Method for resourceful utilization of desorption liquid generated in the resin ion exchange process

Patent metadata

Field	Value
Publication number	US-9908798-B2
Application number	US-201414308616-A
Country	US
Kind code	B2
Filing date	Jun 18, 2014
Priority date	Apr 19, 2013
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

Provided is a method for resourceful utilization of desorption liquid generated in the resin ion exchange process. This method effectively separates highly-concentrated organics and salts from the desorption liquid and puts these two components into comprehensive utilization.

First claim

What is claimed is:

1. A method for resourceful utilization of a desorption liquid generated in a resin ion exchange process, comprising the following steps:
(a) channeling the desorption liquid generated in the resin ion exchange process for water deep purification into an ultrafiltration membrane system at 10-45° C. and 0.2-2.0 MPa, and separating said desorption liquid into a ultrafiltration filtrate and a ultrafiltration concentrate;
(b) adding an acid, Fe 2+ , and H 2 O 2 into the ultrafiltration concentrate obtained in step (a) to obtain a solution having a pH of 2-6, a concentration of Fe 2+ of 2-20 mmol/L, and a concentration of H 2 O 2 of 6-60 mmol/L; stirring the solution for 2-6 hours to obtain a nutrient solution for activated sludge containing Fe 3+ ;
(c) adding the nutrient solution for activated sludge obtained in step (b) into the activated sludge tank of a biochemical treatment unit at a volumetric ratio of 0.1-1.0%;
(d) channeling the ultrafiltration filtrate obtained in step (a) through a nanofiltration membrane system at 10-45° C. and 0.5-5.0 MPa, and separating said ultrafiltration filtrate into the nanofiltration filtrate and the nanofiltration concentrate;
(e) channeling the nanofiltration concentrate obtained in step (d) back to the ultrafiltration system; and
(f) adding an effective amount of NaCl into the nanofiltration filtrate obtained in step (d) and reusing a resulting nanofiltration filtrate as the resin regeneration agent.

2. The method of claim 1 , wherein a molecular weight cutoff (MWCO) of the ultrafiltration membrane in step (a) is 10000-50000 Da.

3. The method of claim 2 , wherein said ultrafiltration filtrate is 60-95% by volume of the original desorption liquid in step (a).

4. The method of claim 1 , wherein a source of Fe 2+ in step (b) is ferrous chloride (FeCl 2 ) or ferrous sulfate (FeSO 4 ).

5. The method of claim 1 , wherein the nutrient solution obtained in step (b) has Fe 3+ of 2-20 mmol/L.

6. The method of claim 1 , wherein, after step (c), the activated sludge in the sludge tank has an increase in MLVSS, a decrease in SV 30 , an increase in a dehydrogenase (DHA) activity, and an increase in an electron transfer system (ETS), and an increase in a specific oxygen uptake rate (SOUR).

7. The method of claim 1 , wherein the MWCO of the nanofiltration membrane in step (d) is 150-400 Da.

8. The method of claim 1 , wherein said nanofiltration filtrate is 60-95% of the ultrafiltration filtrate by volume.

9. The method of claim 1 , wherein a COD cr concentration in the nanofiltration filtrate obtained in step (d) is lower than 300 mg/L and a mass ratio of NaCl therein is 3-10%.

10. The method of claim 1 , wherein a mass ratio of NaCl in the resulting nanofiltration filtrate is 15-20%.

11. The method of claim 1 , wherein the acid is HCl.

Assignees

• Nanjing University Of Technology

Inventors

• Li Aimin
• Xu Zixiao
• Li Wentao
• Jiang Bicun
• Zhou Qing
• Shuang Chendong
• Jiang Yeli
• Wang Mengqiao

Classifications

• C02F9/00

  Multistage treatment of water, waste water or sewage · CPC title

• Y02W10/15

  Cross-Sectional Technologies · mapped topic

• C02F2209/22

  O2 · CPC title

• C02F2209/03

  Pressure · CPC title

• C02F2303/16

  Regeneration of sorbents, filters · CPC title