The photodegradation of organic pollutants and photocatalytic hydrogen generation from water by semiconductor catalysts are regarded as the of the most promising strategies to resolve the crisis of global environmental issues. Herein, we successfully designed and prepared a series of silver-decorated CeO₂(Ag/CeO₂) photocatalysts with different morphologies by a facile hydrothermal route. The physical properties, charge transfer behavior and photocatalytic performances (degradation and hydrogen evolution) over diverse catalysts with nanocubes, nanoparticles and nanorods shapes were comprehensively studied. It was found that the Ag-decorated CeO₂ nanorods (Ag/R-CeO₂) demonstrate the best activity for both photocatalytic methyl orange (MO) degradation and photocatalytic H₂ production reaction with attractive stability during cycling tests, suggesting its desirable practical potential. The superior performance of Ag/R-CeO₂ can be ascribed to (1) the facilitated light absorption due to enriched surface oxygen vacancies (OVs) and plasmonic Ag nanoparticles on nanorods, (2) the facilitated photo-excited charge carrier (e⁻-h⁺) separation efficiency on a metal/oxide hybrid structure and (3) the promoted formation of active reaction intermediates on surface-enriched Ag and oxygen vacancies reactive sites on Ag/CeO₂ nanorods. This study provides a valuable discovery of the utilization of abundant solar energy for diverse catalytic processes.

The eutrophication of coastal water has been a critical environmental problem in China’s offshore areas. How to effectively assess the status of coastal waters is key for pollution treatment and environmental protection. In recent years, eutrophication-symptom-based and multi-indicator methods, termed “phase II” methods, have been gradually adopted to assess the eutrophication status in some coastal waters in China and have achieved success. The cumulative quantile is typically selected to determine the characteristic value of an indicator in “phase II” methods. The influence of small-scale damaged water bodies on eutrophication assessment may be exaggerated, which often leads to the overassessment of the eutrophication status. In this study, the area ratio method was integrated into the assessment of the estuarine trophic status (ASSETS) method in order to assess the eutrophication status of Xiamen Bay in 2016. The results indicated that, in 2016, the eutrophication status of Xiamen Bay coastal waters was moderate and exhibited spatiotemporal variation. The area ratio method can effectively reduce the effect of small-scale coastal waters with extremely high eutrophication on the overassessment of eutrophication at the broader scale, allowing the eutrophication status to be better reflected, even with limited observation data. The centralized distribution of pollution sources and poor hydrodynamic conditions are the main reasons for the aforementioned phenomenon. Controlling the pollution discharge from the Jiulong River in flood seasons is key to reducing eutrophication in Xiamen coastal waters.

Nitrous oxide (N₂O) is one of the most important greenhouse gases and contributes to the depletion of ozone in the stratosphere. Estuaries are areas of intensive biological production and associated N₂O emissions through both denitrification and nitrification processes. The spatial and temporal variations of N₂O in the Jiulong River Estuary, a subtropical estuary, were explored to evaluate sources and sinks of N₂O in this area. The estuary was found to be a strong source of N₂O, its saturation in the surface water ranged from 113 to 2926% relative to the ambient atmospheric concentrations, showing great temporal and spatial variations and was influenced by multiple factors such as the concentration of dissolved inorganic nitrogen (DIN, i.e., NO3−,NH4+, and NO2−), salinity and dissolved oxygen. N₂O concentrations were at a high level in upper estuary but reduced to the lower parts of the estuary. Groundwater input could be another contributor to N₂O in the estuary. Almost all N₂O within the estuary was released into the atmosphere rather than being transported to the bay. The N₂O flux in the estuary (mean 597 μmol/m²/d) was at the higher end of the range observed in estuaries worldwide due to the very high DIN loads in the Jiulong River Estuary. Our data indicate that the N₂O saturation in the estuary continues to increase, although the DIN inputs began to decline in 2011, which might be relate to the improved environmental conditions with increased oxygen concentrations. N₂O production pathways have changed from predominantly denitrification in the past toward significant production from nitrification in the present. Further investigation is needed to better understand the behavior of N₂O in the Jiulong River Estuary.

Luo, Y. and Zhang, J., 2017. Application of a load duration curve for establishing TMDL programs upstream of the Tiaoxi River within the Taihu Watershed, China. In: Zhi, Y. and Guido Aldana, P.A. (eds.), Sustainability of Water Resources and the Development of Coastal Environments: Select Proceedings from the 2016 International Conference on Water Resource and Environment (WRE2016). Journal of Coastal Research, Special Issue No. 80, pp. 80–85. Coconut Creek (Florida), ISSN 0749-0208. The impairment of water quality is a major concern for streams and rivers in China. Total Maximum Daily Loads (TMDLs) can be used to establish a framework and propose a series of techniques and tools to assess water quality at the watershed scale. While TMDLs have been developed for water quality management by the U.S. Environmental Protection Agency, scientists and stakeholders, the development of TMDLs in China is hindered due to the lack of comprehensive data collection system and by the difficulties in incorporat...