浮床栽培海马齿对海水中悬浮颗粒物清除作用的实验研究

Removal of Suspended Particulate Matter in Seawater by Sesuvium portulacastrum L. Planted in Floating-bed

当前,我国许多流域和沿岸水体悬浮颗粒物的浓度较高,给大型海藻和其他底栖水生植物的正常生长带来十分不利的影响.如何有效降低水体的悬浮物浓度,是沿岸水域生态恢复面临的重要问题之一.研究了植物浮床系统中滩涂耐盐植物海马齿(Sesuvium portulacastrumL.)的根系对海水中悬浮颗粒物的净化效果.结果显示,种植海马齿的实验水体悬浮颗粒物浓度显著低于对照组(p<0.01),在24 h内,由海马齿构成的生态浮床模拟系统对水体中悬浮颗粒物的清除率达到90%以上;海马齿根系对不同粒径的悬浮颗粒物清除效果不同,主要作用于粒径<20μm的悬浮颗粒物,且颗粒物粒径越小,根系对其清除效果越明显;随着粒径增大,悬浮颗粒物的自然沉降作用增强,尤其是粒径≥20μm的颗粒物.研究还表明,海马齿根系不仅对水中悬浮颗粒物具有良好的清除作用,同时能使其浓度提前达到稳定水平.

The content of suspended particulate matter （SPM） is commonly high in the catchments and the coastal waters in China,which cause negative effects on the growth of aquatic macrophytes. How to effectively reduce the SPM concentration has become an urgent target in the restoration of such aquatic environments. To examine the removal ability of SPM from seawater by the root sys- tem of halophyte Sesuvium portulacastrum L. , the experiments were conducted in an ecological floating-bed simulating system device with water circulation. The results showed that in less than 24 h,the removal efficiency of S. portulacastrum root system reached〉90%, and the concentration of SPM in the device with plants was significantly lower than that in control device without plants （p〈 0. 01）. In addition,it was found that the range of particle size where S. portulacastrurn root system worked was largely made up of those of less than 20 μm,and the removal amount sharply decreased with particle size, whereas the most SPM of the rest size naturally sunk. Therefore it could be concluded that S. portulacastrum root system produced good removal effect on SPM in the water.