The relative importance of Lemna gibba L., bacteria and algae for the nitrogen and phosphorus removal in duckweed-covered domestic wastewater

algae ammonia ammoniac azote bacteria denitrification fosforo lemna gibba lemnaceae malezas mauvaise herbe nitrogen nutrientes nutrients phosphore phosphorus purification de l'eau substance nutritive tratamiento de aguas residuales uses usos utilisation wastewater treatment water purification weeds