Biochemical tank in the operation process, when the microorganisms once by the load (water, concentration) of the impact, COD removal rate will suddenly drop, in severe cases, the sludge will be dislodged from the biological filler, so that the effluent becomes mixed. At this time should immediately stop the water intake, to the biochemical tank put powdered activated carbon to reduce the sludge load, powdered activated carbon dosage ratio of 10 kg per 100 m3 volume of biochemical tank dosage. When the sludge settling performance has recovered, you can take the sludge domestication of the rapid proliferation method, in the biochemical tank, add sewage or put waste alcohol or dry flour burned wet paste, adding the ratio of 5-10 kg of dry flour per 100 m3 volume of biochemical tank, 2-3 days after the start of the water intake and increase the intake of water day by day until the microorganisms return to normal.
72, when a large number of microorganisms die what to do?
When the microorganisms are seriously damaged and die in large quantities and rescue is ineffective, it should be declared to the local environmental protection authority for record immediately and the activated sludge should be replaced immediately. Then identify the cause to prevent the recurrence of similar accidents. As long as the declaration is timely, the wastewater discharged to the outside during the period of renewing and domesticating the sludge can be treated without sewage penalty.
73, how to ensure that the power equipment is always in good working condition?
The sewage treatment system to achieve good results, it is necessary to make all types of equipment is often in good working condition and maintain due technical performance, correct operation, maintenance, repair equipment is a prerequisite for the normal operation of sewage treatment system.
With the development of sewage treatment, sewage treatment system mechanization and automation degree is also increasing, sewage treatment system using more and more equipment, more and more complex. Sewage treatment system not only use many sewage treatment equipment specific to the use of many general-purpose equipment, all of which should be used, maintained and repaired.
All of this equipment has its operation, operation, maintenance, repair laws, only in accordance with the provisions of the working conditions and operating rules, the correct operation and maintenance, in order to make the equipment to deal with good technical condition. At the same time, mechanical equipment in the long-term operation process, due to friction, high temperature, moisture and a variety of chemical effects and actions, inevitably caused by wear and tear of parts and components, with the disorders, the gradual deterioration of the technical state of the operation effect gradually decline, so it must also be accurate, timely, fast, high-quality dismantling and repair, in order to make the equipment to restore the performance of the work in a good state.
74, sewage treatment system generally have what special equipment?
Specialized equipment: various types of sewage pumps, sludge pumps, storage pumps, metering pumps, screw pumps, air compressors, Roots blowers, centrifugal blowers, surface aerators, automatic water sampling machine, grating cleaning machine, scraper, scraper, scraper, scraper suction machine, sludge thickening and scraping machine, digestate sludge mixing equipment, biogas boiler, heat exchanger, medicine mixer, and sludge dewatering machine.
75, sewage treatment system generally have what special electrical equipment?
Electrical equipment: AC and DC motors, variable speed motors, starting switchgear, lighting equipment, lightning protection equipment, power conversion and distribution equipment (including cables, indoor wiring overhead lines, disconnecting switches, load switches, fuses, a small number of oil switches, voltage transformers, current transformers, power capacitors, disconnectors, protectors, automation and grounding devices, etc.).
76, sewage treatment system generally have what general auxiliary equipment?
General equipment: electric hoist, centrifuge, thermostat, oven, refrigerator, a variety of manual and electric gate valves, butterfly valves, gate opener and check valves, green water spraying trucks, push and electric lawnmowers, winches, lathes, planing machines, milling machines, bridge cranes, transport vehicles and so on.
77, sewage treatment system generally have what instrumentation?
Instrumentation equipment: a variety of balances, laboratory commonly used analytical instruments, electromagnetic flowmeter, level meter, air flow meter and dissolved oxygen meter.
78, sewage treatment system equipment management points are mainly?
Sewage treatment system, equipment management, the following four points:
(1) the use of good equipment
various equipment should have operating procedures, the operating steps. Equipment operating procedures are mainly based on the equipment manufacturer's instructions for the combination of site conditions and development. Workers must operate in strict accordance with the operating procedures. Equipment to be used in the process of making records of working conditions.
(2) maintenance of equipment
A variety of equipment should be developed maintenance regulations, maintenance regulations according to the equipment manufacturer's instructions for the combination of the site and the development of maintenance regulations can also be placed on the operating procedures together. Maintenance regulations, including cleaning, adjustment, fastening, lubrication and corrosion and other content. Maintenance work should also be recorded. Maintenance work can be divided into: routine maintenance - refers to the operation of the inspection and maintenance. Scheduled maintenance - regular downtime inspection and maintenance. Parking maintenance - refers to the maintenance of standby units or idle equipment. Seasonal maintenance - refers to the equipment into the summer, winter, rainy season and other seasonal needs of the maintenance work, including the adoption of sunscreen, cold, moisture, cooling and other measures.
(3) overhaul good equipment
To develop equipment overhaul standards for major equipment, through overhaul, restore technical performance. Some equipment, to clarify the boundaries of large, medium and small repairs, the division of labor to implement. The main equipment must be clear overhaul cycle, the implementation of regular maintenance, do not think of repair when the damage is very serious. Routine repairs, should be developed to overhaul the quota of materials, in order to reduce the cost of overhaul, each overhaul should be made a detailed record.
(4) good equipment management
The "management" here refers to the acquisition of equipment - installation - commissioning - acceptance - use - maintenance - overhaul -End-of-life-renewal of the whole process of management. Including the capital management of equipment (overhaul costs, depreciation, etc.) should be formulated for each part of the regulations.
79, sewage treatment system equipment, what is the standard of integrity?
Can be the following criteria as the standard of integrity:
(1) equipment performance is good, the main technical performance of the original design or minimum bottom should meet the requirements of the sewage treatment process.
(2) the operation and control of the safety system is complete, sensitive and reliable.
(3) stable operation, no abnormal vibration and noise.
(4) The degree of insulation of electrical equipment and safety protection devices should be in accordance with the electrical installation regulations.
(5) The ventilation, heat dissipation and cooling, sound insulation system of the equipment is complete and intact, with good effect, and the temperature rise is within the rated range.
(6) equipment inside and outside neat, well lubricated, no leakage (oil, gas, air, water).
(7) operation records, complete technical data.
80, sewage treatment system equipment maintenance cycle is generally how much?
Equipment used for a period of time, must be repaired, repair, or overhaul of some equipment manufacturers specify its minor repair, overhaul period; some equipment is not specified, it must be based on the complexity of the equipment, the durability of wearing parts and the maintenance conditions of the plant to determine the repair cycle. Repair cycle is the working time between the two repairs of the equipment, sewage treatment system a number of equipment overhaul cycle as shown in the table. (For reference only)
Sequence equipment name overhaul (hours) regular maintenance
1 Centrifugal sewage pump <600r/min 40000 500
2 Centrifugal sewage pump <800r/min 30000 500
3 Centrifugal sewage pump <1000r/min 20000 500
4 Centrifugal sewage pumps >1000r/min 10000 500
5 Sludge pumps (>1000r/min) 8000 500
6 Sludge pumps (<1000r/min = 10000 500
7 Air lift pumps (air lifters) 8 years 1 year
8 Screw pumps 20000 500
9 Centrifugal fan 15000 500
10 Scraper 10000 500
11 Roots blower 15000 500
81.Q: CAST process, sludge dewatering after the mixture is discharged directly into the influent pumping room, resulting in high influent COD, SS, and affect the denitrification reaction of the selection tank (because the previous section of the blast sand sedimentary pool) has degraded part of the C source), how should it be solved?
Answer: This is a problem that is generally ignored in current wastewater treatment plants, i.e., the influence of filtrate after sludge dewatering back to the biochemical tank on the biochemical treatment. Due to the sludge dewatering before the addition of conditioning agents, such as PAC and PAM, some agents have a certain degree of toxicity, sludge dewatering filtrate back to the biochemical reaction pool with the filtrate. Treatment of these filtrates is technically no problem, just a cost issue, if the selection of appropriate sludge conditioning chemicals, and control the dosage and the amount of sludge feed to the dehydrator, etc., the biochemical treatment will not have a major impact on the front. It is still emphasized that the effect of sludge dewatering depends on the whole process management of sludge treatment process, including the management of sludge thickening tank.
82. Q: How is the "sludge age" determined? How is it controlled? Is it determined by the amount of sludge discharged, or other to determine the amount of sludge discharged?
Answer: Age of sludge, F/M, etc. is not so much a control parameter for operation as a design parameter, and is only a reference parameter in process control. The actual operation of mud discharge is usually based on the MLSS value plus experience to control, in the case of SVI is relatively stable, can also be used SV30 for reference.
83. Q: The plant uses the Carrousel oxidation ditch process. Sometimes the device's effluent ammonia nitrogen is higher than the influent, influent TP2.5mg / L or so, the effluent is only 0.2 or so, the aerator 3 full-load operation. I have not been able to find out what the cause is, what is going on?
A: Only according to the preliminary analysis of the situation you provide, may be more nitrogenous organic wastewater, the reaction time is not enough, the rate of ammonification of organic nitrogen is greater than the rate of nitrification of ammonia nitrogen, in addition, it may be not enough phosphorus, affecting ammonia nitrogen through the assimilation pathway to the removal of the effect.
84. Q: In the operation process, the oxidation ditch surface has a thick layer of sludge accumulation, particle size of about 1mm or so of sludge particles yellowish, from time to time, will cause a large number of two sedimentation tank floating sludge, sludge back to the white, there are flocs with the effluent along with the outflow, the SV30 rapid decline in the loss of treatment effect, the accumulation of sludge to reduce thinning elimination. Week after week, may I ask the causes and control measures?
Answer: It means that the sludge has lost its activity, making the ESS increase. There are two possibilities: one is sludge oxidation itself; the other is sludge poisoning. From the phenomenon you described, the former is more likely, you can determine the specific oxygen consumption rate, that is, the ratio of endogenous oxygen consumption rate and substrate oxygen consumption rate to determine, targeted measures.
85. Q: AB method, how to control the A section? Is it a settling tank with the same flow rate to the A section of continuous reflux, SV30 should be controlled at how much? Is it 5-10%?
A: A section of the reflux ratio should be larger, but also can not make the residence time of sludge in the first settling tank is too short, although the A section is mainly adsorption-based, but there is a certain biodegradation, biodegradation is mostly carried out in the settling tank, only the degradation of organic matter adsorbed on the surface of the sludge, in order to restore the adsorption capacity. It should be controlled by MLSS, and SV30 can also be used when the sludge settling performance is stable, according to the actual situation, the settling ratio of 5%-10% is too low.
86. Q: If a wastewater plant has been running for one or two years and has not reached a better state of treatment, should we consider re-cultivation of bacteria (sludge replacement)? What is the difference between changing the sludge and starting the culture?
A: No need to change! If the operating conditions remain unchanged, the change will be the same, even if you use the advantage of bacterial strain dosing is useless, can only be maintained for a period of time, the important thing is to control the operating conditions, if it is a design problem to be rectified in a timely manner.
87. Q: I debugging is industrial wastewater. Process for hydrolysis + anaerobic + aerobic pool 1 + aerobic pool 2 + precipitation. Due to installation problems, the aeration pool gas distribution is not uniform (round aeration head aeration), each aerator, there is a similar fountain up and down (diameter of 1m or so), aeration is not uniform, how much impact on the treatment effect? Also found that the aeration area filler hanging film less, mirror inspection of large afterlife, did not find other organisms, filler biofilm surface for the yellowish, outside the aeration area of the biofilm is as thick as 3cm, can you give me a solution to show?
Answer: The situation you described can not be said to be uneven aeration, is a normal phenomenon. And you said the biofilm is not much, I do not know how much? If the biofilm to filler basic coverage is very good, as for the said aeration area outside the biofilm as thick as 3cm is a serious ballooning, to take measures, such as the use of atmospheric flushing and anaerobic de-membrane and other measures.
88. Q: Please ask about the contact oxidation pool of the following example.
(1) How long does sludge survive on the packing when the contact oxidation tank is emptied?
(2) When the treatment capacity of a contact oxidation tank decreases, should nutrients be added ?
(3) For foam, do you think it is effective to add kerosene to defoam, and if so, how much should be added usually?
Answer: Three questions are answered as follows:
(1) The contact oxidation tank after emptying is not a biofilm sludge can survive for a long time, but to avoid the soft filler drying out and slicing, slicing and then immersed in the water will be very difficult to stretch out again to prevent such a situation;
(2) contact oxidation tank capacity decline should be considered from a number of factors, which biofilm thickness control is very important, the membrane is too thick. The thickness of the control is very important, the membrane is too thick will seriously affect the processing capacity, but also pay attention to the pool can only be slowly put when emptying, or hanging a large number of biofilm soft filler frame will collapse or deformation;
(3) chemical foam spraying water is more effective (can not be directly flushed with water), I do not agree with the use of kerosene and other methods of antifoaming.
89. Q: the plant nearly a week of water intake, water and biochemical pool data average is as follows: Intake: BOD: 253 COD: 810 PH: 7.9 SS: 286 Color: 32 times
Ammonia nitrogen: 28 Total nitrogen: 64 Total phosphorus: 6.0 Output: BOD: 4.8 COD: 74 PH: 8.1 SS: 12 Color: 8 times Ammonia Nitrogen: 7.6 Total nitrogen: 22.6 Total phosphorus: 6.0 Output: BOD: 4.8 COD: 74 PH: 8.1 SS: 12 Color: 8 times: 7.6 Total Nitrogen: 22.8 Total Phosphorus: 1.02 Biochemical Tank: MLSS: 4200 MLVSS: 2340 SV %: 47.2
Sludge Index: 118.9 Sludge age is 35 days
The modified activated sludge treatment process is used, and the current influent is only 25,000 tons per day (designed for 50,000 tons), and more than 80% of it is industrial wastewater. There is also a small amount of highly concentrated waste leachate. The process is aeration and sand sedimentation tank - after the biochemical tank - after the second sedimentation tank, there is no contact tank and hydrolysis tank. The biochemical tank is blower gas supply, deep water rotating disk aeration, dissolved oxygen is less than 1 mg/L when the water is continuously fed, and the dissolved oxygen rises slowly to about 4-5mg/L after the water is stopped. The serious exceedance of the influent water and the defects of the structure have led to the high load of the biochemical tank, and the sludge thickening tank is very small (180 cubic meters), and a considerable portion of the residual sludge back to the influent pump room. The problems encountered now are: (1) The second sedimentation tank is often found to have suspended particles of activated sludge after water intake, is the static settling time insufficient or difficult to settle? (2) three secondary sedimentation tanks are found to gather the red worms (water fleas), water fleas seem to be treated water quality is good performance, is it because of the high concentration of sludge resulting in a large number of reproduction? (3) Sometimes there is a thin layer of floating sludge in the secondary sedimentation tank, is it that the settling performance of the sludge is very poor and the biochemical tank is not sufficiently aerated? Or is it that the sludge reflux is not timely? (4) The triangular weir plate of the secondary sedimentation tank is prone to moss or algae growth, what are the methods to overcome? (5) I think the sludge has been aging seriously, to control the MLSS down to 3000-3500 or lower, increase the residual sludge discharge, reduce the age of the mud, so that the impact resistance of the biochemical tank will not decline? Will the effluent quality go up?
Answer: sludge is some aging, but not very serious, the age of sludge has reached 35 days, according to this projection, the sludge load is less than 0.03. Control of the current sludge concentration of 2/3 is enough, should gradually reduce the concentration of sludge, fleas have no effect on the effluent, analysis of the sampling do not take to fleas. Also pay attention to the sedimentation tank mud layer control, the second sedimentation tank triangular weir plate on the moss and algae can only be removed manually.
90. Q: We are petrochemical wastewater two-stage biochemical treatment, one is a round completely mixed aeration tank, the second is a push-flow aeration tank, a DO 0.2mg / L, the second DO 5.0mg / L. This period of time the first biochemical inlet PH 8.0, 6.5 water, two biochemical pH 5.78, exceeding the target range of 6-9, how is this?
A: A low DO is very normal, because the sludge load is high, the reason for the decline in pH of the first level may be the load is too high acidification, the decline in pH of the second level of effluent may be caused by the consumption of alkalinity in nitrification reaction. Because you introduced too simple, I can only simply analyze and deduce.
91. Q: ammonia nitrogen removal, in addition to sufficient carbon and long enough sludge age and to ensure sufficient reflux, reflux is reflux aerobic tank effluent or the bottom of the secondary sedimentation tank reflux? I am now debugging spandex wastewater, the original design of reflux aerobic tank effluent, but in fact, if the reflux flow doubled, it can not guarantee the anaerobic environment of the anoxic tank in front of me, my master said that the oxygen tank dissolved oxygen control at about 1mg / L will be better, so is it right?
A: According to your introduction should be the front denitrification, need to return to the aerobic tank effluent and secondary sedimentation tank sludge. You said that if the return flow doubled, you can not guarantee the anaerobic environment of the anoxic tank in front of the words is not good, anoxic area is not equal to anaerobic, DO less than 0.5mg / L can be. Your master said good aerobic pool dissolved oxygen control in 1mg / L or so is also reasonable, so that can prevent anoxic area DO is greater than 0.5mg / L. If the aerobic area DO in 1 or so, the return flow of the effluent is doubled, anoxic area DO is still greater than 0.5mg / L, you can not reduce the aerobic area of the DO, and do not arbitrarily reduce the return flow of the effluent (nitrate and nitrogen into the anoxic area will be less), this time can be in the non-depositional area. This time, under the premise of not affecting the effect of mud-water separation in the secondary sedimentation tank, reduce the amount of mud from the secondary sedimentation tank, elevate the sludge layer in the tank, so that the sludge in the secondary sedimentation tank to increase the residence time, so that it is in the state of defective oxygen or anaerobic state, which is also conducive to avoiding anoxic areas of DO rise. Decrease in the amount of sludge discharged from the secondary sedimentation tank will not affect the amount of sludge returned to the reaction tank, because in the case of elevation of the sludge layer in the secondary sedimentation tank, the sludge is concentrated in the sludge layer for a longer period of time, and in this case the amount of sludge discharged is reduced but the concentration of the discharged sludge is increased. If it is a contact oxidation process, the effluent has to be returned and the sludge is not returned. I am not in favor of using front denitrification. Because the energy consumption of the effluent reflux is large, and the large reflux volume requires a large reactor volume. About the removal of nitrifying bacteria is not good, but understand what you mean.