Aquatic macrophytes

There is a further complication in shallow lakes containing macrophytes (aquatic flowering plants, pteridophytes, and macroalgae). These take up and accumulate nutrients from the water and from the aquatic soil in which they are rooted (sediment). Although these plants are sometimes classed as nuisance weeds, they nevertheless act as an important alternative sink for nutrients which are denied to the plankton. In recent times, a key role of macrophytes in the successful and sustained management of water quality has been identified and explained. ... 

Mann, C. J., and R. G. Wetzel. 1996. Loading and utilization of dissolved organic carbon from emergent macrophytes. Aquatic Botany 53 61-72. 

Ottosen, L. D. M., Risgaard-Petersen, N., and Nielsen, L. P. (1999). Direct and indirect measurements of nitrification and denitrification in the rhizosphere of aquatic macrophytes. Aquat. Microb. Ecol. 19, 81-91. 

Sala, M. M., and Glide, H. (1999). Role ofprotzoans on the microbial ectoenzymatic activity during the degradation of macrophytes. Aquat. Mkrob. Ecol. 20, 75—82. 

BCF factors in fish ranging from 1.08 to 1.85, indicating that bioconcentration of methyl parathion is not an important fate process (Crossland and Bennett 1984). In another study, methyl parathion was added to the water of a carp-rearing pond and the concentration of methyl parathion was measured in water, soil, macrophytes, and carp over a 35-day period. Results showed that methyl parathion accumulated in macrophytes for 1 day and in carp for 3 days following exposure, and then dissipated. The concentrations of methyl parathion decreased in macrophytes by 94% by day 35 and by 98% in carp tissue by day 28 (Sabharwal and Belsare 1986). These data indicate the potential for biomagnification in the food chain is likely to be low because methyl parathion appears to be metabolized in aquatic organisms. 

Allelochemic effects of aquatic macrophytes on algae are discussed. Bloassays of chromatographic fractions from Eleocharls mlcrocarpa Torr. Indicate that oxygenated fatty acids are the causative agents. Methods of Isolation of these materials from aquatic macrophytes and from natural waters are described. Purification and structure determinations show that prominent components of the fraction are C q tri-hydroxycydopentyl and hydroxycydopentenone... 

Current reviews on biosorption are related to general approaches90-93 to diverse types of biomass such as microbial biomass, plant wastes, and agro-based waste materials, or to a specific metal.4-94-98 However, a review on metal biosorption using macrophytes biomass is not available. In this chapter, a review on the current knowledge of biosorption using preferentially nonliving biomass from aquatic plants is presented. 

Recent reports on biosorbents based on diverse types of macrophytes are found widely in the literature. Free-floating aquatic plants from the genera Salvinia, Azolla, Eichhornia, Lemna, and Pistia have been described the most. S. natans biomass was able to uptake As(V) at low initial concentrations from 0.25 to 2 mg/L (74.8% and 54%, respectively). The experimental data fitted well to both Langmuir and Freundlich isotherms. The effect of pH and biomass quantities on sorption rate has also been investigated along with some metabolic parameters.105... 

Hu, M.H., Ao, Y.S., Yang, X.E., and Li, T.Q., Treating eutrophic water for nutrient reduction using an aquatic macrophyte (Ipomoea aquatica Forsskal) in a deep flow technique system, Agricultural Water Management, 95, 607-615, 2008. 

Miretzky, P., Saralegui, A., and Fernandez Cirelli, A., Aquatic macrophytes potential for the simultaneous removal of heavy metals (Buenos Aires, Argentina), Chemosphere, 57 (8), 997-1005, 2004. 

Rai, P.K., Phytoremediation of Hg and Cd from industrial effluents using an aquatic free floating macrophyte Azolla Pinnata, International Journal of Phytoremediation, 10, 430-439, 2008b. 

Mishra, V.K., Upadhyaya, A.R., Pandey, S.K., and Tripathi, B.D., Heavy metal pollution induced due to coal mining effluent on surrounding aquatic ecosystem and its management through naturally occurring aquatic macrophytes, Bioresource Technology, 99 (5), 930-936, 2008. 

I. The source of allelochemicals The allelochemicals found in the water are produced by phycoplanktonic or bentonic algae, by aquatic macrophytes cohabiting with the algae, or are they present in the water body accidentally (They can be released by plants living on the border of the water body or by leakage water etc.)... 

Aquatic macrophytes, whole Nile River, Egypt Industrialized area Max. 22 DW 6... 

Knowlton, M.F., T.P. Boyle, and J.R. Jones. 1983. Uptake of lead from aquatic sediment by submersed macrophytes and crayfish. Arch. Environ. Contam. Toxicol. 12 535-541. 

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