Cultivation of biochemical strains

CASS process cultivation plan: The industrial wastewater (pharmaceutical and chemical wastewater) treated by the sewage treatment plant in the medical and chemical industrial park has a daily treatment capacity of 12,500 tons. The main parameters of the influent water quality are as follows: CODcr ≤1000 mg/L, BOD5 ≤500 mg/L, SS ≤500 mg/L, TN ≤50 mg/L, NH3-N ≤40 mg/L, TP ≤4.0 mg/L, pH 6–9, colority ≤300. The quality standards for the treated effluent water are those specified in the “Integrated Wastewater Discharge Standards” (GB8978-1996), specifically the discharge standards applicable to other polluting entities, namely: CODcr ≤150 mg/L, BOD5 ≤30 mg/L, SS ≤150 mg/L, NH3-N ≤25 mg/L, TP ≤1.0 mg/L, pH 6–9, colority ≤80. The process flow is as follows: There is one CASS tank divided into 4 compartments; each compartment has the following dimensions: the biological selection zone (anoxic section) is 15 m long, 6 m wide, with an effective water depth of 6 m, and a hydraulic retention time of 4.2 hours； The main biochemical zone is 47.5 m long, 15 m wide, and has an effective water depth of 6 m. Each cell operates 6 cycles per day using a continuous water feed method, with each cycle lasting 6.0 hours. The specific allocation is as follows: 4.0 hours for water feeding/aeration, 1.0 hour for water feeding/settling, and 1.0 hour for water feeding/skimming. During the aeration period, the sludge load was 0.095 kgBOD5/kgMLss.d, the sludge concentration was 4 g/L, and the discharge ratio was 16.2%. The procedures for the CASS tank need to be adjusted according to the actual quality of the incoming water. Table 6-3 shows the time allocation for each stage in a single CASS cell as well as the operation status of various equipment.  Operation table for single-cell CASS tanks – Table 6-3: Timing, process duration (hours), and equipment status. Stirrer, water inlet, gate valve, sludge skimmer, sludge discharge pump, return pump. Phase 1: Water inlet, aeration – 4.0 hours; status: ON, ON, OFF, OFF, ON. Phase 2: Water inlet, sedimentation – 1.0 hour; status: ON, ON, OFF, OFF, ON. Phase 3: Water inlet, sludge discharge – 1.0 hour; status: ON, ON, ON, ON, ON. Equipment equipped in each CASS biological tank: 8 sludge return pumps are installed within the CASS tanks. The flow rate of a single pump is Q=120 m3/h, H=8 m, N=5.5 kW, with a maximum reflux ratio of 185%. 8 excess sludge pumps are installed in the CASS tank. The flow rate of a single pump is Q=55 m3/h, H=10 m, N=3.0 kW ； The excess sludge can be discharged to a sludge tank or a regulating tank, as well as a hydrolysis-acidification tank; the maximum reflux ratio to the hydrolysis-acidification tank is 85%. A 1,700-meter tubular micro-porous aeration system is installed in the CASS tank, with an oxygen utilization rate of over 20%. Four decanters are installed in the CASS tank, with a decanting capacity of 800 m3/hr and a power rating of 1.5 kW. Four sets of inlet regulating weir gates, with specifications of 1500×500, are installed in the CASS tank. A low-speed submersible mixer with a single-unit power of 2.2 kW is installed in the biological selection zone (anoxic section). The air volume for CASS tanks is 1.5 kgO2/kgBOD5 and 4.7 kgO2/kgNH3-N; the oxygen utilization rate is 20%, and the air volume per cell is 38.7 m3/min. The CASS tank is equipped with 5 blowers, operating in a 4-active-1-redundant configuration. The air volume per fan is 41.2 m3/min, the wind pressure is 7 m, and the power is 75 kW. The blower is a Roots blower equipped with its own sound-insulating and rainproof cover. Sludge production rate: 0.6 kg MLSS/kg BOD; excess sludge production amount: 5.25 t/day, with a moisture content of 99.2%; sludge volume: 656 m3. My microbial cultivation plan: The CASS tank has a volume of 4815 M3 per cell, with four cells in total. Each cell is filled with water, and the sludge inoculated contains a concentration of 1500 mg/l. The dehydrated sludge used for inoculation has a moisture content of 80% and an organic matter content of 80%; 45 tons of sludge are required for inoculation. The culture is expanded in stages: initially, a total of 90 tons of sludge is added to two tanks (1# and 2#) to start the bacterial cultivation. After cultivation, transfer the culture to the other two tanks (3# and 4#) for further cultivation. Let me check if my understanding is correct: The wastewater treatment plant has a daily processing capacity of 12,500 tons, which corresponds to an inflow rate of 520 tons per hour. The CASS tank is divided into four sections, with each section capable of handling 3,125 tons per day. According to the design specifications, each section of the CASS tank operates in cycles of 6 hours; water is supplied continuously, with a maximum inflow rate of 130 tons per hour per section. Time sequence and duration (in hours): Phase 1 – Water inflow and aeration: 4.0 hours; Phase 2 – Water inflow and sedimentation: 1.0 hour; Phase 3 – Water inflow and water discharge: 1.0 hour. In the discharge phase, my understanding is that water inflow should stop, right? In that case, the water inflow per hour is 156 tons. Whether it is 130 or 156, the water inflow rate for single-cell acclimatization is ultimately 130 tons per hour or 156 tons per hour; I am now adjusting the settings so that the acclimatization water flow reaches 156 tons per hour. Schedule for the cultivation and debugging of Cell 1# and 2#
Phase | Time | Water inflow (tons/day) | Water inflow | CASS tank operating cycle
--- | --- | --- | --- | ---
Cultivation | May 4 | Sludge inoculation | Anoxic aeration |
| May 5 | Sludge inoculation | Anoxic aeration |
| May 6 – May 10 | 1000 | Water changed twice a day, 500 tons each time; anoxic aeration for 12 hours |
Acclimatization | May 11 – May 15 | 1500 | Water changed twice a day, 750 tons each time; anoxic aeration for 12 hours |
| May 16 – May 18 | 500 | Continuous water inflow at 25 t/h; aeration for 4 hours, sedimentation for 0.5 hours, then idle time of 0.5 hours |
| May 19 – May 21 | 1000 | Continuous water inflow at 50 t/h; aeration for 4 hours, sedimentation for 0.5 hours, then idle time of 0.5 hours |
| May 21 – May 25 | 1400 | Continuous water inflow at 70 t/h; aeration for 4 hours, sedimentation for 0.5 hours, then idle time of 0.5 hours |
| May 26 – May 30 | 2000 | Continuous water inflow at 100 t/h; aeration for 4 hours, sedimentation for 1 hour, then idle time of 1 hour |
| May 31 – June 6 | 2600 | Continuous water inflow at 130 t/h; aeration for 4 hours, sedimentation for 0.5 hours, then idle time of 0.5 hours (same as above) |
| June 7 – June 12 | 3120 | Continuous water inflow at 156 t/h; aeration for 4 hours, sedimentation for 1 hour, then idle time of 1 hour |

Schedule for the cultivation and debugging of Cell 3#
Phase | Time | Water inflow (tons/day) | Water inflow | CASS tank operating cycle
--- | --- | --- | --- | ---
Cultivation | June 3 | Sludge inoculation | Anoxic aeration |
| June 4 – June 8 | 1000 | Water changed twice a day, 500 tons each time; anoxic aeration for 12 hours |
Acclimatization | June 19 – June 23 | 1500 | Water changed twice a day, 750 tons each time; anoxic aeration for 12 hours |
| June 24 – June 26 | 500 | Continuous water inflow at 25 t/h; aeration for 4 hours, sedimentation for 0.5 hours, then idle time of 0.5 hours |
| June 27 – June 29 | 1000 | Continuous water inflow at 50 t/h; aeration for 4 hours, sedimentation for 0.5 hours, then idle time of 0.5 hours |
| June 30 – July 4 | 1400 | Continuous water inflow at 70 t/h; aeration for 4 hours, sedimentation for 0.5 hours, then idle time of 0.5 hours |
| July 5 – July 11 | 2000 | Continuous water inflow at 100 t/h; aeration for 4 hours, sedimentation for 1 hour, then idle time of 1 hour |
| July 12 – July 18 | 2600 | Continuous water inflow at 130 t/h; aeration for 4 hours, sedimentation for 1 hour, then idle time of 1 hour |
| July 19 – July 25 | 3120 | Continuous water inflow at 156 t/h; aeration for 4 hours, sedimentation for 1 hour, then idle time of 1 hour |

Note: The sludge for Cell 3# is taken from Cells 1# and 2#, starting from May 26. (Question: When sludge is taken from Cells 1# and 2#, how should the operating cycle of the CASS tank be adjusted? Does the water inflow need to be reduced? Will the treatment efficiency decline?)

Schedule for the cultivation and debugging of Cell 4#
Phase | Time | Water inflow (tons/day) | Water inflow | CASS tank operating cycle
--- | --- | --- | --- | ---
Cultivation | July 3 | Sludge inoculation | Anoxic aeration |
| July 4 – July 8 | 1000 | Water changed twice a day, 500 tons each time; anoxic aeration for 12 hours |
| July 9 – July 13 | 1500 | Water changed twice a day, 750 tons each time; anoxic aeration for 12 hours |
Acclimatization | July 14 – July 16 | 500 | Continuous water inflow at 25 t/h; aeration for 4 hours, sedimentation for 1 hour, then idle time of 1 hour |
| July 17 – July 19 | 1000 | Continuous water inflow at 50 t/h (same as above) |
| July 20 – July 25 | 1400 | Continuous water inflow at 70 t/h (same as above) |
| July 26 – July 30 | 2000 | Continuous water inflow at 100 t/h (same as above) |
| July 31 – August 6 | 2600 | Continuous water inflow at 130 t/h (same as above) |
| August 7 – August 14 | 3120 | Continuous water inflow at 156 t/h (same as above) |

Note: The sludge for Cell 4# is taken from Cells 1# and 2#, starting from June 20. This post was last edited by cdpulin on 2009-3-16 11:00]

III. Summary of the culture cultivation plan In order to save on costs associated with culture cultivation and to facilitate the centralized allocation of human and material resources, it is planned to carry out the entire culture cultivation process in three stages. Phase 1: First, activate the sludge in Pool A of Reactor #1 (55,000 tons per day) and Pool B of Reactor #2 (55,000 tons per day). Phase 2: After the sludge in Pool A of Reactor #1 and Pool B of Reactor #2 has been fully activated, proceed with culturing the sludge in Pool B of Reactor #1 and Pool A of Reactor #2. Phase 3: Stable operation and adjustment for phosphorus and nitrogen removal ； Finally, it enters continuous production operation. 　 　IV. Bacterial cultivation method: An intermittent and continuous water exchange combination method is employed. 　 　V. Source and quantity of the microbial inoculum
The microbial inoculum is sourced from the sludge thickener tanks in Phases I and II of the Datansha Wastewater Treatment Plant. A mobile submersible pump with a DN100 diameter is used to pump the thickened sludge into two 4,000-liter slurry transport trucks. These trucks then deliver the thickened sludge to the sides of North Tank No. 1 and South Tank No. 2. Subsequently, another two DN100 mobile submersible pumps (one for each tank) are employed to directly pump the sludge into the respective tanks. Based on calculations regarding the volume of the reaction tanks and process requirements, approximately 5,600 m³ of microbial inoculum with a moisture content of 97% is needed (this figure does not account for special circumstances such as microbial death during the commissioning phase). 　　 VI. Cultivation Period The cultivation process requires a total of 120 days, of which 45 days are needed for the first phase, 30 days for the second phase, and 45 days for the third phase. VII. Staffing 　　 The following working groups are established based on the requirements of the culture cultivation work: 　　 1. Command group: composed of company leaders ； 　　 2. Culture Training Technology Team: 3 process engineers, 2 mechanical engineers, 1 instrumentation engineer, 2 electrical engineers ； 　　 3. Operation team: 5 process technicians, 4 mechanical technicians, 3 electrical technicians, 4 mechanical repair workers, 3 electrical repair workers, and 6 process craftsmen are required ； VIII. Task Allocation 　　 1. Technical management: Formulate various technical plans for the culture process, guide the adjustment of technical parameters, modify the culture plan according to the actual progress of work, and supervise the implementation of the culture plan; this task is carried out by the culture technology team ； 　　 2. Operation and management: Carry out various corresponding operations on-site in accordance with the culture plan, including installing portable submersible pumps to transfer bacterial strains, controlling various inlet and outlet valves, and adjusting the aeration volume in the treatment tank. This work is handled by an operations team, with three shifts—day, night, and overnight—operating continuously ；

Specific procedures for sludge cultivation: 1. First stage: Cultivation of activated sludge in the north tank of Reactor #1 and the south tank of Reactor #2. Using a sludge pump, the activated sludge from the first and second production areas is transferred into sludge transport vehicles (two units), which then carry it to the south tank of Reactor #1 and the area next to the north tank of Reactor #2 respectively. Afterwards, pumps (one sludge pump per tank, totaling two pumps) are used to transfer the sludge into the tanks. 　　 The specific steps are as follows: (1) Open the main inlet valve of the high-level water intake well, as well as the main distribution valves for the east and west areas. 　　 (2) Open the inlet valves of grids 1#–4#, close the two relief valves, and adjust the four adjustable outlet weirs to their lowest position. 　 (3) Open all inlet valves for the north tank of Reactor #1 and the south tank of Reactor #2; close the bypass valves for the north tank of Reactor #1 and the south tank of Reactor #2. Close all inlet valves and bypass valves for the south tank of Reactor #1 and the north tank of Reactor #2. 　　 (4) Adjust the adjustable weir gates at the outlets of the north tank of Reaction Tank No. 1 and the south tank of Reaction Tank No. 2 to their lowest positions. 　　 (5) Open the inlet and sludge discharge valves of water distribution wells 2# and 4#, and close the inlet and sludge discharge valves of secondary sedimentation tanks 1#, 3#, 5#, and 6#. 　　 (6) Start the pumps at the off-site pump station to supply water to the plant area; at this time, activate the drum screen and grit removal system. The wastewater passes through the screen and grit chamber before entering the north tank of Reactor #1 and the south tank of Reactor #2. 　　 (7) When the wastewater covers the aeration pipes, start a blower and gradually open the air valves in each section of Tank 1’s north compartment and Tank 2’s south compartment; then begin pumping the microbial culture into the tanks, adjusting the aeration volume so that the sludge is thoroughly stirred and remains in a suspended state. 　　 (8) Check the installation dimensions of the mixers, and turn on each mixer one by one to conduct no-load tests, in order to examine their performance when operating without a load ； 　　 (9) After the mixer is submerged in water, turn on all mixers to start mixing. 　　 (10) When the sewage level rises to the height of the outlet weir, shut down the sewage pumps in the off-site pumping station to stop supplying water to the plant, continue adding bacteria, adjust the aeration volume, and enter a static anaerobic aeration phase until all the bacteria have been added. 　　 (11) After the addition of the microbial strain is complete, static aeration is carried out for 12 hours; thereafter, the sewage pump at the station outside the plant is started again to supply water to the plant area, entering the intermittent water exchange phase. The intermittent water exchange volume is half of the water volume in the reaction tank, approximately 20,000 m3, with a flow rate of 4,000 m3 per hour; the water pump is turned on (off) every 5 hours. 　　 (12) After the wastewater flows into Secondary Settler No. 2, the sludge scraper is activated to send the sludge back to the sludge return pump room through the sludge discharge valve; the sludge return pump is then started based on the liquid level of the sludge surface, in order to transport the settled sludge back to the reaction tank. 　　 (13) Check the installation dimensions, support conditions, and bearing lubrication of the mixture return pump and the sludge return pump ； 　　 (14) Check whether the valve settings of the pipelines are appropriate and whether the power supply and distribution system is in good condition ； 　　 (15) The intermittent water exchange method is continued for about 20 days; if tests on sludge settling, such as SV > 15, show satisfactory results, then the continuous water exchange phase can be initiated. The sewage pump at the off-site pumping station continuously supplies water to the plant, with a flow rate of 50,000 tons per day. The aeration rate is controlled at DO=1~2mg/l, until the activated sludge in the southern tank of Reactor 1 matures and the MLSS reaches 3500mg/l, after which the process proceeds to the next stage. 　 　2. Second stage: Cultivation of activated sludge in the south tank of Reactor #1 and the north tank of Reactor #2. Since the sludge return pump rooms for the south and north tanks of Reactors #1 and #2 are connected through sludge return channels, when culturing bacteria in the south tank of Reactor #1, it is possible to use the sludge return pump from that south tank to introduce the mature activated sludge microorganisms from the north tank into the south tank; similarly, when culturing bacteria in the north tank of Reactor #2, the sludge return pump from that north tank can be used to introduce the mature activated sludge microorganisms from the south tank into the north tank. 　　  3. Specific operation steps: 　　 (1) Open all the inlet valves for Pool South of Reactor #1 and Pool North of Reactor #2, and adjust the adjustable weir gates for the outlets of Pool South of Reactor #1 and Pool North of Reactor #2 to their lowest position. 　　 (2) An additional sewage pump is put into operation at the off-site pumping station to supply water to the plant. 　　 (3) When the aeration pipes are submerged by wastewater, start the sludge return pump to feed the activated sludge bacteria into the reaction tank where cultivation is required. 　　 (4) Start an additional blower and gradually open the air valves in each section; adjust the aeration volume until the sludge is thoroughly agitated and remains in a suspended state. 　　 (5) When the wastewater covers the mixer blades, turn on all mixers to start mixing. 　　 (6) When the sewage level rises to the height of the outlet weir, open the inlet valves and sludge discharge valves for distribution wells 1#, 3#, 5#, and 6# as well as the secondary sedimentation tanks. 　　 (7) When wastewater flows into sedimentation tanks 1#, 3#, 5#, and 6# and submerges the rotating arms of the sludge scrapers, start the sludge scrapers in tanks 1#, 3#, 5#, and 6#. 　　 (8) When the water levels in sedimentation tanks 1# and 3# rise to the height of the outlet weir, an additional sludge return pump is started, depending on the sludge level in the southern tank of reaction tank 1#, in order to accelerate the return of the microorganisms into that southern tank. When the water levels in sedimentation tanks 5# and 6# rise to the height of the outlet weir, an additional sludge return pump is started, depending on the sludge level in the northern tank of reaction tank 2#, to accelerate the return of the microorganisms to that tank. 　　 (9) By adjusting the water supply valves in the southern and northern tanks of Reactor No. 1 as well as in the three secondary sedimentation tanks, the number of sludge return pumps, and the aeration volume in each section, stable operation is maintained until the sludge in both the southern and northern tanks is fully matured. Once the settlement ratio SV exceeds 15 and MLSS is greater than 3500 mg/l, the process proceeds to the next stage. 　 　4. Phase 3: Stable operation phase The main tasks in this phase are as follows: (1) Since the microbial cultivation process was completed in the previous phase, each tank in this phase discharges the excess sludge according to the actual conditions of the process. 　　 (2) Adjust the inlet valves, distribution valves, air valves, and sludge return pumps in each tank to ensure balanced and stable operation of all tanks. 　　 (3) Open the sewage return valves for Reactor No. 1 and Reactor No. 2, and start the sewage return pump. 　　 (4) Guided by the laboratory analysis data, testing of the phosphorus and nitrogen removal efficiency was initiated to ensure that the five key parameters of the effluent met the required standards. 　 This post was last edited by cdpulin on 2009-3-16 11:07.]

Is this all gibberish? Why is the format so messy? . .