Process debugging scheme of sewage treatment station The purpose of process debugging of sewage treatment station is to repair and correct engineering defects and errors in time to ensure that the treatment station achieves the design function. In the process of sewage treatment process debugging, it is inseparable from the cooperation of electromechanical equipment, automatic control instruments, laboratory analysis and other related majors, so debugging is actually a process of equipment, automatic control and process linkage. Process debugging is an important work before the sewage station is put into production, and its importance is shown in the following aspects: first, find and solve problems in equipment, facilities, control and technology, so that the sewage station can be put into normal operation; The second is to achieve the process design goal, that is, the indicators of effluent meet the design requirements; The third is to determine the control parameters that meet the actual influent and water quality, and reduce the operation cost as much as possible on the premise that the effluent quality meets the design requirements. I. Contents and Purpose of Debugging The main contents of debugging include: First, single-machine trial operation, including single-machine operation after installation of various equipment and water test of various processing unit structures, to check whether the water level and elevation of hydraulic structures meet the design requirements; Secondly, carry out the clean water linkage of the design water quantity for the whole process system, get through the process flow, check the operation of the equipment under the clean water flow, and check whether some automatic control instruments, pipelines and valves connecting each process meet the design requirements; 3. Trial operation with load, testing the treatment effect of each treatment unit, solving various problems affecting continuous operation, and laying a good foundation for the next work (activated sludge culture, mainly accumulating microbial biomass required for treatment). If there is sludge, the main work is sludge domestication; Fourthly, the domestication of activated sludge is the key to ensure the process has good effluent index, and its purpose is to select microorganisms that adapt to the actual water quality and eliminate useless microorganisms; Fifth, determine the process control parameters that conform to the actual influent quality and quantity, reduce energy consumption as much as possible under the premise of ensuring the effluent quality to meet the standard, and compile process control procedures to guide future operation (procedures have been compiled). Second, the debugging method (1) preparation 1. Personnel preparation: a. Technical personnel of technology, laboratory, equipment, automatic control, instrument and other related professions 1 person. B trained personnel for each post are in place, and the number depends on the post setting and shift. C. Instruments and equipment: 1600 times microscope 1 set; 1 set of rapid measuring instrument for dissolved oxygen, pH value and temperature; 1 sampler; 2 100ml measuring cylinders; 2 glass rods; 500ml beaker 2 tube brush1; Pipets10ml, 2ml each1; 1 ball; 2 packs of full pH test paper; Fixed clock:1; 1 spring scale (three 250ml conical bottles are needed for on-site monitoring of COD Mn; 50ml acid burette 2; 3 1000ml brown volumetric flask; 1+3 sulfuric acid 200ml；; 1 set of boiling water bath device; 0.0 1mol/L KMnO 4 standard solution1000 ml; ; 0.0 1mol/L Na 2 C 2 O 4 standard solution1000 ml; ; If there is a physical and chemical treatment unit, just add the corresponding stirring and flocculant. D. Laboratory personnel: 2 people. 1 person operates at night, 1 person conducts laboratory tests and operations during the day. 3. Pressure test and leakage test of the treatment device; The piping system is filled with water and ventilated. 4. Measure the raw water quality (COD Cr, BOD 5, N, P, pH, SS, water temperature) and make a debugging plan. 5. Other preparatory work: a. Collect process design drawings and design descriptions, automatic control, instrument and equipment descriptions and other related materials. B. Check whether the laboratory instruments, appliances and medicines are complete for water quality analysis. C. Check whether the dimensions and elevations of various structures and their ancillary facilities conform to the design, and whether the pipes and structures are blocked. D. check whether the main power supply and the power supply of each equipment are normal. E. Check whether the equipment can be started normally and whether all kinds of gate valves can be opened and closed normally. F. check whether the instrument and control system are normal. G. check whether the maintenance tools are complete and the common wearing parts are complete. H. buy flocculant. (2) On-load trial operation (stand-alone clean water test, the detailed steps of clean water and system linkage are the same below). Open all valves and gate valves in water treatment facilities and pipelines, start the water inlet pump to deliver water, and start other equipment along the process flow in time according to the water inflow of various structures. In this process, the following aspects should be done well: First, check whether the total incoming current meets the requirements, whether the power transformation and distribution equipment works normally, whether all kinds of equipment work normally and meet the design requirements, whether the instruments work normally and whether the automatic control system can meet the design requirements. 2. Volumetric method is used to check the accuracy of inflow and outflow water, backflow and excess sludge flowmeters, check various instruments, detect the quality of inlet water, measure the flow rate, and measure and record the voltage, current, power and speed of equipment. Third, solve the problems found in the trial operation in time. Four, the preparation of equipment operation procedures (compiled). (3) activated sludge culture (or sludge purchased from existing sewage treatment plants) (4) SBR process debugging of activated sludge domestication (same as sludge domestication in ICEASE) 1. Brief introduction of SBR process This process realizes the biochemical treatment of wastewater through the program control of five stages: water intake, reaction, precipitation, drainage, sludge discharge and idling in ice. SBR reactors can be divided into three types: limited aeration, unrestricted aeration and semi-limited aeration. Restricted aeration means that sewage enters the aeration tank for mixing without aeration; Uncontrolled aeration is aeration when water enters; Semi-limited aeration is the aeration that starts when sewage enters the middle. In the reaction stage, aeration can be carried out all the time. For biological denitrification, stirring can also be carried out after aeration, or aeration and stirring can be carried out alternately. Excess sludge can be discharged in idle stage, water inflow stage or late reaction stage. 2. Formulation of debugging scheme The operation mode of SBR reactor should be determined according to the nature of wastewater. Easily degradable organic wastewater should be treated by restricted aeration, while refractory organic wastewater should be treated by unrestricted aeration. The time control of each process in its cycle is related to the final treatment index requirements. For example, if only the treatment effects of COD Cr and BOD 5 are considered in the treatment, the aeration time can be appropriately reduced to achieve the purpose of energy saving; If nitrogen and phosphorus removal are considered, the aeration time needs at least 4 hours; In order to treat industrial wastewater and toxic and harmful wastewater, it is suggested to adopt short-term stirring and long-term aeration. Different sewage treatment projects have different debugging schemes and operation steps. Taking the wastewater treatment project of Jiyuan fur factory as an example, the explanation is as follows: 1. Inoculation: According to the effective volume of the reactor and sludge concentration (generally 3-4g/L), calculate the total amount of sludge to be inoculated. The effective pool capacity of SBR pool is 7× 4× 4 = 1 12m3. According to the volume of each pool1100m3, and the moisture content of inoculated sludge is 97%, the amount of sludge to be pulled is 20-26 m3, and each pool is inoculated with 10- 13 m3. The specific situation is that the average amount of sludge pumped out is put into the ICEASE reaction tank. 2. Domestication start-up: a, batching: in the regulating tank (effective tank volume is12.0× 4.0× 3.5m =168m3 according to the exact size during construction). Because the raw sewage contains a certain amount of toxic and harmful substances, the feed liquid is prepared according to the ratio of raw sewage to diluted water = 1: 4, that is, the raw sewage is 33.6 m 3 and the diluted water is 134.4m 3. According to the water quality of sewage, the prepared feed liquid may not be nutritious enough, and a certain amount of nutrient source (fecal water) needs to be added (generally, the prepared feed liquid is required to have CODCr = 1500-2000 mg/L, pH = 6-9, SS≤200mg/l, and temperature: 10-35℃). B. Feeding operation: After the materials are mixed and stirred for half an hour, they can be directly put into SBR reactor. After adding 150m 3 and 1 hour to each SBR tank, continuous aeration will be started for about 3-4 days (pay attention to the characteristics of sludge, subject to the reactivation of inoculated sludge). C. Drainage: When the sludge recovers its activity, stop aeration and let it stand for 1.0- 1.5 hours. Release the supernatant, about 50-60m3. D. repeat the above steps a, b and c. Refueling interval 1 day, 1 time. E, when the sludge activity is obviously enhanced, the sedimentation performance is good, and the sludge contains a large number of bacterial micelles and ciliate protozoa, such as species, isopods and ciliates. SV = 10-30%, indicating that the sludge has been decomposed and the forced domestication period has basically ended. F. Precautions: During aeration, measure dissolved oxygen, pH value and sludge sedimentation ratio at least twice a day; Record the measurement data. General normal indicators are: do =1-2mg/l ph = 6-9sv =10-30%. Sludge sedimentation ratio (SV) means that the mixed activated sludge liquid in the aeration tank is quickly poured into a 1000ml measuring cylinder to full scale, and after standing for 30 minutes, the volume ratio of the precipitated sludge to the mixed liquid is sludge sedimentation ratio (%), also called sludge sedimentation volume (SV30), which is expressed in ml/L. Because sludge can generally reach or approach the maximum density after settling for 30 minutes, it is generally used as. It can also be 15 minutes (SV 15). G, this stage of forced domestication takes about 5-7 days. 3. Commissioning and operation: When the sludge recovers its activity and the forced domestication is completed, it can enter the stage of domestication and trial operation. At this stage, it is necessary not only to cultivate suitable strains, but also to determine the best operating conditions of activated sludge system. The first stage: a, batching: in the regulating tank (according to the exact size during construction). Prepare feed liquid according to the ratio of raw sewage to diluted water = 1: 3, that is, raw sewage is 42 m 3 and diluted water is 126 m 3. According to the situation, a certain amount of nutrient source (fecal water) can be added appropriately. Open the air valve of the regulating tank, so that the regulating tank is inflated and stirred evenly. Monitor water quality indicators (chemical oxygen demand, pH value, water temperature, SS). B, after the forced domestication is completed, stop aeration, record the static precipitation, determine the static precipitation time (generally 0.5- 1.0 hour) according to the solid-liquid separation, and record the static precipitation time. C, discharging the supernatant of about 40-50m3. Take 100ml supernatant, put it in a conical flask, and monitor the COD value. D, dosing operation: the prepared feed liquid is fed into the SBR reactor at the flow rate of 65438+1100m3/h, with the dosing amount of 80 m3/ pool, and the two pools are operated alternately. First, run it in a 22-hour cycle. Start aeration after feeding 1 hour, continue aeration for 4 hours, and stop aeration for 0.5 hours; Continue aeration for 4 hours, and stop aeration 1.0 hour; Aerate for another 3 hours, and stop aeration for 0.5 hours; Aerate for 3 hours, and stop aeration for 65438 0.0 hours; Aerate for 2 hours, let it stand for 0.5- 1.0 hour, start to drain about 80m 3, record the drainage time (about 0.5 hour), and leave it idle for 0.5- 1.0 hour (ICEASE does not need to be idle). DO and SV% should be monitored in time during aeration; After stopping exposure, DO should be monitored and recorded before re-aeration. General indicators are: do =1-2 mg/l ph = 6-9 SV =10-30% water temperature: 10-35℃. E. repeat the operation according to the above steps a, b, c and d for 3-4 days. pay attention to the characteristics and growth of sludge, observe the growth of microorganisms in activated sludge with a microscope when poSSible, monitor the drainage water quality indicators (DO, COD Cr, pH, ss) in time and make records. The second stage: the operation cycle can be adjusted as follows according to the debugging situation of the first stage, or it can be operated according to the cycle of the previous stage, which mainly depends on the treated water quality and sludge performance. A, batching: in the regulating tank (according to the exact size during construction). Prepare feed liquid according to the ratio of raw sewage to diluted water = 1: 2, that is, raw sewage is 56 m 3 and diluted water 1 12 m 3. According to the situation, a certain amount of nutrient source (fecal water) can be added or not. Open the air valve of the regulating tank, so that the regulating tank is inflated and stirred evenly. Monitor water quality indicators (chemical oxygen demand, PH value, water temperature, SS). B, dosing operation: the prepared feed liquid is fed into the SBR reactor at the flow rate of 65438+1100m3/h, with the dosing amount of 80 m3/ pool, and the two pools are operated alternately. Run at a cycle of 12 hour. Start aeration after feeding 1 hour, continue aeration for 3 hours, and stop aeration for 0.5 hours; Aerate for another 3 hours, and stop aeration for 0.5 hours; Aerate for 2 hours, let it stand for 0.5- 1.0 hour, start to drain about 80m 3, record the drainage time (about 0.5 hour), and leave it idle for 0.5- 1.0 hour (ICEASE does not need to be idle). DO and SV% should be monitored in time during aeration; After stopping exposure, DO should be monitored and recorded before re-aeration. General indicators are: do =1-2 mg/l ph = 6-9 SV =10-30% water temperature: 10-35℃. C, repeat the operation according to the above steps a and b for 3-4 days. Pay attention to the characteristics of sludge, observe the growth of microorganisms in activated sludge with a microscope when possible, monitor the drainage water quality indicators (DO, COD Cr, PH, SS) in time and make records. The third stage: a, batching: in the regulating tank (according to the exact size during construction). According to the ratio of raw sewage to diluted water = 1: 1, the feed liquid is prepared, that is, the raw sewage is 84 m 3 and the diluted water is 84 m 3. Open the air valve of the regulating tank, so that the regulating tank is inflated and stirred evenly. Monitor water quality indicators (chemical oxygen demand, pH value, water temperature, SS). B, dosing operation: the prepared feed liquid is fed into the SBR reactor at the flow rate of 65438+1100m3/h, with the dosing amount of 80 m3/ pool, and the two pools are operated alternately. Run at a cycle of 12 hour, start aeration after feeding 1 hour, continue aeration for 3 hours, and stop aeration for 0.5 hour; Aerate for another 3 hours, and stop aeration for 0.5 hours; Aerate for 2 hours, let it stand for 0.5- 1.0 hour, start to drain about 80m 3, record the drainage time (about 0.5 hour), and leave it idle for 0.5- 1.0 hour (ICEASE does not need to be idle). DO and SV% should be monitored in time during aeration; After stopping exposure, DO should be monitored and recorded before re-aeration. General indicators are: do =1-2 mg/l ph = 6-9 SV =10-30% water temperature: 10-35℃. C, repeat the operation according to the above steps a and b for 3-4 days. Pay attention to the characteristics of sludge, observe the growth of microorganisms in activated sludge with a microscope when possible, monitor the drainage water quality indicators (DO, COD Cr, pH, SS) in time and make records. The fourth stage: a, batching: in the regulating tank. Directly into the original production sewage, according to the situation, a certain amount of nutrient sources (fecal water) can be added appropriately, or not. Open the air valve of the regulating tank, so that the regulating tank is inflated and stirred evenly. Monitor water quality indicators (chemical oxygen demand, pH value, water temperature, SS). B, dosing operation: dosing the prepared feed liquid into the SBR reactor at the flow rate of 65,438+1 100m3/h, with the dosing amount of 80 m3/ pool and the operation period of12h. After dosing1hr, start aeration, continuously aerate for 3h, and stop aeration for 0.5h.. Aerating for another 3 hours, and stopping aeration for 0.5 hours; Aerate for 2 hours, let it stand for 0.5- 1.0 hour, start to drain about 80m 3, record the drainage time (about 0.5 hour), and leave it idle for 0.5- 1.0 hour (ICEASE does not need to be idle). DO and SV% should be monitored in time during aeration; After stopping exposure, DO should be monitored and recorded before re-aeration. General indicators are: do =1-2 mg/l ph = 6-9 SV =10-30% water temperature: 10-35℃. C, repeat the operation according to the above steps A and B for three days, pay attention to the characteristics of sludge, observe the growth of microorganisms in activated sludge with a microscope when possible, monitor the drainage water quality indicators (DO, COD Cr, pH, SS) in time and make records. The fifth stage: according to the records of the above four stages of debugging, find the best living conditions of the flora, choose the best operation period and the best operation mode, and complete the debugging. Ingredients: In the regulating tank. Directly enter the production water, and open the air valve of the regulating tank to make the regulating tank aerate and stir evenly. Monitor water quality indicators (chemical oxygen demand, PH value, water temperature, SS). B, feeding operation: according to the selected optimal operation cycle and operation mode. Control aeration and stagnation time, and monitor DO and SV %； in time during aeration; After stopping exposure, DO should be monitored and recorded before re-aeration. General indicators are: do =1-2 mg/l ph = 6-9 SV =10-30% water temperature: 10-35℃. C, repeat the operation according to the above steps a and b for 3-4 days. Pay attention to the characteristics of sludge, observe the growth of microorganisms in activated sludge with a microscope when possible, monitor the drainage water quality indicators (DO, COD Cr, pH, SS) in time and make records. If the effluent COD Cr is about 300mg/l and the sludge is in a stable growth state, SV = about, it can be considered that the commissioning is over. Enter the formal full-load operation stage. 4. Precautions: A. In order to successfully complete the debugging work, it is necessary to ensure the stability of the SBR reactor at this stage, and avoid the large fluctuation of influent concentration, suspended solids and pH value, which will cause a large impact load on the SBR reactor and lead to sludge deterioration. B during operation, DO, pH and SV water quality indicators must be measured at least once every operation cycle. Before and after changing the pollutant concentration, it is necessary to monitor the water quality in the reactor and entering the reactor with a full set of indicators, focusing on monitoring COD Cr, SS and PH to ensure the rationality of sludge load in the reactor. C, at the beginning of each change of sewage dosage, we must pay attention to observe the characteristics of sludge and record its adaptation time, so as to provide reference for the next change of sewage dosage. D, when the sludge SV% is greater than or equal to 30, a small amount of sludge should be discharged, and the amount of sludge discharged each time is about 10- 15m3. The purpose of domestication is to select microorganisms that adapt to the actual water quality and eliminate useless microorganisms. For the treatment process with nitrogen and phosphorus removal function, nitrifying bacteria, denitrifying bacteria and phosphorus accumulating bacteria become dominant flora through domestication. The specific method is to maintain the normal operation of the process first, and then strictly control the process control parameters. DO in anaerobic tank is controlled below 0. 1mg/l, DO in anoxic tank is controlled below 0.5mg/l, and DO in aerobic tank is controlled below 2-3 mg/l. The aeration time in the aerobic tank is not less than 5 hours, the external reflux ratio is 50% ~ 100%, and the internal reflux ratio is 50% ~ 100%. In this process, the water quality indexes of inlet and outlet water are tested every day until the water quality indexes meet the design requirements. (V) Determination of process control parameters The process control parameters in the design are determined under the conditions of predicted water quantity and water quality, but the water quantity and water quality when the sewage station is actually put into operation are often quite different from the design. Therefore, it is necessary to determine appropriate process control parameters according to the actual water quantity and quality to ensure normal operation and reduce energy consumption as much as possible. 1. Process parameters: The important process parameters to be determined include the control water level of the intake pump house, dissolved oxygen DO and redox potential ORP of the biological pond, sludge reflux ratio R, sludge concentration MLVSS, sludge sedimentation ratio SV%, sludge index SVI, sludge age SRT, residual sludge discharge cycle and daily discharge, and sludge surface height of the secondary sedimentation tank. Among them, the main factors affecting energy consumption are the inlet water level and sludge concentration MLVSS. A. Sludge reflux ratio: the ratio of the reflux sludge flow rate to the influent flow rate of the aeration tank. B. Sludge concentration: the dry solid weight per unit volume of sludge, or the percentage of dry solid in sludge weight. C. Measured by gravimetric method, the unit is gram/liter or mg/liter, which is also called suspended solid concentration (MLSS). D. sludge index SVI: (1) sludge volume index (SVI) The volume (mL) of the mixed liquor at the outlet of the aeration tank after standing for 30min is called sludge volume index (SVI), and its value is calculated according to the following formula: for example, the sludge sedimentation ratio of the aeration tank SV=30%, and the suspended solid concentration of the mixed liquor X = 3000. Then svi = 30x10000/3000 =100e. Sludge age: it is the ratio θc between the total amount of activated sludge in the aeration tank and the amount of residual sludge discharged daily. Unit: day. (Generally 3 to 10d) 2. Determination method: under the premise of ensuring that the water intake system does not overflow, try to control the water level of the water intake pump house. DO and ORP of biological pool are determined according to phosphorus release in anaerobic pool, denitrification in anoxic pool, phosphorus absorption and nitrification in aerobic pool. Generally, DO in anaerobic pool is less than 0. 1mg/l, DO in anoxic pool is less than 0.5mg/l, DO in aerobic pool is controlled between 2 and 3 mg/L, and ORP (redox potential) in anaerobic pool is measured by MV in PH meter. The reflux ratio r should be determined according to the retention time of sludge in the secondary sedimentation tank and the release amount of phosphorus. Generally about 80% is appropriate. The sludge concentration MLVSS is determined by the sludge load, and the sludge load of nitrogen and phosphorus removal process is generally about 0. 12kgBOD5/(kgMLVSS*d). SRT of sludge age should consider the requirements of design water quality. For nitrogen and phosphorus removal process, it is generally controlled in about 8 days. (VI) Process control regulations: Process control regulations are mainly used to guide production and operation, and are the main basis for process operation. They mainly include the following aspects: first, the basic situation of various structures; Second, the operation control parameters of each structure; The third is the operation mode of facilities and equipment; Fourth, the process adjustment method; Fifth, the maintenance method of treatment facilities. After the process parameters are determined, the process control program should be compiled. (VII) Other work in debugging: In order to operate correctly, the sewage plant should also have a set of perfect systems, mainly including management system, post responsibilities, operating procedures, operation records, equipment and facilities files, etc. The above work can be completed step by step in the debugging process. Three. Precautions 1. Before passing through, all facilities, pipelines and underwater equipment shall be inspected, and all sundries shall be thoroughly cleaned, so as to avoid the blockage of pipelines and equipment and the maintenance of underwater equipment from affecting the smooth commissioning. It is quite difficult to maintain underwater facilities and equipment after water supply, mainly because the water tank needs to be emptied for maintenance. The volume of the water tank varies from several thousand cubic meters to tens of thousands of cubic meters, which is quite time-consuming and laborious. Especially after activated sludge, where to put the water is a problem in itself, and pollution accidents will occur when it is released, and it is often impossible to put it into other pools. Therefore, water supply must be carefully checked and cleaned before. 2. Strictly monitor the water quality, especially the pH value, and take corresponding measures immediately when it exceeds the requirements, otherwise the work of cultivating bacteria will be in vain. 3. At the initial stage of bacteria culture, a large number of white bubbles will appear in the aeration tank, which will accumulate two or three meters high in serious cases, polluting the walkways and field instruments. This problem is an inevitable phenomenon in the early stage of bacterial culture, which can be solved as long as the dissolved oxygen is well controlled and appropriate defoaming measures are taken. (Don't worry about the aseptic stage) 4. The quantity and pressure of tap water are often ignored. During the debugging process, some instruments and equipment for sludge dewatering in the laboratory have strict requirements on water quantity and pressure. If the requirements are not met, these instruments and equipment will not be used. Sewage treatment plants are generally far away from cities, and the water pressure is usually very small at the end of the pipe network of tap water. Therefore, some devices should be set up to improve the water pressure. Four. Suggestion: Process debugging is an important work related to whether the sewage treatment station can run normally and play its benefits. With high technical content and great difficulty, it needs professionals or professional institutions with sewage treatment knowledge and long-term operation experience to implement it. Therefore, it is suggested that relevant departments should incorporate process commissioning into the project and arrange enough funds to ensure the effective development of commissioning work. Attached table (PS: the specific operation must be read carefully): the ratio of raw sewage to diluted water is 1: 4, 5-7 days. After feeding 1h, continuous aeration for 3-4 days. In the first stage of trial operation, the ratio of raw sewage to diluted water is 1: 3. After feeding 1h, stop the exposure for 4 hours, 4 hours and 6 hours. 5438+0h aerate for 3h, stop aeration for 0h, stop aeration for 3h, stop aeration 1h, stop aeration for 2h and stop aeration for 0h (drainage). In the second stage, the ratio of raw sewage to diluted water is 1: 2. After feeding 1h, stop aeration for 3h, 0h, 3h, 0h, 2h and 0h. 5- 1h (drainage) The ratio of raw sewage to diluted water in the third stage is 1: 1, which is the same as that in the second stage and the fourth stage for 3 days. The debugging of the second stage and the fifth stage is completed within 3-4 days, and the best operation parameters are obtained (according to the control program).
Satisfied, please adopt.