对河流来说,“营养”可不是我们常吃的面包、水果、大鱼大肉,而是各种有机物、无机盐。人类的生活污水、农田沥出的肥水等,含有丰富的碳、氮、磷、硫等元素,对河流来说是,这就是“营养”。既然是营养,为什么不能太多?污水排放到河流中,会被河水稀释,发生沉淀。然后,好氧细菌便登场了。它们利用水体里的氧气,将那些“大块头” For the river, “nutrition” is not what we eat bread, fruit, big fish, but a variety of organic matter, inorganic salts. Human sewage, farmland leaching fertilizer, etc., is rich in carbon, nitrogen, phosphorus, sulfur and other elements, the river is, this is “nutrition ”. Since it is nutrition, why not too much? Wastewater discharged into rivers, will be diluted with water, precipitation occurred. Then, aerobic bacteria will debut. They make use of the oxygen in the water, turning those “big heads”