Research On The Obsorption Of Heavy Metal By Aquatic Plants In Different Nutritions

Along with the economy develops in our country, the environment pollutions by the industry is seriously day by day. Water heavy metal pollution is already became the restric-tion to the sustainable development of the society. The heavy metal is from mine mining, metal smelting, metal manufacturing, and the waste water of chemical productions, fossil fuel burning, agricultural chemicals, wastes of life and so on. The pollutions from nature is as well as the geology corrodes, the decency and so on. The heavy metal's toxicity is large. It seriously pollutes the water environment when it enters the water. Harms the human and the propagation's survival and security.The artificial wetland is a new technology to treat polluted water, mainly uses the aquatic plant to absorb the contamination. Therefore, the research to the aquatic plant's absorption in artificial wetland is important.Anti-pollution mechanism of aquatic plants was studied by some previous researchers from the following respects:illumination,water level,overhigh nutrient level,epiphytes and so on. Those researchs pays much attention to the single factor effect. The research on heavy metals absorption of aquatic plants under the situation of various external condition, are introduced in this dissertation.This article sees about 6 kinds of aquatic plants, select 3 kinds of good absorption effect plants:Myriophyllum, Canna and Typha orientalis Presl to carry on the experiments.Finally discovers the change of NH4+:NO3- is directly influence the heavy metal's removed rate by aquatic plants, Moreover, the phosphorus content is another nutritive elements to inflect the aquatic plants'ability. The external condition also influence the effect of absorption, generally temperature increases lead the plant to absorb more heavy metal, but also is lied on the rate of NH4+:NO3-.Indicated in the research of time, the aquatic plants absorb the heavy metal rapidly, generally it is spend 3 hours to reach saturation for a sustain aquatic plant, and is also can a aquatic plant of weak absorbency absorb the heavy metal basically complete between 24 hours. Then the growth is slow.