Sewage treatment method based on supernatant reflux of flocculation settling tank

A sewage treatment method and sedimentation tank technology, which are applied in the direction of flocculation/sedimentation water/sewage treatment, etc., can solve the problems of ineffective use of chemicals, large fluctuations in water quality and water quantity, and waste of dosage of chemicals, and are conducive to stability. The effect of meeting the standards, reducing comprehensive operating costs and reducing adverse impacts

Active Publication Date: 2014-12-10
NANJING UNIV
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  • Abstract
  • Description
  • Claims
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Problems solved by technology

[0008] In view of the large fluctuations in water quality and quantity in the traditional coagulation and sedimentation process of sewage treatment in the prior art, resulting in excessive waste of chemical dosage, resulting in excessive concentration of residual chemical in the effluent, and inability to effectively use the chemical, the present invention provides A sewage treatment method based on reflux of supernatant in flocculation sedimentation tank

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  • Sewage treatment method based on supernatant reflux of flocculation settling tank
  • Sewage treatment method based on supernatant reflux of flocculation settling tank
  • Sewage treatment method based on supernatant reflux of flocculation settling tank

Examples

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Embodiment 1

[0033] Taking the treatment of phosphorus-containing sewage in an industry as an example, the sewage treatment capacity is 300m 3 / d, the total phosphorus concentration is 10.2mg / L-50.5mg / L.

[0034] Such as figure 1 As shown, the traditional coagulation-sedimentation reaction to the wastewater treatment process is: add 10% Ca(OH) in the mixing tank2 (calcium hydroxide) mixed reaction, in order to ensure that phosphorus can be completely removed, Ca(OH) 2 The dosage is 2.68m 3 / d; the fully mixed effluent enters the flocculation sedimentation tank, and polyacrylamide (PAM) with a mass percentage of 1‰ is added to the flocculation sedimentation tank for flocculation and precipitation reaction. The dosage of polyacrylamide (PAM) is 0.75m 3 / d. After standing still for 90min to precipitate, the supernatant was discharged after adjusting the pH.

[0035] Such as figure 2 As shown, a kind of sewage treatment method based on the reflux of the supernatant of the flocculation se...

Embodiment 2

[0046] Taking the waste water of a printing and dyeing enterprise as an example, its sewage treatment capacity is 100m 3 / d, the COD (chemical oxygen demand) concentration is 3000-5000mg / L, the SS is 500-1000mg / L, and the chromaticity is 6000-10000 times.

[0047] Such as figure 1 As shown, the traditional coagulation-sedimentation method is used for pretreatment, and the specific treatment process is the same as in Example 1, except that the dosage of flocculant polyaluminum chloride (PAC) is 0.4m 3 / d, its mass percentage is 5%, and the dosage of coagulant aid PAM is 0.4m 3 / d, the mass percentage is 0.5‰, after standing for 120 minutes, the supernatant enters the next processing unit for processing.

[0048] Such as figure 2 As shown, a kind of sewage treatment method based on the reflux of the supernatant of the flocculation sedimentation tank of the present embodiment can treat the sewage of the same type and the same treatment capacity. With the waste water of a cert...

Embodiment 3

[0059] Taking a certain slaughtering wastewater as an example, its sewage treatment capacity is 500m 3 / d, COD concentration is 700-1000mg / L, SS is 400-700mg / L.

[0060] Such as figure 1 As shown, the traditional coagulation sedimentation method is used for pretreatment, and the specific treatment process is the same as in Example 2, the difference is that the dosage of flocculant polyferric sulfate (PFS) is 0.75m 3 / d, its mass percentage is 20%; polyvinylpyrene salt is used as coagulant aid, and the dosage is 0.75m 3 / d, the mass ratio is 2‰, after standing for 90 minutes, the supernatant enters the next processing unit for processing.

[0061] Such as figure 2 As shown, a sewage treatment method based on the reflux of the supernatant of the flocculation sedimentation tank in this embodiment is used to treat the same type of sewage with the same treatment capacity, that is, a certain slaughtering wastewater. The steps are:

[0062] (1) Flow the sewage to be treated int...

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Abstract

The invention discloses a sewage treatment method based on supernatant reflux of a flocculation settling tank, and belongs to the technical field of wastewater treatment. The sewage treatment method based on the supernatant reflux of the flocculation settling tank disclosed by the invention comprises the following steps that firstly, a flocculant is added in a mixing tank to carry out a mixed reaction, water flows into the flocculation settling tank after the mixed reaction, a coagulant aid is added to carry out a flocculation reaction, then supernatants subjected to a flocculation precipitation reaction flow back to the mixing tank and the flocculation settling tank respectively, concentrations of residual agents in the supernatants are fully utilized to carry out a reaction, and the supernatants are discharged externally or enter into the next treatment unit for carrying out a treatment after sewage treatment reaches standards. The sewage treatment method disclosed by the invention lowers a load impact resulted from water quality and quantity fluctuations, and avoids excessive pollutant concentrations caused by insufficient agent dosage, and further reduces agent adding amount in a sewage treatment process and excessive agent concentrations of effluent water to effectively lower the operating cost of the sewage treatment.

Description

technical field [0001] The invention belongs to the technical field of sewage treatment, and in particular relates to a sewage treatment method based on the backflow of the supernatant of a flocculation sedimentation tank. Background technique [0002] With the continuous emergence of environmental problems, my country's requirements for environmental governance are getting higher and higher, and the corresponding pollutant discharge standards are becoming more and more stringent. Although the traditional sewage treatment methods have a certain treatment effect, it is usually difficult to meet the increasingly stringent discharge standards. Therefore, there is an urgent need to develop new processes or improve traditional pollutant treatment processes to meet the needs of continuous upgrading of sewage treatment levels to meet the standards. [0003] Among many sewage treatment processes, the coagulation-sedimentation method is widely used in sewage treatment due to its sim...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F1/52
Inventor 张炜铭陈良吕路潘丙才花铭
Owner NANJING UNIV
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