Photo-Fenton catalytic anti-fouling membranes for efficient elimination of radionuclides and organic contaminants

The complexity of nuclear industry effluents necessitates novel treatment capable of facilitating water recycling and byproduct recovery. Many membrane-based technologies have become increasingly important for sewage water disposal because of their simple operation and scale-up for industrial applications. However, the mem-brane biofouling due to microbial attachment has become a serious issue, resulting in decreased removal effi-ciency for radionuclides and organic pollutants. Herein, by immobilizing the hybrid tannic acid (TA)/zero-valent iron (ZVI) nanostructures (TZ) onto the blow-spun amidoximed polyacrylonitrile (AOP)/zeolitic imidazolate framework-90 (ZIF-90) composite nanofibers, the ultimate AOP/ZIF-90@TA/ZVI (AZ@TZ) membranes with covalently cross-linked coatings were fabricated for synergistic adsorption-chemical reduction of uranium, photo-Fenton catalytic degradation of organic dyes, and ZVI/Zn2+-mediated resistance against bacterial cells. In order to assess the membrane's efficacy in eliminating uranium ions, a series of studies involving adsorption behavior were performed. The antibacterial and antifouling tests were further carried out using typical bacteria and organic dyes. The AZ@TZ hybrid membranes exhibited high uptake kinetics and the elimination capacity of uranium (140.06 mg/g) at pH 5.0, as well as excellent properties for photodegradation of organic dyes and inactivation of the bacteria within the biofilms. The novel integrated photo-Fenton and membrane-based tech-nique offers fresh ideas for extremely effective radioactive sewage disposal.

Automated summary

This study presents a novel method for treating nuclear industry effluents using membrane technology and chemical reduction. AZ@TZ composite membranes were successfully fabricated, which exhibited high uptake kinetics and elimination capacity for uranium ions, as well as excellent properties for photodegradation of organic dyes and inactivation of bacteria. This integrated approach offers new ideas for effective radioactive sewage disposal.