Pay more attention to the public account: environmental protection water treatment
1. Cultivation of activated sludge
It refers to the concentration and type of microorganisms (sludge) required for the treatment of wastewater by inoculating excess sludge in the aeration tank under certain environmental conditions to form the required concentration and type of wastewater treatment. In order to increase the concentration of nutrients, some concentrated feces or rice swill can be added, and the aeration system can be opened, and the aeration disease precipitation is stopped after several hours of aeration without water ingress. After several days of aeration, sedimentation and water exchange, the water can be continuously inflowed, and the active microorganisms can be seen in the activated sludge in the aeration tank under the microscope after about 7-10 days, at this time, the water intake can be increased, the sludge load can be increased, and the sludge concentration and operating load of the aeration tank can reach the design value, even if the sewage reaches the water quality index required for discharge after treatment, but in the early stage of cultivation, because the activated sludge is not formed in large quantities, the sludge concentration is low, and the activity is low, so the system operating load and aeration capacity need to be lower than the parameters of the normal operation period.
Through the recycling process, the number of microorganisms that can use the organic pollutants of wastewater can be increased, and the ones that cannot be used will gradually die and be eliminated, and finally the sludge can reach the normal concentration and load, and have a better treatment effect. Organic pollutants can generally be metabolized and absorbed by microorganisms, simple organic matter can be absorbed and utilized by bacteria, and complex macromolecules with substances or toxic genes of organic matter, must first be secreted by bacteria "inducible enzyme" decomposition and conversion into simple organic matter can be absorbed, where can secrete this inducible enzyme bacteria, is the dominant strain that can adapt to the characteristics of wastewater water quality, the generation, enrichment, rapid reproduction of this bacterium is the sludge of the precept.
2. Review of activated sludge
The effectiveness of activated sludge treatment depends on the activity of microorganisms. Therefore, attention should be paid to observing and detecting the properties of activated sludge and the composition and activity of microorganisms during operation. For example, the sedimentation performance of sludge, the biological equality of sludge.
3. Observation of activated sludge properties
Activated sludge is generally yellowish-brown in color, and fresh activated sludge has a slight mixed earth smell. When the aeration tank is not oxygenated, the sludge will be black and smelly; When the aeration tank is over-oxygenated or the load is too low, the sludge will be lighter.
4. Observation of activated sludge biophase
The observation of the biological phase of the activated sludge treatment system has been widely used to observe the operating state. To understand the status of active microorganisms, it is necessary to observe and understand the types and quantitative dominance of microorganisms in the mud-water mixture, timely grasp the biological phase changes, operation status and treatment effects, timely discover abnormal phenomena or existing problems, and provide guidance for operation management.
Activated sludge is generally composed of bacteria (colloids), fungi, protozoa, etc., among which bacteria are the main ones and there are many types. When water quality conditions and environmental conditions change, there is also a biophase expression. Activated sludge flocs are based on colloidal clusters, interspersed with some filamentous bacteria, but their number is far less than the number of bacteria. Among the microfauna, sessile ciliates are the mainstay, such as bell worms, cap ciliates, and clids, etc., and a small number of ciliates, such as paramecium, nephroids, and metazoans such as rotifers rarely appear. Generally speaking, the activated sludge of the camp domestic sewage treatment station is quite rich in microorganisms, and there are all kinds of organisms.
5. Judge the quality of sewage from the changes of microorganisms
The change of biological species, the microbial species in the sludge will change with the change of water quality and operation parameters. In the cultivation stage, with the gradual generation of activated sludge, the effluent changes from turbidity to clear, and the types of microorganisms in the sludge occur in a regular succession. During operation, the normal change of microbial species in the sludge can predict the adjustment change of operating parameters. For example, when the sludge structure is loose, a large number of swimming ciliates can often be seen, and the turbidity of the effluent is large, and the effluent quality is poor. In this case, the operating parameters and aeration volume should be adjusted appropriately. In actual operation, long-term observation should be carried out to find out the corresponding relationship between the change of wastewater water quality and the change of biological phase.
6. Judge the quality of sewage from the activity state of microorganisms
When the water quality changes, the activity of microorganisms will undergo some changes, and even the shape of microorganisms will change with the change of wastewater quality. Taking bell worms as an example, we can observe how fast or slow their cilia swing, whether they have accumulated more food in their bodies, the size and contraction of the expansion bubbles, and the reproduction. Microfauna are sensitive to changes in dissolved oxygen, and when the dissolved oxygen in the water is too high or too low, a vacuole protrudes from the "head" end of the bell insect. When there are too many incompromised substances or the temperature is too low in the inlet water, it can be seen that the indigestible particles accumulate in the bell worm and are inactive, which will eventually lead to the poisoning and death of the worm. When the pH changes abruptly, the cilia on the worm's body stop wobbling. When water quality changes, thicker cysts may be encased around the periphery of the insect body in order to survive adverse conditions.
7. Changes in the number of microorganisms
There are many types of microorganisms in the activated sludge of sewage treatment stations, but changes in the number of certain microorganisms will reflect changes in water quality. For example, filamentous bacteria are present in small quantities during normal operation, but when a large number of filamentous bacteria appear, the results are reduced bacteria, sludge swelling, and effluent quality deteriorates. The observation of microorganisms in activated sludge is generally done by light microscopy. Observe the status of sludge floc particles with low magnification, observe the state of micro-animals with high magnification, and observe the bacteria with oil microscope. The observation of biological phases in operation management has received more and more attention, so the observation of biological phases requires long-term and careful work.
8. Operation control of activated sludge
In order to maintain the best treatment effect and accumulate experience, the treatment situation should be tested frequently, and the process operation conditions should be constantly adjusted to give full play to the capacity and efficiency of the system, and reduce energy consumption as much as possible without affecting the effluent quality.
9. Water and gas
For various biological treatment facilities, in order to ensure the uniform growth of organisms and the uniformity of treatment effects, water and gas should be evenly distributed to the treatment facilities. Since it is impossible to ensure the absolute uniformity of water and gas distribution in the design, the adjusting device of the water distribution and gas distribution system should be used to adjust the water distribution and air supply volume of each part of each pool to ensure uniform water and gas distribution.
10. Abnormal problems and their solutions
When the whole treatment system is operating normally and the biological treatment effect is good, only the treatment efficiency is reduced, and it is generally not a drastic change in water quality or the entry of toxic pollutants. For this phenomenon, as long as the degree of reduction in processing efficiency can be tolerated, no measures can be taken, and after a period of time, it will return to normal, or some local adjustment measures can be taken to solve it.