Asian Journal of Microbiology, Biotechnology & Environmental Sciences Paper

A CROPHYTES IN PHYTOREMEDIATION OF HEAVY METAL CONTAMINATED WATER AND SEDIMENTS IN PARIYEJ COMMUNITY RESERVE, GUJARAT, INDIA

J.I. NIRIVIAL KUMAR, HIREN SONI, RITA N. KUMAR AND IRA BHATT

Abstract

A phytoremediation study was carried out at Pariyej reservoir, an internationally important wetland listed in Asian Directory of Wetlands, designated as a "Wetland of International Importance" and a proposed community reserve of Gujarat State, India, to ascertain the degree of heavy metal contamination. The study focused on assessment of heavy metal accumulation in certain aquatic macrophytes used as biomonitors, in comparison with water and sediments (abiotic monitors) for phytoremediation. Roots, stems and leaves of native aquatic plants (biomonitors) represented by seven species: Ipomoea aquatica, Forsk, Eichhornia crassipes, (Mart.) Solms, Typha angustata Bory & Chaub, Echinochloa colon= (L.) Link, Hydrilla verticillata (L.f.) Royle, Nelumbo nucifera Gaerth. and Vallisneria spiralis L. alongwith surface sediments and water, were analyzed for Cd, Co, Cu, Ni, Pb and Zn contamination. The greater accumulation of heavy metals was observed in Nelumbo ruicifera and the poor content in Echinochloa colonum. Based on the concentration and toxicity status observed in the lake's vegetation, the six heavy metals are arranged in the following descending order: Zn > Cu > Pb >Ni > Co > Cd. Compared with the standard, normal and critical toxicity range in plants. The detected values of Cd and Pb falls within normal range, while that of Co and Ni was within the critical range. However, Zn and Cu showed the highest accumulation with alarming toxicity levels, which are considered as one of the most hazardous pollutants in Pariyej reservoir. Species like Typha angustata and Iporrwea aqua tica are also proposed as bioremediants, which are the most useful plant species in phytoremediation studies due to their ability to accumulate heavy metal s in h concentration in the roots. The results showed the significant differences in accumulation of metals like Z n, Cu and Pb in different plant organs, in roots than that of stems and leaves. High positive correlation between combinations of different metal pairs in plant's rootstem or leaf system was established. The potential use of these wetland plants in phytoremediation is also discussed.