PHYTOREMEDIATION OF FLUORIDE-CONTAMINATED WATER BY Landoltia punctata

Abstract

ABSTRACT Fluorine is released into the water environment naturally or by anthropogenic activities. Fluorine promotes health benefits at low concentrations, but it promotes adverse effects ranging from fluorosis to carcinogenic problems at high concentrations. Although fluorine removal from environment can occur through processes such as adsorption, reverse osmosis, and electrodialysis, the phytoremediation emerges as an accessible and environmentally friendly treatment. This research aimed to study the phytoremediation potential of Landoltia punctata for treating water contaminated with fluorine ion (fluoride). The central composite rotatable design was used to assess the effect of three variables in the process: pH ranging from 5 to 9; phosphate concentration from 0 to 10 mg L−1; and nitrate concentration from 0 to 800 mg L−1. The plants were exposed to a fluoride initial concentration of 5 mg L-1 in 3L-vessels that also included Clark's solution for a period of 10 days. Experimentally, removal of up to 21% was observed for the supplied fluoride. Values of the order of 30% for the removed fluoride mass can be predicted by the obtained model. Landoltia punctata is a promising candidate for the phytoremediation of fluoride-contaminated waters.

Keywords

• duckweed
• fluoride
• central composite design
• phytoextraction