Reflow sludge lysis technology reduces excess sludge

The lysis technology uses physical, chemical, biological and ultrasonic technology to crush or dissolve the remaining sludge, improve the degradability of the remaining sludge, and then return the broken remaining sludge to the aeration tank to pass the activity The metabolism of sludge is decomposed to achieve the purpose of reducing the output of surplus sludge.
The process diagram is shown in Figure 9-12
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According to the metabolic characteristics of microorganisms in the sewage biological treatment process, part of the organic matter in the sewage is decomposed by microorganisms to provide energy for its life activities, and finally metabolized into carbon dioxide and water; the other part is used for proliferation and transforming organic matter into new organisms

Figure 9-12 Physical, chemical or biological treatment of excess sludge

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Physical lysis methods mainly include heating, mechanical crushing, ultrasonic cracking, etc.
, which have high energy consumption and require special equipment.
In addition, after the sludge bacteria are cracked, the refractory biological substances such as cell wall fragments entering the sewage will cause effluent.
COD, SS increased, while the amount of sludge due to the reduction system, if the unit of mud nitrogen and phosphorus content remains unchanged, the water will increase the nitrogen and phosphorous
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The Cambi process developed by Purac converts the organic components in the sludge from an insoluble state to a dissolved state through a high-temperature hydrolysis process, making it biodegradable, thereby reducing the sludge output

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2 Chemical lysis technology

Chemical lysis methods include lysis ozone, peracetic acid lysis, lysis chlorine, thermo-chemical method in which ozone most studied
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Ozone can destroy cell walls and cell membranes to release proteins, polysaccharides, fats, nucleic acids, etc.

Thermochemical method refers to adding a strong acid or alkali into the sludge treatment system at a certain temperature.
The strong acid or alkali can solubilize the cell wall, so that the substances in the cell are released, and then the sludge is reused in the water treatment system.
, So that it can be easily used by other activated sludge
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Different studies have shown that the release of CODcr is divided into two steps, the first step is relatively rapid, and the second step is relatively slow

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3 Biological lysis technology

The biological lysis method is to lyse the bacteria by adding bacteria or enzyme preparations that can secrete extracellular enzymes and antibiotics
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Enzymes can dissolve cells on the one hand, and can also decompose macromolecular organic matter that is not easily biodegradable into small molecular substances, which is beneficial to the use of secondary substrates by bacteria

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4 Ultrasound

Ultrasound refers to the sound wave with a frequency ranging from 20kHz to 10MHz, which has the characteristics of high frequency, constant directionality, strong penetrating power, and concentrated energy
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Ultrasonic technology is an emerging environment-friendly technology in the past two decades, with the advantages of simple equipment, stable operation, and no secondary pollution

Related Links: Conventional Sludge Treatment and Disposal Methods