人工沉床技术在城市景观河道中的应用及其对总磷去除效果研究

Study on the Effect of Total Phosphor Removing by Constructed Submerged Hydrophyte Bed for Urban Landscape River

提出了一种模块化气浮调节式人工沉床装置,并应用于富营养化水体的生态修复.该装置克服了水深变化大、富营养化水体透明度低、夏季藻类和浮萍泛滥等不利因素对水生植物生长的制约,显著提高了重富营养化水体中植物栽植的成活率.通过在天津市外环河的现场实验表明:当停留时间为5.48 d时,人工沉床对总磷的去除率在植物生长期内可达到30%～40%;冬季仍维持在7%～20%左右.总磷浓度随停留时间的变化符合一级动力学方程,相关系数(R2)在0.9以上.衰减系数(k值)随水温的变化趋势符合S型增长曲线,即在水温过低和过高时,水温的变化对k值的影响并不大,而在某一适当温度范围内,水温的上升将导致k值的快速增加.

A kind of modularized and air adjustable constructed submerged plant bed（CSPB） was used to restore the eutrophic water.This CSPB helps hydrophytes to grow up under poor conditions,like frequently changed water depth,blurred water transparency,algae bloom and duckweed rampant in summer,which are not suitable for growing water plants naturally.The experiments in Waihuan River of Tianjin show that total phosphor（TP） reduces 30%-40% in growing season and 7%-20% in winter when the detention time is 5.48 days.The variation between the concentration of TP and the detention time follows the first-order kinetic equation,the correlation coefficients（R2） is above 0.9.The attenuation coefficients k of the kinetic equation changes with the water temperature.When the water temperature is quite low or quite high,the value of k is not significantly changed with the temperature of water.While when the temperature is in a moderate range,an increase of water temperature leads to a rapid increase of k value.