Phosphorus removal by apatite in horizontal flow constructed wetlands for small communities: pilot and full-scale evidence

摘要

Phosphorus (P) removals in constructed wetlands (CWs) have received particular attention innrecent decades by using specific materials which promote adsorption/precipitation mechanisms.nRecent studies have shown interest in using apatite materials to promote P precipitation ontonthe particle surface. As previous trials were mainly done by lab experiments, this present studynaims to evaluate the real potential of apatites to remove P from wastewater in pilot unitsnand a full-scale plant over a 2 year period. P retention kinetics of two qualities of apatitesnare presented and discussed. In this work apatite appears to have high retention capacityn(480% of P removal) and is still an interesting way for P removal in CWs for limiting the risk ofneutrophication downstream of small communities. Nevertheless, the apatite quality appears to benof great importance for a reliable and long term P removal. The use of materials with low contentnof apatite mineral (40–50%) seems to be not economically relevant.