The compound strain mainly degrades pollutants such as COD/BOD/ ammonia nitrogen/total nitrogen/total phosphorus. The compound strain is facultative, and its main components are nitrifying bacteria, denitrifying bacteria, Bacillus, Pseudomonas, activating enzyme, polysaccharide and so on. At the same time, it also has a very good effect when it is applied to the startup of new and old systems.
2. Glycine nitrifying bacteria: mainly degrade ammonia nitrogen.
The bacteria used to remove ammonia nitrogen are nitrifying bacteria, which belong to aerobic bacteria and are mainly used in aerobic tanks. Their components are mainly nitrite bacteria and nitrate bacteria.
3. Glycine denitrifying bacteria: mainly degrade total nitrogen.
The bacteria used to remove total nitrogen are denitrifying bacteria, which belong to anaerobic bacteria and are mainly used in anaerobic tanks or anoxic tanks. Their main components are Pseudomonas, Bacillus and so on.
Nitrification stage
Nitrification stage: Nitrogen-containing organic matter (organic nitrogen) is ammoniated into ammonia nitrogen in aerobic and anaerobic environment. After some sewage enters the aerobic treatment structure, it is transformed into nitrate nitrogen by nitrite bacteria and nitrifying bacteria, which provides preparation for subsequent denitrification.
Control conditions:
1, dissolved oxygen: the dissolved oxygen is controlled between 2 and 3 mg/L. When the dissolved oxygen is lower than 0.6 mg/L, the nitrification process will be greatly inhibited.
2. Water temperature: The suitable water temperature for nitrifying bacteria is between 25℃ and 35℃. Usually, when the temperature is lower than 5℃, the activity of bacteria will be inhibited, and nitrifying bacteria are difficult to play a role.
3.PH value: Nitrifying bacteria are selected at PH 7.5~8.5.
4. Substrate concentration: Nitrifying bacteria are autotrophic aerobic bacteria, and substrate concentration is not a necessary factor for nitrifying bacteria.
5. Sludge age: It is necessary to ensure that the microorganisms in the aerobic system have enough nitrifying bacteria and provide the concentration of nitrifying bacteria. Usually, the sludge age is controlled around 10d.
Denitrification stage
Denitrification stage: Nitrate nitrogen, the product of nitrification stage, undergoes denitrification reaction, so that nitrate nitrogen is converted into nitrogen and discharged from water.
PH value: The suitable PH value for denitrification is 6.5~7.5. Improper control of PH value will affect the growth rate of denitrifying bacteria and the activity of denitrifying enzyme.
Water temperature: Denitrifying bacteria and nitrifying bacteria have basically the same requirements for water temperature. Denitrifying bacteria are more tolerant to high water temperature than nitrifying bacteria, generally at 20~40℃.
Substrate concentration: Substrate concentration is very important for denitrification, BOD5/RKN >; 4.0, otherwise the substrate needs to be supplemented (adding carbon source).
Dissolved oxygen: Denitrification requires strict control of dissolved oxygen, which is generally controlled at DO >: 0.5 mg/L. Denitrifying bacteria belong to facultative bacteria and can survive under aerobic and silent conditions. What we need to use is the anaerobic metabolism of denitrifying bacteria.
Cultivation method:
1, the so-called activated sludge culture is to provide certain growth and reproduction conditions for activated sludge microorganisms, namely nutrients, dissolved oxygen, suitable temperature and pH value.
(1) nutrients: that is, the ratio of carbon, nitrogen and phosphorus in water should be kept at 100: 5: 1.
(2) Dissolved oxygen: As far as aerobic microorganisms are concerned, if the dissolved oxygen in the environment is above 0.3mg/l, normal metabolic activity is enough. However, because sludge exists in the aeration tank in the form of floc, the diameter is 500? M For activated sludge floc, when the surrounding dissolved oxygen concentration is 2mg/l, the floc is lower than 0. 1mg/l, and the growth of aerobic bacteria is slow, so the dissolved oxygen concentration in the aeration tank is often higher than 3-5 mg/L, and it is often controlled at 5 5- 10 mg/L 0 mg/L. Generally speaking, it is appropriate to control the dissolved oxygen at the outlet of the aeration tank at 2 mg/L.
(3) Temperature: Any kind of bacteria has a suitable growth temperature. With the increase of temperature, the growth of bacteria is accelerated, but there is a low and high growth temperature range, which is generally 10-45? C, the suitable temperature is 15-35? C, the temperature change in this range has little effect on the operation.
(4) PH value: generally, the PH value is 6-9. Under special circumstances, the water inlet height can be pH 9- 10.5. If it exceeds the above specified value, it is necessary to add acid and alkali for adjustment.
Cultivation method:
(1) Domestic sewage culture method: In warm season, the domestic sewage is first filled into the aeration tank, and after several tens of hours of stuffy aeration (i.e. no sewage aeration), water can be discharged. The amount of introduced water is gradually adjusted from small to large, and activated sludge can be seen after several days of continuous operation, and it is gradually increasing. In order to speed up the culture process, some concentrated fecal water or rice swill is added at the initial stage of culture to increase the concentration of nutrients. It is important to note that during the cultivation period (especially in the early stage), sludge has not been formed in large quantities, and the sludge concentration is low, so it is much lower than normal to control the aeration rate.
(2) Inoculation and culture method of dry sludge: Inoculation and culture are carried out with dehydrated dry sludge in the sewage system with the same water quality that has been running normally as the strain source. Generally, according to the total dissolved sludge in the aeration tank of 65438 0%, appropriate amount of water is added for mashing, and then appropriate amount of industrial wastewater and concentrated fecal water are added. By cultivating bacteria in the above way, sludge can be quickly formed and increased to the required concentration.
(3) Multi-stage expansion culture method: According to the characteristics of rapid growth and reproduction of microorganisms, the multi-stage expansion culture process of strains → seed tanks → fermentation tanks in fermentation industry is modeled, and bacteria are expanded in stages. If a project is designed as a three-stage aeration tank, bacteria can be cultured in one tank first, then inoculated in a small amount in the aeration tank, and then directly expanded to the second and third stages after success.
(4) Direct cultivation of industrial wastewater: Some industrial wastewater, such as canned food, bean products and meat processing wastewater, can be directly cultivated; Another kind of industrial wastewater has complete nutrients, but its concentration is not enough, so it needs to be supplemented with nutrients to speed up the cultivation process. Frequently added nutrients: starch slurry, canteen rice swill, noodle soup (carbon source); Or urea, ammonium sulfate, ammonia water (nitrogen source), etc. , the specific situation should be determined according to different water quality.
(5) Bacterial culture of toxic or refractory industrial wastewater: toxic or refractory industrial wastewater can only be cultivated with domestic sewage first, and then gradually introduced into industrial wastewater for domestication.