CN108178305A - A kind of technique and device of biological multielementization processing wastewater of chemical industry with high concentration - Google Patents

Abstract

The invention discloses a kind of techniques of biological multielementization processing wastewater of chemical industry with high concentration, include the following steps：Wastewater from chemical industry is after homogeneous by promotion facility to acidification pool, acidification pool water outlet is sent into oxygenation air lift circulatory pool, it is oxygenated water outlet after the processing of air lift circulatory pool and is sent into membrane bioreactor and carry out mud-water separation, water outlet, which is sent into after floss hole, after Membrane Bioreactor for Wastewater Treatment receives pipe discharge.All kinds of pretreatment wastewater from chemical industry is received to carry out homogeneous and are measured in the homogeneous pond；The acidification that acidification strain carries out waste water is added in acidification pool, improves the biodegradability of wastewater from chemical industry；Air lift cyclic process in oxygenation air lift circulatory pool can make the biological concentration in biological multielementization and raising waste water in waste water, so as to improve the organic removal rate of waste water；The membrane bioreactor integrates the facility of secondary settling tank and clarifying basin, can substantially reduce capital construction Facilities Construction expense and greatly reduce floor space.

Description

A biologically diversified process and device for treating high-concentration chemical wastewater

technical field

The invention relates to the technical field of materials and environmental engineering, in particular to a process and a device for biologically diversified treatment of high-concentration chemical wastewater.

Background technique

The chemical industry in Zhejiang Province is relatively developed. The volume of chemical wastewater is large (accounting for 14% of the total industrial wastewater), and the water quality is relatively complex. The basic characteristics of chemical wastewater are: (1) the water quality is complex, there are many by-products, and the reaction raw materials are often solvent substances or compounds with ring structures, which increases the difficulty of wastewater treatment; (2) the pollutant content in wastewater is high, which It is caused by the incomplete reaction of raw materials and a large amount of solvent medium used in raw materials or production entering the wastewater system; (3) There are many toxic and harmful substances, and many organic pollutants in fine chemical wastewater are toxic and harmful to microorganisms, such as Halogen compounds, nitro compounds, dispersants or surfactants with bactericidal effect, etc.; (4) There are many biodegradable substances, low B/C ratio, and poor biodegradability; (5) High chroma of wastewater.

In order to improve the pollution problems of the chemical industry, the country has also issued wastewater standards for the chemical industry, such as the "Petrochemical Industry Pollutant Discharge Standard" GB31571-2015, "Inorganic Chemical Industry Pollutant Discharge Standard" GB31573-2015, and "Discharge Standard of Water Pollutants for Synthetic Ammonia Industry" GB13458-2013, "Discharge Standard of Water Pollutants for Citric Acid Industry" GB19430-2013, "Discharge Standard of Pollutants for Coking Chemical Industry" GB16171-2012, etc., through the implementation of the above standards, also It can improve the water pollution problem in the chemical industry to a certain extent.

Therefore, in order to achieve the goal of national energy conservation and emission reduction, chemical enterprises should mainly implement it from two aspects. First, implement clean production in production, save water, and reduce water consumption per unit of product; secondly, they need to strengthen sewage treatment technology, improve effluent quality, and maximize The reclaimed water is reused in production to achieve the purpose of emission reduction.

Contents of the invention

The invention provides a biodiversified process for treating high-concentration chemical wastewater, which solves the technical problem of low biochemical treatment efficiency of chemical wastewater.

A biodiversified process for treating high-concentration chemical wastewater, comprising the steps of:

After the chemical wastewater is homogenized, it is lifted by the lifting facility to the acidification tank. The effluent from the acidification tank is sent to the oxygen-filled circulation pool. The final effluent is sent to the discharge port and then discharged through the tube.

The homogeneous tank accepts various types of pretreated chemical wastewater for homogenization and equalization; in the acidification tank, the biodegradability of the chemical wastewater is improved through hydrolysis and acidification; And increase the biological concentration in the wastewater, thereby increasing the organic matter removal rate of the wastewater; the membrane bioreactor is a facility integrating a secondary sedimentation tank and a clarification tank, which can greatly reduce the construction cost of infrastructure facilities and greatly reduce the occupied area.

The oxygenation pool of the present invention simultaneously receives the waste water from the acidification pool and the reflux water of the air lift cycle, so that a stable wastewater concentration gradient is formed from the beginning to the end of the oxygenation pool, so that microorganisms at various concentration stages of the waste water are symbiotic in the oxygenation pool, so that the types of microorganisms reach Diversification, so that the number of microorganisms reaches a certain level, and the treatment efficiency of wastewater reaches the best level.

Preferably, the oxygen-filled circulating pool includes an oxygenated pool and an air-lifted circulating pool, and an air-lifting device is installed in the air-lifting circulating pool, and the wastewater at the outlet of the oxygenated pool flows back to the inlet of the oxygenated pool in a large proportion through the air-lifting device.

Preferably, the air stripping device is several annular aeration tubes controlled independently of each other. It is conducive to the improvement of block wastewater.

Preferably, the oxygenation tank is externally connected with blowing facilities for oxygenation, and the dissolved oxygen concentration in the oxygenation tank is controlled at 2-4 mg/L.

Preferably, the air-lifting circulation tank is externally connected with blowing facilities for oxygenation, and the dissolved oxygen concentration in the air-lifting circulation tank is controlled at 0.5-1 mg/L.

Preferably, the wastewater reflux ratio in the air stripping circulation tank is 30 times to 1000 times. More preferably, the reflux ratio is 500-1000 times; even more preferably, the reflux ratio is 500-600 times.

Preferably, the hydraulic retention time of the wastewater in the acidification tank and the aerated oxygen stripping circulation tank are respectively 8-12 hours and 24-36 hours. Further preferably, the hydraulic retention times are respectively 10h and 30h.

The present invention also provides a biodiversified device for treating high-concentration chemical wastewater, including a homogeneous pool, a lifting facility, an acidification pool, an oxygen-filled circulation pool, a membrane bioreactor, a lifting facility, and a discharge port arranged in sequence.

Preferably, the aerated oxygen-lifting circulation pool includes an oxygenation pool, an air-lifting circulation pool and an air-lifting device arranged in the air-lifting circulation pool, and the air-lifting device is used to return the wastewater at the outlet end of the oxygenation pool to the oxygenation pool Inlet side.

Further preferably, the gas-lifting circulation pool is set half around the oxygenation pool and separated by a partition wall.

Preferably, a membrane group is installed in the membrane bioreactor, and the waste water is discharged to a discharge port through a lifting facility connected outside the membrane group.

Preferably, the air stripping device is several annular aeration tubes controlled independently of each other.

Preferably, an aeration pipe network is arranged at the inner bottom of the oxidation tank.

Preferably, the oxygenation pool is externally connected with oxygenation facilities.

Preferably, the airlift circulation pool is externally connected with oxygenation facilities.

After the pretreated chemical wastewater passes through the homogenization tank, the wastewater is lifted to the acidification tank through the lifting facility, and the biochemical properties of the wastewater are improved through acidification and hydrolysis. At the same time as the pool, a large proportion of the terminal wastewater of the airlifting circulation pool is imported, so that a stable wastewater concentration gradient is formed from the beginning to the end of the oxygenation pool, so that various microorganisms at various concentration stages of the wastewater co-exist in the oxygenation pool, and the concentration gradient makes The variety of microorganisms is diversified, and the stable concentration makes the microorganisms more quantified, which can make the treatment efficiency of the aerated oxygen extraction circulation pool 30% to 70% higher than that of the general biochemical pool. The waste water enters the membrane bioreactor for solid-liquid separation after passing through the aerated oxygen-extraction circulation tank, and simultaneously undergoes precipitation and filtration, which greatly shortens the treatment process and saves the treatment area. After the solid-liquid separation, the waste water is discharged through the outlet tube to meet the standard.

Compared with the prior art, the present invention has the following beneficial effects:

(1) This process adopts conventional acidification bacteria, and through the treatment of conventional high-efficiency acidification bacteria, the biochemical properties of chemical wastewater can be greatly improved.

(2) Compared with general biochemical pools, the oxygen-filled circulating pool used in this process can greatly improve the treatment efficiency, has strong impact resistance, can handle high-concentration raw water, and can greatly reduce the cost of pretreatment.

(3) A large proportion of reflux is adopted in the aerated oxygen extraction circulation tank of this process, so that various microorganisms at various concentration stages of the wastewater can coexist in the oxygenated tank, the concentration gradient makes the types of microorganisms diversified, and the stable concentration makes the microorganisms more quantified , can greatly improve the efficiency of biochemical treatment.

(4) The membrane bioreactor used in this process integrates sedimentation and filtration, which can greatly shorten the wastewater treatment process, greatly save the land occupied by environmental protection facilities, and save land resources.

(5) This process can not only be used in the supporting sewage treatment projects of new chemical enterprises, but also can be implemented after rectification according to the actual situation of the supporting sewage stations of existing chemical enterprises, and has a wide range of applications.

Description of drawings

Fig. 1 is a structural schematic diagram of the present invention.

The reference signs shown in the figure are as follows:

1-Homogenizing pool 2-First lifting facility 3-Enhanced acidification pool

4-Oxygenation pool 5-Air lift circulation pool 6-First blast facility

7-Airlift device 8-Second blast facility 9-Aeration facility

10-Membrane bioreactor 11-Membrane group 12-Second lifting facility

13-Drain port

Detailed ways

As shown in Figure 1, a biodiversified process for treating high-concentration chemical wastewater includes a homogeneous pool 1, a first lifting facility 2, an enhanced acidification pool 3, an oxygen extraction circulation pool, and a membrane bioreactor. 10. The second lifting facility 12 and the discharge port 13, the oxygen-filled circulation pool includes an oxygenation pool 4, an air-lift circulation pool 5 and an air-lift device 7 located in the air-lift circulation pool, and the air-lift circulation pool is semi-surrounded by the oxygenation pool Set, separated by a partition wall, the air lift device 7 adopts several annular aeration pipes controlled independently of each other to return the wastewater from the outlet of the oxygenation tank to the inlet of the oxygenation tank.

The homogeneous pool collects the pretreated chemical wastewater in one place, homogenizing and equalizing the volume.

The lifting facility lifts the chemical wastewater in the homogenizing tank to the enhanced acidification tank.

The air lift circulation pool is provided with air by the first blowing facility 7, which is beneficial to the waste water circulation.

Oxygenation pool is provided with oxygen by the second blowing facility 8 .

Process flow of the present invention is as follows:

(1) The pretreated chemical wastewater enters the homogenization tank, and after homogenization and equalization, the lifting facilities flow into the enhanced acidification tank. After the chemical wastewater is hydrolyzed and acidified in the enhanced acidification tank, the B/C ratio of the wastewater is increased, and at the same time It can greatly reduce the toxicity of wastewater and facilitate subsequent biochemical treatment.

(2) The wastewater enters the oxygenation pool after passing through the enhanced acidification pool, and the second blowing facility is used to provide the dissolved oxygen required by the oxygenation pool, in which the dissolved oxygen is kept at 2-4 mg/L to ensure the oxygen-enriched bacteria in the oxygenation pool group living conditions. Among them, the water inlet of the oxygenation pool receives a large amount of tail water from the end of the oxygenation pool and circulates through the air lift circulation pool at the same time. The high proportion of backflow greatly reduces the concentration of pollutants at the water inlet of the oxygenation pool, which is more conducive to the bacteria's ability to eliminate pollutants. Treatment can more stably reduce the concentration of wastewater pollutants. At the same time, high-efficiency and diversified strains are added to the oxygenation pool to promote the diversification and quantification of the strains in the oxygenation pool, and to improve the biochemical treatment capacity and efficiency. Among them, the ratio of the airlift circulation volume to the influent volume has a large range, which can be adjusted and adjusted according to different wastewater, and the reflux ratio is 30 to 1000 times.

(3) After the wastewater is treated in the oxygenation tank and the air lift circulation tank, most of the pollutants are removed, and then it enters the membrane bioreactor for mud-water separation and filtration, and the effluent is discharged through the discharge port to reach the standard. Among them, the membrane bioreactor integrates sedimentation and filtration, which can greatly save land costs and greatly reduce operating costs.

Example 1

This process was applied to the renovation project of a sewage treatment station of a chemical enterprise. The design volume of sewage treatment is 1500t/d. After the renovation, the treatment process of the sewage station is as follows: pre-treatment of wastewater→regulation tank→gas lift circulation oxygenation tank→membrane biology Reactor→discharge well→sewage treatment plant in the park, the effluent must meet the nanotube standard, the dissolved oxygen concentration in the oxygenation tank is controlled at 2-4mg/L, the dissolved oxygen concentration in the airlift circulation tank is controlled at 0.5-1mg/L, and the reflux ratio is controlled At about 500 times, the hydraulic retention time in the acidification tank and the oxygenation tank are about 10 hours and 30 hours respectively. The quality of sewage influent and effluent and the standards for receiving pipes are shown in Table 1.

Table 1 Sewage Station Influent Water Quality and Intake Standard Index Unit: mg/L

The quality of the effluent after treatment is obviously better than the standard of the tube, and the treatment effect is greatly improved compared with that before the transformation, and it can significantly reduce the salt content and toxicity of the wastewater. The renovation project has obvious emission reduction and obvious economic benefits, and truly achieves a win-win effect of environmental protection benefits and economic benefits for the enterprise.

The above is only a specific implementation case of the patent of the present invention, but the technical characteristics of the patent of the present invention are not limited thereto. Any changes or modifications made by those skilled in the relevant field within the scope of the present invention are covered by the patent of the present invention. within the scope of the patent.

Claims (10)

1. a kind of technique of biological multielementization processing wastewater of chemical industry with high concentration, which is characterized in that include the following steps：

Wastewater from chemical industry is promoted to by promotion facility in acidification pool after homogeneous, and acidification pool water outlet is sent into oxygenation air lift circulatory pool, Membrane bioreactor progress mud-water separation is sent into water outlet after being oxygenated the processing of air lift circulatory pool, is discharged and is sent after Membrane Bioreactor for Wastewater Treatment Enter after floss hole through receiving pipe discharge.

2. technique according to claim 1, which is characterized in that the oxygenation air lift circulatory pool includes oxygenation pond and air lift cycle Pond, the interior setting air-lift device of air lift circulatory pool, the waste water for being oxygenated pond water outlet are back to oxygenation pond by air-lift device large scale Water inlet end.

3. technique according to claim 2, which is characterized in that the oxygenation external air blast facility in pond is oxygenated, and is oxygenated pond Interior Dissolved Oxygen concentration Control is in 2~4mg/L.

4. technique according to claim 2, which is characterized in that the external air blast facility of air lift circulatory pool is oxygenated, gas Dissolved Oxygen concentration Control is carried in circulatory pool in 0.5~1mg/L.

5. technique according to claim 2, which is characterized in that the air-lift device is the annular that several are controlled independently of each other Aeration tube.

6. technique according to claim 2, which is characterized in that the return of waste water ratio of the air lift circulatory pool for 30 times~ 1000 times.

7. technique according to claim 1, which is characterized in that waterpower of the waste water in acidification pool and oxygenation air lift circulatory pool is stopped It is respectively 8~12h and 24~36h to stay the time.

8. a kind of device of biological multielementization processing wastewater of chemical industry with high concentration, which is characterized in that including be sequentially arranged homogeneous pond, It promotes facility, acidification pool, oxygenation air lift circulatory pool, membrane bioreactor, promote facility and floss hole.

9. device according to claim 8, which is characterized in that the oxygenation air lift circulatory pool includes oxygenation pond, air lift cycle Pond and the air-lift device in air lift circulatory pool, the air-lift device are used for return of waste water by pond water outlet is oxygenated to filling Oxygen pond water inlet end.

10. device according to claim 8, which is characterized in that installation film group, waste water pass through film in the membrane bioreactor The external promotion facility of group drains into floss hole.