Storage and dynamics of soil organic carbon in allochthonous-dominated and nitrogen-limited natural and planted mangrove forests in southern Thailand.

Mangrove forests can help to mitigate climate change by storing a significant amount of carbon (C) in soils. Planted mangrove forests have been established to combat anthropogenic threats posed by climate change. However, the efficiency of planted forests in terms of soil organic carbon (SOC) storage and dynamics relative to that of natural forests is unclear. We assessed SOC and nutrient storage, SOC sources and drivers in a natural and a planted forest in southern Thailand. Although the planted forest stored more C and nutrients than the natural forest, the early-stage planted forest was not a strong sink relative to mudflat. Both forests were predominated by allochthonous organic C and nitrogen limited, with total nitrogen being a major driver of SOC in both cases. SOC showed a significant decline along land-to-sea and depth gradients as a result of soil texture, nutrient availability, and pH in the natural forest.

Stable and recyclable Fe3C@CN catalyst supported on carbon felt for efficient activation of peroxymonosulfate.

Stable and recyclable catalysts are crucial to the peroxymonosulfate (PMS) based advanced oxidation process (AOPs) for wastewater treatment. Herein, nitrogen-rich carbon wrapped Fe3C (Fe3C@CN) on carbon felt (CF) substrate was synthesized by using Prussian blue (PB) loaded CF as the precursors. The obtained Fe3C@CN/CF catalyst was applied for degradation of bisphenol A (BPA) via the heterogeneous catalytic activation of PMS. Results showed that ~91.7%, 95.2%, 98.1% and 99.1% of BPA (20 mg/L) were eliminated in the Fe3C@CN/CF + PMS system within 4, 10, 20 and 30 min, respectively. The fast degradation kinetics is attributed to the production of abundant reactive species (OH, SO4- and 1O2) in the Fe3C@CN/CF + PMS system, as demonstrated by the electron paramagnetic resonance spectroscopy and quench experiments. The Fe3C@CN/CF catalyst was stable and can be easily recycled by using an external magnet. The results indicated that the nanoconfined Fe3C endowed Fe3C@CN/CF with high stability and magnetic property and enabled the efficient electron transfer for PMS activation. This study provides a cost-effective approach for the fabrication of stable and recyclable Fe3C@CN/CF catalyst, and shed a new light on the rational design of multifunctional catalyst for advanced water remediation.