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 because of its economy, applicability, good removal efficiency and so on. Wetland plant is one of the most important elements to make up of constructed wetlands and is also one of the most important components to purify the sewage water.In this article, at the base of others' research report, six kind of wetland plants were chose as the experiment object, including reed(Phragmites communis), canna(Canna generalis), flagleaf(Acorus calamus Linn), cattail(Typha latif olia), water hyacinth(Eichharnia crassipes) and waterweed(Elodea Canadensis). After three period of trial, we got the conclusions as follows:1. Wetland plants have good effect to purify the sewage and the removal efficiency of plants to debase the contamination had obviously relation to the growing of plants. While the condition was fit for plant growing, the purifying efficiency was better. Oppositely, the purifying efficiency was lower.2. In order to get better purifying effect, we apology that it is necessary to think over difference among the different plants when choosing wetland plants and it is important to arrange several kind of plants in groups.3. The removal efficiency of plants has definite regulation. That can be gained by the means of mathematics. By analyzing the data got from the trial, we found all the tested plants to purify the same contamination obeyed the same regulation, that is, the removal efficiency of TN and COD_Cr changed in the light of linearity while TP changed in accordance with thrice curve.4. The design of the constructed wetland plants management system is available to help people to make decision of choosing the plants using in constructed wetlands.Through the work of this article, we can have a more clear cognition of the plants how to reduce the contamination in sewage and the rule for this process and also this can be contribute to the plants' choosing and estimate the effect of constructed wetlands.