Recycling treatment method of dilute alkali wastewater

A technology for dilute alkali wastewater and treatment methods, which is applied in chemical instruments and methods, water/sewage multi-stage treatment, water/sludge/sewage treatment, etc. Simple, mild process conditions

Active Publication Date: 2015-12-23
ZHEJIANG QICAI ECO TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The present invention provides a resource treatment method of dilute alkali wastewater, which has mild process conditions, simple operation and easy industrialization, not only solves the pollution problem of dilute alkali wastewater discharge, but also fully recycles and utilizes useful resources in dilute alkali wastewater

Method used

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  • Recycling treatment method of dilute alkali wastewater
  • Recycling treatment method of dilute alkali wastewater
  • Recycling treatment method of dilute alkali wastewater

Examples

Experimental program
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Effect test

Embodiment 1

[0052] raw material:

[0053] The dilute alkali wastewater produced in the production process of certain indigo, wherein the mass fraction of NaOH and KOH is 14% in total, NaOH 2 CO 3 and K 2 CO 3 The total mass fraction of 1% also contains anilines, amides, cyanides, isatin, ammonia, etc.

[0054] The measured COD of waste water=4538mg / L, NH 3 -N=230mg / L, c(OH - )=3.32mol / L, c(CO 3 2- )=0.23mol / L.

[0055] Processing steps:

[0056] (1) Removal of organic matter: take 300g of dilute alkali wastewater, after filtering, continue to pass ozone reaction for 4h, and the ozone flow rate is 50L / h. Add 0.3 g of activated carbon to the oxidized dilute alkaline wastewater, stir for 30 minutes, filter and separate, and collect the filtrate Ⅰ.

[0057] (2) Carbonate recovery: After the filtrate I was concentrated 4 times under reduced pressure, the temperature was lowered to 40°C and filtered to separate the carbonate and filtrate II.

[0058] (3) Denitrification: add sodium s...

Embodiment 2

[0074] raw material:

[0075] A certain indigo dilute alkali wastewater mainly contains sodium salt and amine organic matter. It is determined that the wastewater w(NaOH)=14.64%~15.09%, COD=7495mg / L, NH 3 - N = 100 mg / L.

[0076] Processing steps:

[0077] (1) Removal of organic matter: take 300g of waste water, after filtration, continue to pass ozone reaction for 6h, and the flow rate of ozone is 40L / h. Add 0.15 g of activated carbon to the oxidized dilute alkaline wastewater, stir for 30 minutes, filter and separate, and collect the filtrate Ⅰ.

[0078] (2) Carbonate recovery: the filtrate I was concentrated under reduced pressure, cooled to 30° C., filtered and separated to obtain carbonate and filtrate II.

[0079] (3) Denitrification: Add sodium sulfite with a theoretical dosage of 75% to the filtrate II, stir and react for 1 hour to obtain reaction solution III. The nitrate removal rate measured by sampling was 90%.

[0080] (4) Soda boiling: put the reaction solut...

Embodiment 3

[0085] raw material:

[0086] A certain printing and dyeing wastewater contains NaOH, a small amount of carbonate and other organic matter. The measured COD of waste water=5236mg / L, NH 3 -N=227mg / L, phenolphthalein alkalinity is 18%.

[0087] Processing steps:

[0088] (1) Removal of organic matter: take 400g of dilute alkaline wastewater, after filtration, continue to pass ozone for 5h until the wastewater is completely oxidized. Then add 0.4g of activated carbon to the dilute alkali wastewater, stir for 40 minutes, then filter and separate, and collect the filtrate Ⅰ.

[0089] (2) Carbonate recovery: After the filtrate I was concentrated under reduced pressure, the carbonate and filtrate II were separated by hot filtration at 40°C.

[0090] (3) Denitrification: Add sodium sulfide with a theoretical dosage of 80% to the filtrate II to remove nitrate in the waste water, and stir for 1 hour to obtain the reaction solution III. The nitrate removal rate measured by sampling ...

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Abstract

The invention discloses a recycling treatment method of dilute alkali wastewater, which comprises the following steps: (1) sequentially adding an oxidizer and an adsorbent into dilute alkali wastewater, and filtering and separating the product to obtain a filtrate I; (2) sequentially carrying out vacuum concentration and hot filtration on the filtrate I to obtain carbonate and a filtrate II; and (3) adding a sulfur-containing reducer into the filtrate II, continuing concentration, reacting while keeping the temperature at 450-480 DEG C, and cooling to obtain the solid alkali, wherein the oxidizer is ozone, and the ozone is continuously introduced into the dilute alkali wastewater at the flow rate of 40-60L/hour. The method disclosed by the invention is mild in technological conditions, simple to operate and easy for industrialization, solves the problem of pollution caused by dilute alkali wastewater discharge, and sufficiently recycles useful resources in the dilute alkali wastewater.

Description

technical field [0001] The invention relates to the technical field of industrial wastewater treatment, in particular to a method for resourceful treatment of dilute alkali wastewater. Background technique [0002] Dilute alkali wastewater refers to wastewater containing alkali and a pH value higher than 9, which can be divided into two types: strong dilute alkali wastewater and weak dilute alkali wastewater. Dilute alkali wastewater contains not only alkali, but also organic matter and inorganic salts. It has a wide range of sources and is the most common type of wastewater in industrial wastewater. Papermaking, chemical, textile, food, petrochemical and other industries will produce a large amount of dilute alkali waste water. [0003] If the dilute alkali wastewater is discharged directly into the environment without treatment, it will cause the following huge hazards: ① Strong corrosiveness, which will corrode pipes, channels and artificial buildings; ② Dilute alkali wa...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F9/10C01D1/04
Inventor 周小龙陈丽娜吕伏建陈磊张静
Owner ZHEJIANG QICAI ECO TECH CO LTD
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