Pyromellitic acid dianhydride production wastewater treatment by two-stage adsorption method and resource recovery method

A technology of pyromellitic acid and production wastewater, which is applied in the field of powder coating additives, can solve the problems of insufficient thoroughness and effectiveness in the adsorption, separation and recycling of pyromellitic acid, and achieves improvement of treatment and recovery efficiency, and saving of drug consumption and energy. consumption effect

Inactive Publication Date: 2010-08-25
NANJING UNIV
View PDF0 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The research results show that the conventional resin adsorption method and the one-stage composite functional resin adsorption method are directly adopted. Under the optimized experimental operating conditions, the content of pyromellitic acid after treatment is about 200mg / l, and the content of pyromellitic acid production wastewater Adsorption, separation and recycling of pyromellitic acid are far from thorough and effective

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] Put 20ml of composite functional resin (NDA-910) into two jacketed glass adsorption columns (Φ32×360mm). At room temperature (20°C), the pyromellitic acid production wastewater first passes through the first-stage composite functional resin bed at a flow rate of 2BV / h. The wastewater treatment capacity is 2BV / batch. Through the second-stage composite functional resin bed, the wastewater treatment capacity is 8BV / batch. The COD of the original wastewater is 28800mg / l, and the content of pyromellitic acid is about 18250mg / l. After continuous adsorption by two-stage resin, the COD is about 11200mg / L, and the content of pyromellitic acid is about 7mg / L.

[0016] Use 1BV 8% NaOH aqueous solution + 4BV water to desorb through the first-stage composite functional resin bed at 50°C at 1BV / h, use 2BV 3% NaOH + 2BV aqueous solution at 50°C at a flow rate of 4BV / h Desorption is carried out through the second-stage composite functional resin bed, and the desorption rate of pyromel...

Embodiment 2

[0018] Replace the composite functional resin NDA-910 used in Example 1 with NDA-900, and pass the pyromellitic acid production wastewater at a flow rate of 4BV / h through the first-stage composite functional resin bed at a temperature of 35°C, and the wastewater treatment capacity is 2BV / batch, the first-stage adsorption water is passed through the second-stage composite functional resin bed at a flow rate of 8BV / h, and the wastewater treatment capacity is 8BV / batch. Use 2BV 6% NaOH aqueous solution + 4BV water to desorb through the first-stage composite functional resin bed at a flow rate of 3BV / h at 40°C; The flow is desorbed through the second-stage composite functional resin bed.

[0019] Under the above operating conditions, the adsorption effect of the treated wastewater is slightly improved, the COD is about 11300mg / L, and the content of pyromellitic acid is lower than 5mg / L. The desorption rate of pyromellitic acid on the two-stage resin was >99%.

Embodiment 3

[0021] Replace the two glass adsorption columns in Example 1 with two polypropylene adsorption columns (Φ160 × 1000mm), and fill each column with 10 kilograms (about 13 L) of composite functional resin (NDA-910), according to 700 times the amount of the embodiment The wastewater treatment capacity in 1 is operated, and the adsorption temperature of the two-stage resin is controlled to be 10° C., and the effect of adsorption treatment and resource recovery consistent with that of Example 1 can be obtained.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
clearance rateaaaaaaaaaa
Login to View More

Abstract

The invention discloses a method for treating pyromellitic acid production wastewater through a secondary adsorption method and recovering resources. The method comprises the following steps: the pyromellitic acid production wastewater is subjected to adsorption treatment through a primary compound functional resin so as to recover the pyromellitic acid, and then water is subjected to the adsorption treatment through a secondary compound functional resin in succession; after the treatment, the COD can be reduced to less than 12,000 mg / L from 28,000 to 33,000 mg / L; the content of the pyromellitic acid is lower than 10 mg / L; and the removal rate of organic matter is over 99.9 percent. The compound functional resins can be completely desorbed through a NaOH aqueous solution with the concentration between 2 and 10 percent, and after obtained high-concentration desorption liquid is acidized via a HCl aqueous solution with the concentration between 10 and 20 percent, the pyromellitic acid with the purity of more than 98 percent can be separated and recovered. The method has the advantages that the method cuts down organic pollutants of wastewater discharged into the environment; the CODremoval rate of the method is more than 60 percent, and the resource recovery rate of the pyromellitic acid which is an organic pollutant is more than 99 percent at the same time; and the method has remarkable economic value and environmental benefit in the aspect of pollution control of the pyromellitic acid production wastewater.

Description

technical field [0001] The present invention relates to a kind of important powder coating auxiliary agent, namely curing agent, leveling agent and matting agent, epoxy resin curing agent, plasticizer of polyvinyl chloride resin, treatment and resource recovery method of pyromellitic acid production wastewater, Specifically, it is a method for adsorption separation and recycling of pyromellitic acid in waste water from pyromellitic acid production. Background technique [0002] Pyromellitic acid is an important polymer monomer, and its representative application is the raw material of polyimide, a high-performance material, and is widely used in cutting-edge technologies. At present, pyromellitic acid is produced by oxidation of durene. During the production process, a large amount of high-concentration organic wastewater is discharged, with a pH value of about 1-2, a COD of 28000-33000mg / L, and a content of 18000-22000mg / l Organic matter such as pyromellitic acid, the conc...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & AuthorityPatents(China)
IPC IPC(8): C02F9/14C02F1/58C02F1/28C02F1/42
Inventor刘福强凌盼盼樊健李正斌胡大波龙超李爱民
OwnerNANJING UNIV