Effect And Mechanisms Of Iron Plaque On Root Surface On Phosphorus Removal Of Wetland Plant

This paper adopts simulation method of vertical flow constructed wetland, With new artificial wetland plant Pilea cadierei for experimental material, Research in the Pilea cadierei Fe2+simulation constructed wetland systems, Different concentrations with intermittent water containing P wastewater 42d continued to deal with the way after Fe, P, and their interaction to Pilea cadierei growth and root table iron membrane formation and the amount of influence, and the root table iron plaque studies of artificial wetland system P purification effect and its mechanism. This study will be iron plaque only avoided as plant root table happen physical reaction, but will the soil-iron plaque-plant root-the earth as a organic whole part systematically studies, a deep research on the formation of iron film and action mechanism for a comprehensive understanding of root table, and their ecological effect iron plaque provides a new research method, and for further study of migration in wetland system P lay the foundation for wetland, distribution of phosphorus is of far-reaching significance. The main conclusions are as follows:1. Pilea cadierei in wastewater concentration of 50, 100mg/L with better conditions for 0,5 and 10mg/L processing. It's explaining that high phosphorus concentration wastewater can promote the growth of Pilea cadierei, and it can be applied to the treatment of high concentration phosphorus wastewater.2. Addition of suitable amount of iron in matrix of the growth of Pilea cadierei plays a certain role in promoting, but when the amount of Fe2+reach 1000mg/kg·Soil, the growth of Pilea cadierei suppressing aerial parts.3. The influence of Phosphorus on iron plaque on the roots surface of Pilea cadierei is related of Fe2+concentration in matrix. When without add Fe in matrix, the formation of iron plaque on root surface while decreased with the increase of phosphorus concentration in wastewater. When add 500 and 1000 mg/kg·soil of Fe2+in matrix, the formation volume of iron plaque is increased with the increasing of phosphorus concentration. When Fe2+in matrix was 500 mg/kg·soil, iron plaque on root surface is significant with phosphorus concentration of wastewater.4. Iron concentration on the influence of phosphorus removal system was related with wastewater p concentration. When phosphorus concentration below 50mg/L, the system phosphorus removal rate as matrix iron concentration increases, when the phosphorus concentration reach to 100mg/L, to artificially wetlands plus iron source will reduce system of phosphorus purification efficiency.5. The quantity of iron plaque on the root surface is significant positive correlation purification efficiency with system TP removal rate, correlation coefficient r= 0.586* (P< 0.05), iron plaque on the root surface of wetland plant can help improve the phosphorus removal rate of system.6. Formation volume of iron plaque on the root surface of Pilea cadierei is significant with P uptake positively, correlation coefficient is 0.635* (P< 0.05), and underground part P and the ground part P content is has a certain positive correlation, but the association fails to reach the level of significance.