CN101898847B - System for treating sewage containing nonylphenol polyoxyethylene ether and metabolin - Google Patents

Abstract

The invention relates to a bio-physicochemical system for treating sewage containing nonylphenol polyoxyethylene ether and metabolites and a treatment method for sewage. The composition of the system is: the water outlet of the solid-liquid separator is connected with the water inlet of the anoxic-aerobic integrated bioreactor through the pipeline, and the water outlet of the anoxic-aerobic integrated bioreactor is connected with the filter through the pipeline. The water inlet is connected, and the water outlet of the filter is connected with the water inlet of the ozone oxidation device through a pipeline. The solid-liquid separator separates inorganic solid substances in sewage; the anoxic-aerobic integrated bioreactor removes organic pollutants, ammonia nitrogen, nonylphenol polyoxyethylene ether and metabolites in sewage; Suspended solids in water; Ozonation unit removes NPA remaining in water. The system of the invention has the characteristics of simple operation and maintenance, high pollutant removal efficiency, etc., and avoids the discharge of nonylphenol polyoxyethylene ether and its metabolites with estrogen effect to nature.

Description

System for treating sewage containing nonylphenol polyoxyethylene ether and metabolites

technical field

The invention belongs to a sewage treatment system, in particular to a biological-physicochemical system for treating sewage containing nonylphenol polyoxyethylene ether and its metabolites, and using the bio-physical system to treat sewage containing nonylphenol polyoxyethylene ether and its metabolites processing method.

Background technique

Nonylphenol ethoxylates (NPnEOs), as a kind of surfactant with excellent performance, are widely used in industry, agriculture and civil fields, some of which enter the urban sewer system with sewage after use. In the biological treatment unit of municipal sewage treatment plants, NPnEOs can be degraded by microorganisms to form metabolites such as nonylphenol (NP), short-chain NPEOs, and nonylphenol ethoxylates (NPECs). However, these metabolites are refractory substances and have stronger bioaccumulation and estrogenic effects than the parent compound. At present, there is no treatment process for sewage that specifically targets nonylphenol polyoxyethylene ether and its metabolites at home and abroad. The main technologies capable of treating sewage containing nonylphenol polyoxyethylene ether and its metabolites include physical and chemical treatment technology and biological treatment technology. Physical and chemical treatment technologies include chemical oxidation, electrolysis, photocatalytic oxidation, etc.; biological treatment technologies include activated sewage Mud and biofilm etc.

The current technology for treating sewage containing nonylphenol polyoxyethylene ether and its metabolites has the following main problems:

(1) Although the physical and chemical treatment technology has a good treatment effect, it is expensive and consumes a lot of energy.

(2) Although the biological treatment technology is economical and simple, the effluent water contains NPECs with strong estrogen effect, which has potential harm to the receiving water environment. NPECs are one of the metabolites of nonylphenol ethoxylates.

The present invention combines biological technology and chemical oxidation technology to form a bio-physicochemical system that can effectively treat sewage containing nonylphenol polyoxyethylene ether and its metabolites. The system can not only degrade nonylphenol polyoxyethylene in sewage Ether, and its metabolites can be completely removed.

Contents of the invention

One of the purposes of the present invention is to overcome the problems faced by the existing facilities for treating sewage containing nonylphenol polyoxyethylene ether and metabolites; to combine biotechnology with solid-liquid separation, filtration and chemical oxidation technologies to provide a treatment The biological-physicochemical combined system of sewage containing nonylphenol polyoxyethylene ether and its metabolites provides an effective way for the control of nonylphenol polyoxyethylene ether and its metabolites in sewage.

Another object of the present invention is to provide a method for treating sewage containing nonylphenol polyoxyethylene ether and its metabolites by using a bio-physicochemical system for treating sewage containing nonylphenol polyoxyethylene ether and its metabolites.

The system for treating sewage containing nonylphenol polyoxyethylene ether and metabolites of the present invention is a biological-physicochemical system, which is composed of a solid-liquid separator, anoxic-aerobic integrated bioreactor, filter and ozone oxidation The reaction device is combined; among them, the anoxic-aerobic integrated bioreactor belongs to the utilization of biological technology, the ozone oxidation reaction device belongs to the utilization of chemical technology, and the solid-liquid separator and filter belong to the utilization of physical technology.

The system for treating sewage containing nonylphenol polyoxyethylene ether and metabolites of the present invention is shown in Figure 1, comprising a solid-liquid separator, anoxic-aerobic integrated bioreactor, a filter and an ozone oxidation reaction device;

The water outlet of the solid-liquid separator is connected with the water inlet of the anoxic-aerobic integrated bioreactor through the pipeline, and the water outlet of the anoxic-aerobic integrated bioreactor is connected with the water inlet of the filter through the pipeline The water outlet of the filter is connected with the water inlet of the ozone oxidation device through a pipeline.

Described solid-liquid separator is as shown in Figure 2, and this solid-liquid separator is the container of the conical shape of opening substantially, has a water outlet on the wall of the upper part of the container, and has a water outlet on the wall of the upper part of the water outlet. The overflow weir has a mud discharge port at the bottom of the container, and a mud discharge pipe is further installed at the mud discharge port; the inner cavity of the container is a solid-liquid separation area.

The described anoxic-aerobic integrated bioreactor is shown in Fig. 3, and this bioreactor is substantially the container of rectangular shape (such as rectangle), and this container is divided into anoxic by 2 baffle plates with different heights respectively. zone, an aerobic zone and a sedimentation zone, and there is a sludge channel between the bottom of the low baffle and the container; wherein, the area between the two baffles is an aerobic zone, and the high baffle in the two baffles The area formed between the plate and the container wall is an anoxic area, and the area formed between the lower baffle plate of the two baffles and the container wall is a precipitation area; The water inlet is equipped with an agitator in the anoxic zone; there are sludge flow ports at the bottom of the container forming the aerobic zone and the anoxic zone respectively, and the sludge flow ports at the two places pass through the pipeline and the sludge return pump respectively. The inlet and outlet are connected; a water outlet is opened on the upper part of the side wall of the container constituting the sedimentation zone, and the water outlet is connected with the outlet pipe.

The two baffles are respectively provided with overflow weirs.

Described filter is as shown in Figure 4, and this filter is the container of cylindrical shape substantially, and there is a filter material opening at the top of the container, and a water outlet is opened at the bottom of the container, and there is a loading iron in the container. The filter material area of chips and activated carbon particles, the water collection area is between the bottom of the filter material area and the bottom of the container; there is a water inlet on the container wall above the filter material area, and a water inlet is installed at the water inlet to extend into the container. There is a water inlet pipe for unloading filter material and an observation port on the container wall at the lower part of the filter material area.

A water outlet pipe is further installed at the water outlet at the bottom of the container.

The described ozonation reaction device is shown in Figure 5, and the device is mainly composed of units such as an ozone generator, an ozonation reactor and an ozone tail gas destroyer.

The bottom of the described ozonation reactor has a pipeline connected with the ozone generator, and a water outlet is provided on the wall of the ozonation reactor above the pipeline; a water inlet is provided on the top of the ozonation reactor, and the ozone The top of the oxidation reactor has a pipeline connected with the ozone tail gas destroyer.

The system for treating sewage containing nonylphenol polyoxyethylene ether and metabolites of the present invention uses a solid-liquid separator to precipitate and separate inorganic solid particles such as sediment in sewage, and at the same time controls the residence time to avoid strong hydrophobicity of sewage adsorption The suspended organic matter of nonylphenol polyoxyethylene ether precipitates; anoxic-aerobic integrated bioreactor is divided into anoxic zone, aerobic zone and precipitation zone, long-chain nonylphenol polyoxyethylene ether in anoxic It is converted into short-chain nonylphenol polyoxyethylene ether in the zone, and then the carboxylation reaction of EO chain continues to occur in the aerobic zone to generate nonylphenol polyoxyethylene acid; at the same time, the anoxic-aerobic integrated bioreactor It also effectively removes biodegradable organic matter and nitrogen in the sewage; the filter can intercept the suspended solids in the effluent water of the bioreactor; the ozone oxidation reaction device further oxidizes the nonylphenol polyoxyethylene acid in the water through the strong oxidation of ozone decomposed and removed.

The system for treating sewage containing nonylphenol polyoxyethylene ether and metabolites of the present invention is as follows:

The sewage containing nonylphenol polyoxyethylene ether and its metabolites enters the solid-liquid separator from the inlet pipe of the solid-liquid separator and stays in the solid-liquid separator; The solid-liquid separation area of the device is precipitated and discharged through the sludge discharge pipe; the obtained supernatant flows out through the outlet pipe of the solid-liquid separator, and enters the anoxic area in the anoxic-aerobic integrated bioreactor through the pipeline , the supernatant is mixed with the activated sludge containing microorganisms in the anoxic zone, and the mud-water mixture in the anoxic zone reaches the aerobic zone through the overflow weir with high baffles, and then passes through the sludge return pump in the anoxic zone and the aerobic zone Circulation between zones to effectively remove biodegradable organic matter, nitrogen, nonylphenol ethoxylates and their metabolites in the supernatant; removal of biodegradable organic matter, nitrogen, nonylphenol ethoxylates and their metabolites The mixed liquid enters the sedimentation area through the overflow weir of the low baffle for solid-liquid separation, and the precipitated sludge automatically flows back to the aerobic bioreactor in the anoxic-aerobic integrated bioreactor through the sludge channel at the lower part of the low baffle. zone, and the obtained supernatant from the removal of biodegradable organic matter, nitrogen and nonylphenol polyoxyethylene ether and its metabolites enters the filter through the outlet of the precipitation zone in the anoxic-aerobic integrated bioreactor , the suspended solids in the supernatant of biodegradable organic matter, nitrogen and nonylphenol polyoxyethylene ether and its metabolites are intercepted by the filter material; the filtered water enters the ozone through the outlet pipe of the filter and the inlet pipe of the ozone oxidation reaction device In the oxidation reactor, the residual nonylphenol polyoxyethylene acid in the water is removed, and the treated effluent is discharged from the outlet.

The residence time is 3 to 10 minutes.

The supernatant is mixed with the activated sludge containing microorganisms in the anoxic zone, and the content of the activated sludge containing microorganisms in the supernatant is generally 2-4 g/L.

The present invention combines biotechnology and physicochemical technology to form a system capable of effectively treating nonylphenol polyoxyethylene ether and its metabolites in sewage, and avoids nonylphenol polyoxyethylene ether and its metabolites with estrogenic effects to the greatest extent. The release of its metabolites to nature. The invention has the characteristics of simple operation and maintenance, high pollutant removal efficiency and the like. The present invention has following characteristics:

1. The sewage does not pass through the primary sedimentation tank before the biological treatment, so as to avoid the strong hydrophobic nonylphenol and short-chain nonylphenol polyoxyethylene ethers in the sewage from being adsorbed on the primary sludge without biological treatment. Discharge from the sewage plant with the primary sludge;

2. After the sewage is treated with anoxic and aerobic conditions of the present invention, most of the nonylphenol polyoxyethylene ethers are converted into water-soluble carboxylated short-chain nonylphenol polyoxyethylene ethers; avoid as far as possible its conversion into Nonylphenol and short-chain nonylphenol polyoxyethylene ether with strong hydrophobicity, thereby reducing the burden of treating nonylphenol polyoxyethylene ether metabolites in sludge.

3. The carboxylated short-chain nonylphenol polyoxyethylene ether converted after biological treatment is easy to be removed by ozone oxidation, so biological treatment provides conditions for subsequent ozone oxidation treatment. The combination of the two is very important for the removal of nonylphenol polyoxyethylene ether Oxyethylene ethers and their metabolites have good effects.

Description of drawings

Fig. 1. The schematic diagram of the system for treating sewage containing nonylphenol polyoxyethylene ether and metabolites of the present invention.

Figure 2. Schematic diagram of the solid-liquid separator in the present invention.

Fig. 3. Schematic diagram of anoxic-aerobic integrated bioreactor in the present invention.

Figure 4. Schematic diagram of the filter in the present invention.

Fig. 5. The schematic diagram of the ozone oxidation reaction device in the present invention.

reference sign

1. Water inlet pipe 2. Solid-liquid separation area 3. Overflow weir

4. Water outlet pipe 5. Mud discharge pipe 6. Water inlet pipe

7. Bioreactor anoxic zone 8. Stirrer

9. Aerobic zone of bioreactor 10. Sedimentation zone of bioreactor

11. Outlet pipe 12. Sludge return pump 13. Overflow weir

14. Overflow weir 15. Inlet pipe 16. Filter area

17. Water collection area 18. Outlet pipe 19-1. Filter material inlet

19-2. Unloading filter material and observation port 20. Inlet pipe 21. Ozone generator

22. Ozone oxidation reactor 23. Ozone tail gas destroyer 24. Outlet pipe

Detailed ways

Example 1

See Figure 1. The system of the invention comprises a solid-liquid separator, anoxic-aerobic integrated bioreactor, a filter and an ozone oxidation reaction device.

The water outlet of the solid-liquid separator is connected with the water inlet of the anoxic-aerobic integrated bioreactor through the pipeline, and the water outlet of the anoxic-aerobic integrated bioreactor is connected with the water inlet of the filter through the pipeline The water outlet of the filter is connected with the water inlet of the ozone oxidation device through a pipeline.

See Figure 2. The solid-liquid separator is substantially an open cone-shaped container, and the water inlet pipe 1 extends into the container, and a water outlet is provided on the wall of the upper part of the container, and a water outlet pipe 4 is further installed at the water outlet; An overflow weir 3 is opened on the upper container wall, and a mud discharge port is opened at the bottom of the container, and a mud discharge pipe 5 is further installed at the mud discharge port; the inner cavity of the container is a solid-liquid separation area 2 .

See Figure 3. The bioreactor is substantially a rectangular container, and the container is divided into a bioreactor anoxic zone 7, a bioreactor aerobic zone 9 and a bioreactor sedimentation zone 10 by two baffle plates with different heights, and the There is a sludge channel between the lower baffle and the bottom of the container; the area between the two baffles is the aerobic zone of the bioreactor, and the area between the high baffle and the container wall of the two baffles It is the anoxic zone of the bioreactor, and the area formed between the low baffle in the two baffles and the container wall is the sedimentation zone of the bioreactor; there is a water inlet on the top of the side wall of the container forming the anoxic zone, A water inlet pipe 6 is installed at the water inlet, and an agitator 8 is installed in the anoxic zone; sludge circulation ports are respectively opened at the bottom of the containers forming the aerobic zone and the anoxic zone, and the sludge in the two places is circulated The ports are respectively connected to the inlet and outlet of the sludge return pump 12 through pipelines; a water outlet is opened on the upper part of the side wall of the container forming the sedimentation zone, and an outlet pipe 11 is installed at the outlet.

An overflow weir 13 is opened on the high baffle, and an overflow weir 14 is opened on the low baffle.

See Figure 4. This strainer is the container of cylindrical shape substantially, has the dress filter port 19-1 at the top of container, has water outlet at the bottom of container, and is further installed with outlet pipe 18 at water outlet; There is a filter material area 16 loaded with iron filings and activated carbon particles inside, and between the bottom of the filter material area 16 and the bottom of the container is a water collection area 17; there is a water inlet on the container wall above the filter material area, and the water inlet A water inlet pipe 15 extending into the container is installed at the place, and the filter material and the observation port 19-2 are provided on the container wall at the bottom of the filter material area.

See Figure 5. The ozone oxidation reaction device is mainly composed of an ozone generator 21, an ozone oxidation reactor 22, an ozone tail gas destroyer 23 and other units.

The bottom of described ozonation reactor has the pipeline that communicates with ozone generator, has water outlet on the wall of the ozonation reactor above this pipeline, and water outlet pipe 24 is installed at water outlet place; A water inlet is opened on the upper part of the reactor, and a water inlet pipe 20 is installed at the water inlet; there is a pipeline connected with the ozone tail gas destroyer at the top of the ozonation reactor.

The method for treating urban sewage containing nonylphenol polyoxyethylene ether and its metabolites by using the above-mentioned system for treating sewage containing nonylphenol polyoxyethylene ether and its metabolites is as follows:

The sewage containing nonylphenol polyoxyethylene ether and its metabolites enters the solid-liquid separator from the water inlet pipe 1 of the solid-liquid separator and stays in the solid-liquid separator for 5 minutes; The solid-liquid separation area of the solid-liquid separator is precipitated and discharged through the mud discharge pipe 5; the obtained supernatant flows out through the outlet pipe 4 of the solid-liquid separator, and is passed through the inlet of the anoxic-aerobic integrated bioreactor. The water pipe 6 enters the anoxic zone 7 for a residence time of 1 hour, and the supernatant is mixed with the activated sludge containing microorganisms in the anoxic zone, wherein the activated sludge containing microorganisms (the sludge is taken from the sedimentation tank of the sewage treatment plant) The content in the supernatant ranges from 2 to 4 g/L. The mud-water mixture in the anoxic zone reaches the aerobic zone 9 through the overflow weir 13 of the high baffle, and the residence time is 8 hours, and then circulates between the anoxic zone 7 and the aerobic zone 9 through the sludge return pump 12, and the aerobic zone The sludge reflux ratio between the zone and the anoxic zone is 200-300%, which effectively removes biodegradable organic matter, nitrogen, nonylphenol polyoxyethylene ether and its metabolites in the supernatant; removes biodegradable organic matter, nitrogen and The mixed liquid of nonylphenol polyoxyethylene ether and its metabolites enters the sedimentation zone 10 through the overflow weir 14 of the low baffle for solid-liquid separation, and the precipitated sludge automatically flows back to the deficient through the sludge channel at the lower part of the low baffle. The aerobic zone in the oxygen-aerobic integrated bioreactor, and the supernatant obtained from the removal of biodegradable organic matter, nitrogen and nonylphenol ethoxylates and their metabolites is passed through the anoxic-aerobic integrated bioreactor The water outlet pipe 11 at the water outlet of the precipitation area in the reactor and the water inlet pipe 15 of the filter enter the filter, and the filter material in the filter material area 16 intercepts and removes biodegradable organic matter, nitrogen and nonylphenol polyoxyethylene Suspended solids in the supernatant of ether and its metabolites; filtered water enters the ozonation reactor 22 through the outlet pipe 18 of the filter and the water inlet pipe 20 of the ozonation reaction device, and removes the nonylphenol polyoxyethylene acid remaining in the water , the treated outlet water is discharged by the outlet pipe 24 at the outlet.

The amount of ozone provided by the ozone generator is 4mg/L, and the ozone time provided is 10min. The concentrations of nonylphenol polyoxyethylene ether and its metabolites in sewage and water after biological treatment and ozone oxidation are listed in Table 1. It can be seen that after biological treatment, the removal rate of nonylphenol polyoxyethylene ether and its metabolites is 89.9%; after ozone oxidation treatment, the removal rate of nonylphenol polyoxyethylene ether and its metabolites is 93.3% . After the sewage is treated by the system of the present invention, the total removal rate of the nonylphenol polyoxyethylene ether and its metabolites is as high as 99.3%, and the emission of such substances to the nature is avoided to the greatest extent.

Table 1 Concentration changes of nonylphenol polyoxyethylene ether and its metabolites before and after sewage treatment (μmol/L) (ND means lower than the detection limit)

NP NPnEOs (n=1, 2) NPnEOs(n≥3) NPECs sum raw water 0.037 0.064 0.016 0.032 0.149 Biological treatment of effluent 0.001 0.001 0.001 0.012 0.015 Ozone oxidation water 0.0006 0.0004 ND ND 0.001

Claims (8)

1. a processing contains the system of polyoxyethylene nonylphenol ether and meta-bolites sewage, and this system comprises solid-liquid separator, anaerobic-aerobic integrated bioreactor, strainer and ozone oxidation reaction device; It is characterized in that:

The water outlet of described solid-liquid separator is connected by the water-in of pipeline with the anaerobic-aerobic integrated bioreactor, the water outlet of anaerobic-aerobic integrated bioreactor is connected with the water-in of strainer by pipeline, and the water outlet of strainer is connected by the water-in of pipeline with the ozone oxidation device.

2. processing according to claim 1 contains the system of polyoxyethylene nonylphenol ether and meta-bolites sewage, it is characterized in that: described solid-liquid separator is the container of the cone shape of opening, on the wall on container top, have water outlet, on the wall of container on water outlet top, have overflow weir, have mud discharging mouth in the bottom of container.

3. processing according to claim 1 contains the system of polyoxyethylene nonylphenol ether and meta-bolites sewage, it is characterized in that: described anaerobic-aerobic integrated bioreactor is the container of rectangular shape, this container is the oxygen-starved area by the different barrier partitions of 2 tile heights respectively, aerobic zone and settling region, and between the bottom of described low baffle plate and container the mud passage is arranged; Wherein, the zone between 2 baffle plates is an aerobic zone, and the zone that constitutes between high baffle plate in 2 baffle plates and the wall of container is the oxygen-starved area, and the zone that constitutes between low baffle plate in 2 baffle plates and the wall of container is the settling region; Top at a sidewall of the container that constitutes the oxygen-starved area has water-in, and agitator is installed in the oxygen-starved area; Bottom at the container that constitutes aerobic zone and oxygen-starved area has the sludge stream port, and the sludge stream port at 2 places is connected with the import and export of sludge reflux pump by pipeline respectively; Top at a sidewall of the container that constitutes the settling region has water outlet, and water outlet is connected with rising pipe.

4. processing according to claim 3 contains the system of polyoxyethylene nonylphenol ether and meta-bolites sewage, it is characterized in that: have overflow weir on described 2 baffle plates.

5. processing according to claim 1 contains the system of polyoxyethylene nonylphenol ether and meta-bolites sewage, it is characterized in that: described strainer is the container of cylindrical shape, have dress filtrate mouth at the top of container, bottom at container has water outlet, the filtrate district of loading iron filings and activated carbon granule is arranged in the inside of container, is the catchment area between the bottom in filtrate district and the bottom of container; On the wall of container above the filtrate district, have water-in, and the water inlet pipe that stretches in the container is installed, on the wall of container at place, bottom, filtrate district, have and unload filtrate and porthole in the water inlet.

6. processing according to claim 1 contains the system of polyoxyethylene nonylphenol ether and meta-bolites sewage, it is characterized in that: described ozone oxidation reaction device is made of ozonizer, ozone oxidation reaction device and ozone tail gas destructor unit;

The pipeline that is connected with ozonizer is arranged at the bottom of described ozone oxidation reaction device, has water outlet on the wall of the ozone oxidation reaction device above this pipeline; Top at the ozone oxidation reaction device has water-in, and the pipeline that is connected with the ozone tail gas destructor is arranged at the top of ozone oxidation reaction device.

7. one kind is utilized system that any described processing of claim 1～6 contains polyoxyethylene nonylphenol ether and meta-bolites sewage to containing the treatment process of polyoxyethylene nonylphenol ether and meta-bolites sewage thereof, it is characterized in that:

To contain polyoxyethylene nonylphenol ether and meta-bolites sewage thereof is entered in the solid-liquid separator by the water inlet pipe of solid-liquid separator and stops, the supernatant liquor that obtains flows out through the rising pipe of solid-liquid separator, and enter oxygen-starved area in the anaerobic-aerobic integrated bioreactor by pipeline, supernatant liquor mixes with the microbic activity mud that contains in the oxygen-starved area, the mud mixture of oxygen-starved area arrives aerobic zone by the overflow weir of high baffle plate, circulate between oxygen-starved area and aerobic zone by sludge reflux pump then, remove the biodegradable organic in the supernatant liquor, nitrogen and polyoxyethylene nonylphenol ether and meta-bolites thereof; Remove biodegradable organic, the overflow weir of the mixed solution of nitrogen and polyoxyethylene nonylphenol ether and meta-bolites thereof through hanging down baffle plate enters the settling region and carries out solid-liquid separation, the mud that the is settled out mud passage by low baffle plate bottom automatically is back to aerobic zone in the anaerobic-aerobic integrated bioreactor, and the removal biodegradable organic that obtains, the water outlet of the settling region of the supernatant liquor of nitrogen and polyoxyethylene nonylphenol ether and meta-bolites thereof in the anaerobic-aerobic integrated bioreactor enters in the strainer, holds back the removal biodegradable organic through filtrate, suspended solids in the supernatant liquor of nitrogen and polyoxyethylene nonylphenol ether and meta-bolites thereof; Filtered water enters in the ozone oxidation reaction device through the rising pipe of filter and the water inlet pipe of ozone oxidation reaction device, removes residual Nonyl pheno acid in the water, and treat effluent is discharged by water outlet.

8. method according to claim 7 is characterized in that: the time of described stop is 3～10min.

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