Method for recovering phosphorus in crystallization way from semiconductor industrial waste water

A technology for producing wastewater and semiconductors, applied in chemical instruments and methods, phosphorus compounds, multi-stage treatment of water/sewage, etc., can solve the problems of difficulty in recycling phosphorus resources, low technical stability, complex operation and operation, and achieve low equipment investment. , Significant environmental benefits, easy operation and operation

Inactive Publication Date: 2011-08-03
NANJING UNIV
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Problems solved by technology

[0009] In order to solve the problems of low stability of the phosphorus removal technology in semiconductor production wastewater, high cost investment, difficult recovery of phosphorus resources, and complicated operation, etc., and improve the recovery efficiency of phosphorus resources, the present invention provides a method for crystallization and recovery of phosphorus in semiconductor production wastewater , based on ammonium magnesium phosphate crystallization precipitation technology to recycle high-concentration phosphorus in semiconductor industry production wastewater, which can reduce the interference of other substances in wastewater, reduce reaction time, improve the quality of crystallization products, enhance processing stability, and efficiently recover phosphorus resources

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  • Method for recovering phosphorus in crystallization way from semiconductor industrial waste water
  • Method for recovering phosphorus in crystallization way from semiconductor industrial waste water
  • Method for recovering phosphorus in crystallization way from semiconductor industrial waste water

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Embodiment 1

[0031] The semiconductor production wastewater sample A was passed into the reaction vessel, and the contents of the main pollutants were: phosphorus concentration c(PO 4 3- -P)=120mg / L, ammonia nitrogen concentration c(NH 4 + -N)=30mg / L, fluoride ion concentration c(F - )=940mg / L. Add magnesium chloride and ammonium chloride to the wastewater, so that the molar ratio of each component ion in the reaction system is: magnesium salt: ammonia nitrogen: phosphate = 1.2~1.7: 2.0~2.5:1. Add pH adjusting solution to the waste liquid to make the pH value 8.8-9.3. Stir mechanically for 30 minutes with a double-blade single-blade stirring paddle at a stirring speed of 100 rpm. During the initial stage of stirring for 12 minutes, the temperature of the waste liquid is gradually increased from 18°C ​​to 30°C and stabilized. After the stirring is completed, the waste liquid returns to the natural water temperature, gravity sediments for 60 minutes, separates the supernatant liquid fro...

Embodiment 2

[0033] The semiconductor production wastewater sample B was passed into the reaction vessel, and the contents of the main pollutants were: phosphorus concentration c(PO 4 3- -P)=170mg / L, ammonia nitrogen concentration c(NH 4 + -N)=100mg / L, fluoride ion concentration c(F - )=870mg / L. Add magnesium chloride to the waste water, so that the molar ratio of the ions of each component in the reaction system is: magnesium salt: ammonia nitrogen: phosphate = 1.3~1.8: 3.1~3.4:1. Add pH adjusting solution to the waste liquid so that the pH value is 8.9-9.4, and use a double-bladed single-blade stirring paddle to mechanically stir for 35 minutes at a stirring speed of 100 rpm. Within 10 minutes of the initial stage of stirring, gradually increase the temperature of the waste liquid from 20°C to 35°C and stable. After the stirring is completed, the waste liquid returns to the natural water temperature, gravity sediments for 60 minutes, separates the supernatant liquid from the crystal...

Embodiment 3

[0035] The semiconductor production wastewater sample C was passed into the reaction vessel, and the contents of the main pollutants were: phosphorus concentration c(PO 4 3- -P)=250mg / L, ammonia nitrogen concentration c(NH 4 + -N)=210mg / L, fluoride ion concentration c(F - )=1330mg / L. Add magnesium chloride to the wastewater, so that the molar ratio of the ions of each component in the reaction system is: magnesium salt: ammonia nitrogen: phosphate = 1.2~1.6: 4.2~4.5:1. Add pH adjusting solution to the waste liquid so that the pH value is 8.5-9.1, mechanically stir with double blades and double paddles for 40 minutes, the stirring speed is 80rpm, within 9 minutes of the initial stage of stirring, gradually increase the temperature of the waste liquid from 20°C to 33°C and stable. After the stirring is completed, the waste liquid returns to the natural water temperature, and the gravity sedimentation is carried out for 70 minutes. The supernatant liquid is separated from th...

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Abstract

The invention discloses a method for recovering phosphorus in a crystallization way from semiconductor industrial waste water. Main operation steps of the method are as follows: adding magnesium source to semiconductor industrial waste water; supplementing nitrogen source if necessary; controlling pH value of waste liquid; adjusting the molar ratio of magnesium salt: ammonia nitrogen: phosphate salt, blending the mixture for a certain time in a mechanical blending mode; continuously heating waste liquid in the initial phase of stirring; and keeping temperature constant after waste liquid reaches a certain temperature till the blending is over. After blending, waste liquid is statically placed and settled for a certain time; after static settling, liquid supernatant and crystallized precipitates are separated; and the crystallized precipitates can be recycled after being dried. By the process treatment, more than 90% of phosphorus in the semiconductor industrial waste water can be effectively recycled; the recycled product is dense and plump; the technology has the advantages of short response time, high product purity, simple process, simple and convenient operation, low cost and the like and has obvious environmental, economic and social benefits.

Description

technical field [0001] The invention relates to a treatment method for semiconductor industry production wastewater, in particular to a method for crystallizing and recovering phosphorus from semiconductor production wastewater. Background technique [0002] Semiconductor industry production wastewater has the characteristics of large discharge, various types of pollutants, and complex components. It not only contains high concentrations of organic matter, but also contains a large amount of phosphorus, fluorine, acids, alkalis, and heavy metals, etc., which is a difficult treatment. Industrial waste. The removal and recovery of high-concentration phosphorus in semiconductor production wastewater has always been a technical bottleneck. A large amount of phosphorus-containing wastewater is discharged into surface water bodies, which will cause serious eutrophication problems; at the same time, phosphorus is an indispensable and important element in life activities. It is an ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B25/45C02F9/04
Inventor 任洪强李秋成张涛丁丽丽许柯任鑫坤
Owner NANJING UNIV
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