Drying Technology
Ⅺ
Q: What indicators can be detected for the microbiological ratio? And how can it be measured?
Answer:
The microfood ratio refers to the ratio of the organic matter content to the activated sludge concentration in the biochemical system before entering the biochemical system. Through this ratio, the load can be judged and the operation can be adjusted to avoid sludge aging and overage as well as the occurrence of excessive load effluent in the biochemical system. The calculation formula is an empirical formula. For details, please refer to the previous relevant exchange content.
Ⅻ
Q: In the previous post on how to reduce the operating costs of sewage treatment plants, you said, "If sludge costs are incurred, they can be used for composting flowers and trees in the plant according to the situation. This only requires additional labor costs." I am very Agree with this statement. We have a small-scale domestic sewage treatment plant in a small town. The sludge produced is considered for composting flowers and trees. Does the sludge need to be treated before use? What kind of method is used to deal with the most reliable and economical?
Answer:
I think you can dig a ditch half a meter wide and 0.3 meters deep next to the flowers and trees, fill in the sludge and cover it with the original soil. I don’t think it needs to be treated. After all, your sewage is municipal Sewage! You don't have to worry about harmful microorganisms and pathogens in the sludge that will affect the environment and people. The microorganisms in wastewater treatment are the normal flora of nature and are not infectious. Don't the microorganisms free in the drainage pollute the water body? ! It is the sludge of industrial wastewater, which is controlled by law. Considering that the new crown virus will spread through the feces, it is recommended to use the sludge drying technology to compost. For the municipal sludge drying solution, please click on the consultation.
XⅢ
Q: After the general sludge expands, how long will it take to slow down? After my sludge swelled (for about two or three weeks), the quality of the effluent was still good, but the removal rate of ammonia nitrogen was not high, and there were not many filamentous bacteria under the microscope, so the preliminary judgment was that the pH of the influent was too low. So I added lime for a week or two. The nitrification rate increased, but the sedimentation performance of the sludge was still not good. Finally, the sludge ran away. May I ask what happened?
Answer:
1. As you said, filamentous bacteria expansion is periodic, and the length of time is related to water quality and treatment conditions.
2. Sludge running is the consequence of filamentous bacteria swelling. Find out the reason to relieve the swelling.
XIV
Q: Which flocculant should be used in the primary sedimentation tank, the secondary sedimentation tank, and the sewage desludge room (of course, the flocculant in the sludge desludge room is not very urgent). What is the general concentration and input amount? Now the flocculation effect of the primary and secondary sedimentation tanks is not very good (I used polyaluminum PAC).
Answer:
It is recommended to use aluminum iron sulfate flocculant instead of polyaluminum PAC, which may have better effects. The concentration and input amount can be determined in a small test according to the specific conditions of the sewage. I think it seems unreasonable to add flocculant to the secondary sedimentation tank. Even if the sludge deteriorates, it should be decided carefully!
XV
Q: What is the reason for the excessive increase of sludge concentration in the oxidation ditch and how to solve it?
Answer:
The increase in substrate concentration is the main reason for the growth of sludge. Of course, the factor of rising temperature should also be considered!
XVI
Q: Our factory is a primary treatment, and it is intermittently influent. The quality of the influent water is a bit over the standard, and the treatment effect is not up to the standard. I want to ask you, what are the factors that affect the effect of the primary treatment?
Answer:
1. Regarding the primary treatment, there are many influencing factors, including: original design, operation technology, drug selection, operation method, etc.
2. The main aspects that can be changed are the choice and dosing method of drugs.
3. I think you can choose flocculant carefully to get the ideal treatment effect.
XVII
Q: The sludge density of the hydrolysis acidification tank is 1.002-1.006 (learned from books), so the sludge loss is inevitable, and the sludge must be set up to return to the hydrolysis tank after aerobic digestion. However, there is a manual introduction, part of the sludge in contact with the oxidation tank is suspended, and the other part is used for the filler. Then you pointed out that when it is debugged, the sludge is first exposed, and then the remaining activated sludge is discharged (to prevent free microorganisms from competing with the microorganisms on the filler for organic nutrients ), contradicts it? If the mixed liquor after aerobic digestion is returned to the hydrolytic acidification tank, what range of hydrolytic acidification DO should be controlled? Please advise.
Answer:
1. Slight loss, I don't think there is any need for returning. The microorganisms reproduce themselves through the hydrolysis tank, and it should be able to meet the loss of replenishment.
2. At the same time, in this process, the focus of treatment and the final checkpoint are no longer the hydrolysis tank. Therefore, the appropriate fluctuation of the concentration of the hydrolysis tank will not have much impact on the subsequent processes.
3. Regarding the problem of suffocation, I think this approach is not inconsistent with the sludge discharge, because this is only in the culture stage, not the normal production operation.
XVIII
Q: There is a type of industrial waste which is produced in the process of producing refined cotton. The content of organic matter is relatively high, and the waste water becomes alkaline. I want to add acid here to adjust the pH value of the wastewater and at the same time to acidify and hydrolyze the organic matter in the wastewater. Is this possible? The water quality is somewhat similar to that of papermaking wastewater, but its water quality index is much smaller than that of papermaking wastewater.
Answer:
Artificial acidification, I think that can not effectively degrade organic matter, through hydrolysis acidifying bacteria can degrade organic matter. I don't think it is necessary to add acid to adjust it!
XIX
Q: I have just finished a project of 7000 tons food waste water. I would like to ask some questions about microbial cultivation: I want to use direct inoculation for cultivation. Can I use the sludge cake after dehydration of the municipal sewage treatment plant? This sludge is added with PAM in the process of dewatering, will it affect the microorganisms? Has the microbial culture time been increased?
Answer:
I think there is no problem, the cultivation time will not be increased, and it will remain active.
XX
Q: How to design the bar screen of sewage station with small water volume? The bar screen width calculated according to the design formula in the textbook or design manual is too small for layout.
Answer:
For projects with small water volume, if the calculated grid width is too small, you could keep the grid gap constant, and directly enlarge the width to the width of the channel, without being too constrained by the manual.
