Boosting Peroxymonosulfate Activation via CoS/MXene Nanocomposite for Rhodamine B Degradation under Simulated Sunlight Irradiation.

Cobalt-based heterogeneous catalysts have been demonstrated as an effective PMS activator for pollutant degradation. However, the limited active sites on their surface lead to an unsatisfactory catalytic efficiency. Immobilizing the catalysts on the support material can be a promising modification strategy to solve this problem. MXene has been considered as an ideal support material due to its unique morphology and physicochemical properties. Therefore, in this work, the CoS-loaded Ti3 C2 MXene (CoS/Ti3 C2 MXene) catalyst for peroxymonosulfate (PMS) activation was successfully synthesized through a solvothermal method. Under the simulated sunlight irradiation, the CoS/Ti3 C2 MXene+PMS system achieved an impressive efficiency in removing the organic pollutant rhodamine B (97.2 % in 10 min). Among the tested catalysts, 30 %-CoS-TC stood out, exhibited a broad pH tolerance from 5 to 9 and maintained robust degradation performance over cycles. Upon detailed analysis, the degradation mechanism revealed the collaborative action dominated by singlet oxygen, and supplemented by photogenerated holes and superoxide radicals in the process. Notably, the sandwich-like structure of MXene played a pivotal role, not only dispersing the CoS particles evenly on the surface of catalysts, but also providing ample space for the active sites, thus accelerating the PMS activation for the degradation of rhodamine B. Overall, this study developed an innovative MXene-based catalyst for the application of environmental remediation.

Phytoremediation for Co-contaminated Soils of Cadmium and Polychlorinated Biphenyls Using the Ornamental Plant Tagetes patula L.

In this study, pot-culture experiments were conducted to investigate the single effect of Cd, PCBs, and the combined effect of Cd-PCBs with Tagetes patula L. The study highlights that the minimum concentration of PCBs (100 µg kg-1) could enable the growth of the plant with an increase in biomass by 27.76% when compared with the control. In all the experiments performed, the Cd concentrations over the surface parts were found to be above 100 mg kg-1. Significant positive correlations were observed between the Cd and PCBs concentrations accumulated in tissues of the soil and plants (p < 0.05). T. patula exhibited high tolerance to Cd and PCBs, and the plant promoted the removal rate of PCBs. The removal rates of PCB18 and PCB28 were up to 42.72 and 42.29%, respectively. The study highlights the potential and suitability of T. patula for phytoremediation of Cd and PCBs in contaminated soils.