CN105330099B - An integrated wastewater treatment device and petrochemical secondary effluent treatment method - Google Patents

Abstract

The invention discloses Integral waste water processing means, including the reactor of upward flowing type, ozone generator (7), water tank (1), Venturi tube (8)；Wherein, described reactor includes denitrification zone (3), catalytic ozonation district (4) and BAF district (5) from bottom to up successively, the bottom of described denitrification zone (3) is provided with water inlet (18), and reactor head is provided with delivery port (10)；It is provided with the first refluxing opening (16) and the second refluxing opening (17) on the top of described reactor；Described water inlet (18) is connected with described water tank (1) by the first pipeline (13), is connected with described first refluxing opening (16) by the second pipeline (14).The invention also discloses the processing method using described Integral waste water processing means to carry out petrochemical wastewater.The present invention reaches preferable organic matter and the effect of total nitrogen removal when Advanced Treatment of Petrochemical Wastewater.

Description

An integrated wastewater treatment device and petrochemical secondary effluent treatment method

technical field

The invention relates to the field of wastewater treatment, in particular to an integrated wastewater treatment device and a method for using the device to treat secondary petrochemical effluent.

Background technique

The petrochemical industry is a key industry in the national economy, and it is also a high-consumption and high-pollution industry. The amount of wastewater discharged from the petrochemical industry varies with the depth of petroleum refining and processing. The amount of wastewater generated per ton of crude oil refining is about 2.86 tons; the amount of wastewater generated per ton of petrochemical products is 117 tons; the amount of wastewater generated per ton of processing The amount of waste water generated by petroleum and chemical fiber products is 161.8 tons; the amount of waste water generated by each ton of chemical fertilizer products is 4.25 tons. In 2008, enterprises above designated size in my country's petroleum and chemical industries discharged 4.382 billion tons of industrial wastewater, accounting for 20.2% of the total amount of wastewater discharged by enterprises above designated size in the country, ranking first in industrial water discharge. In addition, petrochemical wastewater has the characteristics of large wastewater volume, complex pollution components, and large fluctuations in water quality and volume, which seriously pollutes the environment. General petrochemical wastewater is biologically treated by the sewage plant, and the effluent can meet the discharge standard (COD≤100mg·L ^-1 ) in the "Integrated Wastewater Discharge Standard" (GB 8978-1996). However, the "Petrochemical Industry Pollutant Discharge Standard" (GB 31571-2015) issued in 2015 stipulates that the development density of the land is already high, the environmental carrying capacity has begun to weaken, or the water environment capacity is small, the ecological environment is fragile, and serious pollution is prone to occur. In areas where special protection measures are required due to water pollution problems, the highest value of COD discharged directly to the receiving water body is 50mg·L ^-1 , and the highest value of total nitrogen is 30mg·L ^-1 . Therefore, the advanced treatment of petrochemical wastewater is imminent.

Biological aerated filter is a common biofilm treatment process, which has the characteristics of small footprint, good effluent quality, low sludge production, low cost, modular structure, and high degree of automation. The biological aerated filter fully draws on the design ideas of the contact oxidation method of sewage treatment and the fast water filter, and combines the two treatment processes of biodegradation and adsorption filtration in the same unit reactor. With the granular filler filled in the filter (such as ceramsite, coke, quartz sand, activated carbon, etc.) The high concentration of active microorganisms in the biofilm attached to the filter material has strong oxidative decomposition and the characteristics of the small particle size of the filter material, giving full play to the biological metabolism of microorganisms, bioflocculation, physical adsorption and retention of biofilm and fillers, and the along the edge of the reactor. The graded predation effect of the food chain in the direction of water flow realizes the efficient removal of pollutants. The functions of biological oxidation and solid-liquid separation are simultaneously completed in one unit reactor, and it has been widely used in the field of advanced sewage treatment. However, traditional BAF can only remove easily biodegradable organic matter in sewage, and has the function of oxidizing ammonia nitrogen in sewage to nitrate nitrogen. The removal effect of this process alone on difficult biodegradable organic matter and total nitrogen in water is not good. Ozone has strong oxidizing properties and can oxidize refractory organic matter in petrochemical wastewater into easily biodegradable organic matter. The combination of ozone and BAF and the design of the denitrification zone in the reaction column can effectively make up for the shortcomings of BAF.

Contents of the invention

The technical problem to be solved by the present invention is to provide an integrated wastewater treatment device and a method for using the device to treat secondary effluent of petrochemical industry. It solves the problem that the removal efficiency of refractory organic matter and total nitrogen is not high when using a single BAF process for advanced treatment of industrial wastewater. From the two aspects of strengthening the removal effect of refractory organic matter and improving the denitrification effect of reaction operation, the research and invention of this method can make the BAF process achieve better organic matter and total nitrogen removal effect in the advanced treatment of petrochemical secondary effluent.

An integrated wastewater treatment device, including a reactor, an ozone generator, a water tank, and a venturi tube; among them, in order to improve the biological aerated filter process to remove refractory organic matter and denitrification in petrochemical secondary effluent, the traditional BAF design Three areas, the reactor includes a denitrification area, an ozone catalytic oxidation area and a biological aerated filter area from bottom to top, a water inlet is provided at the bottom of the denitrification area, and a water outlet is provided at the top; The upper part of the reactor is provided with a first return port and a second return port; the water inlet is connected to the water tank through a first pipeline, and connected to the first return port through a second pipeline;

In the integrated wastewater treatment device of the present invention, an inlet pump and a first valve are arranged on the first pipeline, a first return pump and a second valve are arranged on the second pipeline, and A second return pump and a third valve are arranged on the third pipeline.

In the integrated wastewater treatment device of the present invention, a filter material support layer and a material intake are all provided at the lower part of the denitrification zone, the ozone catalytic oxidation zone and the biological aerated filter zone, It is convenient to replace the filter material in the reactor, and a vent port is arranged at the lower part of the reactor; it is convenient to empty the waste water in the reactor. The volume ratio of the denitrification zone, the ozone catalytic oxidation zone and the biological aerated filter zone is 1:1:4.

The integrated wastewater treatment device of the present invention, wherein, the fillers in the denitrification zone and the biological aerated filter zone are volcanic rocks with a particle size of 2-5 mm; the fillers in the ozone catalytic oxidation zone are loaded transition metals The oxides have a particle size of 2-5mm; the filling rate of the denitrification zone and the ozone catalytic oxidation zone is 85%, and the filling rate of the biological aerated filter zone is 80%.

In the integrated wastewater treatment device of the present invention, the transition metal oxide supported is a solid catalytic filler of Al ₂ O ₃ or CuO.

Due to the low price of volcanic rocks and the developed pore structure, the pores are uneven in size and light in weight. Due to the large and small pores, the surface is rough and the specific surface area is large. It is inert and corrosion-resistant. Stable, its surface is highly hydrophilic, rough and porous, and the attached biofilm is fast and large, with positive charges, which is conducive to the growth of biofilm. It is a good carrier for biofilm and has no inhibitory effect on the fixed microbial elements. , does not affect the activity of microorganisms, and can provide good conditions for the implantation of microorganisms; the catalytic oxidation filler in the ozone catalytic oxidation zone can fully mix and contact ozone with petrochemical secondary effluent, enhance the oxidation effect of ozone, and improve the utilization rate of ozone .

The method for carrying out petrochemical secondary effluent treatment using the integrated wastewater treatment device of the present invention comprises the following steps:

The wastewater in the water tank enters the reactor through the water inlet pump, passes through the denitrification zone, the ozone catalytic oxidation zone and the biological aerated filter zone in turn, and flows out from the water outlet. At the same time, there are two return lines, one through the first return flow port , the first reflux pump and the second pipeline realize reflux, and the second one reaches the Venturi tube through the second reflux port, the second reflux pump and the third pipeline, and the reflux waste water is generated with the ozone generator in the Venturi tube The mixed ozone enters the lower part of the ozone catalytic oxidation zone to realize backflow.

The wastewater treatment method of the present invention, wherein, when the treated petrochemical secondary effluent COD is lower than 100mg/L and TN is lower than 30mg/L, the reflux rate of the ozone catalytic oxidation zone is 100%-200%, so The reflux rate of the denitrification zone is 100%, the residence time of the reactor is 3h, and the dosage of ozone is 10mg/L.

The difference between the integrated waste water treatment device of the present invention and the prior art is that the integrated waste water treatment device of the present invention and the method of using the device for petrochemical secondary effluent treatment have the following advantages:

1) The denitrification zone and ozone catalytic oxidation zone are set in the reactor, which improves the effect of the reactor on treating refractory organic matter and total nitrogen in the petrochemical secondary effluent, making the effluent more secure.

2) There is a reflux device in the reactor, which increases the contact time between ozone and petrochemical secondary effluent during pre-oxidation, and improves the utilization rate of ozone.

3) Ozone generates oxygen during the reaction process with wastewater, which provides aeration for the subsequent BAF unit, eliminates the aeration device during the operation of the traditional BAF process, and saves operating costs.

4) The present invention combines the traditional denitrification device, ozone mixing device and BAF device in one reactor, which reduces the floor area of the reactor and reduces the investment cost.

5) The dosage of ozone is small, which saves energy consumption, and the ozone content in the exhaust gas after passing through the ozone catalytic oxidation zone and the biological aerated filter zone is low, so there is no need to install an ozone destruction device.

Technical principle of the present invention is as follows:

The integrated wastewater treatment device and the secondary effluent treatment method of petrochemical wastewater treatment are an integrated combination process that combines four technologies of ozone chemical oxidation, biodegradation, aerobic nitrification and anaerobic denitrification. The petrochemical secondary effluent first passes through the denitrification zone, ozone catalytic oxidation zone and BAF zone, and then a branch stream flows into the ozone catalytic oxidation zone through the return pump through the Venturi tube, and then flows into the ozone catalytic oxidation zone. The refractory organic matter in the secondary effluent is oxidized into easily biodegradable organic matter, which improves the effect of subsequent BAF unit biodegradation of refractory organic matter, and ozone generates oxygen during the reaction process with wastewater, which provides the follow-up BAF unit The oxygen used for microbial nitrification replaces the traditional aeration equipment and saves operating costs; another branch stream returns the wastewater from the BAF unit to the denitrification area through the return pump, so that the nitrate ions and nitrite in the wastewater Ions generate nitrogen through the action of denitrifying bacteria attached to the volcanic rock, so as to achieve the effect of further removing total nitrogen.

The integrated wastewater treatment device of the present invention and the method of using the device for petrochemical secondary effluent treatment will be further described below in conjunction with the accompanying drawings.

Description of drawings

Fig. 1 is a schematic structural view of the integrated wastewater treatment device of the present invention.

Among them, 1—water tank, 2—inlet pump, 3—denitrification zone, 4—ozone catalytic oxidation zone, 5—biological aerated filter zone, 6—second return pump, 7—ozone generator, 8—venturi Pipe, 9—first return pump, 10—water outlet, 11—venting port, 12—feeding port, 13—first pipeline, 14—second pipeline, 15—third pipeline, 16—first Return port, 17—second return port, 18—water inlet.

detailed description

Example 1

As shown in Figure 1, the integrated wastewater treatment device of the present invention includes a reactor, an ozone generator 7, a water tank 1, and a Venturi tube 8; wherein, the reactor includes a denitrification zone 3 and an ozone catalytic oxidation zone from bottom to top. 4 and biological aerated filter zone 5, a water inlet 18 is provided at the bottom of the denitrification zone 3, and a water outlet 10 is provided at the top; a first return port 16 and a second return port are provided at the top of the reactor Port 17; the water inlet 18 is connected to the water tank 1 through the first pipeline 13, and connected to the first return port 16 through the second pipeline 14;

Described ozone generator 7 is connected with described Venturi tube 8, and the water inlet of described Venturi tube 8 is connected with described second return port 17 by the 3rd pipeline 15, and the water outlet of described Venturi tube 8 is connected with The lower part of the ozone catalytic oxidation zone 4 is connected.

The first pipeline 13 is provided with an inlet pump 2 and a first valve, the second pipeline 14 is provided with a first return pump 9 and a second valve, and the third pipeline 15 is provided with There is a second return pump 6 and a third valve.

In the lower part of the denitrification zone 3, the ozone catalytic oxidation zone 4 and the biological aerated filter zone 5, a filter support layer and a material intake 12 are arranged, and in the lower part of the reactor, a The volume ratio of the vent 11 ; the denitrification zone 3 , the ozone catalytic oxidation zone 4 and the biological aerated filter zone 5 is 1:1:4.

The fillers in the denitrification zone 3 and the biological aerated filter zone 5 are volcanic rocks with a particle size of 2-5 mm; the fillers in the ozone catalytic oxidation zone 4 are loaded transition metal oxides, such as Al ₂ O ₃ or CuO The solid catalytic packing with a particle size of 2-5 mm; the packing rate of the denitrification zone 3 and the ozone catalytic oxidation zone 4 is 85%, and the packing rate of the biological aerated filter zone 5 is 80%.

Example 2

The method for carrying out petrochemical secondary effluent treatment using the integrated wastewater treatment device of the present invention comprises the following steps:

The wastewater in the water tank 1 enters the reactor through the water inlet pump 2, passes through the denitrification zone 3, the ozone catalytic oxidation zone 4 and the biological aerated filter zone 5 in turn, and flows out from the water outlet 10. At the same time, there are two return lines, One realizes reflux through the first reflux port 16, the first reflux pump 9 and the second pipeline 14, and the second one reaches the Venturi tube 8 through the second reflux port 17, the second reflux pump 6 and the third pipeline 15, and the reflux The waste water enters the lower part of the ozone catalytic oxidation zone 4 after being mixed with the ozone generated by the ozone generator 7 in the venturi tube 8 to realize reflux.

Preferably, the reflux of the ozone catalytic oxidation zone 4 is 100%-200%, the reflux of the denitrification zone 3 is 100%, the residence time of the reactor is 3h, and the dosage of ozone is 10mg /L.

Example 3

In this example, the secondary effluent of a typical petrochemical wastewater is treated as the treatment object. The wastewater quality indicators are as follows: COD is between _60-120mg /L, BOD5 is between 0.95-4mg/L, and UV ₂₅₄ is between 0.6-0.81/cm The concentration of NH ₄ ⁺ -N is below 2 mg/L, the content of TN is about 20 mg/L, the pH is between 7 and 8, the SS is between 20 and 27 mg/L, and the TP is between 1.0 and 1.5 mg/L between. _The dosage of ozone is 10mg/L, the reflux ratio of ozone catalytic oxidation unit is 200%, ^and the reflux ratio of denitrification unit is 100%. The N concentration is below 0.5mg/L, and the TN content is about 15mg/L.

The fillers used in the denitrification zone and the BAF zone are all volcanic rocks, the catalytic oxidation fillers used in the ozone catalytic oxidation unit are catalyst fillers loaded with Al ₂ O ₃ , and the residence time HRT of wastewater in the whole process is 3h.

The above-mentioned embodiments are only descriptions of preferred implementations of the present invention, and are not intended to limit the scope of the present invention. Variations and improvements should fall within the scope of protection defined by the claims of the present invention.

Claims (4)

1. an Integral waste water processing means, it is characterised in that: include reactor, ozone generator (7), water tank (1), literary composition mound In pipe (8)；Wherein, described reactor includes that denitrification zone (3), catalytic ozonation district (4) and aeration are raw from bottom to up successively Thing filter tank district (5), is provided with water inlet (18) in the bottom of described denitrification zone (3), and top is provided with delivery port (10)；Institute The top stating reactor is provided with the first refluxing opening (16) and the second refluxing opening (17)；Described water inlet (18) passes through the first pipeline (13) it is connected with described water tank (1), be connected with described first refluxing opening (16) by the second pipeline (14)；

Described ozone generator (7) is connected with described Venturi tube (8), the water inlet of described Venturi tube (8) and described second Refluxing opening (17) is connected by the 3rd pipeline (15), the delivery port of described Venturi tube (8) and described catalytic ozonation district (4) Bottom be connected；

It is all provided with in the bottom in described denitrification zone (3), described catalytic ozonation district (4) and described BAF district (5) It is equipped with filtrate supporting layer and material taking mouth (12), be provided with drain (11) in the bottom of described reactor；Described denitrification zone (3), the volume ratio in described catalytic ozonation district (4) and described BAF district (5) is 1:1:4；

The filler in described denitrification zone (3) and described BAF district (5) is volcanic rock, particle diameter 2-5mm；Described ozone is urged The filler changing zoneofoxidation (4) is carrying transition metal oxide, particle diameter 2-5mm；Described denitrification zone (3) and described ozone catalytic The media-filling rate of zoneofoxidation (4) is 85%, and the media-filling rate of described BAF district (5) is 80%；

Described Integral waste water processing means is for the process of petrochemical industry secondary effluent.

2. Integral waste water processing means according to claim 1, it is characterised in that: set on described first pipeline (13) It is equipped with intake pump (2) and the first valve, described second pipeline (14) is provided with the first reflux pump (9) and the second valve, It is provided with the second reflux pump (6) and the 3rd valve on described 3rd pipeline (15).

3. Integral waste water processing means according to claim 2, it is characterised in that: described carrying transition metal oxide For Al₂O₃Or the solid catalysis filler of CuO.

4. use the Integral waste water processing means described in any one in claims 1 to 3 to carry out petrochemical industry secondary effluent process Method, it is characterised in that: comprise the steps:

Waste water in water tank (1) enters in reactor by intake pump (2), passes sequentially through denitrification zone (3), ozone catalytic oxygen Changing district (4) and BAF district (5), flowing out from delivery port (10), concurrently there are two reflux lines, one article is passed through the One refluxing opening (16), the first reflux pump (9) and the second pipeline (14) realize backflow, Article 2 by the second refluxing opening (17), the Two reflux pumps (6) and the 3rd pipeline (15) reach Venturi tube (8), and backflow waste water is sent out with ozone in described Venturi tube (8) The bottom of described catalytic ozonation district (4) is entered, it is achieved backflow after the ozone mixing that raw device (7) produces；Described in processing Petrochemical industry secondary effluent COD is less than 100mg/L, and when TN is less than 30mg/L, the capacity of returns of described catalytic ozonation district (4) is 100%-200%, the capacity of returns of described denitrification zone (3) is 100%, and the time of staying of described reactor is 3h, the throwing of ozone Amount is at 10mg/L.