RESUMEN
The performance and temporal variation of hybrid vertical-subsurface flow constructed wetlands (VFCWs) in response to two-stage combinations of vertical upflow (VUF) and vertical downflow (VDF) were analyzed in this research. The results of high carbon (C) treatment and high nitrogen (N) treatment were similar. The Lythrum salicaria treatment showed higher removal efficiency than CWs planted with Acorus calamus. Under high C- and N-loading treatments, the optimum two-stage combination was VDF-VUF VFCWs planted with A. calamus. Furthermore, the highest nutrient removal efficiencies were achieved in late summer (July and August) and early autumn (September). The chemical oxygen demand and total nitrogen removal efficiencies were significantly affected (P < 0.05) by season, system, and wetland plant.
Asunto(s)
Eliminación de Residuos Líquidos/métodos , Aguas Residuales/química , Humedales , Acorus/metabolismo , Biodegradación Ambiental , Análisis de la Demanda Biológica de Oxígeno , Carbono/análisis , Carbono/química , Lythrum/metabolismo , Nitrógeno/análisis , Nitrógeno/química , Fósforo/análisis , Fósforo/química , Aguas Residuales/análisisRESUMEN
Landscape planning is clearly ecologically and socially relevant. Concern about sustainability between human and environment is now a driving paradigm for this professional. However, the explosion of the sustainable landscape in China is a very recent phenomenon. What is the sustainable landscape? How is this realized in practice? In this article, on the basis of the reviews of history and perplexities of Chinese landscape and nature analysis of sustainable landscape, the ecothinking model, an implemental tool for sustainable landscape, was developed, which applies ecothinking in vision, culture, conservation and development of site, and the process of public participation for a harmonious relationship between human and environment. And a case study of the south entrance of TongNiuling Scenic Area was carried out, in which the most optimum scenario was chosen from among three models according to the ecothinking model, to illustrate the construction of the ecothinking model and how to achieve a sustainable landscape.
Asunto(s)
Conservación de los Recursos Naturales/métodos , Conservación de los Recursos Naturales/tendencias , Ecosistema , Planificación Ambiental/tendencias , Plantas , HumanosRESUMEN
The reaction of a crotonate-derived chiral phosphonium salt with alpha,beta-unsaturated carbonyl compounds in the presence of Cs(2)CO(3) affords optically active cyclohexa-1,3-diene derivatives with up to 90% ee in good yields.
