Conformation Of WSFCW And Test Of Treatment Domestic Wastewater

This dissertation has focused on Wavy Subsurface Flow Constructed Wetlands(WSFCW), studied the treatment efficiency of organic compound,nitrogen and phosphorus in low concentration domestic sewage by substrate biologic unit,macrophytes ecological unit,wetlands ecosystem respectively, and the effect of distributing system by stages on the treatment efficiency is also examined. (1) The removal efficiency of COD of WSFCW substrate biologic unit under 0.8m³/m²Â·d hydraulic load is good and the average removal rates is 50.1%; the removal efficiency of NH₃-N and TP is low and the average removal rates are 9.9% and 15.3% respectively. The main cause is the anaerobic environment of the system. (2) Canna flaccida,cyperus alternifolius,typha latifolia and juncus effuses are tested for purifying domestic sewage in autumn and winter in macrophyte unit: The pollutant removal efficiency by the four macrophyte species in three days is perfect and the efficiency is higher than the blank unit, the average removal rates of COD in macrophyte unit is 37.6% higher than the blank unit, the average removal rates of NH₃-N is 65.2% higher than the blank unit, the average removal rates of TP is 82.6% higher than the blank unit. (3) WSFCW ecosystem is studied in treating domestic sewag under 0.8m³/m²Â·d hydraulic load, the average removal rates of COD is 57.8% when the plant grow well, the average removal rates of NH3-N and TP are 24.5% and 33.7% respectively; the removal rates of NH₃-N and TP are 15% higher than the the removal rates of substrate unit ,the results indicats that the plant contribute a lot in the removal of N and P. The pollutant removal efficiency declines in the subsequent phase after the plant damps off. In this condition, the effect of the distributing system by stages on the the removal efficiency is examined, the results indicates that the distributing system enhanced the removal rates of TP, but the effect on the removal of COD and NH₃-N is negligible in short order. Thus it can be seen that WSFCW substrate could meet the need of the organic matter removal demand under 0.8m3/m2?d hydraulic load, the supplement of the macrophyte unit could enhance the removal efficiency of N and P remarkably; farther investigation should be carried through on the distributing system by stages and the mechanism of the removal of N and P in WSFCW.