Method for pretreating surplus sludge by using extracellular polymer lyase

An extracellular polymer and excess sludge technology, applied in biological sludge treatment, dewatering/drying/concentrating sludge treatment, etc., can solve problems such as increasing treatment costs, reduce treatment costs, reduce the use of enzymes, The effect of improving digestive performance and dehydration performance

Active Publication Date: 2015-09-16
TONGJI UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, since the total amount of extracellular polymers in the remaining sludge is generally between 200 and 500 mg/g-VS, that is, 20% to 50% of the sludge organic matter is distributed outs

Method used

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  • Method for pretreating surplus sludge by using extracellular polymer lyase

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] use as figure 1The process shown performs residual sludge pretreatment, including the following steps:

[0031] (1) Take 100mL of activated excess sludge (water content 90%) from the domestic sewage treatment plant, put it in a 500mL beaker, and adjust the pH of the excess sludge with catering waste fermentation liquid (containing acetic acid 8000mg / L, butyric acid 1500mg / L) It is 4.0, and then stand for 1hr. Next, 0.416 g of polygalacturonase powder with an activity of 1 U / mg was added under the action of magnetic stirring, and continuous cultivation was carried out in a constant temperature incubator at 35° C. for 5 hours.

[0032] (2) Take the sludge cultivated in step (1) and carry out centrifugal dehydration treatment, the centrifugation condition is 2000g, 10min.

[0033] By adopting the above-mentioned method, after 5 hours of enzymatic hydrolysis treatment, the capillary water absorption time (CST) of the sludge is reduced by 57%, the specific resistance (SRF)...

Embodiment 2

[0035] use as figure 1 The process shown performs residual sludge pretreatment, including the following steps:

[0036] (1) Take 100mL of residual sludge from domestic garbage sewage treatment plant (moisture content is 88%, organic matter accounts for 68% of dry basis, polysaccharide content accounts for 6.6% of dry basis, protein content accounts for 37% of dry basis), placed in In a 500mL beaker, adjust the pH to 5.0 with the remaining sludge fermentation broth (containing 3000mg / L acetic acid, 500mg / L propionic acid, and 400mg / L butyric acid), and let stand for 2h. Then, under the action of magnetic stirring, 0.416 g of polygalacturonase powder with an activity of 2.5 U / mg was added, and continuous cultivation was carried out in a constant temperature incubator at 55° C. for 4.5 hours.

[0037] (2) Take the sludge cultivated in step (1) and perform anaerobic digestion at 55° C. for 30 days.

[0038] Using the above-mentioned treatment method, before the sludge is treated...

Embodiment 3

[0040] use figure 1 The process shown, using extracellular polymeric lyase to carry out residual sludge pretreatment, includes the following steps:

[0041] (1) Acidification preconditioning of excess sludge: adjust the pH of the excess sludge to 4.0 with the fermented liquid generated after sludge hydrolysis and acidification, and then let it stand for 1 hr;

[0042] (2) Enzyme pretreatment: Add extracellular polymer lyase powder directly to the remaining sludge adjusted by pH in step (1), and the amount of extracellular polymer lyase powder added is 31.5U / kg dry sludge , mix evenly, and react for 5 hours at 20°C.

[0043] (3) Treatment of sludge after enzyme pretreatment: the sludge after step (2) enzyme pretreatment directly enters the dehydration process.

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Abstract

The invention relates to a method for pretreating surplus sludge by using extracellular polymer lyase, which comprises the following steps: (1) regulating the pH value of the surplus sludge to 4.0-5.0; (2) directly adding extracellular polymer lyase powder into the surplus sludge subjected to pH regulation, uniformly mixing and reacting; and (3) directly sending the sludge subjected to enzyme pretreatment into a dehydration procedure, or directly carrying out anaerobic digestion treatment. Compared with the prior art, the method can greatly enhance the release rate of sludge polysaccharides only by adding a small amount of extracellular polymer lyase, can form saccharide micromolecules, and is convenient for microbe utilization. Molecules coated by the saccharides and saccharide-like proteins are released, thereby enhancing the sludge utilization ratio and enhancing the integral digestion efficiency and dehydration property. The acidification conditioning solution before enzyme treatment can adopt a waste fermentation liquid, thereby further lowering the treatment cost.

Description

technical field [0001] The invention relates to a method for pretreatment of excess sludge, in particular to a method for pretreatment of excess sludge by using extracellular polymer lyase. Background technique [0002] Sewage plant surplus sludge is the main secondary pollutant produced by urban sewage treatment. At present, China's wet sludge (water content 80%) production has reached 34 million tons / year. If such a huge amount of sludge is not properly disposed of, it will cause serious secondary pollution to the environment. [0003] The goal of excess sludge treatment is to reduce the amount of sludge disposal, increase the sludge dehydration rate and reduce the amount of sludge conditioner. Dehydration performance and anaerobic digestion performance are important indicators for evaluating the treatability of residual sludge in urban sewage plants. Dehydration is the main technical bottleneck of sludge treatment, and its cost can reach 30% to 50% of the annual oper...

Claims

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Application Information

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IPC IPC(8): C02F11/02C02F11/04C02F11/12
Inventor 吕凡王静文何品晶邵立明
Owner TONGJI UNIV
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