Macrophytes play an important role in nutrient dynamics of the lake ecosystem. The aim of this study is to determine the growth pattern and to evaluate the nutrient accumulation capacity of water hyacinth [Eichhornia crassipes (Mart) Solms] growing in Robrtson Lake, Jabalpur. The paper is outcome of in situ experiment conducted in Robertson lake (which has a dense mat of water hyacinth), as well as laboratory microcosms experiment. Water hyacinth grew at an average rate of 3.85 g dw m -2 d and it accumulates 263 kg N ha -1 yr -1 and 67 kg P ha -1 yr -1 , respectively. The chemistry of lake water does not show any significant seasonal variation; however the growth of water hyacinth in laboratory microcosms removed 79% of PO 4 -P and 58% NO 3 -N from the growth medium. Thus, the data reveal that water hyacinth stands growing in the lake highly buffered the water chemistry by reducing nutrient level, in spite of heavy nutrient load in the lake from domestic waste and factory effluent.

No abstract

Various chromophores are used to make our day-to-day life colorful. Dyes that are used at a large scale are made using these chromophores. The dyes, especially azo dyes are recalcitrant to the degradation due to the presence of aromatic rings in their structure. Several methods have been developed to reduce the harmful impacts of these dyes on the environment. However, none of the processes is safe and fully effective. In this study, we used bacteria as a bioremediation agent and optimized the various parameters for the bacteria to degrade the dye at its maximum ability. It was found that the isolated bacteria were Aneurinibacillus sp. and it completely decolorized methyl orange at a concentration of 20 mg.L-1 after 4 days of incubation. The optimum pH for the functioning of bacteria was 5 and the activity decreased as the pH increased. It was also observed that the addition of glucose and yeast extract increased the dye degradation significantly.