BDO process wastewater treatment process

Abstract

A BDO process wastewater treatment process comprises the steps that BDO wastewater, diluted phenol water and part of polyformaldehyde wastewater are received by a phenol recycling and regulating tank and are preliminarily separated and recycled, the polyformaldehyde wastewater receiving ratio of the phenol recycling and regulating tank to a mixed wastewater tank is 1: 1, and the total wastewater receiving ratio of the phenol recycling and regulating tank to the mixed wastewater tank is 8.5: 0.5. According to the invention, the polyformaldehyde wastewater is partially introduced into the mixed wastewater pool to reduce the sludge load of the IMC pool, the formaldehyde concentration of the polyformaldehyde wastewater is diluted by using low-concentration wastewater such as domestic sewage, ground flushing water, rainwater and the like entering the mixed wastewater pool, and 1, 4-butanediol production wastewater and polyformaldehyde production wastewater do not need to be independently treated, so that the treatment cost is reduced. The wastewater can be treated together with phenol-containing wastewater generated by gasification by a traditional biological method, so that the phenol-containing wastewater of a phenol recovery device, formaldehyde-containing wastewater of a 1, 4 butanediol device, formaldehyde-containing wastewater of a polyformaldehyde device and TOX wastewater can be treated by a sewage treatment station, a sewage system operates stably, and the wastewater reaches the standard and is discharged.

Description

Technical Field

[0001] The invention relates to the technical field of coal chemical wastewater treatment, and in particular to a BDO process wastewater treatment process. Background Art

[0002] In the BDO production process, the main components of wastewater generated in the gasifier production process, 1,4-butanediol and polyoxymethylene process are phenols, trioxymethylene (TOX), dioxolane, methylal, etc., with high phenol and formaldehyde content, high salt content, high COD and other characteristics. When different types of wastewater are mixed, various types of pollutants such as phenols, formaldehyde, ammonia nitrogen, etc. coexist at high concentrations, are difficult to biodegrade, and have extremely high organic content. In particular, the inhibitory effect of toxic substances such as formaldehyde and TOX causes the loss of microbial activity and cannot achieve effective biodegradation. Generally, this part of wastewater is treated separately by oxidation, condensation, electrochemical, and stripping methods. After the toxic substances in the wastewater are treated, traditional biological methods are used for treatment. For this reason, the wastewater treatment link is added, and the wastewater treatment capacity is limited. Summary of the invention

[0003] In order to solve the defect that toxic substances such as formaldehyde and TOX in the BDO process need to be treated separately before traditional biological treatment, which increases the wastewater treatment process, the purpose of the present invention is to provide a BDO process wastewater treatment process.

[0004] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a BDO process wastewater treatment process, comprising a phenol recovery regulating tank 1, an oil separation sedimentation tank 2, a primary flotation tank 3, a secondary flotation tank 4, a hydrolysis acidification tank 5, an IMC tank 6, a mixed wastewater tank 7, a contact oxidation tank 8, a secondary tank 9, a coagulation flotation tank 10, an ozone reaction tank 11, a BAF tank 12, a rapid filter tank 13, and an activated carbon filter tank 14.

[0005] The phenol recovery regulating tank 1 receives BDO wastewater, dilute phenol water and part of polyoxymethylene wastewater and performs preliminary separation and recovery. The oil separation sedimentation tank 2, the primary flotation tank 3, the secondary flotation tank 4, the hydrolysis acidification tank 5, the IMC tank 6, the mixed wastewater tank 7, the contact oxidation tank 8, the secondary tank 9, the coagulation flotation tank 10, the ozone reaction tank 11, the BAF tank 12, the rapid filtration tank 13 and the activated carbon filtration tank 14 are sequentially located in the subsequent wastewater treatment links. The phenol recovery regulating tank 1 and the mixed wastewater tank 7 receive polyoxymethylene wastewater in a ratio of 1:1, and the phenol recovery regulating tank 1 and the mixed wastewater tank 7 receive a total amount of wastewater in a ratio of 8.5:0.5.

[0006] Furthermore, the processing capacity of the single set of oil-water sedimentation tank 2 is 135 m³ / h, and its residence time is 2.5h. When the oil content of the incoming water is less than 70㎎ / L, the oil-water sedimentation tank can remove the grease in the wastewater without adding chemicals.

[0007] Furthermore, the flocculation and coagulation time of the primary flotation tank 3 and the secondary flotation tank 4 are both 10 minutes, and the speed of the stirrer is 76rp / m; the primary flotation tank 3 and the secondary flotation tank 4 each have three sets of flotation equipment, and the processing capacity of each set is 135m³ / h; when the oil content of the incoming water is greater than 70㎎ / L or the COD is greater than 4000㎎ / L, the flotation equipment of the primary flotation tank 3 and the secondary flotation tank 4 is turned on, otherwise the flotation equipment is not turned on.

[0008] Furthermore, the hydrolysis acidification tank 5 adjusts the pH value of the wastewater to 7.2-8.3, and the hydrolysis time is 24 hours.

[0009] Furthermore, the IMC pool 6 performs biodegradation and solid-liquid separation, the temperature of the IMC pool 6 is between 25-35°C, the pH is 7.2-8.3, the primary dissolved oxygen is 6.5-7.0 mg / L, the secondary dissolved oxygen is 0.3-1.2 mg / L, the total phosphorus is 0.4-0.6 mg / L, the sludge concentration is 5.0-6.0 g / L, the influent ammonia nitrogen is <200 mg / L, and the COD is <2500 mg / L.

[0010] Furthermore, the contact oxidation pond 8 performs oxidation treatment, the overall dissolved oxygen is less than 7.0 mg / L, the influent COD is less than 350 mg / L, the ammonia nitrogen is less than 25 mg / L, the sludge concentration is controlled at 1.5-2.5 g / L, and the organic matter is oxidized into a form that is easier to handle.

[0011] Furthermore, the secondary tank 9 removes residual organic matter and impurities.

[0012] Furthermore, the coagulation flotation tank 10 gathers small suspended matter in the sewage through flocculants and coagulants, and then oxidizes it with hyposodium to make it lighter, and then it is lifted to the surface of the water by a tiny steam drum to form scum, which is then removed by a scraper. Hyposodium can also degrade some organic matter and remove color. The ozone reaction tank 11 oxidizes and decomposes the oxidized organic matter in the wastewater through the strong oxidizing property of ozone, and can remove color at the same time.

[0013] Furthermore, the temperature in the BAF pool 12 is 25-35° C., the residence time is 2 hours, and the microbial flora includes microfilaments, sulfur-producing bacteria, and filamentous fungi.

[0014] Furthermore, the rapid filter 13 and the activated carbon filter 14 remove suspended matter through physical filtration of the filter material layer.

[0015] Compared with the existing mixed wastewater technology, the present invention has the following advantages.

[0016] The invention discloses a BDO process wastewater treatment process, in which part of the polyoxymethylene wastewater is introduced into a mixed wastewater pool 7 to reduce the sludge load of an IMC pool 6, and low-concentration wastewater such as domestic sewage, ground washing water, rainwater, etc. entering the mixed wastewater pool 7 is used to dilute the formaldehyde concentration of the polyoxymethylene wastewater, and there is no need to separately treat 1,4-butanediol production wastewater and polyoxymethylene production wastewater, and the wastewater can be treated together with the phenol-containing wastewater generated by gasification by using a traditional biological method, so that the phenol-containing wastewater of a phenol recovery device, the formaldehyde-containing wastewater of a 1,4-butanediol device, the formaldehyde-containing wastewater of a polyoxymethylene device, and the TOX wastewater can all be treated by a sewage treatment station, and the sewage system can operate stably, and the wastewater can be discharged in compliance with the standards. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The present invention is a flow chart of a BDO process wastewater treatment process. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0019] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "top", "bottom", "one side", "the other side", "front", "back", "middle part", "inside", "top end", "bottom end", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention; the terms "first", "second", and "third" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance; in addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Example

[0020] like Figure 1As shown, the present invention provides a BDO process wastewater treatment process, comprising a phenol recovery regulating tank 1, an oil separation sedimentation tank 2, a primary flotation tank 3, a secondary flotation tank 4, a hydrolysis acidification tank 5, an IMC tank 6, a mixed wastewater tank 7, a contact oxidation tank 8, a secondary tank 9, a coagulation flotation tank 10, an ozone reaction tank 11, a BAF tank 12, a rapid filter tank 13, and an activated carbon filter tank 14.

[0021] The phenol recovery regulating tank 1 and the mixed wastewater tank 7 receive polyoxymethylene wastewater in a ratio of 1:1, and the phenol recovery regulating tank 1 and the mixed wastewater tank 7 receive a total wastewater ratio of 8.5:0.5. The phenol recovery regulating tank 1 separates phenolic substances from the wastewater and purifies the wastewater after phenol recovery treatment; the preliminarily treated waste liquid is sent to the oil separation sedimentation tank 2 to remove floating oil and part of suspended solids in the wastewater to reduce the load of subsequent treatment facilities; the wastewater enters the primary flotation tank 3 and the secondary flotation tank 4 to dissolve the pressurized air in the wastewater, and the suspended solids in the wastewater are removed by air bubbles through decompression. Solids and grease are brought to the surface of the water to achieve solid-liquid separation; organic matter is decomposed into smaller molecules through hydrolysis and acidification in the hydrolysis acidification tank 5 to improve its biodegradability; the IMC tank 6 mixes the wastewater with activated sludge, uses a membrane component to filter the mixed liquid, and separates clear filtrate and concentrated sludge; the polyoxymethylene wastewater is partially introduced into the mixed wastewater tank 7 to reduce the sludge load of the IMC tank 6, and the water entering the mixed wastewater tank 7 is used to dilute the formaldehyde concentration of the polyoxymethylene wastewater; the wastewater flows through the mixed wastewater tank 7 to evenly distribute pollutants and adjust the wastewater flow rate, making the subsequent treatment process more stable. The wastewater flows into the contact oxidation tank 8; the contact oxidation tank 8 does not need sludge return and does not produce sludge expansion, so it can achieve rapid biochemical treatment of high BOD load wastewater and effectively remove organic pollutants in the wastewater; the wastewater is nitrogen and phosphorus removed in the secondary tank 9, reducing the risk of eutrophication of the water body; by adding coagulant to the wastewater flowing into the coagulation flotation tank 10, suspended solids and soluble pollutants are aggregated into larger flocs, and then these flocs are brought to the water surface through the flotation process, thereby achieving solid-liquid separation; the wastewater after removing suspended solids flows into the ozone reaction tank 11, and the ozone Oxygen gas diffuses into the treated water, completing the deodorization, decolorization and reduction of COD and BOD of the wastewater; the wastewater flows through the BAF tank 12, and the microorganisms on the biofilm continue to deeply degrade the BOD and COD remaining in the wastewater, converting organic pollutants into harmless substances; finally, the wastewater with organic pollutants effectively removed flows into the rapid filter tank 13 and the activated carbon filter tank 14 in turn; the rapid filter tank 13 is used to remove suspended solids and turbidity in the water, and the activated carbon filter tank 14 reduces the organic odor, color, turbidity and the content of certain organic matter in the water, and finally achieves a high degree of purification of the wastewater.

[0022] Table 1 and Table 2 are the tests on COD and ammonia nitrogen of mixed wastewater after 1,4-butanediol wastewater was not treated by Fenton reactor and polyoxymethylene wastewater was discharged into the sewage device. The test results are shown in the table.

[0023] Table 1 IMC pool water inlet data test results

[0024] Table 2 IMC pool effluent data test results

[0025] As can be seen from the above table, high concentrations of toxic substances such as formaldehyde enter the sewage system. The effluent COD and ammonia nitrogen of IMC pool 6 can be stabilized at around 200 mg / L and 6 mg / L, respectively. The pollutant removal rate of the biochemical system reaches more than 90%, and the system is very stable.

[0026] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0027] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A BDO process wastewater treatment process, comprising a phenol recovery regulating tank (1), an oil separation sedimentation tank (2), a primary flotation tank (3), a secondary flotation tank (4), a hydrolysis acidification tank (5), an IMC tank (6), a mixed wastewater tank (7), a contact oxidation tank (8), a secondary tank (9), a coagulation flotation tank (10), an ozone reaction tank (11), a BAF tank (12), a rapid filter tank (13), and an activated carbon filter tank (14), wherein the phenol recovery regulating tank (1) receives BDO wastewater, dilute phenol water, and part of polyoxymethylene wastewater and performs preliminary separation and recovery, and the oil separation sedimentation tank (2), the primary flotation tank (3), the secondary flotation tank (4), the hydrolysis acidification tank (5), the IMC tank (6), the mixed wastewater tank (7), the contact oxidation tank (8), the secondary tank (9), the coagulation flotation tank (10), the ozone reaction tank (11), the BAF tank (12), the rapid filter tank (13), and the activated carbon filter tank (14) are sequentially located in the subsequent wastewater treatment links, characterized in that The ratio of the polyoxymethylene wastewater received by the phenol recovery regulating tank (1) and the mixed wastewater tank (7) is 1:1, and the ratio of the total amount of wastewater received by the phenol recovery regulating tank (1) and the mixed wastewater tank (7) is 8.5:0.

5.

2. A BDO process wastewater treatment process according to claim 1, characterized in that The treatment capacity of a single set of the oil-separating sedimentation tank (2) is 135 m³ / h, and its retention time is 2.5 h. When the oil content of the incoming water is less than 70 mg / L, the oil-separating tank does not need to add chemicals to remove the grease in the wastewater.

3. A BDO process wastewater treatment process according to claim 1, characterized in that The flocculation and coagulation time of the first-level flotation tank (3) and the second-level flotation tank (4) are both 10 minutes, and the speed of the stirrers is 76 rp / m; the first-level flotation tank (3) and the second-level flotation tank (4) each have three sets of flotation equipment, and the processing capacity of each set is 135 m³ / h; when the oil content of the incoming water is greater than 70 mg / L or the COD is greater than 4000 mg / L, the flotation equipment of the first-level flotation tank (3) and the second-level flotation tank (4) are turned on, otherwise the flotation equipment is not turned on.

4. A BDO process wastewater treatment process according to claim 1, characterized in that The hydrolysis acidification tank (5) adjusts the pH value of the wastewater to 7.2-8.3, and the hydrolysis time is 24 hours.

5. A BDO process wastewater treatment process according to claim 1, characterized in that The IMC pool (6) performs biodegradation and solid-liquid separation. The temperature of the IMC pool (6) is between 25-35°C, the pH is 7.2-8.3, the primary dissolved oxygen is 6.5-7.0 mg / L, the secondary dissolved oxygen is 0.3-1.2 mg / L, the total phosphorus is 0.4-0.6 mg / L, the sludge concentration is 5.0-6.0 g / L, the influent ammonia nitrogen is less than 200 mg / L, and the COD is less than 2500 mg / L.

6. A BDO process wastewater treatment process according to claim 1, characterized in that The contact oxidation pond (8) performs oxidation treatment, the overall dissolved oxygen is less than 7.0 mg / L, the influent COD is less than 350 mg / L, the ammonia nitrogen is less than 25 mg / L, the sludge concentration is controlled at 1.5-2.5 g / L, and the organic matter is oxidized into a form that is easier to handle.

7. A BDO process wastewater treatment process according to claim 1, characterized in that The secondary tank (9) removes residual organic matter and impurities.

8. A BDO process wastewater treatment process according to claim 1, characterized in that The coagulation flotation tank (10) gathers small suspended matter in the sewage through flocculants and coagulants, and then uses hyposodium to oxidize the small suspended matter to make it lighter, and then it is lifted to the surface of the water by a tiny steam drum to form scum, which is then removed by a scraper. Hyposodium can also degrade some organic matter and remove color. The ozone reaction tank (11) uses the strong oxidizing property of ozone to oxidize and decompose the oxidized organic matter in the wastewater, and can also remove color.

9. A BDO process wastewater treatment process according to claim 1, characterized in that The temperature in the BAF pool (12) is 25-35°C, the residence time is 2 hours, and the microbial flora includes microfilaments, sulfur bacteria, and filamentous fungi.

10. A BDO process wastewater treatment process according to claim 1, characterized in that The rapid filter (13) and the activated carbon filter (14) remove suspended matter through physical filtration of the filter material layer.

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