The removal of cesium (Cs) from contaminated clay minerals is still a challenge due to the limited efficiency of the process. Thus, this study aimed to enhance the removal for Cs+ ions during the conventional acid washing process by incorporating a bead-type adsorbent. Polyacrylonitrile-based nickel potassium hexacyanoferrate (NiFC-PAN) was utilized as the Cs adsorbent to selectively adsorb Cs+ ions in a strongly acidic solution that contained competing ions. To enable easy separation of clay particles and protect the adsorbent from harsh environmental conditions, PAN was deliberately constructed as large beads. The synthesized adsorbent (NiFC/PAN in a 2:1 ratio) displayed high selectivity for Cs+ ions and had a maximum capacity of 162.78 mg/g for Cs+ adsorption in 0.5 M HNO3 solution. Since NiFC-PAN exhibited greater Cs selectivity than the clay mineral (hydrobiotite, HBT), adding NiFC-PAN during the acid washing substantially increased Cs desorption (73.3%) by preventing the re-adsorption for Cs+ ions on the HBT. The acid treatment in the presence of NiFCPAN also significantly decreased the radioactivity of 137Cs-HBT from 209 to 27 Bq/g, resulting in a desorption efficiency of 87.1%. Therefore, these findings suggest that the proposed technique is a potentially useful and effective method for decontaminating radioactive clay.

A large amount of acidic wastewater was generated from the soil washing process. This study focuses on the capture for the radionuclide, especially cesium (Cs), in soil washing wastewater. We conducted the two-step process to reduce the amount of radioactive wastewater after soil washing using the coagulants and adsorbents in each step. We synthesized the adsorbent to capture Cs radionuclides in acidic wastewater (pH < 1). Based on the results, we found that the optimum ratio (NiFC:PAN) was 3.5:1 for the removal efficiency and strength of adsorbent. We compare the NiFC powder and NiFC-PAN for removal efficiency and separation of adsorbent after batch test, showing that the removal efficiency and separation of NiFC-PAN was lower and higher than NiFC power, respectively. We conducted the radioactive experiment to evaluate the satisfaction below release criteria (< 10 Bq·L−1, Cs), reporting that NIFC-PAN adsorbent meet the release criteria. These results showed that NiFC-PAN is promising adsorbent for Cs capture in strong acidic wastewater generated from soil washing and separation after capture process.

The root extracts of Paeonia lactiflora cv. ‘Red Charm’ has been studied by many groups, however, little attention has been paid to its flower petal. Paeonia is the genus in the Paeoniaceae family. ‘Red Charm’ Paeonia is a soft-stemmed herbaceous peony hybrid of P. officinalis and P. lactiflora. We previously showed the flower petal extract of Red Charm might have anti-oxidant and anti-inflammatory activities, however, it was not clear which components might be involved in this activity. Bioinformatics analysis previously indicated these extracts have potential anti-oxidant materials. One of them is identified as paeoniflorin, which is major component in root extract of Red Charm. In this study, we compared paeoniflorin and oxypaeoniflorin using DPPH assays to measure its anti-oxidant activities. Oxypaeoniflorin showed higher levels of radical scavenging activity, similar to ascorbic acid control, whereas paeoniflorin did not. Furthermore, nitric oxide assay showed they have similar anti-inflammatory effects. Taken together, these results suggest oxypaeoniflorin may play a more important role in the anti-oxidant activity of the flower petal and root extracts of Red Charm, compared to paeoniflorin. Further studies may be able to provide a platform to develop potential dual effects therapeutics for oxidant-mediated and inflammation-mediated disease in the near future.