Research On Removal Efficiency Of Constructed Wetland Plants For Domestic Sewage

Constructed wetland is a new type of sewage treatment technology.It is Popular with the environmental engineer and researchers beeause of its economy, applicability, good removal effieiency and so on.Wetland plant is one of the most important components to purify the sewage water.In this article,at the base of others' research report,two kind of wetland plants were chose as the experiment object, including Phragmites communis and Acorus calamus Linn. After four period of trial, we got the conclusions as follows:1. Wetlang plants have good effect to purify the sewage and removal efficiency of plants to debase the contamination had obviously relation to the growing of plants.In the spring, the summer and the autumn, The contamination of the sewage: CODcr 500mg/L.While in the winter it is 200mg/L. hydraulic retention time for 7d on CODcr:removal rate of Phragmites communis for summer (79.7%)> autumn (70.8%)> spring (63.7%)> winter (60.8%); Acorus calamus Linn removal rate for summer (78.1%)>spring (69.7%)>autumn(67.7%)>winter (60.8%).2.The plants to remove pollutants in wastewater treatment has certain selectivity, such as in the summer of CODcr removal for Phragmites communis (79.7%)> Acorus calamus Linn (78.1%), And the removal of TN is higher for Acorus calamus Linn, in the summer for the removal of TN Acorus calamus Linn (76.7%)> Phragmites communis (58.6%).3. The collocation between plants,should remove contaminants by strengthening for the purpose, by the experiments of artificial wetland systems of cultivated plants is unfavorable to the Acorus calamus Linn and Phragmites communis together, as in the summer Acorus calamus Linn and Phragmites communis wetland remove the unit of TN is 58.82% which below the same planting densities of the Phragmites communis (79.59%), Acorus calamus Linn(63.81%).4.Different reed planting density on the removal efficiency of TP is obvious.For example the Reed 1 (125/m2)> Reed 2 (94/m2)> Reed 3 (63/m2), but in the summer, the removal of the TP were reed 1 (92.1%)> Reed 2 (91.1%)> Reed 3 (79.3%).5. The main research trials the removal of pollutants with wetland plants and the time,using the SPSS statistical software on both the regression analysis. Regression analysis results show that three times more accuratly fits equation relationship between the removal and the time, such as the removal rate of CODcr in the summer is Y, the time is x, the regression equation betweenY and x: Typha Y=-0.586+16.927x-0.890x2+0.011x3; Reed. Y=-1.814+19.525x-1.531x2-0.058x3.