The Comparison of Physio-ecological Characteristics and Nitrogen/Phosphorus Removal Capacity of Reed and Gaintreed under Two Types of Constructed Wetlands
|Keywords||Constructed Wetland Surface flow wetland Photosynthetic rate Chlorophyll Leaf water potential|
Since the 1970s, artificial wetlands as a new ecological wastewater treatment technology, due to the effectiveness of sewage purification, as well as low-input, low-power characteristics are widely used. Plants as part of the wetland system, plays an important role in the sewage purification process. In recent years, the main research direction is to compare plants on wetland sewage treatment efficiency and the same types of wetlands in different plant physiological and ecological characteristics of the different types of wetlands in the same plant physiological ecology and decontamination characteristics system comparison study less, thus necessary to study the different types of artificial wetland characteristics of Plant Physiology and Ecology and decontamination capabilities. In order to assess the situation as well as physiological and ecological characteristics of growth of plants in the different types of wetlands, this study selected surface flow artificial wet land (SFW) and undercurrents artificial wet land (SSFW) conditions, growth of reed (Phragmites communis) and Lo bamboo (Arundo donax) as The object of study. To determine the growth of plants by measuring the height of aboveground dry weight, wet weight, root growth situation and calculate the parameters of plants relative growth rate, relative moisture; determination of leaf net photosynthetic rate (P_n), transpiration rate (T_r ) stomatal conductance (g_s), leaf water potential, chlorophyll content to compare the different types of wetlands on the physiological effects of plant growth; through the determination of the nitrogen and phosphorus content of the plants on this basis, to understand the types of wetlands of different plant decontamination capabilities. The experimental results show that the plant leaf water potential of two different types of wetlands growth is consistent. Significantly better than the surface of the plant relative growth rate, leaf chlorophyll content, photosynthetic rate, transpiration rate, stomatal conductance indicators, reed between the different types of wetlands, the difference was not significant indicators, the growth characteristics of Arundo donax Constructed Wetland flow wetland, the difference between the two is very significant. Water supply and demand that is not the factors that affect plant physiological differences from the condition of root growth and leaf water potential; positively related to performance of the chlorophyll content and the rate of photosynthesis chlorophyll is the main factors to affect plant physiological characteristics of both types of wetlands on differences; plant nitrogen and phosphorus removal capacity analysis found that, under the conditions of two wetland unit mass of reeds absorb a large quantity of nitrogen and phosphorus in Arundo donax unit mass of TN and TP content were the Arundo donax 2-fold and 1.5-fold. However, due to differences in wetland types cause different plant growth conditions, the undercurrent wetlands Arundo donax biomass is far greater than the reed, Arundo donax plant overall nitrogen and phosphorus content greater than reeds, reeds of 3.5 times and 3.8 times, respectively. In surface flow wetlands under the conditions of the poor growth status of Arundo donax, average per plant absorption of nitrogen and phosphorus content with reeds similar. Plant aerial parts of nitrogen, phosphorus content of about 80% and 60% of the plants that has a certain effect through the harvesting of the aerial parts of nitrogen and phosphorus removal of wetlands. Collectively, these results illustrate the reed for two wetland habitats, Arundo donax environmental conditions suitable for planting in subsurface flow constructed wetland. Better understand the link between the wetland plants, sewage three, can better select the appropriate wetland plants, provide the basis for better construction and management of artificial wetland ecosystems, the better application of constructed wetland technology sewage treatment.