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Abstract: Ecological treatment engineering has been widely accepted as an artificially designed work to deal with the deteriorating ecological environment with low energy and resource consumption. To measure the energy and resource consumption and environmental support contained in the constructed wetland as a kind of ecological treatment engineering, emergy as embodied solar energy based assessment is performed and relative emergy-based indices including emergy yield ratio (EYR), emergy load ratio (ELR), emergy sustainability index (ESI), net economic benefit index (Np), and renewable percentage index (Pr), are also modified to evaluate the local sustainability of the constructed wetland in this paper. A case study on Longdao River constructed wetland compared with those of some earlier conventional treatment systems indicate that more local renewable resources and less ecological cost are involved, thus promoting the economic benefit due to less energy and resource consumption and simultaneously lowering the environmental stress of the treatment system on the local areas. [Copyright &y& Elsevier]

Abstract: Presented in this paper is an integrated cost and efficiency analysis of a pilot vertical subsurface-flow constructed wetland (CW) built up in 2004 near the Longdao River in Beijing, China. The CW has been monitored over one year and proved to be a good solution to treat the polluted water and restored the ecosystem health of the Longdao River. The modified CW system in accordance with local conditions costs less in construction, operation and maintenance than traditional wastewater treatment system and occupies less land than conventional CW. Also, derived from the efficiency analysis, the Longdao River CW provides better elimination effects for nutrient substances in the polluted river water and has stable performances in cold seasons. [Copyright &y& Elsevier]

Because of water shortage in Beijing, most ponds and moats there have not enough water. In some times of each year, there is even no water. Therefore, wastewater reclamation and reuse has been paid more and more attention. Reclaimed water used as scenic water such as to supplement city moats, lakes etc. is considered. In this paper, some experiments were done to investigate whether constructed wetlands can reduce the nitrogen and phosphorus concentration further in order to avoid the eutrophication of water bodies through use of reclaimed water for scenic environment. As we know, phosphorus is an important factor to cause algae bloom directly in water bodies. So investigation on phosphorus elimination is a key object for this study, which is composed of two main parts. The first part is laboratory scale testing to select the appropriate substrates of constructed wetlands among some materials. The second part is pilot scale experiments to find out optimal operational condition of different kinds of constructed wetlands. Based on the lab tests, we found that foamy-brick could provide a good condition for plants and microorganisms. According to the pilot scale experiments, it could be concluded that under optimal operational conditions, horizontal flow wetlands could work well. The results of the experiments also showed that integrated vertical flow wetlands are not suitable for hosphorus elimination of reclaimed water. [ABSTRACT FROM AUTHOR]