Wetland ecosystem is the physical

chemical and biological triple role

through filtration

adsorption

ion exchange

etc. to achieve efficient purification of sewage

fillers screening is very important. Through this paper

experimental study found that the adsorption capacity of ammonia from strong to weak zeolite> sand> gravel> vermiculite> limestone> high slag. Each filler for total phosphorus are more readily absorbed

the adsorption capacity from strong to weak is vermiculite> high slag> sand> zeolite> gravel> limestone.