CN112707584A - Method for treating cold-rolling oily wastewater of iron and steel enterprises - Google Patents
Method for treating cold-rolling oily wastewater of iron and steel enterprises Download PDFInfo
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Abstract
The invention discloses a method for treating cold-rolling oily wastewater of iron and steel enterprises, belonging to the technical field of industrial wastewater treatment. The technical scheme is as follows: the concentrated oil wastewater generated in the steel rolling procedure is sequentially treated by a regulating reservoir, a concentrated oil pH value regulating reservoir, a advection oil interceptor, a concentrated oil cavitation air flotation reservoir and a concentrated oil dissolved gas flotation reservoir, and then is sequentially treated by a dilute oil regulating reservoir, a dilute oil pH value regulating reservoir, a two-stage cavitation air flotation reservoir, a cooling tower, a two-stage dissolved gas flotation reservoir, a hydrolysis acidification reservoir, an anaerobic reservoir, a two-stage contact oxidation reservoir, a secondary sedimentation reservoir, a high-stage oxidation reservoir and an aeration biological filter with the dilute oil wastewater generated in the steel rolling procedure, and the effluent is discharged to a sewage treatment plant for advanced treatment. The invention has the advantages of low energy consumption, low cost, simple equipment, easy operation, high regulation performance and stable treatment effect, can effectively solve the current water treatment problem of iron and steel enterprises, and has important significance for promoting the iron and steel enterprises to realize energy conservation, emission reduction and green sustainable development.
Description
Technical Field
The invention belongs to the technical field of industrial wastewater treatment, and particularly relates to a method for treating cold-rolled oily wastewater of iron and steel enterprises.
Background
A large amount of oily wastewater can be generated in the rolling process of the cold-rolled sheet of the iron and steel enterprise, and the main sources of the oily wastewater comprise 3 approaches: firstly, in the rolling process, in order to eliminate thermal denaturation generated by cold rolling, emulsion cooling and lubrication are adopted (the emulsion mainly comprises mineral oil, vegetable oil, animal oil, anionic or nonionic emulsion and water), and cold rolling emulsion wastewater is generated; secondly, cold rolling is carried out before coil loosening and annealing, alkaline solution is adopted for degreasing, and alkaline oily wastewater is generated; and thirdly, oil-containing and fat-containing wastewater continuously or discontinuously discharged in other production processes. The highest oil content of the wastewater can reach 50g/L, and the COD is up to 150000PPM, which is a 'old, big and difficult' problem in the field of water treatment in the steel industry. Along with the continuous improvement of water treatment technology, the combined treatment processes of electrocatalytic oxidation, ultrafiltration, nanofiltration and the like are developed, and the quality of the effluent water is greatly improved. However, with the increasingly strict and standard national pollutant emission indexes of iron and steel enterprises, the operation cost of the existing process is found to be extremely high in daily operation, meanwhile, the treated effluent cannot meet the current pollutant emission standard of the iron and steel industry, and the internal recycling also causes a plurality of bottleneck problems of polluting the water quality of the system and the like, thereby seriously restricting the production and sustainable development of high-quality products of the iron and steel enterprises.
In the prior art, in daily use, the manufacturing cost of the titanium alloy electrode plate, the ultrafiltration membrane and the nanofiltration membrane adopted in electrocatalytic oxidation is very high, the service life of the equipment is less than 3 years due to the characteristics of treated wastewater, the replacement cost becomes financial burden of enterprises, and meanwhile, the water quality cannot be stabilized in the later period of the service life of the equipment, so that the hidden danger of water quality fluctuation is caused. Therefore, the method for efficiently and deeply treating the cold-rolled oily wastewater of the iron and steel enterprises and realizing the reutilization of wastewater resources is developed, can save water resources for the iron and steel enterprises, particularly the iron and steel enterprises in water-deficient areas, and has great significance for improving the water environment of the iron and steel enterprises and realizing water conservation and emission reduction.
Disclosure of Invention
In order to solve the technical problems, the invention provides a method for treating cold-rolled oily wastewater of steel enterprises, which aims at carrying out advanced treatment on oily wastewater generated in the production process of cold-rolled sheets and realizes that the quality of effluent meets the recycling standard of the steel enterprises on the premise of economic operation.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows: a method for treating cold-rolled oily wastewater of iron and steel enterprises specifically comprises the following steps:
(1) concentrated oil wastewater treatment process
A. The method comprises the following steps that concentrated oil wastewater generated in a steel rolling process firstly enters a concentrated oil regulating tank to regulate and buffer water quantity and water quality, and simultaneously enters a concentrated oil pH value regulating tank after being heated by steam to regulate the pH value to be acidic, then oil sludge is removed through an advection oil separation tank, the separated oil sludge enters a scum tank, and the sludge and water are separated by a centrifugal dehydrator after being concentrated in an oil sludge-containing concentration tank; the COD content of the concentrated oil wastewater is more than 5000mg/L, and the oil content is more than 50 mg/L;
B. adding PAC and PAM into effluent of the advection oil separation tank through a pipeline mixer, uniformly mixing, and allowing the effluent to enter a concentrated oil cavitation air flotation tank after coagulation to remove oil substances and suspended matters;
C. the effluent of the concentrated oil cavitation air flotation tank enters a concentrated oil steam-dissolved air flotation tank to further remove oil substances and suspended matters, and the effluent enters a thin oil wastewater treatment process for further treatment;
(2) thin oil wastewater treatment process
D. C, enabling the thin oil wastewater generated in the steel rolling process and/or the effluent water obtained in the step C to enter a thin oil adjusting tank for adjusting and buffering the water quantity and the water quality, and then entering a thin oil pH value adjusting tank for adjusting the pH value to be acidic; the COD content of the inlet water of the thin oil regulating tank is less than or equal to 5000mg/L, and the oil content is less than or equal to 50 mg/L;
E. adding PAC and PAM into the effluent of the pH value adjusting tank through a pipeline mixer, coagulating, and sequentially entering a primary cavitation air flotation tank and a secondary cavitation air flotation tank; the method adopts a mode of using two stages of cavitation air floatation tanks in series, wherein water discharged from a first stage cavitation air floatation tank is water inlet of a second stage cavitation air floatation tank, 40-50% of suspended matters and oil pollutants are removed from the first stage cavitation air floatation tank, and 20-30% of suspended matters and oil pollutants are removed from the second stage cavitation air floatation tank;
F. the water discharged from the second-stage cavitation air flotation tank is cooled by a cooling tower and then sequentially enters a first-stage dissolved air flotation tank and a second-stage dissolved air flotation tank, a two-stage dissolved air flotation tank series mode is adopted, the water discharged from the first-stage dissolved air flotation tank is the water entering from the second-stage dissolved air flotation tank, 30-40% of suspended matters and oil pollutants are removed from the first-stage dissolved air flotation tank, and 10-20% of suspended matters and oil pollutants are removed from the second-stage dissolved air flotation tank;
G. discharging water from the secondary steam-dissolving air flotation tank to a hydrolysis acidification tank, and performing hydrolysis acidification by using hydrolysis and fermentation bacteria;
H. the effluent of the hydrolysis acidification tank is subjected to biochemical treatment through an anaerobic tank, a first-stage contact oxidation tank and a second-stage contact oxidation tank, nitrifying liquid in the two-stage contact oxidation tank flows back to the anaerobic tank, the reflux ratio is controlled to be 200-400%, the effluent enters a secondary sedimentation tank, sludge in the secondary sedimentation tank flows back to the anaerobic tank, and the sludge reflux ratio is controlled to be 20-30%; wherein the dissolved oxygen of the first-stage contact oxidation tank is more than or equal to 2mg/L, and the dissolved oxygen of the second-stage contact oxidation tank is 3-4 mg/L;
I. the effluent of the secondary sedimentation tank enters an advanced oxidation tank after passing through an intermediate water tank, and is oxidized by ozone;
J. the effluent of the advanced oxidation pond enters an aeration biological filter, the filler of the base layer of the aeration biological filter adopts natural pebbles, the biological filler adopts light ceramsite, and the effluent of the aeration biological filter enters a water production pond and is discharged to a sewage treatment plant for advanced treatment through an outer discharge pond.
And in the step A, HCl is added to adjust the pH value to 5.5-6.5, and the retention time of the concentrated oil wastewater in the advection oil separation tank is 1.0-1.5 h.
B, the retention time of the concentrated oil wastewater in the concentrated oil cavitation air flotation tank is 1.0-1.5 h; step C, the retention time of the concentrated oil wastewater in the concentrated oil steam-soluble air floating pool is 1.0-1.5 h; and D, adding HCl to adjust the pH value to 5.5-6.5.
And E, the retention time of the wastewater in the first-stage cavitation air flotation tank and the second-stage cavitation air flotation tank is 1.0-1.5 h.
Step F, cooling the water discharged from the secondary cavitation air flotation tank to 15-30 ℃ through a cooling tower; the retention time of the wastewater in the first-stage dissolved steam floating tank and the second-stage dissolved steam floating tank is 0.8-1.5 h.
And in the step G, the retention time of the wastewater in the hydrolysis acidification tank is 1.5-2.5 h.
In the step H, the retention time of the wastewater in the anaerobic tank is 1.5-2.0H, and the retention time in the two-stage contact oxidation tank is 12-14H.
In the step I, the retention time of the wastewater in the advanced oxidation pond is 0.5-1.2h, and the concentration of ozone is 2-3%; step J, carrying out thin-wall cultivation on the natural pebble with the bulk density of 1.7-2.0 g/cm; the light ceramsite has the grain diameter of 3-6mm and the bulk density of 0.7-1.0g/cm3The retention time of the wastewater in the biological aerated filter is 1.0-1.5 h.
Scum generated by the concentrated oil cavitation air flotation tank, the concentrated oil dissolved steam air flotation tank, the primary cavitation air flotation tank, the secondary cavitation air flotation tank, the primary dissolved steam air flotation tank and the secondary dissolved steam air flotation tank enters the scum tank, and then is concentrated by the concentration tank and then is separated from water by the centrifugal dehydrator.
The water quality COD of the produced water of the aeration biological filter is less than or equal to 50mg/L, the ammonia nitrogen is less than or equal to 5mg/L, the suspended matters are less than or equal to 20mg/L, and the oil is less than or equal to 3 mg/L.
Adopt the produced beneficial effect of above-mentioned technical scheme to lie in: the invention carries out advanced treatment on the waste water containing thick oil and thin oil generated in the cold rolling procedure of iron and steel enterprises, the produced water meets the requirement of reuse water of other procedures of the iron and steel enterprises of enterprises, the reuse of the treated water is realized, the energy consumption is low, the cost is low, the equipment is simple, the operation is easy, the regulation performance is high, and the treatment effect is stable. The method can effectively solve the current water treatment problem of the iron and steel enterprises, and has important significance for promoting the water environment improvement of the iron and steel enterprises, realizing energy conservation and emission reduction and green sustainable development.
Drawings
FIG. 1 is a flow chart of the concentrated oil wastewater treatment process of the present invention;
FIG. 2 is a flow chart of the process for treating the thin oil wastewater.
Detailed Description
The technical solutions in the embodiments of the present invention are clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.
The COD value of concentrated oil wastewater generated in the steel rolling process of a certain steel enterprise is 20000mg/L, the ammonia nitrogen is 150mg/L, the suspended matters are 300mg/L, and the oil is 60 mg/L;
the COD value of the thin oil wastewater generated in the steel rolling process is 1000mg/L, the ammonia nitrogen is 100mg/L, the suspended matters are 100mg/L, and the oil content is 40 mg/L.
The oily wastewater treatment method is adopted to treat the wastewater, and the main process flow is as follows:
(1) concentrated oil wastewater treatment process
A. The method comprises the following steps of firstly enabling concentrated oil wastewater generated in a steel rolling process to enter a concentrated oil regulating tank for regulating and buffering water quantity and water quality, meanwhile, enabling the concentrated oil wastewater to enter a concentrated oil pH value regulating tank after being heated by steam, adding HCl to regulate the pH value to be 6.0, ensuring that oil can be sufficiently demulsified under an acidic condition to form floating oil, then removing oil sludge through an advection oil separation tank, enabling the remaining time to be 1.5h, enabling the separated oil sludge to enter a scum tank, and realizing mud-water separation through a centrifugal dehydrator after concentrating an oil-containing sludge concentrating tank.
B. And adding PAC and PAM into the outlet water of the advection oil separation tank through a pipeline mixer, uniformly mixing, allowing the mixed water to enter a concentrated oil cavitation air flotation tank after coagulation, and allowing the mixed water to stay for 1.5 hours to remove oil substances and suspended matters. Scum generated by the concentrated oil cavitation air flotation tank enters a scum tank, and then is concentrated by a concentration tank and then is subjected to sludge-water separation by a centrifugal dehydrator.
C. The effluent of the concentrated oil cavitation air flotation tank enters a concentrated oil steam-dissolved air flotation tank to stay for 1.5h, oil substances and suspended matters are further removed, the effluent quality COD4779mg/L, ammonia nitrogen 20mg/L, suspended matters 50mg/L and oil 40mg/L enter a thin oil wastewater treatment process for further treatment. Scum generated by the concentrated oil steam-dissolved air flotation tank enters a scum tank, and then is concentrated by a concentration tank and then is subjected to sludge-water separation by a centrifugal dehydrator.
(2) Thin oil wastewater treatment process
D. And D, enabling the thin oil wastewater generated in the steel rolling process and the effluent water obtained in the step C to enter a thin oil regulating reservoir for regulating and buffering the water quantity and the water quality, then enabling the effluent water to enter a thin oil pH value regulating reservoir, adding HCl to regulate the pH value to be 6.0, and ensuring that the oil can be fully demulsified under an acidic condition to form floating oil.
E. The effluent of the pH value adjusting tank is added with PAC and PAM through a pipeline mixer for coagulation and then sequentially enters a first-stage cavitation air flotation tank and a second-stage cavitation air flotation tank, a two-stage cavitation air flotation tank series connection use mode is adopted, the effluent of the first-stage cavitation air flotation tank is namely the water inlet of the second-stage cavitation air flotation tank, so that the effluent is closer to a plug flow type reaction, the effective removal of pollutants is realized, the first-stage cavitation air flotation tank creates favorable treatment conditions for the second-stage cavitation air flotation tank, 40-50% of suspended matters and oil pollutants can be removed by the first-stage cavitation air flotation tank, 20-30% of suspended matters and oil pollutants can be removed by the second-stage cavitation air flotation tank, and 60-80% of suspended matters and oil pollutants in the inlet water; the retention time of the wastewater in the first-stage cavitation air flotation tank and the second-stage cavitation air flotation tank is 1.3 h. Scum generated by the two-stage cavitation air flotation tank enters a scum tank, and then is concentrated by a concentration tank and then is subjected to sludge-water separation by a centrifugal dehydrator.
F. And the water discharged from the secondary cavitation air flotation tank is cooled to 20 ℃ by a cooling tower and then sequentially enters a primary dissolved steam air flotation tank and a secondary dissolved steam air flotation tank to further remove oil and suspended matters. In order to ensure the treatment effect, a two-stage dissolved air flotation tank series connection mode is adopted, the effluent of the first-stage dissolved air flotation is the water inlet of the second-stage dissolved air flotation, so that the water is more close to the plug flow type reaction, the effective removal of pollutants is realized, 30-40% of suspended matters and oil pollutants are removed by the first-stage dissolved air flotation tank, and 10-20% of suspended matters and oil pollutants are removed by the second-stage dissolved air flotation tank; the two-stage steam-dissolving air-floating tanks are connected in series to remove 40-60% of suspended matters and oil pollutants in the inlet water; because the diameter of the bubbles generated by the dissolved air flotation is one fourth to one tenth of that of the cavitation air flotation, the effluent of the cavitation air flotation tank can be further purified, and suspended matters and oil substances are further removed. The residence time in the first-stage dissolved steam floating tank and the second-stage dissolved steam floating tank is 0.8-1.5h respectively. Scum generated by the two-stage steam-dissolved air flotation tank enters the scum tank, and then is concentrated by the concentration tank and then is subjected to mud-water separation by the centrifugal dehydrator.
G. The second grade solution gas air supporting pond goes out water and stays 1.5~2.5h to hydrolysis acidification pool, utilizes hydrolysis and fermentation bacterium to carry out hydrolysis acidification, hydrolysis and fermentation bacterium are the bacterium that the sewage treatment field is commonly used, and the majority is the obligation anaerobe, and the minority is the facultative anaerobe, mainly is cellulose decomposition bacterium, carbohydrate decomposition bacterium, protein decomposition bacterium and fat decomposition bacterium etc. and carries out hydrolysis acidification, breaks the organic matter carbon bond, improves the biodegradability of waste water and alleviates follow-up contact oxidation pond processing load simultaneously.
H. Effluent of the hydrolysis acidification tank is subjected to biochemical treatment through an anaerobic tank, a first-stage contact oxidation tank and a second-stage contact oxidation tank, nitrifying liquid in the two-stage contact oxidation tank flows back to the anaerobic tank, the reflux ratio is 300%, effluent enters a secondary sedimentation tank, 3% of sludge in the secondary sedimentation tank flows back to the anaerobic tank, wastewater stays in the anaerobic tank for 2 hours, and the stay time in the first-stage contact oxidation tank and the stay time in the second-stage contact oxidation tank are respectively 1.5 hours.
I. The effluent of the secondary sedimentation tank enters the advanced oxidation tank after passing through the intermediate water tank and stays for 1.0h, ozone with high oxidation efficiency, no pollution, low cost and 3% concentration is adopted for oxidation, and the addition amount is 1.5kg/h to oxidize refractory organic matters into biochemical organic matters, so that the subsequent treatment effect is improved.
J. Enabling the effluent of the high-grade oxidation pond to enter an aeration biological filter and stay for 1.2h, wherein natural pebbles are adopted as a base layer filler of the aeration biological filter, and the stacking density is 1.85g/cm for carrying out high speed cultivation; the biological filler is light ceramsite with the particle size of 3-6mm and the bulk density of 0.89g/cm3Under the condition that the lower part of the filter material layer provides aeration oxygen supply, the microbial film leads organic matters in the wastewater to be degraded aerobically and leads partial ammonia nitrogen in the wastewater to be nitrified. The effluent of the aeration biological filter tank meets the water quality requirement of other processes, enters a water producing tank and is sent out to a sewage treatment plant in a factory for advanced treatment. To eliminate the aged microbial membrane proliferated on the surface of the filter material and ensure the activity of the microbesThe filter chamber can be backwashed by using the treated effluent at regular intervals.
The COD value of the produced water of the aeration biological filter is 50mg/L, the ammonia nitrogen is 5mg/L, the suspended matter is 10mg/L and the oil is 3 mg/L.
Therefore, the effluent quality of the oily wastewater treated by the method meets the requirement of other procedures on reuse water quality, and the oily wastewater enters a water producing pool and is sent to a sewage treatment plant in a factory for advanced treatment.
Claims (10)
1. A method for treating cold-rolled oily wastewater of iron and steel enterprises is characterized by comprising a concentrated oil wastewater treatment process and a thin oil wastewater treatment process, and specifically comprises the following steps:
(1) concentrated oil wastewater treatment process
A. The method comprises the following steps that concentrated oil wastewater generated in a steel rolling process firstly enters a concentrated oil regulating tank to regulate and buffer water quantity and water quality, and simultaneously enters a concentrated oil pH value regulating tank after being heated by steam to regulate the pH value to be acidic, then oil sludge is removed through an advection oil separation tank, the separated oil sludge enters a scum tank, and the sludge and water are separated by a centrifugal dehydrator after being concentrated in an oil sludge-containing concentration tank; the COD content of the concentrated oil wastewater is more than 5000mg/L, and the oil content is more than 50 mg/L;
B. adding PAC and PAM into effluent of the advection oil separation tank through a pipeline mixer, uniformly mixing, and allowing the effluent to enter a concentrated oil cavitation air flotation tank after coagulation to remove oil substances and suspended matters;
C. the effluent of the concentrated oil cavitation air flotation tank enters a concentrated oil steam-dissolved air flotation tank to further remove oil substances and suspended matters, and the effluent enters a thin oil wastewater treatment process for further treatment;
(2) thin oil wastewater treatment process
D. C, enabling the thin oil wastewater generated in the steel rolling process and/or the effluent water obtained in the step C to enter a thin oil adjusting tank for adjusting and buffering the water quantity and the water quality, and then entering a thin oil pH value adjusting tank for adjusting the pH value to be acidic; the COD content of the inlet water of the thin oil regulating tank is less than or equal to 5000mg/L, and the oil content is less than or equal to 50 mg/L;
E. adding PAC and PAM into the effluent of the pH value adjusting tank through a pipeline mixer, coagulating, and sequentially entering a primary cavitation air flotation tank and a secondary cavitation air flotation tank; the method adopts a mode of using two stages of cavitation air floatation tanks in series, wherein water discharged from a first stage cavitation air floatation tank is water inlet of a second stage cavitation air floatation tank, 40-50% of suspended matters and oil pollutants are removed from the first stage cavitation air floatation tank, and 20-30% of suspended matters and oil pollutants are removed from the second stage cavitation air floatation tank;
F. the water discharged from the second-stage cavitation air flotation tank is cooled by a cooling tower and then sequentially enters a first-stage dissolved air flotation tank and a second-stage dissolved air flotation tank, a two-stage dissolved air flotation tank series mode is adopted, the water discharged from the first-stage dissolved air flotation tank is the water entering from the second-stage dissolved air flotation tank, 30-40% of suspended matters and oil pollutants are removed from the first-stage dissolved air flotation tank, and 10-20% of suspended matters and oil pollutants are removed from the second-stage dissolved air flotation tank;
G. discharging water from the secondary steam-dissolving air flotation tank to a hydrolysis acidification tank, and performing hydrolysis acidification by using hydrolysis and fermentation bacteria;
H. the effluent of the hydrolysis acidification tank is subjected to biochemical treatment through an anaerobic tank, a first-stage contact oxidation tank and a second-stage contact oxidation tank, nitrifying liquid in the two-stage contact oxidation tank flows back to the anaerobic tank, the reflux ratio is controlled to be 200-400%, the effluent enters a secondary sedimentation tank, sludge in the secondary sedimentation tank flows back to the anaerobic tank, and the sludge reflux ratio is controlled to be 20-30%; wherein the dissolved oxygen of the first-stage contact oxidation tank is more than or equal to 2mg/L, and the dissolved oxygen of the second-stage contact oxidation tank is 3-4 mg/L;
I. the effluent of the secondary sedimentation tank enters an advanced oxidation tank after passing through an intermediate water tank, and is oxidized by ozone;
J. the effluent of the advanced oxidation pond enters an aeration biological filter, the filler of the base layer of the aeration biological filter adopts natural pebbles, the biological filler adopts light ceramsite, and the effluent of the aeration biological filter enters a water production pond and is discharged to a sewage treatment plant for advanced treatment through an outer discharge pond.
2. The method for treating the cold-rolled oily wastewater of the steel enterprises according to claim 1, which is characterized by comprising the following steps: and in the step A, HCl is added to adjust the pH value to 5.5-6.5, and the retention time of the concentrated oil wastewater in the advection oil separation tank is 1.0-1.5 h.
3. The method for treating the cold-rolled oily wastewater of the steel enterprises according to claim 2, which is characterized in that: b, the retention time of the concentrated oil wastewater in the concentrated oil cavitation air flotation tank is 1.0-1.5 h; step C, the retention time of the concentrated oil wastewater in the concentrated oil steam-soluble air floating pool is 1.0-1.5 h; and D, adding HCl to adjust the pH value to 5.5-6.5.
4. The method for treating the cold-rolled oily wastewater of the steel enterprises according to claim 3, which is characterized by comprising the following steps: and E, the retention time of the wastewater in the first-stage cavitation air flotation tank and the second-stage cavitation air flotation tank is 1.0-1.5 h.
5. The method for treating the cold-rolled oily wastewater of the steel enterprises according to claim 4, which is characterized in that: step F, cooling the water discharged from the secondary cavitation air flotation tank to 15-30 ℃ through a cooling tower; the retention time of the wastewater in the first-stage dissolved steam floating tank and the second-stage dissolved steam floating tank is 0.8-1.5 h.
6. The method for treating the cold-rolled oily wastewater of the steel enterprises according to claim 5, which is characterized by comprising the following steps: and in the step G, the retention time of the wastewater in the hydrolysis acidification tank is 1.5-2.5 h.
7. The method for treating the cold-rolled oily wastewater of the steel enterprises according to claim 6, which is characterized in that: in the step H, the retention time of the wastewater in the anaerobic tank is 1.5-2.0H, and the retention time in the two-stage contact oxidation tank is 12-14H.
8. The method for treating the cold-rolled oily wastewater of the steel enterprises according to claim 7, which is characterized in that: in the step I, the retention time of the wastewater in the advanced oxidation pond is 0.5-1.2h, and the concentration of ozone is 2-3%; step J, carrying out thin-wall cultivation on the natural pebble with the bulk density of 1.7-2.0 g/cm; the light ceramsite has the grain diameter of 3-6mm and the bulk density of 0.7-1.0g/cm3The retention time of the wastewater in the biological aerated filter is 1.0-1.5 h.
9. The method for treating the cold-rolled oily wastewater of the steel enterprises according to claim 8, which is characterized in that: scum generated by the concentrated oil cavitation air flotation tank, the concentrated oil dissolved steam air flotation tank, the primary cavitation air flotation tank, the secondary cavitation air flotation tank, the primary dissolved steam air flotation tank and the secondary dissolved steam air flotation tank enters the scum tank, and then is concentrated by the concentration tank and then is separated from water by the centrifugal dehydrator.
10. The method for treating the cold-rolled oily wastewater of the steel enterprises according to claim 9, which is characterized in that: the water quality COD of the produced water of the aeration biological filter is less than or equal to 50mg/L, the ammonia nitrogen is less than or equal to 5mg/L, the suspended matters are less than or equal to 20mg/L, and the oil is less than or equal to 3 mg/L.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113511740A (en) * | 2021-05-11 | 2021-10-19 | 山东泰山轧钢有限公司 | Secondary demulsification treatment method for cold rolling oily wastewater |
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| CN202519129U (en) * | 2012-02-17 | 2012-11-07 | 武汉都市环保工程技术股份有限公司 | System for coprocessing cold-rolled oil-contained wastewater by physical-chemical and bio-chemical methods |
| CN104743748A (en) * | 2015-03-28 | 2015-07-01 | 东华工程科技股份有限公司 | High-concentration sewage treatment technology for refinery wastewater |
| CN105036465A (en) * | 2015-07-07 | 2015-11-11 | 安徽东华环境市政工程有限责任公司 | Zero-emission process for oil refining wastewater |
| CN109650648A (en) * | 2018-12-16 | 2019-04-19 | 邯郸钢铁集团有限责任公司 | A kind of processing system and method for cold rolling wastewater |
| WO2019098255A1 (en) * | 2017-11-14 | 2019-05-23 | 国立大学法人名古屋大学 | Method, system and apparatus for treating oil- and fat-containing wastewater |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN202519129U (en) * | 2012-02-17 | 2012-11-07 | 武汉都市环保工程技术股份有限公司 | System for coprocessing cold-rolled oil-contained wastewater by physical-chemical and bio-chemical methods |
| CN104743748A (en) * | 2015-03-28 | 2015-07-01 | 东华工程科技股份有限公司 | High-concentration sewage treatment technology for refinery wastewater |
| CN105036465A (en) * | 2015-07-07 | 2015-11-11 | 安徽东华环境市政工程有限责任公司 | Zero-emission process for oil refining wastewater |
| WO2019098255A1 (en) * | 2017-11-14 | 2019-05-23 | 国立大学法人名古屋大学 | Method, system and apparatus for treating oil- and fat-containing wastewater |
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| CN113511740A (en) * | 2021-05-11 | 2021-10-19 | 山东泰山轧钢有限公司 | Secondary demulsification treatment method for cold rolling oily wastewater |
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