Study On Nitrogen And Phosphorus Removal By Nutrient Enrichment Contructed Wetland

Water eutrophication is a global environmental problem. Especially in the urban landscape water and the surrounding waters, where is widespread havary-nutrition or eutrophication status. Nowadays, the lake eutrophication problem is not merely the pure water pollution problems, but is becoming the major problem which is influencing the national economy and the people's livelihood. This article takes the Water Special Project lake subject Yunnan Dali state Erhai basin comprehensive improvement project (2008ZX07105- 003-3) as a backing, based on the constructed wetland technology, combined nitrogen phosphorus adsorption technology is used for the water body eutrophication control technology research of lake inflow rivers. Through this topic research, provides a reference basis for project topics, and provides a new approach for the ecological eutrophication control technology.In this paper the main research contents include: (1) The plant screening research, including alternative plant breeding experimental research and cultivation research. (2) Study of substrates base nitrogen and phosphorus adsorption ability. (3) Through the construction of third-level simulation wetland system, comparative study on the intermittent flow and continuous flow conditions, In vertical flow with horizontal flow conditions, In different hydraulic remain time conditions, under different substrates laid condition, Nutrient enrichment hydroponic wetland system nitrogen and phosphorus removal capacity were studied. (4) The hydroponic wetland system design, including the optimal analog wetland system model design and engineering practice of artificial wetland technology graphic design.The research indicates that, in plant screening, under suitable conditions (at least the temperature is 15°C above); Water spinach's life superiority is strong. But under the cool condition (the temperature between -5 and 15°C), the reed and the green radish's vitality are stronger than the water spinach. Plant's choice needs to give dual attention to the nitrogen phosphorus elimination ability, the landscape effect as well as economical back coupling effectiveness. In the nitrogen phosphorus elimination aspect, the hydrated calcium silicate has the prominent phosphorus elimination ability, in static state adsorption test; the phosphorus elimination rate is above 97%.The vermiculite shows the strongest ammonia nitrogen elimination ability. In The constructed wetland, besides the substrates themselves, the plants and the microorganism have also played the remarkable role. The mixed mode to wetland system's nitrogen and phosphorus elimination effect is not so obvious. In hydraulic remain time for 24h, the average removal efficiency of TN reached over 80%, Far more than the single substrate static test and potted experiment. The removal rate of phosphate is also over 75%. Can achieve the micro pollution river water from the poor V kind of purification water leakage II kind of water standard, but the dephosphorization potential of hydration calcium silicate in the construct- ed wetland is far from fulfilled.In experimental study's foundation, and unifies Erhai LuoShi River the scene demonstration project, designed processing current capacity 8000m3/d to enter the lake rivers constructed wetland system, used in examining the topic research the scientific nature, provided the practice reference for the eutrophication initial period lake's ecology control technology.