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Huanchuang (Xiamen) Technology Co.,Ltd
Phone: ：+86 592 5029670
Fax: +86 592 5029673
Email:info@hcwater.com
Add; 22 Guanri Road, Software Park 2, Xiamen, China
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| Easily solve the the sludge bulking pipes broken machine |
| Edited：HuanChuang technology Date：2012-11-12 17:15:18 |
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Pipe crusher has a large degree of a lot of water industrial solid waste treatment and environmental applications, the use of machinery is the best way in order to save human resources and improve efficiency. When more carbohydrates in the wastewater, N, P content is unbalanced, low pH value, oxidation ditch sludge load is too high, the lack of dissolved oxygen concentration, the mud poor could lead to sludge bulking filamentous bacteria; non-filamentous bacterium sludge expansion occurs when the the wastewater water temperature is relatively low sludge load. High load of microorganisms, bacteria absorb a large number of nutrients, so that the surface of the activated sludge attached water greatly increased, due to the low temperature, slower metabolism, since a large number of highly viscous product storage polysaccharides, SVI value is high, the formation of sludge bulking.
For the cause of sludge bulking, can be taken to tackle: high water temperature caused by hypoxia, can increase the amount of aeration or reduce the amount of water in order to reduce the load, or appropriate to reduce the MLSS (control sludge return flow), pipe crusher oxygen demand reduction; sludge load is too high, can increase the MLSS, in order to adjust the load, if necessary, to stop the water, stuffy exposed for some time; by adding nitrogen, phosphorus, adjust the balance of nutrients in the mixture ( of BOD5: N: P = 100:5:1); pH value is too low, lime dosing adjustment; bleaching powder and liquid chlorine (0.3% -0.6% of the dry sludge dosing), can inhibit the proliferation of filamentous bacteria control combined with a water-based sludge bulking.
Flocculation method
Expansion of the density of the activated sludge is generally smaller than water, as emergency measures, consider adding coagulant to improve its settlement performance. Initially, we select commonly used polymer coagulants - cationic polyacrylamide and inorganic coagulant - ferrous sulfate comparison test.
The polyacrylamide dosage and sludge settling performance relationship
50L / h water in the processing of a small test apparatus dosing cationic polyacrylamide, and that its concentration reached 10, 20, 30, 40, 50, and 60 mg / L, the sludge SV value variation.
Dosing for improvement of sludge settling properties polyacrylamide certain, and there is an optimum dosage, but the effect is not very satisfactory. The water reuse system uses a new type of the Submerged composite membrane bioreactor, aeration large hydraulic stirring strong floc particles gathered easily damaged, resulting in coagulation effect is not ideal; When the dosage is higher than The optimum dosage, floc in addition to the negative charge and colloidal excessive positive charge of the colloidal ion to impart a positive charge to re-stabilize.
Dosage of ferrous sulfate sludge settling performance relationship
Dosing in the water pipeline crusher processing 50L / h pilot plant of ferrous sulfate solution, so the variation of the mass concentration of between 10 to 180mg / L, the sludge SV value changes; the Zoogloea state of before and after dosing.
Dosing solution of ferrous sulfate sludge settling performance has been significantly improved, the SV value dropped by about 15 per cent. But there is no further improvement of more than 60mg / L after sludge settling properties, so make sure the actual operation of the ferrous sulfate dosage was 60 mg / L. Emergency coagulant dosing period, in accordance with the prices of the commercially available ferrous sulfate, the processing cost increase of about 0.05 yuan per ton of sewage pipe crusher.
Ferrous sulfate (60mg / L) before and after dosing, measuring mixture PH value decreased from 7.63 to 7.07, a small negative impact on the sludge activity.
Dosage effect of cationic polyacrylamide by hydraulic conditions and other factors limit is not very satisfactory, pipe crusher while its monomer toxic, biodegradable, there is the problem of secondary pollution, and economic benefits than the ferrous sulfate dosage.
Ferrous sulfate is inexpensive, simple to use, there is no negative impact on the film and sludge, sludge density is effective, but it can not fundamentally solve the problem of nutritional imbalance, so only as an emergency control measures.
Adjustment Act of nutrients
Pipeline crusher recovery and control of sludge bulking sludge bulking problem is a very important link. Dosing ferrous sulfate, activated sludge settling property once improvements in the original organic loading conditions, such as stop dosing proceed with treatment, activated sludge settling properties in the running of the water reuse project will gradually deteriorate, and three days later to return to the state it was in prior to dosing. So it is necessary to find an effective recovery after activated sludge bulking control methods.
Other control methods
In the the sludge to viscous for expansion most serious case (container sludge pipe crusher, no matter what method of sludge is always adhered to the surface of the container) may be considered appropriate to drain some of the expansion of the sludge, and then re-taken some new mud, in order to reduce the coverage of the polysaccharide substance of the sludge; while increasing the hydraulic retention time, so that was not completely oxidized organic have enough time to be consumed.
Due to the high content of raw water detergent, combined with large aeration intensity, often white, sticky foam, and piled more sludge swell, great harm. The night of 29 December 2002, due to the bubble accumulation of up to one meter high foam Mountain, resulting sludge huge loss. Later after the accident, in addition to adding defoamer, take hydraulic defoaming. Install sprinklers in the top of the reaction cell, the MBR reactor effluent reaction Ikegami Ministry to control the expansion of the hazards of sludge and foam reactor spray pipe crusher, and has achieved good results.
The first category: emergency measures
Apply to temporary emergency, the main method of drug dosing to enhance sludge settling properties or directly kill filamentous bacteria. Cast aluminum salts such as ferric salt coagulants can directly increase the the sludge pressure tightness guarantee precipitated water. In addition, adding some chemicals, such as chlorine, is applied to the return sludge can also achieve the elimination of sludge bulking phenomenon. Adding hydrogen peroxide and ozone can also play the effects of the destruction of the filamentous fungus.
With this method generally lower SVI value faster pipe crusher but these methods do not fundamentally control the breeding of filamentous bacteria, sludge bulking phenomenon will come back once to stop dosing. And dosing may destroy the biochemical system microbial growth environment, leading to the treatment effects reduced Therefore, this approach can only be used as a temporary emergency use.
The second category: improved biochemical environment
Wastewater treatment plant sludge bulking generally can not change from the process, pool type, and aeration to solve, can only be in the running processes on the basis of microbial growth environment by changing the biochemical tanks to suppress or eliminate the filamentous bacteria the over-breeding. In the case of different processes and water quality, it is difficult to have a one size fits all solution. But often met several of the biochemical process should pay attention to the problem must be addressed.
Sewage nature of control
Should first check and adjust the pH, when the pH is below 5, the benefit not only of the sludge bulking and will harm the normal biochemical reactions, so when the low pH value should be timely adjustment. Also in the cold northern regions should certainly pay attention to the winter when the water temperature, water temperature low heating, low temperature can lead to sludge bulking. Using diffused aeration Higher water temperatures in the winter.
Dosing should be added when the lack or imbalance of nutrients in the sewage. N, P content should be controlled in the BOD: N: P = 100:5:1.
Sewage treatment before the biochemical system of digestion occurrence of the phenomenon, the resulting low-molecular organic acid there will be conducive to the growth of filamentous bacteria, then adjusting the pool pre-aeration of wastewater to be improved. Generally use the air diffuser the regulation pond aeration effective depth to 3-5 meters, gas volume can be controlled in the 0.5-1.0m3 / wastewater meters? Hour. Which enables regulation pool wastewater remain fresh and effectively prevent the odor due to the anaerobic.
Sufficient dissolved oxygen in holding tanks for high load biochemical system is particularly important, 3) Average DO> 2 mg / L, should be controlled at least.
Sludge sedimentation tanks should be promptly discharged or reflux.
Prevent its occurrence anaerobic phenomenon. Anaerobic phenomenon occurs, various gases adsorbed in the sludge, but also make the floating sludge poor settling characteristics. And anaerobic sludge return will trigger blooms of filamentous bacteria. This case, in addition to mud and dead ends clear the sedimentation tanks and shorten the sludge residence time in the pool outside. DO values should also improve the aeration tank. Access to the the sedimentation tank's water to maintain than the dissolved oxygen. Or before the sludge backflow into the biochemical pool aeration regeneration. |
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