Ecology, Environment and Conservation Paper

IMPACT OF LEACHATE CHEMICALS OF RED MUD WASTE OFALUMINA INDUSTRY: ITS TOXICITY, IMPACT ONPHOTOSYNTHETIC EFFICIENCY AND PRODUCTION OF A CROPPLANT

Swarnalata Patnaik, A. Leelaveni and A.K. Panigrahi

Abstract

The leached chemicals of the red mud pond at Damonjodi pollutes the surrounding environment, particularlythe crop fields, where green gram is cultivated as a second crop of the year after either rice or ragi. Thelethal concentration values deduced were -MAC=0.2%; LC10-1.25% and LC50-2% leachate concentration.Hundred percent mortality or LC100 was found to be 2.8% lechate concentration. Browening of roots weremarked in leachate exposed seedlings and at higher exposure period root death and decay was seen inexposed seedlings. Petri plateexperiments revealed that pigments like chlorophyll-a, b; phaeophytin andcarotene content significantly declined in leachate exposed green gram seedling leaves compared to controlvalue. Little increment of chlorophyll pigment at lower concentration of the lechate can be attributed to thetriggering affect but not stimulatory affect of the toxicant. Significant depletion in respiration rate wasnoted in lechate exposed seedling leaves. In case of analysis of photosynthetic rate, an initial increase in theparameter and with the increase in leachateconcentration the PR decreased significantly. The GPP of thelechate exposed seedlings depleted with the increase in leachate concentration. Interesting results wereobtained at sub-lethal concentration of the leachate, where decrease in parameters were not observed, instead an increase or no significant change was noticed. All care should be taken to dispose the wastes of theindustry in the mega environment, where complex interaction patterns are not well known and wellunderstood.