摘要 |
<p>A multistage treatment system (10) for treating nutrient-rich water containing nitrogen compounds, phosphorus compounds and other minerals. Three or more vessels or stages (20, 30, 40) typically constitute the multistage treatment system (10). Each stage of the system is a reaction vessel (20, 30, 40) having a first zone (22, 32, 42) containing a substantially insoluble salt for precipitating phosphorus compounds and other minerals, a second zone (24, 34, 44) containing a microorganism retained on an inert substrate for converting nitrogen compounds, and a separation device (26, 36, 46) for removing precipitates from the water. The effluent from the multistage system may be further treated in ponds (60, 65, 70) cultivated with aquatic grass or in a packed algae filter (100) having a medium (108) for supporting algae growth and an artificial light source (104).</p> |