Ecology, Environment and Conservation Paper

BIOTECHNOLOGICAL POTENTIAL OF AZOLLA FILICULOIDES, AZOLLA MICROPHYLLA AND AZOLLA PINNATA FOR BIOSORPTION OF PB(II), MN (II), CU (II) AND ZN(II)

N. Jafari, Z. Senobari and R.K. Pathak

Abstract

Azolla, an aquatic fern is an ideal candidate for exploitation in constructed wetlands for treating metalcontaminated wastewaters. The aim of this paper was to investigate the capacity of a small water fern, Azolla spp. namely A. microphylla, A. pinnata and A. filiculoides (Azollaceae), to purify waters polluted by Pb2+,Cu2+, Mn2+ and Zn2+. Many plants are capable of accumulating heavy metals (called hyperaccumulators) and one of them is the water fern. The highest bioconcentration potential of Pb2+, Cu2+, Mn2+ and Zn2+ was observed by A. microphylla (94%), A. filiculoides (96%), A. pinnata (71 %) and A. microphylla (98 %) respectively. It was observed that upto 10 mg/L of copper, lead, zinc and manganese, the fern was able to survive without any apparent negative side effects on its growth. All the three species showed increased accumulation of metals when the concentration of metals in the medium was increased. It could be proposed that all species were highly efficient in Pb2+, Cu2+, Mn2+ and Zn2+ uptake.