CN111977916A - Condensate fine treatment regeneration wastewater recycling system and method - Google Patents

Abstract

The invention discloses a system and a method for reusing condensed water for refining and regenerating wastewater. The outlet of a coagulation sedimentation tank is communicated with the inlet of a first-level denitrification tank through a wastewater conditioning tank, and the outlet of the first-level denitrification tank is subjected to a first-level nitrification tank. The tank, the secondary denitrification tank and the secondary nitrification tank are connected with the inlet of the ultrafiltration system, and the outlet of the ultrafiltration system is connected with the inlet of the reverse osmosis system through the ultrafiltration production tank and the nanofiltration system; The concentrated water outlet is connected with the primary denitrification tank and the sludge thickening tank, the sedimentation outlet at the bottom of the coagulation sedimentation tank is connected with the inlet of the sludge thickening tank, and the outlet of the sludge thickening tank is connected with the inlet of the sludge dewatering machine. The supernatant outlet of the sludge dewatering machine is communicated with the inlet of the waste water conditioning tank, and the system and method can process and recover high-salt, high-ammonia condensate and finely treat regenerated waste water.

Description

A system and method for reusing condensate fine treatment and regeneration wastewater

technical field

The invention belongs to the technical field of water treatment, and relates to a system and a method for reusing condensate fine treatment and regeneration wastewater.

Background technique

At present, the conventional disposal method of the regenerated wastewater from the condensate polishing system of the power plant is to discharge fire after reaching the standard after neutralization. With the increasingly strict national environmental protection regulations, the need for zero discharge of waste water is becoming more and more obvious. How to treat and recycle high-salt and high-ammonia condensate to finely treat and regenerate waste water is a technical problem that power plants urgently need to solve.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art, and to provide a condensate fine treatment regeneration wastewater reuse system and method, which can process and recover high-salt, high-ammonia condensate fine treatment regeneration wastewater.

In order to achieve the above purpose, the condensate fine treatment regeneration wastewater reuse system of the present invention includes a coagulation sedimentation tank, a wastewater conditioning tank, an MBR system, an ultrafiltration water production tank, a nanofiltration system, a reverse osmosis system, a sludge concentration tank and Sludge dehydrator; the MBR system includes a primary denitrification tank, a primary nitrification tank, a secondary denitrification tank, a secondary nitrification tank and an ultrafiltration system;

The outlet of the coagulation sedimentation tank is connected with the inlet of the first-level denitrification tank through the wastewater regulating tank. The outlet of the ultrafiltration system is connected with the inlet of the reverse osmosis system through the ultrafiltration water production tank and the nanofiltration system;

The concentrated water outlet of the ultrafiltration system is connected with the primary denitrification tank and the sludge thickening tank, the sedimentation outlet at the bottom of the coagulation sedimentation tank is connected with the inlet of the sludge thickening tank, and the outlet of the sludge thickening tank is connected with the sludge dewatering tank. The inlet of the sludge dewatering machine is communicated with the inlet of the waste water conditioning tank.

It also includes that a waste water lifting pump is arranged between the waste water regulating tank and the first-stage denitrification tank.

An ultrafiltration water pump is arranged between the ultrafiltration production tank and the nanofiltration system.

A stirring device is arranged in the primary denitrification tank.

It also includes a nitrification reflux pump, wherein the inlet of the nitrification reflux pump is communicated with the outlet of the primary nitrification tank, and the outlet of the nitrification reflux pump is communicated with the primary denitrification pool.

The method for reusing condensate fine treatment regeneration wastewater according to the present invention comprises the following steps:

The waste water enters the coagulation sedimentation tank to remove some suspended solids and impurities, and the sludge output from the bottom of the coagulation sedimentation tank enters the sludge thickening tank;

The water output from the coagulation sedimentation tank enters the wastewater adjustment tank to adjust the pH value to 6-8, and then sends it to the first-level denitrification tank to remove nitrite nitrogen in the water under the action of denitrifying bacteria;

The water output from the first-level denitrification tank enters the first-level nitrification tank, and the water is aerated in the first-level nitrification tank to convert the ammonia nitrogen in the water into nitrite nitrogen;

The water output from the primary nitrification tank enters the secondary denitrification tank, and the water output from the secondary denitrification tank enters the secondary nitrification tank, and the water is deeply denitrified through the secondary denitrification and nitrification;

The water output from the secondary denitrification tank enters the ultrafiltration system to separate the water from mud and water, and the produced water output from the ultrafiltration system enters the ultrafiltration production tank. In the denitrification tank, the other way enters the sludge thickening tank;

The clean water output from the ultrafiltration water production tank enters the nanofiltration system. In the nanofiltration system, the high-valence salts in the water are removed by nanofiltration. The produced water output from the nanofiltration system enters the reverse osmosis system, and the concentrated water output from the nanofiltration system flows back. into the wastewater conditioning tank;

Part of the organic matter, ammonia nitrogen, nitrate nitrogen and ions in the nanofiltration effluent are intercepted by the reverse osmosis system, and the product water output by the reverse osmosis system is used as the influent water of the boiler make-up water treatment system, the make-up water of the circulating water system or the make-up water of the industrial water system and reused. The concentrated water output by the system is reused as water for desulfurization process or water for lime pulping system;

The sludge output from the sludge thickening tank is dewatered by the sludge dewatering machine, the dewatered sludge is sent to the boiler for coupled incineration, and the water produced by the sludge dewatering machine is reused in the wastewater conditioning tank.

The present invention has the following beneficial effects:

During the specific operation, the system and method for reusing condensate fine treatment and regeneration wastewater according to the present invention process the suspended solids and impurities in the fine treatment regeneration wastewater through a coagulation sedimentation tank, an MBR system, an ultrafiltration system, a nanofiltration and a reverse osmosis system. , Ammonia nitrogen and salt, among which, the output water is used as the feed water of the boiler feed water treatment system, the circulating water system replenishment water or the industrial water system replenishment water reuse, and the output concentrated water is reused as the desulfurization process water or the lime pulping system water, and the output The sludge is sent to the boiler for coupled incineration, so as to realize the recycling of waste water and sludge, and realize zero discharge of waste water, which has significant environmental protection and energy saving benefits.

Description of drawings

FIG. 1 is a schematic flow chart of the present invention.

Among them, 1 is a coagulation sedimentation tank, 2 is a wastewater conditioning tank, 3 is a wastewater lifting pump, 4 is a first-level denitrification tank, 5 is a first-level nitrification tank, 6 is a second-level denitrification tank, and 7 is a second-level nitrification tank. , 8 is an ultrafiltration system, 9 is an ultrafiltration water production tank, 10 is an ultrafiltration water pump, 11 is a nanofiltration system, 12 is a reverse osmosis system, 13 is a sludge thickening tank, and 14 is a sludge dewatering machine.

Detailed ways

Below in conjunction with accompanying drawing, the present invention is described in further detail:

Referring to FIG. 1, the condensate fine treatment regeneration wastewater reuse system according to the present invention includes a coagulation sedimentation tank 1, a wastewater conditioning tank 2, an MBR system, an ultrafiltration water production tank 9, a nanofiltration system 11, a reverse osmosis system 12, and a sewage system. Sludge concentration tank 13 and sludge dehydrator 14; the MBR system includes a first-level denitrification tank 4, a first-level nitrification tank 5, a second-level denitrification tank 6, a second-level nitrification tank 7 and an ultrafiltration system 8; coagulation sedimentation The outlet of the pool 1 is communicated with the inlet of the first-level denitrification tank 4 through the waste water regulating tank 2, and the outlet of the first-level denitrification tank 4 is connected to the supernatant through the first-level nitrification tank 5, the second-level denitrification tank 6 and the second-level nitrification tank 7. The inlet of the filtration system 8 is connected, and the outlet of the produced water of the ultrafiltration system 8 is communicated with the inlet of the reverse osmosis system 12 through the ultrafiltration water production tank 9 and the nanofiltration system 11; the concentrated water outlet of the ultrafiltration system 8 is connected with the first-level denitrification. The tank 4 is connected with the sludge thickening tank 13, the sedimentation outlet at the bottom of the coagulation sedimentation tank 1 is connected with the inlet of the sludge thickening tank 13, and the outlet of the sludge thickening tank 13 is connected with the inlet of the sludge dewatering machine 14, The supernatant outlet of the sludge dewatering machine 14 is communicated with the inlet of the waste water conditioning tank 2 .

In the present invention, a wastewater lifting pump 3 is arranged between the wastewater regulating tank 2 and the first-level denitrification tank 4; an ultrafiltration water pump 10 is arranged between the ultrafiltration water production tank 9 and the nanofiltration system 11; The present invention also includes a nitrification reflux pump, wherein the inlet of the nitrification reflux pump is communicated with the outlet of the primary nitrification tank 5 , and the outlet of the nitrification reflux pump is communicated with the primary denitrification pool 4 .

The method for reusing condensate fine treatment regeneration wastewater according to the present invention comprises the following steps:

The incoming waste water enters the coagulation sedimentation tank 1 to remove most of the suspended solids and impurities, and the sludge output from the bottom of the coagulation sedimentation tank 1 enters the sludge thickening tank 13;

The output water of the coagulation sedimentation tank 1 enters the wastewater adjustment tank 2 to adjust the pH value to 6-8, and then is sent to the first-level denitrification tank 4 through the wastewater lifting pump 3, and the nitrite nitrogen in the wastewater is removed under the action of denitrifying bacteria. , a stirring device is arranged in the first-level denitrification tank 4 to ensure that the sludge and the wastewater in the first-level denitrification tank 4 are fully mixed;

The water output from the first-level denitrification tank 4 enters the first-level nitrification tank 5, and the wastewater is aerated in the first-level nitrification tank 5 to convert the ammonia nitrogen in the water into nitrite nitrogen. The first-level nitrification tank 5 is provided with nitrification. Reflux pump, through which part of the nitrification liquid is returned to the first-stage denitrification tank 4, and the short-range nitrification and denitrification is used to improve the denitrification effect of the system;

The water output from the primary nitrification tank 5 enters the secondary denitrification tank, and the water output from the secondary denitrification tank enters the secondary nitrification tank 7, and the wastewater is deeply denitrified by the secondary denitrification and nitrification;

The water output from the secondary denitrification tank 6 enters the ultrafiltration system 8 to separate the mixed liquid from mud and water, the output water from the ultrafiltration system 8 enters the ultrafiltration water production tank 9, and the concentrated water output from the ultrafiltration system 8 is divided into two paths, One of them enters the first-level denitrification tank 4, and the other enters the sludge thickening tank 13;

The clean water output from the ultrafiltration water production tank 9 enters the nanofiltration system 11 through the ultrafiltration water pump 10. In the nanofiltration system 11, most of the high-valence salts in the water quality are removed by nanofiltration, and the produced water output from the nanofiltration system 11 enters the reverse osmosis system. In 12, the concentrated water output by the nanofiltration system 11 is returned to the waste water conditioning tank 2;

The reverse osmosis system 12 intercepts a small amount of organic matter, ammonia nitrogen, nitrate nitrogen and ions in the nanofiltration effluent water, and the output water from the reverse osmosis system 12 can be reused for the influent water of the boiler make-up water treatment system, the make-up water of the circulating water system or the industrial water system For water replenishment, the concentrated water output from the reverse osmosis system 12 can be reused for desulfurization process water or lime pulping system water;

The sludge output from the sludge thickening tank 13 is dewatered by the sludge dehydrator 14 , the dehydrated sludge is reused in the boiler for coupled incineration, and the water produced by the sludge dehydrator 14 is reused in the wastewater conditioning tank 2 .

The present invention treats suspended solids, impurities, ammonia nitrogen and salts in the refined and regenerated wastewater through coagulation sedimentation, MBR system, ultrafiltration system 8, nanofiltration and reverse osmosis system 12, and finally realizes the recycling and utilization of wastewater and sludge, and realizes wastewater treatment. Zero emission, with significant environmental protection and energy saving benefits.

Claims (6)

1. a condensate fine treatment regeneration waste water reuse system, is characterized in that, comprises coagulation sedimentation tank (1), waste water regulating tank (2), MBR system, ultrafiltration water production tank (9), nanofiltration system (11 ), a reverse osmosis system (12), a sludge thickening tank (13) and a sludge dehydrator (14); the MBR system includes a primary denitrification tank (4), a primary nitrification tank (5), a secondary reverse a nitrification tank (6), a secondary nitrification tank (7) and an ultrafiltration system (8); The outlet of the coagulation sedimentation tank (1) is communicated with the inlet of the first-level denitrification tank (4) through the wastewater regulating tank (2), and the outlet of the first-level denitrification tank (4) is connected with the first-level nitrification tank (5), the second The primary denitrification tank (6) and the secondary nitrification tank (7) are communicated with the inlet of the ultrafiltration system (8), and the outlet of the produced water of the ultrafiltration system (8) is passed through the ultrafiltration water production tank (9) and the nanofiltration system (8). 11) communicate with the inlet of the reverse osmosis system (12); The concentrated water outlet of the ultrafiltration system (8) is communicated with the primary denitrification tank (4) and the return sludge thickening tank (13), and the bottom sedimentation outlet of the coagulation sedimentation tank (1) is connected with the sludge thickening tank (13) The inlet of the sludge concentration tank (13) is connected with the inlet of the sludge dewatering machine (14), and the supernatant liquid outlet of the sludge dewatering machine (14) is connected with the inlet of the waste water conditioning tank (2). . 2. The condensate fine treatment regeneration waste water reuse system according to claim 1, is characterized in that, also comprises that between the waste water conditioning tank (2) and the first-level denitrification tank (4) is provided with the waste water lift pump (3) . 3. The condensate fine treatment regeneration wastewater reuse system according to claim 1, characterized in that, an ultrafiltration water pump (10) is provided between the ultrafiltration water production tank (9) and the nanofiltration system (11). 4. The condensate polishing treatment regeneration wastewater reuse system according to claim 1, characterized in that, a stirring device is provided in the primary denitrification tank (4). 5. The condensate fine treatment regeneration waste water reuse system according to claim 1, is characterized in that, also comprises nitrification reflux pump, wherein, the inlet of nitrification reflux pump is communicated with the outlet of one-stage nitrification tank (5), nitrification The outlet of the return pump is communicated with the primary denitrification tank (4). 6. A method for reusing condensate fine treatment regeneration waste water is characterized in that, it is characterized in that, comprises the following steps: The incoming wastewater enters the coagulation sedimentation tank (1) to remove some suspended solids and impurities, and the sludge output from the bottom of the coagulation sedimentation tank (1) enters the sludge thickening tank (13); The water output from the coagulation sedimentation tank (1) enters the wastewater adjustment tank (2) to adjust the pH value to 6-8, and then is sent to the first-level denitrification tank (4) to remove nitrous in the water under the action of denitrifying bacteria nitrogen; The water output from the first-level denitrification tank (4) enters the first-level nitrification tank (5), and the water is aerated in the first-level nitrification tank (5) to convert ammonia nitrogen in the water into nitrite nitrogen; The water output from the primary nitrification tank (5) enters the secondary denitrification tank (6), and the water output from the secondary denitrification tank (6) enters the secondary nitrification tank (7). Deep denitrification of water; The water output from the secondary denitrification tank (7) enters the ultrafiltration system (8) to separate the water from mud, and the produced water output from the ultrafiltration system (8) enters the ultrafiltration water production tank (9), and the ultrafiltration system (8) ) output concentrated water is divided into two paths, one of which enters the first-level denitrification tank (4), and the other enters the sludge thickening tank (13); The clean water output from the ultrafiltration water production tank (9) enters the nanofiltration system (11), and in the nanofiltration system (11), the high-valence salts in the water are removed by nanofiltration, and the produced water output from the nanofiltration system (11) enters the reaction chamber. In the permeation system (12), the concentrated water output by the nanofiltration system (11) is returned to the waste water conditioning tank (2); Part of the organic matter, ammonia nitrogen, nitrate nitrogen and ions in the nanofiltration effluent are intercepted by the reverse osmosis system (12), and the product water output by the reverse osmosis system (12) is used as the influent water of the boiler make-up water treatment system, the make-up water of the circulating water system or the industrial water system Make-up water reuse, the concentrated water output by the reverse osmosis system (12) is reused as the desulfurization process water or the lime pulping system water; The sludge output from the sludge thickening tank (13) is dewatered by the sludge dewatering machine (14), the dewatered sludge is sent to the boiler for coupled incineration, and the water produced by the sludge dewatering machine (14) is reused to in the wastewater conditioning tank (2).

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