Reactive media wetlands

These are wetlands with special media that are chosen to have chemical properties that will react with the water to achieve particular treatment outcomes. Common examples are media to react with soluble phosphorous to form insoluble metal phosphates, or media with high capacity to absorb heavy metals or cause them to form insoluble metal sulphides.  Typically reactive media will have a finite life span and will need to be recharged or replaced once they are exhausted.