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Deep dehydration method for excess sludge of urban sewage plant

A technology for deep dewatering and excess sludge, applied in the direction of dewatering/drying/concentrating sludge treatment, can solve the problem of high labor cost or energy consumption, save investment and manpower, and achieve the effect of high-efficiency deep dewatering

Inactive Publication Date: 2015-11-11
FUDAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Secondly, although natural drying, freezing-dissolving and thermal drying technologies can reduce the moisture content of remaining sludge to less than 60%, or even reach 30%, they are greatly affected by external factors such as weather, and labor costs or energy consumption also higher

Method used

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  • Deep dehydration method for excess sludge of urban sewage plant
  • Deep dehydration method for excess sludge of urban sewage plant

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] Take 30mL, 50mL, 70mL formaldehyde, ethanol, acetone and n-butanol respectively, mix with 70mL, 50mL, 30mL pure water to prepare formaldehyde, ethanol, acetone and n-butanol solutions with concentrations of 30%, 50%, 70%, and Take 100mL of each solution with a concentration of 100% for use, and put 100mL of the above solution into a 250mL Erlenmeyer flask.

[0021] Take 30±5g of the concentrated sludge from the secondary sedimentation tank and the sludge after mechanical dehydration into organic solutions of different concentrations, place them in a shaker at room temperature (25±3°C), and mix for 30 minutes at 120±5rpm;

[0022] Use qualitative filter paper to filter the mixed sludge mixture. After the filtration, the sludge sample is flattened and dried at room temperature (25±3°C) until the moisture content no longer changes, and the deep dehydration process is completed.

[0023] The results showed that the higher the concentration of dehydrating agent, the lower th...

Embodiment 2

[0025] Take 30mL, 50mL, 70mL formaldehyde, ethanol, acetone and n-butanol respectively, mix with 70mL, 50mL, 30mL pure water to prepare formaldehyde, ethanol, acetone and n-butanol solutions with concentrations of 30%, 50%, 70%, and Take 100mL of each solution with a concentration of 100% for use, and put 100mL of the above solution into a 250mL Erlenmeyer flask.

[0026] Take 30±5g of the concentrated sludge from the secondary sedimentation tank and the sludge after mechanical dehydration into organic solutions of different concentrations, place them in a shaker at room temperature (25±3°C), and mix for 30 minutes at 120±5rpm;

[0027] Put the 0.45μm filter membrane into the vacuum filtration device, then pour the sludge mixture into the device, and carry out vacuum filtration at room temperature (25±3°C) under a pressure of 100-400mmHg until the moisture content does not change That is to complete the deep dehydration process.

[0028] The results showed that the higher the...

Embodiment 3

[0030] Take 30mL, 50mL, 70mL formaldehyde, ethanol, acetone and n-butanol respectively, mix with 70mL, 50mL, 30mL pure water to prepare formaldehyde, ethanol, acetone and n-butanol solutions with concentrations of 30%, 50%, 70%, and Take 100mL of each solution with a concentration of 100% for use, and put 100mL of the above solution into a 250mL Erlenmeyer flask.

[0031] Take 30±5g of the concentrated sludge from the secondary sedimentation tank and the sludge after mechanical dehydration into organic solutions of different concentrations, place them in a shaker at room temperature (25±3°C), and mix for 30 minutes at 120±5rpm;

[0032] Use qualitative filter paper to filter the mixed sludge mixture. After the filtration is completed, the sludge samples are flattened and placed in constant temperature drying boxes at 65, 80, and 120°C, until the moisture content does not change, and the deep dehydration is completed. process.

[0033] The results showed that the higher the co...

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Abstract

The invention belongs to the technical field of environmental protection, and particularly relates to a deep dehydration method for excess sludge of an urban sewage plant. Concentrated sludge (water content ranging from 90% to 99%) at the bottom of a secondary sedimentation tank of the urban sewage plant and preliminarily-dehydrated sludge (water content ranging from 75% to 85%) obtained after mechanical dehydration are regarded as objects, formaldehyde or ethanol or acetone or normal butanol with the concentration ranging from 30% to 100% is adopted as a dehydration agent, and pretreatment is performed; then, deep dehydration is performed through natural drying or vacuum filtration or cyclic heating under an indoor temperature till the water content is not changed. Results indicate that the higher the concentration of the dehydration agent is, the lower the water content of a treated sludge sample will be; as for the dehydration effect of the dehydration agent, formaldehyde>acetone>ethanol>normal butanol; after dehydration, the minimum water content of the concentrated sludge is 12.2+ / -2.6% (100% formaldehyde + vacuum filtration), and the minimum water content of the preliminarily-dehydrated sludge is 16.8+ / -2.1% (100% formaldehyde + cyclic heating).

Description

technical field [0001] The invention belongs to the technical field of environmental protection, and in particular relates to a method for dehydrating excess sludge in urban sewage plants. Background technique [0002] At present, the process of my country's urban sewage treatment facilities is still dominated by biological methods, and a large amount of excess sludge will be generated in the process of wastewater treatment. Sludge not only contains a large amount of water, but also contains toxic and harmful substances such as organic pollutants, pathogenic bacteria, and heavy metals. If it is not properly disposed of, it will cause serious secondary environmental pollution problems. Therefore, attention to the disposal of sludge has become urgent. [0003] Due to the high moisture content and large volume of the excess sludge, before the sludge is disposed of, it must be dehydrated to reduce the volume of the sludge as much as possible, thereby reducing the subsequent tra...

Claims

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Application Information

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IPC IPC(8): C02F11/14
Inventor 温磊陈思万春黎王利刘翔
Owner FUDAN UNIV
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