Abstract: As an essential component of constructed wetland system, filler combines all reactions into a coherent whole and plays an important role in removal of various pollutants in the wastewater treatment process. This paper reviews the progress of research on filler applications in constructed wetlands. The major types of wetland fillers are natural minerals, industrial byproducts and modified media. The characteristics, pollutant removal capacity and mechanism, application feasibility and limitation of the major filler types were compared. The problems observed in engineering application examples and relevant countermeasures for improving the filler application efficiency were discussed. The purpose of this review is to provide reference for screening and integrated use of fillers in construction of wetland systems for treatment of various types of wastewaters.

Key words: quantitative, ecosystem services flow, supply and demand coupling, ecosystem service value.