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Recycling treatment method for low-concentration amide type wastewater

A treatment method and technology of amide compounds, applied in water/sewage treatment, chemical instruments and methods, degassed water/sewage treatment, etc., can solve the problems of large impact on biochemical systems, large amounts of calcium salt precipitation, and low reuse value , to achieve the effect of reducing treatment cost, simple operation and reducing pollution

Active Publication Date: 2018-11-23
SHANDONG WEIFANG RAINBOW CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Patent CN107673571A discloses a treatment method for DMF wastewater in membrane production. The steps are: first, alkali hydrolysis blowing treatment uses hydrochloric acid to recover dimethylamine, but quicklime is used to adjust pH in the alkali hydrolysis process, which will produce a large amount of calcium salts. The use value is low, causing secondary pollution
At the same time, the wastewater after alkali hydrolysis enters the biochemical system. For high COD wastewater, this method is obviously not applicable, otherwise it will have a greater impact on the biochemical system and cause system paralysis.

Method used

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  • Recycling treatment method for low-concentration amide type wastewater

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Experimental program
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Effect test

Embodiment 1

[0025] Take 300L of low-concentration DMF (DMF mass fraction 1.87%) production wastewater, the COD of the wastewater is 8600mg / L, and the TN is 4868mg / L. Adjust the pH of the wastewater with sodium hydroxide. The molar ratio of NaOH to DMF is 1.2:1. At this time, the pH of the solution is 12.9. Then, it is alkaline hydrolyzed at 60°C for 2 hours. The DMF content in the wastewater is 0.0008%.

[0026] Cool the wastewater after alkaline hydrolysis and transfer it to the stripping tower to separate dimethylamine, and control the gas-liquid ratio to 3000:1. The gas from the stripping tower is separated by a cyclone separator and then enters the absorption spray tower for secondary spraying Absorption, the primary spray uses condensed water, the secondary spray uses waste hydrochloric acid, and the concentration of waste hydrochloric acid is 10wt%. After the secondary spray absorption, the TVOCs at the air outlet are 0. The TN content of the waste water after stripping was detecte...

Embodiment 2

[0029] Take 300kg of DMAC (DMAC mass fraction 1.98%) production wastewater, the COD of the wastewater is 8762mg / L, and the TN is 4983mg / L. Adjust the pH of the wastewater with sodium hydroxide. The molar ratio of NaOH to DMAC is 1.3:1. At this time, the pH of the solution is 13.4. Then, it is alkaline hydrolyzed at 40°C for 2 hours. The content of DMAC in the wastewater is 0.0007%.

[0030] The waste water after alkali hydrolysis is lowered to room temperature, and then transferred to the stripping tower to separate dimethylamine, and the gas-liquid ratio is controlled to be 3500:1. The gas from the stripping tower is separated by a cyclone separator and then enters the absorption spray tower for secondary purification. Spray absorption, the primary spray uses condensed water, the secondary spray uses waste hydrochloric acid, and the concentration of waste hydrochloric acid is 15wt%. After the secondary spray absorption, the TVOCs at the air outlet are 0. The TN content of th...

Embodiment 3

[0033]Take 250kg of low-concentration DMF production wastewater. The DMF content in the wastewater is 1.89%, the COD is 8762mg / L, and the TN is 4983mg / L. Adjust the pH of the wastewater with sodium hydroxide. The molar ratio of NaOH to DMF is 1.25:1. At this time, the pH of the solution is 13.2. Then, it is alkaline hydrolyzed at 50°C for 2 hours. The DMF content in the wastewater is 0.0006%.

[0034] The waste water after alkaline hydrolysis is lowered to room temperature, and then transferred to the stripping tower to separate dimethylamine, and the gas-liquid ratio is controlled to be 4000:1. The gas from the stripping tower is separated by a cyclone separator and then enters the absorption spray tower for secondary purification. Spray absorption, the primary spray uses condensed water, the secondary spray uses waste hydrochloric acid, and the concentration of waste hydrochloric acid is 5wt%. After the secondary spray absorption, the TVOCs at the air outlet are 0. The TN c...

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Abstract

The invention discloses a recycling treatment method for low-concentration amide type wastewater. The recycling treatment method comprises the following steps: carrying out alkaline hydrolysis on thelow-concentration amide type wastewater, wherein an alkaline hydrolysis product is dimethylamine and carboxylate; after complete alkaline hydrolysis is carried out, separating free dimethylamine in the wastewater by adopting a blowing-off method, so as to reduce the content of total nitrogen in the wastewater. The blown-off wastewater is treated through adopting a high-grade oxidization technology, so as to reach emission standards. Meanwhile, the blown-off dimethylamine is absorbed through two-grade spraying and the dimethylamine is completely absorbed, so that zero emission is realized. Therecycling treatment method disclosed by the invention is simple to operate and wide in wastewater applicable range; new wastes are not produced, and waste gas and wastewater emission reaches standards; the recycled dimethylamine can be used as a downstream product for selling; the recycling treatment method has certain economic value, the treatment cost is reduced and the requirements on a green and environment-friendly strategic route capable of realizing sustainable development are met.

Description

technical field [0001] The invention relates to a waste water treatment method, which relates to a resource treatment method for waste water containing low-concentration amides compounds, and belongs to the technical field of waste water treatment. Background technique [0002] Amide compounds are a general term for a class of compounds with amide groups. They have a wide range of functions and can be used as raw materials for chemical synthesis and as solvents in various industries. DMF is one of the amide compounds and is a commonly used organic reaction solvent. In the process of chemical organic synthesis, a large amount of DMF wastewater will be produced. High-concentration DMF wastewater can be treated by rectification, extraction and other methods, and the recovery value is relatively high. However, for low-concentration DMF wastewater, the rectification method consumes too much energy, and the recovery value is low. The simple use of advanced oxidation technology c...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F9/04C02F101/38
CPCC02F1/20C02F1/58C02F1/66C02F1/72C02F1/722C02F1/725C02F1/78C02F9/00C02F2101/38
Inventor 孙国庆侯永生宋伟李盼盼
Owner SHANDONG WEIFANG RAINBOW CHEM
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