论凤眼莲的是非功过

凤眼莲在城市河湖的污染与净化中的是非功过争议很大,双方意见均有部分正确,但各有片面性。凤眼莲耐污能力、净化能力强;生产力高,生产量大;从环境中吸收、转化的污染物种类多、量大;本身有一定的利用和经济价值.它本是水体中营养盐、有机质等污染物的迁移转化和输出链网中一个重要环节。目前一些地方水体中凤眼莲因未及时收获、输出水体,失控而过度发展、排斥其他多种生物的生存和发展,而成为外来入侵种,其残体留存水体中造成二次污染。决定它功过是非的关键是能否及时从其生长水体中收获和输出,防止他们疯长蔓延。而合理利用凤眼莲是促进它们的收获与输出一项条件.如能抓住这一关键,就可解决这一争论.发挥凤眼莲净化水体,变废为宝,化害为利.兼收生态环境和经济效益。

Merit and Fault of Water Hyacinth on Wastewater Purification and Utilization in Water-bodies

There was a heated dispute between the merit and fault of water hyacinth on purification or pollution in water-bodies.Each opinion of the two contending sides was partly right but each took one sided approach to problems respectively.Water hyacinth has strong tolerance to pollution and purifying capacity;its production is high and more kinds and great amount of pollutants can be absorbed,transformed,transplanted by this plant.It has some utilized and economic value.It is a link of the chain of translated,transformed and exported pollutants,such as nutrient salts,organic matter etc.While water hyacinth became an exotic invader species in some water-bodies because they had not been harvested and exported from the water-body on time and resulted in secondary pollution by decomposition and putrefaction of their wreckage,and exclusion from the survey,and development of many other species by overgrowth and out of control.It is the key of merit or fault of water hyacinth on purification or pollution in water-bodies that the water hyacinth was not harvested and exported from the water body by man on time.The utilization of this plant was an important condition to encourage the harvest and export of this plant.To hold this key should settle this dispute.The water hyacintil could purify the contaminated water,translate the waste into the resources and wealth,turn the harmful into the beneficial,and take both ecological environmental and economic benefits simultaneously.