Aagesencochran5280

The findings of this study facilitate a better understanding of the fate of ZnO in soils, which could be leveraged for remediation of ZnO-polluted soils.Arsenic (As) contamination is a worldwide problem and threatens human health. Here, we found that Rhizobium symbiosis can improve the tolerance to arsenate [As(V)], and a wild type R. meliloti Rm5038 symbiosis can significantly decrease the accumulation of As in Medicago truncatula shoots. The As content in plants could be decreased by nitrogen and the mutation of nitrate transporter NRT3.1. The expression of M. truncatula NRT3.1-like gene NRT3.1L1 could reverse the As(V)-tolerance phenotype of the Arabidopsis nrt3.1 mutant. Rm5038 symbiosis significantly increased the level of nitrogen in the shoot and reduced the expression of NRT3.1Ls in plants afflicted by As(V). The genetic analyses of aba2-1, pyr1/pyl1/2/4/5/8, and abi1-2/abi2-2/hab1-1/pp2ca-1 mutants revealed that abscisic acid (ABA) signaling regulates the tolerance of plants to As(V). ABA and linalool could promote the expression of NRT3.1Ls, however, their root biosynthesis was inhibited by ammonium, the first form of nitrogen fixed by Rhizobium symbiosis. Moreover, ABA and linalool may also control As and nitrate accumulation in Rhizobium symbionts via signaling pathways other than ammonia and NRT3.1Ls. Thus, Rhizobium symbiosis modulates the accumulation of As in plants via nitrogen and NRT3.1Ls regulated by ABA and linalool, which provides novel approaches to reduce As accumulation in legume crops.As emerging contaminants, microplastics (mPS, less then 5 mm) have been reported to adversely affect the plant growth; however, the mechanisms of mPS-induced growth limitation are rarely known. Here, it was found that the plastic particles were absorbed and accumulated in barley plants, which limited the development of rootlets. The mPS-treated plants had significantly higher concentrations of H2O2 and O2- in roots than the control. The mPS significantly increased the activities of dehydroascorbate reductase, glutathione reductase, ADP-Glucose pyrophosphorylase, fructokinase and phosphofructokinase, while decreased the activities of cell wall peroxidase, vacuolar invertase, sucrose synthase, phosphoglucomutase, glucose-6-phosphate dehydrogenase and phosphoglucoisomerase in roots. The changes in activities of carbohydrate and ROS metabolism enzymes in leaves showed a different trend from that in roots. The mPS plants possessed a higher trans-zeatin concentration while lower concentrations of indole-3-acetic acid, indole-3-butyric acid and dihydrozeatin than the control plants in leaves. However, the phytohormone changes in roots were distinct from those in leaves under mPS. In addition, significant correlations between enzyme activities and phytohormone concentrations were found. It was suggested that the phytohormone regulatory network plays key roles in regulating the activities of key enzymes involved in carbohydrate and ROS metabolisms in response to mPS in barley.The sustainable development of civil nuclear energy requires the fabrication of the durable nuclear wasteforms, in particular for high-level radioactive waste, which involves the design of the composition and microstructure. Herein, we demonstrated that high-entropy ceramics (Eu1-xGdx)2(Ti0.2Zr0.2Hf0.2Nb0.2Ce0.2)2O7 are the potential candidate as immobilizing hosts for high-level radioactive waste. The static aqueous leaching test indicates that the normalized leaching rates for the simulated radionuclides Ce (LRCe) and Gd (LRGd) in as-prepared high-entropy ceramics are approximately 10-6~10-8 g·m-2·d-1 after 42 days testing, much lower than those reported values in doped-Gd2Zr2O7 (10-6~10-3 g·m-2·d-1). The excellent chemical durability is mainly due to the synergistic effects of the compositional complexity and severe lattice distortion. Compared to their ternary oxides, the low oxygen vacancy concentration slows down the migration and diffusion of cations. Moreover, the lattice distortion increases the lattice potential energy, also inhibiting the migration of cations. This study provides a strategy for the development and application of high-entropy ceramics as the wasteforms.The effects of ferric iron on the photo-treatment of simulated BDE-47 (2,2',4,4'- terabromodiphenyl ether)-Brij35 (Polyoxyethylene lauryl ether) washing waste were studied to evaluate the influences of ferric iron on BDE-47 removal and Brij35 recovery. The results show that Fe3+ accelerated BDE-47 degradation at lower concentrations ( less then 0.5 mM) but attenuated it at higher concentrations (0.5-5 mM) and that Brij35 loss was increased with increasing Fe3+. These results likely are caused by changes in the rate of •OH production due to the ferric ion, association of Fe3+ and electron transfer from Brij35, and light attenuation at high concentration. The BDE-47 and Brij35 had different degradation rates at different pH values and at different dissolved oxygen concentrations. IPA-3 mw The BDE-47 products were identified by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS). The results indicated that BDE-47 transformed into mainly lower-brominated products, a few bromodibenzofurans, some rearrangement products, and some hydroxylated polybrominated diphenyl ethers. A series of Brij35 oxidization products were detected by ultra-performance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS), including hydroxylation products, carboxylation products, and some hydrophilic chain-breaking products. Brij35 was mainly oxidized by Fe3+ and/or reactive oxygen species (ROS) with the final products of CO2 and H2O. The iron ions apparently cycled from ferric to ferrous ions in the micelles such that the Fe3+-Brij35 complex dominated the main redox reaction, leading to both BDE-47 and Brij35 degradation. It appears that in any applied soil washing system, the ferric ions in the washing waste need to be removed because of the adverse effects on BDE-47 removal and eluate reuse.Constructed wetlands (CWs) are commonly used for the treatment of wastewater. However, the removal of microplastics in CWs are poorly understood. In this work, the fate and behavior of microplastics of different shapes (film, fragment, and fiber) and sizes (0.5-1 mm and 2-4 mm) were studied. Results showed that the microplastic removal rate was 81.63% in surface flow constructed wetlands (SF-CWs) and 100% in horizontal subsurface flow constructed wetlands (HSF-CWs). Fragments and fibers with 2-4 mm sizes flowed out preferentially from SF-CWs. Retained microplastics accumulated dominantly near the inlet area. Biofilm attachment and physical filtration played an important role in the retention of microplastics. The microplastics' morphological features and the apertures of the substrate related to the transport of microplastics in the substrate. We observed the formation of holes, cracks, and weeny fibers on the surface of the microplastics extracted from the microcosms with a scanning electron microscope (SEM), but we detected no oxidation based on the Fourier transform infrared spectra.