Pollution Research Paper

MONOCULTURE OF WETLAND PLANTS: A POTENT TOOL FOR REMEDIATION OF TANNERY EFFLUENT

Kumkum Mishra and Sumati Gaumat

Abstract

The ability of wetland plants to reduce the level of heavy metals in polluted waters has led to development of several phytoremediation systems. In this context experiment was conducted to investigate the ability of wetland plants (Bacopa monnieri, Cyperus flabelliformis, Typha latifolia, Scirpus lacustris) for treatment of tannery effluent (C.E.T.P, Unnao, U.P.) under mono-and mixed culture. The plants were treated with 100% effluent for 9 days to assess the improvement in physico-chemical properties of the effluent and reduction in its Cr level. They were treated with different effluent concentrations (25, 50, 75, and 100%) and durations (3, 6 and 9 d) under mono-and mixed- species culture for Cr accumulation. Effluent treated with plants (mono-and mixed-species culture) showed a significant improvement in several physico-chemical properties and reduction in Cr level in the following order: B. monnieri (97.33%) C. flabelliformis (93.18%) > mixed plant culture (90.72%) > T. latifolia (89.68%)> S. lacustris (88.78%). Cr accumulation was found to be more in roots than in shoots and it was interesting to note that plants under monoculture accumulated more metal than mixed species culture. On the basis of average concentration of metal (µg g-1 dw Cr) in root and shoot in mono-and mixed-culture it was found that B. monnieri (197.16 and 192.50) accumulated maximum amount of Cr followed C. flabelliformis (144.50 and 135.55), T. latifolia (142.69 and 133.70) and S. lacustris (131.40 and 123.78) respectively at 100% concentration after 9 d. In addition, plants exhibited different anatomical variations in their roots in response to stress condition. Overall performance of plants indicates that B. monnieri is best among all and can be recommended for treatment of tannery effluent.