Nine Plant Species Adaptability To Constructed Wetland Environment

Because constructed wetlands have both landscape and ecological functions, it is becoming more and more accepted by people as the wastewater treatment system. Plants are the main characters of the constructed wetland, which is responsible for the removal of pollutants and the promotion of nutrient salts. In the same time, it can maintain the wetland environment. Therefore, it is great significant to study the adaptability of plant to wetland environment. This article takes the common local aquatic or wetland plants as the object and research on the adaptability of them to wetland environment and got the scientific results as follows:In the root number and root length, the overall difference of Plant physiology indicators on these four species of aquatic plants and five species of terrestrial plants is not big but only a few individual species differences. From root activity, the root activity of aquatic plants is a little weak than terrestrial plants. The contents of MDA in aquatic plants were higher than that in terrestrial plants. In Nitrogen and phosphorus content in plants regard, Willow, Canna, calamus and reed can better adapt to the water environment of high nitrogen and high phosphorus, and the terrestrial plant is not suitable for long-term survival. Through Nitrogen and Phosphorus accumulation in the nine plants we can see that Willow, Canna, calamus and reed can accumulate more biomass in the artificial wetland sewage environment. Nitrogen accumulation amount is above 20g/m2 and Phosphorus accumulation is above 3.83g/m2. In this experiment, the strongest matrix urease activity and the matrix phosphatase is the reed in the middle of nine kinds of plants. Followed by terrestrial plants such as willow and Canna and their matrix urease activity reached 70mg·100g-1·24h-1 and their matrix phosphatase activity was above 80 mg·100g-1·24h-1. According to the comparison of the actual conditions of wetland plants, comprehensive evaluation system of purification potential, we use 11 specific indicators which divided into 2 kinds including adaptation ability and physiological characteristics (root number, root length, root activity, leaf peroxidase activity) and resistance to pollution and decontamination capability(plant growth, plant N concentration, plant P concentration, plant N accumulation, accumulation of P, Matrix urease activity, matrix phosphatase activity) for analysis, we got the results show that the best purification potential are land plants such as willow, Canna and aquatic plants reed. Their ability to adapt pollution, bear pollution and remove pollution is very strong. Compared with the reed, the willow tree can grow into a tree, for it is woody plants and it is conducive to the formation of multi level ecological system of artificial wetland. So these 3 plants can be used as the main plant in the constructed wetland, especially suitable for a quick start water cycle processing system. Second major categories for medium including aquatic plants such as water hyacinth, water lily and calamus and they can be used as artificial wetland dominant plants. Third major categories terrestrial plant including Iris, red wood, rose are weak and they can be used as an auxiliary plant of constructed wetland. According to the need, we can configure them in the environment of the constructed wetland treatment system in order to increase the biological diversity and landscape effect of constructed wetland.