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Kunshan Pinhong EPT Co.,Ltd
Kunshan Pinhong EPT Co.,Ltd
Add : (Qiandeng Yuanchuang Base) No. 125, Jinxing South Road, Qiandeng Town, Kunshan, Jiangsu, China
Tel : （0086）15995617314
Fax : +86-512-50130524
E-mail :lvfang@ksphxs.com
23. What is this dot chlorination?
When the organic matter in the water is mainly ammonia and nitrogen compounds, after the actual chlorine demand is met, the amount of chlorine added increases and the amount of residual chlorine increases, but the latter increases slowly. After a period of time, the amount of chlorine added increases and the amount of residual chlorine decreases instead. As the amount of chlorine added increases, the amount of residual chlorine rises again. After this break point, free residual chlorine appears, and the best disinfection effect is to continue adding chlorine, that is, add chlorine at the break point.
24. How many systems are there in the activated sludge process?
The activated sludge process is composed of an aeration tank, a sedimentation tank, a sludge return system, and an excess sludge removal system.
25. What is the sludge sedimentation ratio?
Sludge settlement ratio (SV%): Refers to the volume ratio (%) of the mixed liquid in the aeration tank, which is left to settle in a 1000ml measuring cylinder for 30 minutes, and the settled sludge to the mixed liquid.
26. What is the sludge index?
Sludge index (SVI): refers to the volume occupied by each gram of dry sludge after the mixed solution at the outlet of the aeration tank has been allowed to settle for 30 minutes, and l is measured in JmL.
If the SVI value is too low, it means that the mud particles are small and dense, with many inorganic substances, and lacks activity and adsorption capacity; if the SVI value is too high, it means that the sludge is difficult to settle and separate, and it is about to expand or has already expanded. The reason must be found out and measures should be taken.
27. What are sludge bulking, disintegration, decay, floating and foaming?
Sludge bulking: When the sludge deteriorates, the sludge is not easy to settle, the SVl value increases, the structure of the sludge is loose, the volume expands, the water content increases, the clarified liquid is less, and the color also changes.
Sludge disintegration: The water quality of the treated water is turbid, the sludge is turbulent and fine-grained, and the treatment effect is deteriorated, which is the phenomenon of sludge disintegration.
Sludge decay: In the secondary sedimentation tank, anaerobic fermentation may occur due to long-term retention of sludge, and gas will be generated, resulting in the phenomenon of large sludge floating.
Sludge floating: The phenomenon that sludge floats in lumps in the secondary sedimentation tank.
Foam Problem: Foam in the aeration tank is mainly caused by the presence of large amounts of synthetic detergent or other foaming substances in the sewage.
28. What is the activated sludge growth curve?
Activated sludge microorganisms are a multi-species mixed population, and their growth laws are relatively complex, but their growth curves can also be used to express certain laws. This curve expresses the proliferation and decay of the number of microorganisms over time when the environmental conditions such as temperature and dissolved oxygen meet the growth requirements of microorganisms, and a certain amount of initial microorganisms are inoculated.
The change in the growth rate of activated sludge is mainly caused by the ratio of nutrients or organic matter to microorganisms (usually expressed in F/M), and the F/M value is also the degradation rate of organic substrates, oxygen utilization rate, coagulation and adsorption performance of activated sludge important influencing factors.
There are four stages of activated sludge growth curve: adaptation period, logarithmic growth period, deceleration growth period (maximum biomass), and endogenous respiration period (best water quality treatment effect).
29. The purification of activated sludge is divided into several processes?
Activated sludge purification of wastewater is accomplished through three stages: In the first stage, wastewater is purified mainly through the adsorption of activated sludge. The adsorption is carried out very quickly, generally completed within 30 minutes, and the removal rate of BOD5 can be as high as 70%. At the same time, it also has the effect of partial oxidation, but the adsorption is the main effect.
The second stage is also called the oxidation stage. It is mainly to continue to decompose the organic matter adsorbed and absorbed in the pre-oxidation stage, and at the same time continue to adsorb some residual dissolved substances.
The third stage is the mud-water separation stage. In this stage, the activated sludge is separated by sedimentation in the secondary settling tank. Microbial anabolism and catabolism can both remove organic pollutants in sewage, but the products are different.
30. What are the characteristics of the secondary sedimentation tank?
The characteristics of the secondary sedimentation tank: In terms of function, it not only separates mud and water, but also concentrates sludge, and temporarily stores sludge due to changes in water quality and water quantity.