CN-122010350-A - Method for treating polychlorinated nitrobenzene-containing wastewater by adopting calcium hydroxide alkaline hydrolysis

Abstract

The invention discloses a method for treating polychlorinated nitrobenzene wastewater by adopting alkaline hydrolysis of calcium hydroxide. Firstly adding calcium hydroxide into wastewater containing polychlorinated nitrobenzene, carrying out hydrolysis reaction under stirring and temperature control conditions, carrying out nucleophilic substitution on activated chlorine substitution sites and nitro substitution sites in polychlorinated nitrobenzene molecules by utilizing hydroxide ions to generate phenol substances such as trinitrodichlorophenol and the like until the solution turns yellow and the chromaticity is not increased any more, obtaining a first treatment liquid, and then carrying out ultrasonic treatment, washing and filtering on the first treatment liquid to remove precipitated solids, thus obtaining the treatment liquid. The method realizes the preliminary attenuation of the wastewater containing the polychlorinated nitrobenzene and improves the treatability of the wastewater.

Inventors

• WANG YIXUAN
• Qi Yibei
• SHEN JINYOU
• JIANG XINBAI
• HOU CHENG

Assignees

• 南京理工大学

Dates

Publication Date

20260512

Application Date

20260323

Claims (8)

1. 1. The method for treating the polychlorinated nitrobenzene-containing wastewater by adopting the alkaline hydrolysis of calcium hydroxide is characterized by comprising the following steps of: (1) Adding calcium hydroxide into the wastewater containing the polychlorinated nitrobenzene, carrying out hydrolysis reaction under the conditions of stirring and temperature control, and carrying out nucleophilic substitution on activated chlorine substitution sites and nitro substitution sites in polychlorinated nitrobenzene molecules by utilizing hydroxide ions to generate phenol substances such as trinitrodichlorophenol and the like until the solution turns yellow and the chromaticity is not increased any more, thereby obtaining a first treatment solution; (2) And carrying out ultrasonic treatment, washing and filtering on the first treatment liquid to remove precipitated solids and obtain the treatment liquid.
2. 2. The method of claim 1, wherein in step (1), the polychlorinated nitrobenzene is TCTNB.
3. 3. The method according to claim 1, wherein in the step (1), the mass fraction of calcium hydroxide is 97%, and the amount of calcium hydroxide added is 11 when the pH of the wastewater is added.
4. 4. The method according to claim 1, wherein in the step (1), the stirring is performed by magnetic stirring at a stirring speed of 300 r/min.
5. 5. The method according to claim 1, wherein in the step (1), the temperature control process is to control the initial temperature to 25-28 ℃ and then raise the temperature to 60 ℃ at a temperature raising rate of 1-3 ℃ per minute, and keep the constant temperature reaction at 60 ℃.
6. 6. The method according to claim 1, wherein in the step (2), the ultrasonic treatment is performed at a vibration frequency of 50 to 200kHz and a vibration frequency gradient of 0 to 30 kHz/min.
7. 7. The method of claim 1, wherein in step (2), the frequency of vibration of the ultrasonic treatment is 80 kHz.
8. 8. The method according to claim 1, wherein in the step (2), the filtering mode is that a 0.22 μm organic phase filtering membrane is adopted and a vacuum sand core suction filtration device is used for suction filtration.

Description

Method for treating polychlorinated nitrobenzene-containing wastewater by adopting calcium hydroxide alkaline hydrolysis Technical Field The invention belongs to the technical field of polychlorinated nitrobenzene-containing wastewater treatment, and particularly relates to a method for treating polychlorinated nitrobenzene-containing wastewater by adopting calcium hydroxide alkaline hydrolysis. Background 1,3, 5-Triamino-2, 4, 6-trinitrobenzene (TATB) is an important insensitive high-energy explosive, and has the characteristics of low sensitivity, good thermal stability, excellent comprehensive performance and the like compared with traditional explosives such as 2,4, 6-trinitrotoluene (TNT), cyclotrimethylene trinitroamine (RDX), cyclotetramethylene tetranitramine (HMX) and the like. TATB produces a certain amount of acidic wastewater during the production process, which Typically Contains Trinitrotrichlorobenzene (TCTNB) and the like with polychlorinated nitrobenzene. The polychlorinated nitrobenzene has stronger toxicity and environmental hazard, and is easy to cause adverse effects on ecological environment and biological health, so that the wastewater treatment has higher safety disposal requirement. The existing polychlorinated nitrobenzene wastewater treatment technology mainly comprises biological methods and physical-chemical methods, such as biodegradation, bioelectrochemistry, advanced oxidation, reduction-oxidation coupling, photoelectrocatalysis and the like. However, typical chloronitroaromatic compounds have stable molecular structure, poor biodegradability and difficult effective degradation by a conventional biological method, and meanwhile, the chloro groups and the nitro groups in the molecules have strong electron-withdrawing effect, so that the advanced oxidation and other methods are adopted to realize deep degradation or complete mineralization, and the medicament consumption is high and the treatment cost is high. The prior art also has the problems of complex process, higher operation cost, easy secondary pollution and the like. Disclosure of Invention The invention provides a method for treating wastewater containing polychlorinated nitrobenzene by alkaline hydrolysis of calcium hydroxide, which aims to solve the problems of high cost, harmful byproducts and secondary pollution of the existing wastewater treatment method containing polychlorinated nitrobenzene. The method adopts calcium hydroxide for treatment, can provide hydroxide ions in a system, promotes the gradual hydrolysis of polychlorinated nitrobenzene to generate phenol substances such as trinitrodichlorophenol, reduces the toxicity of the phenol substances and improves the feasibility of subsequent treatment of wastewater. The technical scheme of the invention is as follows: the method for treating the polychlorinated nitrobenzene-containing wastewater by adopting the alkaline hydrolysis of calcium hydroxide comprises the following steps: (1) Adding calcium hydroxide into the wastewater containing the polychlorinated nitrobenzene, carrying out hydrolysis reaction under the conditions of stirring and temperature control, and carrying out nucleophilic substitution on activated chlorine substitution sites and nitro substitution sites in polychlorinated nitrobenzene molecules by utilizing hydroxide ions to generate phenol substances such as trinitrodichlorophenol and the like until the solution turns yellow and the chromaticity is not increased any more, thereby obtaining a first treatment solution; (2) And carrying out ultrasonic treatment, washing and filtering on the first treatment liquid to remove precipitated solids and obtain the treatment liquid. Further, in step (1), polychlorinated nitrobenzene includes, but is not limited to TCTNB and the like. Further, in the step (1), the mass fraction of the calcium hydroxide is 97%, and the addition amount of the calcium hydroxide is 11 when the pH of the wastewater is added. Further, in the step (1), the stirring mode is magnetic stirring, and the stirring speed is 300 r/min. Further, in the step (1), the temperature control process is that the initial temperature is controlled to be 25-28 ℃, then the temperature is raised to 60 ℃ at the temperature rising rate of 1-3 ℃ per minute, and the constant temperature reaction is kept at 60 ℃. Further, in the step (2), the vibration frequency of the ultrasonic treatment is 50-200 kHz, preferably 80 kHz, and the vibration frequency gradient is 0-30 kHz/min. In the step (2), the filtering mode is that a 0.22 mu m organic phase filtering membrane is adopted and a vacuum sand core suction filtration device is used for suction filtration. Compared with the prior art, the invention has the following beneficial effects: (1) According to the invention, the acidic wastewater containing polychlorinated nitrobenzene is subjected to alkaline hydrolysis treatment by adopting calcium hydroxide, so that the preliminary neutralization of the was