Method for recovering potassium nitrate from anthraquinone dye alkali wastewater
A recovery method and anthraquinone technology are applied in the field of recycling and reuse of printing and dyeing wastewater, which can solve the problems of immature technology, unsatisfactory effect and high equipment requirements, and achieve the effects of improved recovery efficiency, low decomposition rate and high removal rate.
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Method used
Image
Examples
Embodiment 1
[0026] In this example, the alkaline wastewater (pH=13, COD=211000mg / L) was first subjected to acid precipitation, and only one acid precipitation was performed. Concentrated nitric acid (with a concentration of 65%) accounting for 25% of the waste water mass was added and stirred for 1.5 After hours, add active carbon accounting for 0.4% of the wastewater mass, continue to stir and react for 1 hour, and filter; the filtrate COD is about 121,000 mg / L. The filtrate was slowly added with concentrated nitric acid accounting for 4% of the waste water mass, kept at 85-95°C, stirred for 4 hours, and then cooled to 40-50°C and filtered. After the filtrate is concentrated, the salt obtained is reddish-brown in color, and the salt is still slightly yellow after adding 15% of washing water, and the COD of the condensed water is greater than 1000 mg / L.
Embodiment 2
[0028] Add 65% mass fraction of concentrated nitric acid to alkaline wastewater (pH=13, COD=211000mg / L), keep the wastewater pH=4, stir and react for 1 hour, consume 20% acid, then add 0.3% of the total mass of wastewater to be treated The activated carbon was stirred and reacted for 0.5 hours and then filtered, the filtrate COD=104100mg / L, the COD removal rate was about 51%, but the color was still large; add 5% concentrated nitric acid to the filtrate, stir and react for 0.5 hours and then add 0.1% The activated carbon was stirred and reacted for 0.5 hours, and the wastewater COD was about 80,000 mg / L by filtration. The waste water is heated to 85-95℃, while slowly adding concentrated nitric acid, while bubbling with air, and constantly stirring, keep the reaction for 4 hours, add 4% nitric acid, cool to 40-50℃ and filter again, the filtrate shows wine red color. COD=10000mg / L, and then add 0.1% activated carbon to stir and adsorb for 0.5 hours. The filtrate obtained by filtr...
Embodiment 3
[0031] The configuration and working principle of this embodiment are the same as that of embodiment 2, but the difference is: after nitric acid is oxidized, it is filtered directly without adding activated carbon, and the salt obtained is wine-red. After washing with 25% washing water, it is still slightly yellow, and the condensed water is orange-red. , COD is about 700mg / L.
[0032] From Example 3, it can be seen that after the nitric acid is oxidized, the salt is directly filtered, and the salt obtained is darker, the amount of washing water increases, and the COD and chromaticity of the condensed water increase.
PUM
Login to View More Abstract
Description
Claims
Application Information
Login to View More