozone catalytic oxidation tank, an aeration biological filter tank, a micro-sand carbon-adding sedimentation tank, a V-shaped filter tank and an external discharge monitoring tank; the ozone catalytic oxidation tank is connected with an ozone generator; a backwashing device is arranged at the bottom of the biological aerated filter; the high-efficiency sedimentation tank, the denitrification filter tank, the micro-sand carbon-adding sedimentation tank and the V-shaped filter tank are respectively connected with a filter press. The utility model has scientific and reasonable design, selects an economic and reasonable pretreatment and advanced oxidation treatment combined device, ensures that the reverse osmosis concentrated water reaches the national and industrial sewage discharge standard, saves energy, protects environment and has obvious economic benefit.

Description

RO concentrated water treatment system of chemical industry sewage treatment plant

Technical Field

The utility model belongs to the technical field of reverse osmosis sewage treatment, and particularly relates to an RO concentrated water treatment system of a sewage treatment plant in the chemical industry.

Background

At present, the reverse osmosis technology has the characteristics of mature technology, good water quality of produced water and simple operation, and is widely applied to the aspect of domestic sewage recycling. The desalination units of the current sewage reuse device of the Qilu division all adopt the 'ultrafiltration and reverse osmosis' desalination process. From the actual operation effect, the biggest problem of the reverse osmosis desalination technology is the concentrated water treatment problem generated by the system, and the concentrated water subjected to reverse osmosis is difficult to treat to reach the discharge standard due to high salt concentration and difficult biodegradation of organic matters, so that the technology becomes one of the main bottlenecks restricting the application of the reverse osmosis desalination technology in the field of sewage recycling.

At present, two main solutions exist in reverse osmosis concentrated water treatment:

the scheme is that the sewage recycling technology is adopted to treat reverse osmosis concentrated water for recycling, so that a large amount of water resources can be saved, and the discharge of concentrated water can be greatly reduced. The method mainly adopts processes of 'alkali adding and hardness removing-membrane distillation' or 'alkali adding and hardness removing-reverse osmosis concentration-multiple-effect evaporation-drying' and the like, but the processes have large investment, complex process, high operation cost and limited industrial application range.

The second scheme adopts an advanced oxidation treatment process to directly treat reverse osmosis concentrated water to reach the discharge standard, and the current reverse osmosis concentrated water treatment process mainly comprises a Fenton oxidation process, an electrocatalytic oxidation process, an ozone catalytic oxidation process and other technologies. The technological schemes are relatively small in investment and low in operation cost, and the current stage is a main solution for reverse osmosis concentrated water treatment.

As the chemical wastewater has the characteristics of complex wastewater quality, large fluctuation range of the wastewater, poor degradability of organic pollutants and the like, the reverse osmosis concentrated water produced by the wastewater recycling has larger water quality difference, and the main indexes of COD, total nitrogen, ammonia nitrogen, total phosphorus and suspended matters all exceed the standards to different degrees. Therefore, economic and reasonable process units are selected according to the water quality characteristics of the reverse osmosis concentrated water, and all indexes of the reverse osmosis concentrated water after treatment are ensured to be discharged after reaching standards.

SUMMERY OF THE UTILITY MODEL

Aiming at the defects in the prior art, the utility model aims to provide an RO concentrated water treatment system of a sewage treatment plant in the chemical industry, which is scientific and reasonable in design, selects an economic and reasonable pretreatment and advanced oxidation treatment combined device, ensures that the RO concentrated water reaches the national and industrial sewage discharge standard, is energy-saving and environment-friendly, and has remarkable economic benefit.

The RO concentrated water treatment system of the sewage treatment field in the chemical industry comprises a homogenization tank, wherein the homogenization tank is sequentially connected with a high-efficiency sedimentation tank, a denitrification filter tank, an ozone catalytic oxidation tank, an aeration biological filter tank, a micro-sand carbon-adding sedimentation tank, a V-shaped filter tank and an external discharge monitoring tank; the ozone catalytic oxidation tank is connected with an ozone generator; a backwashing device is arranged at the bottom of the biological aerated filter; the high-efficiency sedimentation tank, the denitrification filter tank, the micro-sand carbon-adding sedimentation tank and the V-shaped filter tank are respectively connected with a filter press.

Preferably, a sewage lifting pump is arranged on a pipeline connecting the homogenizing tank and the high-efficiency sedimentation tank.

Preferably, the high-efficiency sedimentation tank is respectively connected with a flocculating agent feeder and an alkali liquor feeder.

Preferably, the biological aerated filter is connected with a liquid caustic soda storage tank.

Preferably, the V-shaped filter chamber is connected with a flocculating agent feeder.

When the system is used, RO concentrated water generated by an industrial sewage regeneration system firstly enters a homogenizing tank, automatically flows into a high-efficiency sedimentation tank after the quality of the water is homogenized and adjusted, is added with caustic soda liquid, forms calcium carbonate sediment by soda ash to remove the hardness in sewage, and then enters an advanced treatment unit.

The advanced treatment unit is an important unit for removing organic pollutants, effluent of the pretreatment unit enters a denitrification filter tank, a carbon source is added to ensure that nitrate nitrogen in the sewage is generated and removed through denitrification reaction, then the effluent enters an ozone catalytic oxidation tank, an ozone catalyst is fixed in the tank, ozone generated by an ozone generator is added into the ozone catalytic oxidation tank through a water injector and is fully mixed and reacted with the sewage, and the biochemical performance of the sewage is improved. The effluent water after catalytic oxidation by ozone enters a Biological Aerated Filter (BAF) to remove the residual organic pollutants in the sewage to the maximum extent and ensure that the COD and the TOC of the effluent water stably reach the standard. And (3) enabling effluent of a Biological Aerated Filter (BAF) to enter a micro-sand and carbon adding sedimentation tank, wherein the adding of powdered activated carbon mainly deals with the impact on a system, and when COD (chemical oxygen demand) effluent cannot stably reach the standard, the concentration of total phosphorus and suspended matters in sewage is reduced by adding PAC (polyaluminium chloride) and PAM (polyacrylamide). And (3) adding carbon into the micro-sand to precipitate the effluent, feeding the effluent into a subsequent V-shaped filter, and filtering by using a filter material to remove residual floc suspended matters in the sewage, thereby finally ensuring that the effluent suspended matters and the total phosphorus are discharged after reaching the standard.

Compared with the prior art, the utility model has the following beneficial effects:

the utility model has scientific and reasonable design, selects an economic and reasonable pretreatment and advanced oxidation treatment combined device, finally treats the effluent to reach the discharge standard of pollutants for petrochemical industry (GB31571-2015) and the discharge standard of local sewage, saves energy, protects environment and has obvious economic benefit.

Drawings

FIG. 1 is a schematic structural view of the present invention;

in the figure: 1. homogenizing tank; 2. a flocculant feeder; 3. an alkali liquor feeder; 4. a high-efficiency sedimentation tank; 5. a denitrification filter; 6. an ozone catalytic oxidation tank; 7. an ozone generator; 8. a liquid caustic soda storage tank; 9. an aeration biological filter; 10. a micro-sand and charcoal adding sedimentation tank; 11. a V-shaped filter chamber; 12. an efflux monitoring pool; 13. a backwashing device; 14. and (4) a filter press.

Detailed Description

The present invention is further described below with reference to examples.

Example 1

As shown in fig. 1, a RO concentrated water treatment system of a sewage treatment plant in chemical industry comprises a homogenization tank 1, wherein the homogenization tank 1 is sequentially connected with a high-efficiency sedimentation tank 4, a denitrification filter tank 5, an ozone catalytic oxidation tank 6, an aeration biological filter tank 9, a micro-sand carbon-adding sedimentation tank 10, a V-shaped filter tank 11 and an external discharge monitoring tank 12; the ozone catalytic oxidation tank 6 is connected with an ozone generator 7; the bottom of the biological aerated filter 9 is provided with a backwashing device 13; the high-efficiency sedimentation tank 4, the denitrification filter tank 5, the micro-sand and carbon adding sedimentation tank 10 and the V-shaped filter tank 11 are respectively connected with a filter press 14.

And a sewage lifting pump is arranged on a pipeline connecting the homogenization tank 1 and the high-efficiency sedimentation tank 4.

The high-efficiency sedimentation tank 4 is respectively connected with the flocculating agent feeder 2 and the alkali liquor feeder 3.

The biological aerated filter 9 is connected with a liquid caustic soda storage tank 8.

The V-shaped filter 11 is connected with a flocculating agent feeder 2.

The utility model is applied to treat RO concentrated water of an ethylene sewage farm recycling device of a certain company:

the sewage reuse treatment scale is 800m³H, water yield of 75 percent and discharge amount of RO concentrated water of 200m³/h。

The quality of inlet water of the sewage treatment plant is CODcr: 200mg/L, NH₃-N: 16.5mg/L, total nitrogen: 50 mg/L.

(1) Alkali adding precipitation unit

The RO concentrated water discharged by the recycling device firstly enters a homogenizing tank 1 for homogenizing adjustment and then is conveyed to a high-efficiency sedimentation tank 4 by a sewage lifting pump. A stirring tank is arranged in a contact tank at the front end of the efficient sedimentation tank 4, a liquid caustic soda adding system is arranged to control the pH value of sewage to be within 10.0, then the sewage automatically flows into a subsequent flocculation reaction zone, the PAC adding concentration is 150mg/L, PAM, the PAC adding concentration is 2mg/L, the sewage automatically flows into the sedimentation zone after the flocculation reaction is finished, and the ascending flow velocity of the sedimentation zone is kept to be not more than 20 m/h. The total hardness of the effluent of the sedimentation tank is controlled to be not more than 500 mg/L.

(2) Denitrification filter 5 unit

Conveying the sewage subjected to the pretreatment of adding alkali for precipitation and hardness removal to a denitrification filter tank 5 through a sewage lifting pump, wherein 50mg/L of carbon source sodium acetate is added to ensure the concentration of COD in the sewage, denitrifying bacteria attached to a filler in the denitrification filter tank 5 reduce nitrate nitrogen in the sewage through denitrification reaction to generate nitrogen to be removed, and finally reducing the total nitrogen concentration in the sewage.

(3) Ozone catalytic oxidation unit

Effluent of a unit of the denitrification filter tank 5 automatically flows into an ozone catalytic oxidation tank 6, an ozone catalyst is filled in the ozone catalytic oxidation tank 6, sewage enters from the bottom of the ozone catalytic oxidation tank 6, ozone is added into the bottom of the tank through a jet pump and fully mixed with the sewage, then the ozone enters an ozone catalyst filling layer, and under the catalytic action of the ozone catalyst, the ozone generates hydroxyl radicals to oxidize and remove organic matters in the sewage. The catalytic reaction time of the ozone is 60min, and the total adding amount of the ozone is 60 kg/h. And tail gas generated by the ozone reaction is conveyed to a tail gas destructor through a pipeline to be treated and discharged after reaching the standard. The water discharged from the ozone catalytic oxidation tank 6 enters a buffer tank to eliminate residual ozone, the hydraulic retention time is 1 hour, and the adverse effect of the residual ozone on microorganisms in the subsequent aeration biological filter tank is avoided.

(4) Aeration biological filter 9 unit

The effluent of the ozone buffer tank automatically flows into the biological aerated filter 9, the filter tank is in a downward inlet and upward outlet mode, COD (chemical oxygen demand) and ammonia nitrogen in the sewage are degraded by microorganisms on ceramsite in the biological aerated filter 9, and liquid caustic soda is added in the filter tank to ensure the pH of the sewage: 7.5-8.5. The bottom of the filter is provided with a backwashing device 13 for periodically backwashing.

(5) Micro-sand and charcoal efficient sedimentation tank

The effluent of the biological aerated filter 9 enters a subsequent micro-sand carbon adding sedimentation tank 10, and the adding of the powdered activated carbon mainly deals with the impact on the system, so that the COD effluent can not reach the standard stably. And the concentration of total phosphorus and suspended matters in the sewage is reduced by adding 100mg/L PAC and 2mg/L PAM.

(6) V-shaped filter tank

The V-shaped filter tank mainly filters suspended matters in the effluent of the micro-sand and carbon adding sedimentation tank 10, the filtering speed is 15m/h, and the SS of the effluent is not more than 10 mg/L.

Final treatment effluent index:

CODcr：40-50mg/L、NH₃-N: 1-5mg/L, total nitrogen: 10-15mg/L, total phosphorus: 0.2-0.5mg/L, SS: 5-10mg/L, which reaches the discharge Standard of pollutants for the petrochemical industry (GB 31571-2015).

Claims

1. The utility model provides a dense water processing system of chemical industry sewage treatment plant RO, includes homogeneous jar (1), its characterized in that: the homogenization tank (1) is sequentially connected with a high-efficiency sedimentation tank (4), a denitrification filter tank (5), an ozone catalytic oxidation tank (6), an aeration biological filter tank (9), a micro-sand and carbon adding sedimentation tank (10), a V-shaped filter tank (11) and an external discharge monitoring tank (12); the ozone catalytic oxidation tank (6) is connected with an ozone generator (7); the bottom of the biological aerated filter (9) is provided with a backwashing device (13); the high-efficiency sedimentation tank (4), the denitrification filter tank (5), the micro-sand and carbon sedimentation tank (10) and the V-shaped filter tank (11) are respectively connected with a filter press (14).

2. The RO concentrated water treatment system of the chemical industry sewage treatment plant according to claim 1, characterized in that: a sewage lifting pump is arranged on a pipeline connecting the homogenizing tank (1) and the high-efficiency sedimentation tank (4).

3. The RO concentrated water treatment system of the chemical industry sewage treatment plant according to claim 1, characterized in that: the high-efficiency sedimentation tank (4) is respectively connected with the flocculating agent feeder (2) and the alkali liquor feeder (3).

4. The RO concentrated water treatment system of the chemical industry sewage treatment plant according to claim 1, characterized in that: the biological aerated filter (9) is connected with a liquid caustic soda storage tank (8).

5. The RO concentrated water treatment system of the chemical industry sewage treatment plant according to claim 1, characterized in that: the V-shaped filter (11) is connected with a flocculating agent feeder (2).