Treatment of wastewater by nanofiltration-ion exchange technology in uranium conversion process

The uranium in the radioactive wastewater produced by uranium conversion process is higher than the emission limit value, so it is of great significance to treat it to reduce its concentration. Nanofiltration technology and ion exchange technology were combined to treat uranium-containing wastewater and it can achieve the discharge standard. For the treatment system, uranium was firstly enriched in nanofiltration concentrate, and the concentrate entered the ion exchange system for selective adsorption of uranium. Because uranium exists in the form of complex cations or anions at different pH conditions, the use of cation–anion exchange resin tandem treatment technology can effectively and selectively adsorb almost all uranium. Both laboratory and engineering application results showed that the uranium concentration in the nanofiltration solution can be reduced to less than 50 μg/L after treating by the nanofiltration system for the wastewater containing 5-100 mg/L uranium. This work demonstrated that nanofiltration-ion exchange technology is practical and valuable for the treatment of acidic or alkaline uranium-containing waste liquid. (author)