A method for quickly recovering a biochemical unit in a sewage treatment plant after being subjected to a high-load impact

Abstract

The present invention discloses a method for rapidly recovering a biochemical unit after a sewage treatment plant is subjected to a high-load shock. The method comprises the following steps: when the biochemical unit is subjected to a high-load shock, and the fluctuation amplitude of the respiration rate is more than 10% below the lower limit of the normal range for more than 30 minutes, an alarm is triggered to notify the control system, water intake is stopped, and powdered activated carbon and a biosorbent are added to the system until the respiration rate returns to the normal range, the alarm is lifted, the addition of activated carbon and biosorbent is stopped, and water intake is restarted to continue operation, thereby achieving rapid recovery after the shock; the biosorbent includes a metal-loaded carrier and a sugar ester-producing microorganism. The method of the present invention uses two detection indicators, the activated sludge respiration rate and the chemical oxygen demand, to perform early diagnosis of the shock risk, thereby achieving early warning, timely elimination of the shock risk, and rapid recovery. There is no need to re-acclimate the sludge, thus reducing recovery time and ensuring the long-term stable operation of the system.

Description

Technical Field

[0001] The present invention belongs to the technical field of sewage treatment, and in particular relates to a method for quickly recovering a biochemical unit of a sewage treatment plant after being impacted by an abnormal load. Background Art

[0002] The biochemical units of existing sewage treatment systems are frequently subjected to load shocks, including pollutant and hydraulic loads. Severe shocks that exceed the system's capacity can suppress or even eliminate microbial activity, necessitating re-cultivation and acclimation. This can lead to prolonged recovery times for sewage treatment systems and, in severe cases, disrupt normal production. Therefore, monitoring microbial activity is crucial. Operating parameters such as pH and DO are commonly used to assess changes in the system's media environment, but they cannot be used solely to characterize the working status and activity of microorganisms. If microbial activity can be detected at an early stage and timely measures implemented, loss of microbial activity can be avoided.

[0003] CN109354160A discloses a method for chemical wastewater quality control, which specifically includes the following steps: Step 1, using an OUR online measuring instrument to measure the respiration rate of the wastewater; Step 2, using an activated sludge respirometer to measure the endogenous respiration rate of the activated sludge in the aeration tank of the wastewater control system; Step 3, by comparing the respiration rates, the wastewater is divided into three categories: biodegradable wastewater, non-toxic wastewater that is difficult to degrade, and toxic wastewater; Step 4, different categories of wastewater are discharged into different treatment systems for treatment. This invention solves the problem of high cost and unstable treatment effect of the existing indiscriminate treatment of chemical wastewater by classifying the wastewater and then discharging it into different treatment systems for treatment. However, it is impossible to classify the wastewater before impact, so this method cannot solve the impact recovery problem of the sewage treatment plant.

[0004] CN102629134A discloses a control system for Orbal oxidation ditch in urban sewage treatment to resist the impact of industrial toxic pollutants. The system mainly selects pH and conductivity as indicators of comprehensive toxicity reflection and early warning based on the results of toxicity correlation analysis, determines the toxicity warning threshold based on the toxicity test analysis of activated sludge in the Orbal oxidation ditch, selects toxicity monitoring points according to the characteristics of the pipe network, and establishes an online monitoring and wireless remote transmission system for early warning of industrial toxic pollution. On this basis, an Orbal oxidation ditch operation linkage control system is established, which is linked to the pipe network monitoring system. By adjusting the inlet flow rate, sludge return ratio and aeration intensity, the Orbal oxidation ditch is enhanced to resist the impact of industrial toxic pollutants, maintains biological activity in the ditch, and ensures the treatment efficiency of sewage. This method is more suitable for urban sewage treatment systems with obvious water quality changes and containing toxic substances such as acids, alkalis, and heavy metals. It can realize automatic early warning, decision-making and linkage control of industrial toxic substances. However, this method still maintains biological activity by adjusting process operating parameters and cannot achieve rapid repair after impact.

[0005] CN102815788A discloses an emergency control method for a CASS process to cope with abnormal influent water quality shocks. The method includes the following steps: judging whether the CASS reaction tank is about to be impacted by abnormal influent water according to an online detection device installed at the total water inlet of the CASS process sewage treatment plant; if abnormal influent water enters the CASS reaction tank during a certain period of time, adjusting the CASS reaction tank that is in or about to enter the influent stage to the lowest achievable filling ratio (f) and the highest sludge return ratio (R) according to the influent flow rate to create the maximum buffering capacity; then controlling the time distribution and corresponding dissolved oxygen concentration level of the four stages of influent, aeration, sedimentation and decanting in one operating cycle of the CASS reaction tank that is in or about to enter the influent stage according to the water quality characteristics of the abnormal influent water; if it is a normal situation, operating in normal mode. However, this method only adjusts the CASS process operation method, and the emergency control effect of the abnormal influent water quality shock is not ideal, and the system function cannot be restored in time.

[0006] Because load shocks at sewage treatment plants are uncertain and irregular, especially during oil refining, when source materials and processes change, the quality and quantity of wastewater generated during the process are affected. Sewage treatment systems often take a week, a month, or even longer to recover from a single shock. Existing technologies mitigate shock risks by replenishing microbial agents during shocks. However, fresh agents must be produced, making timely replenishment impossible. Pre-stored agents, if not added promptly, risk inactivation and increase treatment costs. Summary of the Invention

[0007] To address the challenges of existing technologies, the present invention provides a method for rapidly recovering biochemical units in sewage treatment plants after a high-load shock. This method uses two indicators—activated sludge respiration rate (OUR) and chemical oxygen demand (COD)—to diagnose shock risks in advance. This method provides early warning, eliminates shock risks promptly, and enables rapid recovery. This eliminates the need for re-acclimation of the sludge, reduces recovery time, and ensures long-term stable operation of the system.

[0008] The respiration rate described in the present invention is measured online using an activated sludge respirometer, and COD is measured using an online chemical oxygen demand analyzer. During operation, when the system is subjected to a load shock, the activity of the sludge will be temporarily enhanced, and the flocculation between the corresponding activated sludge particles will deteriorate. After a period of reaction, small unflocculated activated sludge particles will be lost with the water, the biomass will decrease, and the respiration rate will decrease. If the system can withstand the shock, the respiration rate will return to its initial state in a short time. If it still does not recover after taking measures such as adjusting the water volume and aeration volume, it proves that the loss of functional bacteria is greater than the range that the system can withstand.

[0009] A first aspect of the present invention provides a method for rapidly recovering a biochemical unit after a high-load impact, comprising:

[0010] When the biochemical unit is subjected to a high load shock and the fluctuation amplitude of the respiration rate (OUR) is less than 10% (preferably 10% to 20%) below the lower limit of the normal range for more than 30 minutes, an alarm is triggered to notify the control system, water intake is stopped, and the activated carbon dosing device is activated to add powdered activated carbon to the system. Simultaneously, the biosorbent dosing device is activated to add biosorbent to the system. The alarm is released when the respiration rate (OUR) returns to the normal range, and the addition of activated carbon and biosorbent is stopped. Water intake is restarted and operation is continued. The system achieves rapid recovery from the shock and enters a stable operating state. The biosorbent includes a metal-loaded carrier and a sugar ester-producing microorganism.

[0011] In the present invention, the metal content in the biosorbent as oxides accounts for 1% to 20% of the mass of the modified aerogel, the humic acid accounts for 0.1% to 10% of the mass of the modified aerogel, and the sugar ester-producing microorganisms account for 5% to 50% of the mass of the modified aerogel, preferably 10% to 30%.

[0012] In the present invention, when the chemical oxygen demand (COD) of the biochemical unit is 20% or more lower than the normal value, preferably 20% to 100%, it is considered a low-load shock; when the chemical oxygen demand (COD) of the biochemical unit is 20% or more higher than the normal value, preferably 20% to 100%, it is considered a high-load shock. The normal value of the chemical oxygen demand (COD) refers to the chemical oxygen demand when the biochemical unit is operating normally and stably. If the chemical oxygen demand (COD) during normal and stable operation is allowed to operate within a certain range, the normal value during high-load shock refers to the upper limit of the range, and the normal value during low-load shock refers to the lower limit of the range.

[0013] In the present invention, the normal range of the respiration rate (OUR) refers to the allowable range of the endogenous respiration rate (OUR) of the activated sludge in the aeration tank when the biochemical unit is operating normally and stably.

[0014] A second aspect of the present invention provides a method for rapidly recovering a biochemical unit of a sewage treatment plant after it is impacted by an abnormal load, comprising:

[0015] (1) When the effluent from the biochemical unit cannot meet the discharge standard requirements, the shock type, i.e., low-load shock or high-load shock, is determined based on the chemical oxygen demand (COD) of the biochemical unit;

[0016] (2) When the biochemical unit is subjected to high load, and the fluctuation range of the respiratory rate (OUR) is less than 10% (preferably 10% to 20%) of the lower limit of the normal range and the respiratory rate returns to the value within the normal range within 10 to 30 minutes, no measures are required;

[0017] (3) When the biochemical unit is subjected to a high load shock and the fluctuation range of the respiration rate (OUR) is lower than the lower limit of the normal range by more than 10% (preferably 10% to 20%) for more than 30 minutes, an alarm is issued to the control system, water is stopped, and the activated carbon dosing device is started to add powdered activated carbon to the system. At the same time, the biosorbent dosing device is started to add biosorbent to the system. When the respiration rate OUR returns to the normal range, the alarm is lifted, the addition of activated carbon and biosorbent is stopped, and water is started to continue to operate. The system achieves rapid recovery after the shock and enters a stable operating state.

[0018] (4) When the biochemical unit is subjected to a low load shock, and the fluctuation range of the respiratory rate (OUR) is less than 10% (preferably 10% to 20%) of the lower limit of the normal range and the respiratory rate returns to a value within the normal range within 60 to 120 minutes, no measures are required;

[0019] (5) When the biochemical unit is subjected to a low load shock and the fluctuation amplitude of the respiration rate (OUR) exceeds 10% (preferably 10% to 20%) of the lower limit of the normal range for more than 120 minutes, an alarm is notified to the control system, and the activated carbon dosing device is started to add powdered activated carbon to the system until the OUR returns to the normal range. The alarm is lifted and the addition of activated carbon is stopped to achieve rapid recovery of the shock system and enter a stable operating state.

[0020] In the present invention, when the chemical oxygen demand (COD) of the biochemical unit is lower than the normal value by more than 20%, preferably 20% to 100%, it is considered a low-load shock; when the chemical oxygen demand (COD) of the biochemical unit is higher than the normal value by more than 20%, preferably 20% to 100%, it is considered a high-load shock. The normal value of the chemical oxygen demand (COD) refers to the chemical oxygen demand of the wastewater when the biochemical unit is operating normally and stably. If the chemical oxygen demand (COD) is allowed to operate within a certain range during normal and stable operation, the normal value during high-load shock refers to the upper limit of the range, and the normal value during low-load shock refers to the lower limit of the range.

[0021] In the present invention, the emission standard requirements described in step (1) are generally requirements for COD and ammonia nitrogen concentrations, such as COD concentration not greater than 40 mg / L, and ammonia nitrogen concentration not greater than 5 mg / L, that is, the emission standard limit COD concentration is 40 mg / L, and ammonia nitrogen concentration is 5 mg / L.

[0022] In the present invention, the normal range of the respiration rate (OUR) refers to the allowable range of the endogenous respiration rate (OUR) of the activated sludge in the aeration tank when the biochemical unit is operating normally and stably.

[0023] In the method of the present invention, the biochemical unit wastewater can be any aerobic biochemical unit wastewater that has been pretreated by oil separation flotation, wherein the petroleum is 5-30 mg / L, COD is 300-1000 mg / L, ammonia nitrogen is 100-300 mg / L, and total nitrogen is 100-300 mg / L.

[0024] In the present invention, when the biochemical unit is subjected to high load impact, the activated carbon is added every 30 to 60 minutes, and each addition is performed according to the concentration of the solid-liquid mixture after addition of 30 to 50 mg / L. The biosorbent is added simultaneously with the activated carbon, wherein the mass ratio of the activated carbon to the biosorbent during each addition is 1:1 to 15:1, preferably 1:1 to 10:1.

[0025] In the present invention, the activated carbon is well known to those skilled in the art, and can be powdered activated carbon or coal-based crushed carbon.

[0026] In the present invention, when the biochemical unit is subjected to low load impact, the activated carbon is added every 30 to 60 minutes, and each addition is performed so that the concentration of the solid-liquid mixture after addition is 30 to 50 mg / L.

[0027] Furthermore, in the biosorbent, the metal content in terms of oxides accounts for 1% to 20% of the mass of the modified aerogel, the humic acid accounts for 0.1% to 10% of the mass of the modified aerogel, and the sugar ester-producing microorganisms account for 5% to 50% of the mass of the modified aerogel, preferably 10% to 30%.

[0028] In the present invention, the biosorbent is prepared according to the following method: (a) placing an aerogel in an acetic acid solution for reaction, taking it out and washing it to neutrality; (b) dissolving humic acid in an Fe(OH)3 solution, adding the aerogel, reacting it at 50-70°C, and washing it to weak alkalinity to obtain a modified aerogel; (c) loading an active metal on the modified aerogel to obtain a metal-loaded carrier; (d) adsorbing sugar ester-producing microorganisms on the metal-loaded carrier, and drying the adsorption to obtain the biosorbent.

[0029] In the present invention, the aerogel in step (a) is at least one of carbon aerogel, silicon aerogel, cellulose aerogel, etc., preferably carbon aerogel. It is usually obtained by homemade or commercial purchase, and the specific surface area of ​​the aerogel is 600 to 1100 m 2 / g, porosity is 80% to 98%.

[0030] In the present invention, the concentration of the acetic acid solution in step (a) is 1.0 to 2.0 mol / L. The aerogel is immersed in the acetic acid solution for reaction at a temperature of 30 to 50°C for 1.0 to 2.0 hours. The reaction can be carried out directly or in a water bath, preferably in a water bath at 30 to 50°C. After removal, the aerogel is washed until the pH is neutral, typically 6.5 to 7.5.

[0031] In the present invention, the concentration of the Fe(OH)3 solution in step (b) is 0.5-0.8 mol / L, and the mass ratio of the Fe(OH)3 solution to humic acid is 1:1-3:1.

[0032] In the present invention, in step (b), the aerogel is immersed in a mixture of humic acid and Fe(OH)3 solution and reacted in a water bath at 50-70°C for 3-5 hours. After removal, the aerogel is washed until the pH value is weakly alkaline, generally 7.6-8.0.

[0033] In the present invention, the active metal in step (c) is Cu 2+ 、Fe 2+ Mg 2+ At least one of the following, preferably Fe 2+ The active metal loading can be carried out using conventional impregnation methods in the art, such as equal volume impregnation or excess impregnation. Typically, a soluble salt solution of the active metal is used, wherein the metal ion concentration is 1 to 4 mol / L. For example, the modified aerogel can be impregnated into the active metal solution at 60 to 70°C for 6 to 10 hours.

[0034] In the present invention, step (d) involves immersing the metal-loaded carrier in the fermentation broth of a sugar ester-producing microorganism for adsorption growth of the microorganism, with the volume ratio of the metal-loaded carrier to the fermentation broth being 1:1 to 3. The adsorption growth conditions are: a temperature of 20°C to 38°C, preferably 20°C to 30°C, a pH of 6.0 to 8.5, preferably 6.0 to 7.0, and a reaction time of 12 to 36 hours.

[0035] In the present invention, the sugar ester-producing microorganism in step (d) is a microorganism that ferments and produces at least one sugar ester among rhamnosyl ester, trehalose lipid, sophorolipid and sucrose ester, etc., such as at least one of rhamnosyl ester-producing Pseudomonas aeruginosa and trehalose lipid-producing Pseudomonas aeruginosa. The preparation method of the sugar ester-producing microbial fermentation broth is conventional in the art.

[0036] In the present invention, the drying step (d) is performed at 35-50°C for 24-48 hours. The biosorbent comprises metals (as oxides) accounting for 1% to 20% of the mass of the modified aerogel, humic acid accounting for 0.1% to 10% of the mass of the modified aerogel, and sugar ester-producing microorganisms accounting for 5% to 50% of the mass of the modified aerogel, preferably 10% to 30%. The biosorbent needs to be stored in a vacuum prior to use, typically for 1 to 3 months.

[0037] In the present invention, the rapid recovery method for a sewage treatment plant after an abnormal load shock uses the operating conditions of normal stable operation without any adjustments. The operating conditions are a pH of 7.0 to 8.5, a temperature of 25 to 35°C, a controlled dissolved oxygen concentration of less than 0.5 mg / L in tank A, and a controlled dissolved oxygen concentration of 2 to 5 mg / L in tank O.

[0038] In the present invention, the activated carbon or the biosorbent is added to the aeration tank, such as the O tank.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] (1) The present invention adopts the linkage of OUR and COD as the comprehensive early warning and control indicators of the sewage treatment system, which makes it easy to realize online and timely monitoring of abnormal load impact received by the sewage treatment system. The linkage of the two detection indicators serves as an early diagnosis signal, reducing the impact risk.

[0041] (2) When the present invention encounters a high-load shock, the water intake is first stopped. The added activated carbon can temporarily adsorb the organic pollutants in the incoming water, slowing down the toxic interference of high-concentration or toxic pollutants on the microorganisms in the activated sludge. The biosorbent can intercept and quickly adsorb the microorganisms released after deflocculation, and at the same time adsorb small molecules. While providing nutrition for the normal growth and metabolism of microorganisms, it ensures the water quality of the effluent, realizes rapid recovery after the system shock, and ensures the long-term stable operation effect of the system.

[0042] (3) When the present invention encounters a low-load impact, the addition of powdered activated carbon can reduce the dissolved oxygen and the loss of functional microorganisms for deflocculation with water, thereby achieving rapid recovery after the system impact and ensuring the long-term stable operation of the system.

[0043] (4) The present invention adopts the synergistic effect of adding activated carbon and biological adsorbent at the same time, which can isolate high-concentration toxic substances from contact with microorganisms, temporarily store macromolecular substances and synergistically degrade them by biological enzymes, while ensuring biological activity and reducing the loss. It can greatly shorten the recovery time, achieve rapid recovery after system impact, and ensure the long-term stable operation of the system.

[0044] (5) The inventors found in their research that after loading active metals on the modified aerogel, the synthesized biosorbent can avoid the loss of active metals during use by adsorbing and growing microorganisms that produce sugar esters, thereby improving the adsorption performance of functional microorganisms and increasing biomass, which is conducive to achieving rapid recovery after system impact. DETAILED DESCRIPTION

[0045] The following examples further illustrate the method and effects of the present invention. The examples are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operating processes, but the scope of protection of the present invention is not limited to the following examples.

[0046] The experimental methods in the following examples, unless otherwise specified, are all conventional methods in the art. The experimental materials used in the following examples, unless otherwise specified, can all be purchased from biochemical reagent stores.

[0047] In the present invention, the COD concentration adopts GB11914-89 "Water quality - Determination of chemical oxygen demand - Dichromate method"; the ammonia nitrogen concentration adopts GB7478-87 "Water quality - Determination of ammonium - Distillation and titration method"; the total nitrogen concentration adopts GB11894-89 "Water quality - Determination of total nitrogen - Alkaline potassium persulfate digestion ultraviolet spectrophotometry"; the petroleum adopts HJ970-2018 "Water quality - Determination of petroleum - Ultraviolet spectrophotometry".

[0048] In the present invention, the respiration rate is measured online by an activated sludge respirometer, COD is measured by a chemical oxygen demand online analyzer, and ammonia nitrogen is measured by a Hach online analyzer.

[0049] Example 1

[0050] Preparation of adsorbent.

[0051] According to the method provided in the document "Screening of Biosurfactant-producing Bacteria" (Pan Bingfeng, Journal of Microbiology, June 1996, 39(3)), after enrichment culture and screening using blood plates, a strain with stable genetic traits and rhamnosyl ester production was obtained through shake flask fermentation and rescreening. It was identified as Pseudomonas aeruginosa by 16S rRNA and other methods. The preparation method of Pseudomonas aeruginosa fermentation broth is as follows: pick the colony on the slant and inoculate it into LB medium, incubate at 37°C, 200 rpm, and obtain seed liquid. Then, according to the following formula (by mass fraction): 5.0% glucose, 0.5% yeast extract, 0.02% KH2PO4, MgSO4, FeSO4·7H2O, and CaCl·2H2O, the fermentation medium was prepared. The seed liquid was inoculated into the fermentation medium at a 5% inoculum, and incubated at pH 6.5, 35°C, 200 rpm, for 7 days to obtain rhamnosyl ester-producing Pseudomonas aeruginosa fermentation broth, which was stored in the refrigerator for future use.

[0052] The carbon aerogel (specific surface area of ​​800m 2 / g, with a porosity of 80%) was immersed in a 1.5 mol / L acetic acid solution for a water bath reaction at 40°C, shaken for 1.5 hours, and then washed with deionized water to a pH of 7.0 to obtain the pretreated carbon aerogel. Humic acid was dissolved in a 0.6 mol / L Fe(OH)3 solution at a mass ratio of 2:1 between the Fe(OH)3 solution and humic acid. The pretreated carbon aerogel was then added to the solution and shaken in a water bath at 60°C for 4 hours. The solution was then washed with deionized water to a pH of 8.0 to obtain the modified aerogel. A ferrous sulfate solution with an iron ion concentration of 1 mol / L was added to the modified aerogel and immersed at 65°C with stirring for 8 hours to obtain an active metal-loaded carrier. The active metal-loaded carrier was mixed with a rhamnosyl ester-producing Pseudomonas aeruginosa fermentation broth at a volume ratio of 1:1. Adsorption growth was allowed to proceed at 30°C and a pH of 6.5 for 12 hours to obtain the carrier that adsorbed Pseudomonas aeruginosa. The carrier with adsorbed microorganisms was taken out and dried at 45°C for 24 hours to finally obtain adsorbent A.

[0053] Compared with the preparation method of adsorbent A, other conditions remain unchanged, except that: the above preparation process uses a specific surface area of ​​1000m 2 / g, and the porosity of 85% of silicon aerogel was used to replace the carbon aerogel, and finally the adsorbent B was obtained;

[0054] Compared with the preparation method of adsorbent A, other conditions remain unchanged, except that: the metal ions in the above preparation process are Cu 2+ , prepare 3 mol / L copper chloride solution instead of ferric sulfate solution, and finally obtain adsorbent C;

[0055] Compared with the preparation method of adsorbent A, other conditions remained unchanged except that (NH4)6Mo7O2·4H2O and CoCl2 were added to the active metal ion solution at a molar ratio of 1:4 at 0.5 mg / L. Finally, adsorbent D was obtained.

[0056] Compared with the preparation method of adsorbent A, other conditions remain unchanged, except that the aerogel is not subjected to the pretreatment process of step (1), and is directly subjected to the humic acid modification process of step (2). Finally, adsorbent E is obtained.

[0057] Compared with the preparation method of adsorbent A, other conditions remain unchanged except that humic acid is not used in the modification in step (2), and only Fe(OH)3 solution is used. Finally, adsorbent F is prepared.

[0058] Compared with the preparation method of adsorbent A, other conditions remain unchanged, except that in step (2), the solution is washed to neutrality instead of weak alkalinity after the reaction. Finally, adsorbent G is obtained.

[0059] Example 2

[0060] After two-stage flotation oil removal treatment, the electro-desalted wastewater from a refinery wastewater treatment plant enters an A / O unit for further biochemical treatment. Operating conditions are a pH of 7.3-7.8 and a temperature of 30-33°C. The A tank maintains a dissolved oxygen concentration of less than 0.5 mg / L, while the O tank maintains a dissolved oxygen concentration of 3-4 mg / L. Normally, the wastewater entering the A / O unit contains less than 20 mg / L of petroleum, 500-600 mg / L of COD, and 30-100 mg / L of ammonia nitrogen. After treatment, the effluent pollutant concentrations are all below the standard discharge limits: COD concentrations below 40 mg / L and ammonia nitrogen concentrations of 5 mg / L. Due to a change in the type of oil used, the quality of wastewater generated during the refinery process changed, causing the effluent to fail to meet the above-mentioned discharge requirements. At this point, the COD concentration in the wastewater increased to 1000 mg / L, and the online respiration rate (OUR) in the wastewater treatment system gradually decreased. When it remained below 15% of the lower limit of the normal range for more than 30 minutes, the control system automatically triggered an alarm. Water intake was then automatically stopped, and all other process operating conditions remained unchanged. The activated carbon and biosorbent dosing devices were promptly activated to add activated carbon and adsorbent A to the O tank. The activated carbon dosage was adjusted to achieve a solid-liquid mixture concentration of 40 mg / L after addition, with a mass ratio of 5:1. The activated carbon and biosorbent dosing devices were activated every 30 minutes. After eight consecutive additions, the OUR gradually returned to the normal range. The control system cleared the alarm, restarted water intake, and stopped adding activated carbon and biosorbent. After 260 minutes of the shock, the system quickly recovered and entered a stable operating state, with effluent pollutant concentrations remaining below the standard discharge limits.

[0061] Example 3

[0062] The biochemical aeration system at a refinery wastewater treatment plant operates at a pH of 7.3-7.8 and a temperature of 30-33°C. The A tank maintains a dissolved oxygen concentration of less than 0.5 mg / L, while the O tank maintains a dissolved oxygen concentration of 3-4 mg / L. Normally, the wastewater entering the A / O unit contains less than 20 mg / L of petroleum compounds, 400-500 mg / L of COD, and 30-100 mg / L of ammonia nitrogen. After treatment, the effluent pollutant concentrations are below the standard discharge limits: COD below 40 mg / L and ammonia nitrogen 5 mg / L. Due to a change in the type of oil used, the quality of wastewater generated during the refinery process changed, causing the effluent to fail to meet the above-mentioned discharge requirements. At this point, the COD concentration in the wastewater increased to 800 mg / L, and the online respiration rate (OUR) in the wastewater treatment system gradually decreased. When it remained below 10% of the lower limit of the normal range for more than 30 minutes, the control system automatically triggered an alarm. Water intake was then automatically stopped, and all other process operating conditions remained unchanged. The activated carbon dosing unit and the biosorbent dosing unit were promptly activated to add activated carbon and adsorbent B to the O tank. The activated carbon dosage was adjusted to achieve a solid-liquid mixture concentration of 40 mg / L after addition, with a mass ratio of 5:1. The activated carbon dosing unit and the biosorbent dosing unit were activated every 30 minutes. After eight consecutive additions, the OUR gradually returned to the normal range. The control system released the alarm, restarted water intake, and stopped adding activated carbon and biosorbent. Within 270 minutes after the shock, the system rapidly recovered and entered stable operation, with effluent pollutant concentrations remaining below the standard discharge limits.

[0063] Example 4

[0064] Similar to the wastewater treatment plant in Example 2, the wastewater quality generated during the oil refining process changed, causing the effluent to fail to meet the above-mentioned discharge requirements. At this point, the COD concentration in the wastewater increased to 900 mg / L, and the online respiration rate (OUR) in the wastewater treatment system gradually decreased. When it remained below 17% of the lower limit of the normal range for more than 30 minutes, the control system automatically issued an alarm. The system automatically stopped water intake, while other process operating conditions remained unchanged. The activated carbon dosing device and the biosorbent dosing device were promptly activated to add activated carbon and adsorbent C to the O tank. The activated carbon was added in an amount such that the solid-liquid mixture concentration after addition was 40 mg / L, and the mass ratio of activated carbon to biosorbent was 5:1. The activated carbon dosing device and the biosorbent dosing device were activated every 30 minutes to add the above-mentioned amounts. After nine consecutive additions, the respiration rate (OUR) gradually returned to the normal range. The control system released the alarm, restarted water intake, and stopped adding activated carbon and biosorbent. After 280 minutes of the system shock, it quickly recovered and entered a stable operating state, with effluent pollutant concentrations below the discharge limits.

[0065] Example 5

[0066] Similar to the wastewater treatment plant in Example 2, the wastewater quality generated during the oil refining process changed, causing the effluent to fail to meet the above-mentioned discharge requirements. At this point, the COD concentration in the wastewater increased to 1100 mg / L, and the online respiration rate (OUR) in the wastewater treatment system gradually decreased. When it remained below 15% of the lower limit of the normal range for more than 30 minutes, the control system automatically issued an alarm. The system automatically stopped water intake, while other process operating conditions remained unchanged. The activated carbon dosing device and the biosorbent dosing device were promptly activated to add activated carbon and adsorbent D to the O tank. The activated carbon was added in an amount such that the solid-liquid mixture concentration after addition was 40 mg / L, and the mass ratio of activated carbon to biosorbent was 5:1. The activated carbon dosing device and the biosorbent dosing device were activated every 30 minutes to add the above-mentioned amounts. After eight consecutive additions, the respiration rate (OUR) gradually returned to the normal range. The control system released the alarm, restarted water intake, and stopped adding activated carbon and biosorbent. The system quickly recovered after 250 minutes and entered a stable operating state, with effluent pollutant concentrations below the discharge limits.

[0067] Example 6

[0068] Similar to the wastewater treatment plant in Example 2, the wastewater quality generated during the oil refining process changed, causing the effluent to fail to meet the aforementioned discharge requirements. At this point, the COD concentration in the wastewater increased to 1000 mg / L, and the online respiration rate (OUR) in the wastewater treatment system gradually decreased. When the system remained below 15% of the lower limit of the normal range for more than 30 minutes, the control system automatically issued an alarm. The system automatically stopped water intake, while other process operating conditions remained unchanged. The activated carbon dosing device and the biosorbent dosing device were promptly activated to add activated carbon and adsorbent A to the O tank. The activated carbon was added in an amount such that the solid-liquid mixture concentration after addition was 50 mg / L, and the mass ratio of activated carbon to biosorbent was 2:1. The activated carbon dosing device and the biosorbent dosing device were activated every 30 minutes to add the aforementioned amounts. After eight consecutive additions, the respiration rate (OUR) gradually returned to the normal range. The control system released the alarm, restarted water intake, and stopped adding activated carbon and biosorbent. After 260 minutes of the system shock, it quickly recovered and entered a stable operating state, with effluent pollutant concentrations below the standard discharge limits.

[0069] Example 7

[0070] The biochemical aeration system at a refinery wastewater treatment plant normally contains less than 20 mg / L of petroleum, 500-700 mg / L of COD, and 50-150 mg / L of ammonia nitrogen in the wastewater entering the A / O unit. However, due to a change in the type of oil used, the quality of the wastewater generated during the refinery process changed, and the effluent failed to meet these discharge standards. The COD concentration in the wastewater then dropped to 200 mg / L, and the online respiration rate (OUR) in the wastewater treatment system gradually decreased. When the OUR remained below 10% of the lower limit of the normal range for more than 120 minutes, the control system automatically triggered an alarm. All other process operating conditions remained unchanged, and the activated carbon dosing device was activated to add activated carbon to the O tank. The amount of activated carbon added was based on the concentration of the solid-liquid mixture after addition of 30 mg / L. The activated carbon dosing device was started every 60 minutes and added once according to the above dosage. After four consecutive additions, the respiration rate OUR gradually returned to the normal range, the control system released the alarm, started water intake and stopped adding activated carbon. The system recovered quickly 310 minutes after the shock and entered a stable operating state. The concentrations of effluent pollutants were all lower than the standard emission limits.

[0071] Example 8

[0072] The aeration system for the biochemical unit of a certain refinery's wastewater treatment plant has a design COD value of 400-500 mg / L. Under normal circumstances, the wastewater entering the A / O unit contains less than 20 mg / L of petroleum, a COD concentration of 400-500 mg / L, and an ammonia nitrogen concentration of 30-100 mg / L. Due to a change in the type of oil used by the company, the quality of the wastewater generated during the refining process changed, causing the effluent to fail to meet the aforementioned discharge standards. At this point, the COD concentration in the wastewater increased to 700 mg / L, and the online respiration rate (OUR) in the wastewater treatment system gradually dropped to 10% of the lower limit of the normal range. However, after 10-20 minutes, it gradually rose back to the normal range and then gradually declined again, generally fluctuating within 20 minutes. The system has an automatic recovery capability, and no measures are required.

[0073] Example 9

[0074] The aeration system for the biochemical unit of a certain refinery's wastewater treatment plant has a design COD value of 500-700 mg / L. Under normal circumstances, the wastewater entering the A / O unit contains less than 20 mg / L of petroleum, a COD concentration of 500-700 mg / L, and an ammonia nitrogen concentration of 50-150 mg / L. Due to a change in the type of oil used by the company, the quality of the wastewater generated during the refining process changed, causing the effluent to fail to meet the above-mentioned discharge standards. At this point, the COD concentration in the wastewater dropped to 200 mg / L, and the online respiration rate (OUR) in the wastewater treatment system gradually decreased. After falling to 10% below the lower limit of the normal range, it returned to the normal range within 100 minutes, demonstrating the system's self-recovery capability and requiring no action.

[0075] Comparative Example 1

[0076] Similar to the sewage treatment system in Example 7, when the COD concentration dropped to 200 mg / L, the activated sludge respiration rate (OUR) in the sewage treatment system gradually decreased. When the OUR remained below 10% of the lower limit of the normal range for more than 120 minutes, the control system automatically triggered an alarm. After the system continued to operate for 120 minutes, the OUR dropped to 12% below the lower limit of the normal range, failing to achieve a rapid recovery. After two days of continued operation, the OUR was 5% of the lower limit of the normal range, and the system had essentially returned to normal, and water intake was restarted and continued operation.

[0077] Comparative Example 2

[0078] Similar to the system in Example 2, when the inlet COD concentration increased to 1000 mg / L, the activated sludge respiration rate (OUR) in the sewage treatment system gradually decreased. When the OUR remained below 15% of the lower limit of the normal range for more than 30 minutes, the control system automatically sounded an alarm. At this point, the system automatically stopped water intake and activated the biosorbent dosing device to add adsorbent A to the O tank at a solid-liquid mixture concentration of 8 mg / L. The adsorbent dosing device was activated every 30 minutes to add the above dosage. After eight consecutive additions, the OUR remained below 10% of the lower limit of the normal range, indicating that the system had not recovered rapidly after the shock. After four days of operation, the OUR returned to normal, and the system essentially returned to normal, allowing water intake to resume operation.

[0079] Comparative Example 3

[0080] In the same system as Example 2, when the COD concentration of the incoming water increases to 1000 mg / L, the activated sludge respiration rate (OUR) in the sewage treatment system gradually decreases. When the time it drops to 15% below the lower limit of the normal range exceeds 30 minutes, the control system automatically alarms, and the system automatically stops taking in water, and starts the activated carbon dosing device to add activated carbon to the O pool according to the concentration of the solid-liquid mixture after addition of 40 mg / L. The activated carbon dosing device is started every 30 minutes and added once according to the above dosage. After 8 consecutive additions, the respiration rate OUR is still below 10% of the lower limit of the normal range, and the system does not achieve rapid recovery after the shock. After continuing to operate for 4 days, the activated sludge respiration rate OUR is within the normal range, the system basically returns to normal, and the water intake is started for continuous operation.

[0081] Comparative Example 4

[0082] The system was identical to that of Example 2, except that adsorbent E was added after the system shock. The activated carbon dosage was such that the solid-liquid mixture concentration after addition was 40 mg / L, and the mass ratio of activated carbon to biosorbent was 5:1. The activated carbon and biosorbent dosing devices were activated every 30 minutes and added at the above dosages. After eight consecutive additions, the respiration rate (OUR) remained below 10% of the lower limit of the normal range, indicating that the system had not achieved rapid recovery after the shock. After two days of operation, the activated sludge respiration rate (OUR) returned to the normal range, and continuous operation with water inflow was initiated.

[0083] Comparative Example 5

[0084] The system was identical to that of Example 2, except that adsorbent F was added after the system shock. The activated carbon dosage was such that the solid-liquid mixture concentration after addition was 40 mg / L, and the mass ratio of activated carbon to biosorbent was 5:1. The activated carbon and biosorbent dosing devices were activated every 30 minutes and added at the aforementioned dosages. After eight consecutive additions, the respiration rate (OUR) remained below 10% of the lower limit of the normal range, indicating that the system had not achieved rapid recovery after the shock. After two days of operation, the activated sludge respiration rate (OUR) returned to the normal range, and continuous operation with water inflow was initiated.

[0085] Comparative Example 6

[0086] The system was identical to that of Example 2, except that adsorbent G was added after the system shock. The activated carbon dosage was such that the solid-liquid mixture concentration after addition was 40 mg / L, and the mass ratio of activated carbon to biosorbent was 5:1. The activated carbon and biosorbent dosing devices were activated every 30 minutes and added at the above dosages. After eight consecutive additions, the respiration rate (OUR) remained below 10% of the lower limit of the normal range, indicating that the system had not achieved rapid recovery after the shock. After two days of operation, the activated sludge respiration rate (OUR) returned to the normal range, and continuous operation with water inflow was initiated.

[0087] Comparative Example 7

[0088] The system was identical to that of Example 2, except that the mass ratio of activated carbon to biosorbent was 20:1. The activated carbon and biosorbent dosing devices were activated every 30 minutes, adding the aforementioned amounts. After eight consecutive additions, the respiration rate (OUR) remained below 10% of the lower limit of the normal range, indicating that the system had not rapidly recovered from the shock. After three days of operation, the activated sludge respiration rate (OUR) returned to the normal range, and continuous water inlet operation was initiated.

Claims

1. A method for rapid recovery of a biochemical unit after high-load impact, comprising: When the biochemical unit is subjected to a high load shock and the fluctuation amplitude of the respiration rate OUR is more than 10% lower than the lower limit of the normal range for more than 30 minutes, an alarm is notified to the control system, water supply is stopped, and the activated carbon dosing device is started to add powdered activated carbon to the system. At the same time, the biosorbent dosing device is started to add biosorbent to the system. When the respiration rate OUR returns to the normal range, the alarm is lifted, the addition of activated carbon and biosorbent is stopped, and water supply is started to continue operation. The system achieves rapid recovery after the shock and enters a stable operating state. The biosorbent includes a metal-loaded carrier and a sugar ester-producing microorganism. The biosorbent is prepared according to the following method: (a) placing an aerogel in an acetic acid solution for reaction, removing it and washing it until it is neutral; (b) dissolving humic acid in a Fe(OH)3 solution, adding it to the aerogel, reacting it at 50-70°C, and washing it until it is weakly alkaline to obtain a modified aerogel; (c) loading an active metal on the modified aerogel to obtain a metal-loaded carrier; (d) adsorbing sugar ester-producing microorganisms on the metal-loaded carrier, and drying it after adsorption to obtain a biosorbent. The mass ratio of activated carbon to biosorbent is 1:1~15:1 each time it is added.

2. The method according to claim 1, characterized in that When the biochemical unit is subjected to high load and the fluctuation range of the respiratory rate OUR is lower than the lower limit of the normal range by 10%~20% for more than 30 minutes, an alarm will be notified to the control system.

3. The method according to claim 1, characterized in that In the biosorbent, the metal content in terms of oxides accounts for 1% to 20% of the mass of the modified aerogel, the humic acid accounts for 0.1% to 10% of the mass of the modified aerogel, and the sugar ester-producing microorganisms account for 5% to 50% of the mass of the modified aerogel.

4. The method according to claim 3, characterized in that In the biosorbent, the sugar ester-producing microorganisms account for 10% to 30% of the mass of the modified aerogel.

5. The method according to claim 1, wherein The high load shock refers to the chemical oxygen demand (COD) of the biochemical unit being more than 20% higher than the normal value.

6. The method according to claim 1, wherein The high load shock refers to the chemical oxygen demand (COD) of the biochemical unit being 20% ​​to 100% higher than the normal value.

7. A method for rapidly restoring a biochemical unit of a sewage treatment plant after an abnormal load impact, comprising: (1) When the effluent from the biochemical unit cannot meet the discharge standard requirements, the shock type, i.e., low-load shock or high-load shock, is determined based on the chemical oxygen demand (COD) of the biochemical unit; (2) When the biochemical unit is subjected to high load shock, and the fluctuation range of the respiratory rate OUR is less than 10% of the lower limit of the normal range and the respiratory rate returns to the value within the normal range within 10 minutes to 30 minutes, no measures need to be taken; (3) When the biochemical unit is subjected to high load shock and the fluctuation amplitude of the respiration rate OUR is lower than the lower limit of the normal range by more than 10% for more than 30 minutes, the alarm is notified to the control system, the water supply is stopped, and the activated carbon dosing device is started to add powdered activated carbon to the system. At the same time, the biosorbent dosing device is started to add biosorbent to the system. When the respiration rate OUR returns to the normal range, the alarm is lifted, the addition of activated carbon and biosorbent is stopped, and the water supply is started to continue operation. The system achieves rapid recovery after the shock and enters a stable operating state. (4) When the biochemical unit is subjected to low load shock, and the fluctuation range of the respiratory rate OUR is less than 10% of the lower limit of the normal range and the respiratory rate returns to the value within the normal range within 60 minutes to 120 minutes, no measures need to be taken; (5) When the biochemical unit is subjected to low load shock and the fluctuation amplitude of the respiratory rate OUR exceeds 10% of the lower limit of the normal range for more than 120 minutes, the alarm is notified to the control system, and the activated carbon dosing device is started to add powdered activated carbon to the system until OUR returns to the normal range. The alarm is lifted and the addition of activated carbon is stopped to achieve rapid recovery of the shock system and enter a stable operating state; The biosorbent is prepared according to the following method: (a) placing an aerogel in an acetic acid solution for reaction, removing it and washing it until it is neutral; (b) dissolving humic acid in a Fe(OH)3 solution, adding it to the aerogel, reacting it at 50-70°C, and washing it until it is weakly alkaline to obtain a modified aerogel; (c) loading an active metal on the modified aerogel to obtain a metal-loaded carrier; (d) adsorbing sugar ester-producing microorganisms on the metal-loaded carrier, and drying it after adsorption to obtain a biosorbent. The mass ratio of activated carbon to biosorbent is 1:1~15:1 each time it is added.

8. The method according to claim 7, characterized in that In step (2), when the biochemical unit is subjected to high load shock, and the fluctuation range of the respiratory rate OUR is lower than 10%~20% of the lower limit of the normal range and the respiratory rate returns to the value within the normal range within 10min~30min, no measures need to be taken.

9. The method according to claim 7, characterized in that In step (3), when the biochemical unit is subjected to high load impact and the fluctuation range of the respiratory rate OUR is lower than the lower limit of the normal range by 10% to 20% for more than 30 minutes, an alarm is notified to the control system.

10. The method according to claim 7, characterized in that In step (4), when the biochemical unit is subjected to a low load shock, and the fluctuation range of the respiratory rate OUR is lower than 10% to 20% of the lower limit of the normal range and the respiratory rate returns to a value within the normal range within 60 minutes to 120 minutes, no measures need to be taken.

11. The method according to claim 7, characterized in that In step (5), when the biochemical unit is subjected to a low load shock and the fluctuation range of the respiratory rate OUR exceeds 10% to 20% of the lower limit of the normal range for more than 120 minutes, an alarm is notified to the control system.

12. The method according to claim 1 or 7, characterized in that The biochemical unit wastewater is the wastewater of the aerobic biochemical unit after oil separation flotation pretreatment, in which petroleum is 5~30mg / L, COD is 300~1000mg / L, ammonia nitrogen is 100~300mg / L, and total nitrogen is 100~300mg / L.

13. The method according to claim 1 or 7, characterized in that When the biochemical unit is subjected to high load impact, the activated carbon is added every 30 to 60 minutes, and each time the concentration of the solid-liquid mixture after addition is 30 to 50 mg / L. The biosorbent and activated carbon are added at the same time.

14. The method according to claim 13, characterized in that When the biochemical unit is subjected to high load impact, the mass ratio of activated carbon to biosorbent is 1:1~10:1 each time it is added.

15. The method according to claim 7, characterized in that When the biochemical unit is subjected to low load impact, the activated carbon is added every 30 to 60 minutes, and each time the concentration of the solid-liquid mixture after addition is 30 to 50 mg / L.

16. The method according to claim 1 or 7, characterized in that The aerogel in step (a) is at least one of carbon aerogel, silicon aerogel, and cellulose aerogel.

17. The method according to claim 16, characterized in that The aerogel in step (a) is carbon aerogel.

18. The method according to claim 1 or 7, characterized in that The concentration of the acetic acid solution in step (a) is 1.0-2.0 mol / L; the aerogel is immersed in the acetic acid solution for reaction at a reaction temperature of 30-50° C. for a reaction time of 1.0-2.0 h; and the aerogel is taken out and washed until the pH value is neutral.

19. The method according to claim 1 or 7, characterized in that The concentration of the Fe(OH)3 solution in step (b) is 0.5-0.8 mol / L, and the mass ratio of the Fe(OH)3 solution to humic acid is 1:1-3:

1.

20. The method according to claim 1 or 7, characterized in that Step (b) immersing the aerogel in a mixed system of humic acid and Fe(OH)3 solution, shaking in a water bath at 50-70°C for 3-5 hours; and taking out and washing the aerogel until the pH value is weakly alkaline.

21. The method according to claim 20, characterized in that In step (b), weak alkalinity refers to a pH value of 7.6 to 8.

0.

22. The method according to claim 1 or 7, characterized in that The active metal in step (c) is Cu 2+ 、Fe 2+ Mg 2+ At least one of .

23. The method according to claim 22, characterized in that The active metal in step (c) is Fe 2+ .

24. The method according to claim 1 or 7, characterized in that Step (d) is to immerse the metal-loaded carrier in the fermentation broth of the sugar ester-producing microorganism for adsorption growth of the microorganism, with the volume ratio of the metal-loaded carrier to the fermentation broth being 1:1-3; the adsorption growth conditions are: temperature 20-38°C, pH 6.0-8.5, and reaction time 12-36 hours.

25. The method according to claim 24, characterized in that In step (d), the adsorption growth conditions are: temperature 20-30° C., pH 6.0-7.

0.

26. The method according to claim 1 or 7, characterized in that The sugar ester-producing microorganism in step (d) is a microorganism that ferments and produces at least one sugar ester selected from rhamnosyl ester, trehalose biosurfactant, sophorolipid and sucrose biosurfactant.

27. The method according to claim 26, characterized in that The sugar ester-producing microorganism in step (d) is at least one of rhamnosyl ester-producing Pseudomonas aeruginosa and trehalose lipid-producing Pseudomonas aeruginosa.

28. The method according to claim 1 or 7, characterized in that The drying in step (d) is carried out at 35-50° C. for 24-48 hours.

29. The method according to claim 28, characterized in that In the adsorbent, the metal content in terms of oxides accounts for 1% to 20% of the mass of the modified aerogel, the humic acid accounts for 0.1% to 10% of the mass of the modified aerogel, and the sugar ester-producing microorganisms account for 5% to 50% of the mass of the modified aerogel.

30. The method according to claim 29, characterized in that In the adsorbent, the sugar ester-producing microorganisms account for 10% to 30% of the mass of the modified aerogel.