Evaluation of heavy metals in levels of wetland Marimbus, Bahia, Brazil

ABSTRACT

In recent years, concentration of heavy metals like zinc (Zn), lead (Pb), chromium (Cr), nickel (Ni), copper (Cu) and cadmium (Cd) has increased over the past years in water bodies due to indiscriminate use of fertilizers in agriculture, lack of sanitation and irregular disposal of untreated industrial waste. The main goal of this study was to investigate the presence of heavy metals in the water and in the Salvinia auriculata Aubl. found in flooded areas of Marimbus, Bahia. The samples were subjected to acid digestion (HNO₃, HClO₄) and the analyses of heavy metals used an air-acetylene flame atomic absorption spectrometer. The detected levels of lead and zinc found in the water samples were within the limits set for water class 01 by CONAMA no. 357/2005 (BRASIL, 2005). An accumulation of metal concentration in the order of Zn>Cr>Pb>Ni>Cu was observed in S. auriculata. Thus, the presence of S. auriculata in water bodies serves as an important remover of heavy metals and their presence in aquatic environments is extremely important to allow the various uses such environments may provide.

Keywords:
lead; zinc; cadmium; copper; nickel; chromium; Salvinia auriculata