| Lab-scale constructed wetlands were used to investigate performance and thedistribution of nitrogen and phosphorus in the constructed wetland system. Sixconstructed wetlands located in Anji County, Zhejiang Province was monitored toobserve the pollutant removal efficiency during twelve months. The results obtainedwere summarized as follows:1. Two lab-scale constructed wetland systems using sands as their substrates,with and without plants (Lythrum salicaria Linn), were used to investigate nitrogenand phosphorous removal efficiency and their distribution in the systems. The meanremoval efficiency of NH4+-N, TN, TP in the planted system were 55.02％, 45.44％,98.52％, respectively, and 38.08％, 33.63％, 91.37％in the unplanted system,respectively; the removal efficiency of nitrogen and phosphorus in the planted systemwere higher than the unplanted system. Biomass and accumulation of nitrogen andphosphorus in plants decreased along the transect from the inlet to the outlet in thesubsurface constructed wetland, the concentration of TP in substrates showed thesimilar pattern as nitrogen and phosphorus distribution in plants; the results suggestedthat proper combination of different plant species was helpful for the enhancement ofnitrogen and phosphorus removal efficiency. Analysis of nitrogen and phosphorusremoval pathway showed that nitrogen was mainly removed throughnitrification/denitrification process and phosphorus through adsorption andsedimentation by substrates; plant uptake amounted for 9.38％and 12.77％,respectively, of the amount of nitrogen and phosphorus loaded into the wetland, plantuptake was also an important pathway for nitrogen and phosphorus removal.2. To evaluate pollutants removal efficiency and dynamic feature of CODCr,nitrogen and phosphorus removal in six constructed wetland systems in Anji County,Zhejiang Province, water samples collected from April. 2006 to March. 2007 wereanalyzed. Significantly different from municipal wastewater, the contents of CODCr,nitrogen and phosphorus in rural sewage varied in different treatments and lifestyles. The six constructed wetlands were highly effective in reducing CODCr and TP and themean removal efficiency of CODCr and TP were 63.91％～88.98％and 60.93％～95.91％, respectively. However, the removal efficiency of TN (34.44％～74.03)andNH4-N (31.08％～71.39％)was relatively lower compared to CODCr and TP. Theremoval efficiency of NH4-N and TN were affected by the temperature, whichdecreased in cold months from December.2006 to March. 2007.
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