Use of aquatic macrophytes as ecological solution for improvement of the water quality

Abstract

A study was conducted at the Bodocongó lake, in Campina Grande city, Paraíba state, Brazil, to analyse the efficiency of aquatic macrophytes in the reduction of nutrient concentrations, organic matter and microbiological pollution indicators. Monitoring, was done at four collecting stations situated at two stream entrance points (one an the easteren side and the other one an the westeren side) and two points in the same areas inside the lake after water had passed through the macrophytes bank in the dry and rainy seasons. Accentuated reductions in the parameters were verified at the monitored points after the passage of the streams through the two macrophytes areas. The greatest reduction of N-NH₃ happened at the easteren side (> 78%) and N-NO₃ at the westeren (42%). Ptot reduction was between 23 and 86% and PO₄ ^-3 between 8 and 76%. High BOD (89 to 95%) reduction was noticed, and CTerm reductions varied between 35 and 98% while EF, between 35 e 88%.

Key words:
aquatic macrophytes; eutrophicated aquatic bodies; water quality