This paper compares the removal efficiency of water hyacinth{Eichhornia crassipes)with different coverage in flow and still water systems, the physical and chemical indicators of water in the two systems have been monitored continuously. In flow water system, when the coverage of water hyacinth exceeds 80%, the removal of TN, TP, BOD5 is significantly increased to 44.35%, 45.46%, 56.98%, respectively which indicates the removal efficiency of TN, TP, BOD5 are improved with increasing water hyacinth coverage. In still water system, DO concentration decreases significantly with the water hyacinth coverage increasing. Generally water hyacinth shows higher removal performance, 36.60%, 88.84%, 36.74%, 79.39% for TN, NH4+-N, NO3-N, NO2-N, with a coverage below 50% than above 50%. Planting water hyacinth significantly increases TP in water but decreases the PO43--P. The water hyacinth removes PO43--P significantly when its coverage is below 95%, while the removal performance decreases when the coverage reached 100%. Thus, effective ecological restoration of polluted water using water hyacinth requires consideration of water characteristic and the coverage controll.%研究凤眼莲(Eichhornia crassipes)盖度对不同水流模式下的净化效果,分别对生长有凤眼莲的流动和静止水体进行长期监测,结果表明:流动水体中,随凤眼莲盖度增加,水体TN、TP、BOD5去除率均有提高,其中以盖度＞80％最为显著,去除率分别为44.35％、45.46％、56.98％.静止水体中,随凤眼莲盖度增加,水体DO显著降低；凤眼莲对TN、NH4+-N、NO3--N、NO2--N有显著吸收作用,尤其以盖度＜50％时效果较好,较对照水体分别低出36.60％、88.84％、36.74％、79.39％,远高于其他盖度时期；当盖度＞50％时,虽有一定的吸收作用,但吸收率较低；有凤眼莲水体TP含量显著上升,而PO43--P含量有所降低,尤其当盖度低于95％时,凤眼莲对水体PO43--P吸收显著,一旦盖度达100％,凤眼莲对PO43--P吸收作用减弱.故利用凤眼莲对污染水体进行生态修复时,要区别水体性质,控制其盖度.
展开▼
