Silver Nanomaterial-Immobilized Desalination Systems for Efficient Removal of Radioactive Iodine Species in Water

Abstract

Increasing concerns regarding the adverse effects of radioactive iodine waste have inspired the development of a highly efficient and sustainable desalination process for the treatment of radioactive iodine-contaminated water. Because of the high affinity of silver towards iodine species, silver nanoparticles immobilized on a cellulose acetate membrane (Ag-CAM) and biogenic silver nanoparticles containing the radiation-resistant bacterium Deinococcus radiodurans (Ag-DR) were developed and investigated for desalination performance in removing radioactive iodines from water. A simple filtration of radioactive iodine using Ag-CAM under continuous in-flow conditions (approximately 1.5 mL/s) provided an excellent removal efficiency (>99%) as well as iodide anion-selectivity. In the bioremediation study, the radioactive iodine was rapidly captured by Ag-DR in the presence of high concentration of competing anions in a short time. The results from both procedures can be visualized by using single-photon emission computed tomography (SPECT) scanning. This work presents a promising desalination method for the removal of radioactive iodine and a practical application model for remediating radioelement-contaminated waters.

Functionalized Nanomaterial Assembling and Biosynthesis Using the Extremophile Deinococcus radiodurans for Multifunctional Applications

“…As reported, the MIC of Au(III) chloride in Escherichia coli was 0.02 m m . The extremophile D. radiodurans at the OD 600 value of 1.0 was able to tolerate high concentrations beyond 1.25 m m of chloroauric acid (HAuCl 4 ) and 2.5 m m of silver nitrate (AgNO 3 ) . The extremophile still kept active under the above conditions.…”

“…The silver nanomaterials isolated from D. radiodurans cells (Ag−DR) appeared to have an absorption peak from 400 to 450 nm. The average size of Ag−DR was approximately 30 nm …”

“…Recently, the wide use of radioactive isotopes for medical and industrial applications has introduced drastic quantities of radioactive toxic pollutants and after‐use radioactive species to the environment . The serious adverse effects, such as genetic mutations, metabolic imbalances, and acute diseases, will follow due to the exposure of recalcitrant radioactive materials . Thus, it is necessary to develop sustainable treatment methods to remove radioactive materials for public health and environmental safety.…”

“…Although D. radiodurans has an excellent radiation tolerant nature, D. radiodurans alone has no ability to capture 125 I ions that are generated from radiation therapy for cancer treatment. The engineered nanomaterials play a vital role in nuclear waste treatment when used as adsorbents due to their large surface area . The biogenic gold nanomaterial‐containing D. radiodurans (Au−DR) exhibited excellent capability for the removal of radioactive iodine with an efficiency of >99% in several aqueous solutions, which was accomplished through the adsorption process ( Figure A) .…”

“…Schematic illustration of the bioremediation procedure of radioactive iodine anions using Au−DR (A), (Reproduced with permission . Copyright 2017, Royal Society of Chemistry); and Ag−DR (B) (Reproduced with permission . Copyright 2018, MDPI AG).…”