Coupling study on the flow field and purification efficiency in root system region of ecological floating bed under different hydrodynamic conditions

摘要：

　　The artificial ecological floating bed is a common in situ treatment technique for repairing and purifying polluted water.The plant root system of floating bed is the primary region to absorb and degrade the pollutant of water.Its inner flow field characteristic and interactive water quantity with surrounding water greatly impact the purification efficiency of floating bed.In this paper, by the particle image velocimetry (PIV) technology and boundary velocity directly extraction method, the velocity distribution of the root system region is studied by numerical simulations and experiments in an experimental water channel.Meanwhile, the pollution removal rate (PRR) evaluation model is introduced here to calculate the PRR by coupling with the flow velocity field of root system region.In addition, the variations of total pollutant removal rate (TPRR) are discussed under conditions of different center distances (L=30cm, 45cm, 60cm), flow velocities (v =0.7 cm/s,1.5c m/s, 2.5 cm/s, 4.0cm/s, 5.5cm/s, 7.0cm/s) and root system porosity (P=54.73%, 68.33%, 79.17%).The results indicate that the arrangement position of the floating beds influences TPRR significantly, and the distance should be limited in a reasonable range to bring high purification efficiency.Moreover, the root systems with high porosity (porosity=68.33%,79.17%) can produce higher TPRR value than low porosity root system (porosity=54.73%) within a certain flow velocity range, and high porosity root system can brings less fluctuation of TPRR value than low porosity situation within a wide flow velocity range.Furthermore, under the same center distance condition, low flow velocity condition brings higher TPRR value than high flow velocity situation significantly.

关键词： ecological floating bed root system region flow velocity pollutant removal rate PIV

作者: Lei Rao Peifang Wang Yang Lei Chao Wang

作者单位: College of Mechanics and Materials, Hohai University, Nanjing 21100, China Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Educa College of Environment, Hohai University, Nanjing 210098, China

会议类型: 国际会议

会议名称: The Second Conference of Global Chinese Scholars on Hydrodynamics(第二届全球华人水动学学术会议)

会议地点: 江苏 无锡

会议语种:英文

页码: 891-901

在线出版日期: 2016-11-11（万方平台首次上网日期，不代表论文的发表时间）