Biomass macrophytes

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. 

Spirodela intermedia, L. minor, and P. stratiotes were able to remove Pb(II), Cd(II), Ni(II), Cu(II), and Zn(II), although the two former ions were removed more efficiently. Data fitted the Langmuir model only for Ni and Cd, but the Freundlich isotherm for all metals tested. The adsorption capacity values (K ) showed that Pb was the metal more efficiently removed from water solution (166.49 and 447.95 mg/g for S. intermedia and L. minor, respectively). The adsorption process for the three species studied followed first-order kinetics. The mechanism involved in biosorption resulted in an ion-exchange process between monovalent metals as counterions present in the macrophytes biomass and heavy metal ions and protons taken up from water.112... 

This equation provides a relatively simple estimation method and should yield acceptable results when log Kow is less than 5 and there is no metabolism in or on the surface of the macrophytes. For substances with a greater Knu, changes in macrophyte biomass, i.e., growth dilution, can be important. If appropriate data regarding rate constants are available, a kinetic model may be preferable in assessing the bioconcentration of hydrophobic organic substances in aquatic macrophytes (e.g., Gobas et al., 1991). However, in most cases, this information is not available. 

Robertson, A.I. and Lucas, J.S., Food choice, feeding rates and the turnover of macrophyte biomass by a surf-zone inhabiting amphipod, J. Exp. Mar. Biol. Ecol., 72, 99, 1983. 

Figure 14.7 Periphyton and macrophyte biomass and areal coverage at Lake Calado dominant genera are listed in bottom panel T. R. Fisher, D. Engle, and R. Doyle, unpublished data.

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... 

Verma, V.K., Tewari, S., and Rai, J.P.N., Ion exchange during heavy metal bio-sorption from aqueous solution by dried biomass of macrophytes, Bioresource Technology, 99 (6), 1932-1938, 2008. 

The photo synthetic aquatic biomass comprises cyanobacteria (formerly called blue-green algae), planktonic, filamentous and macrophytic algae, and vascular macrophytes. The net productivity of the floodwater depends on the level of primary production by the photosynthetic biomass versus its consumption by grazing animals, particularly cladocerans, copepods, ostracods, insect larvae and molluscs. Their role will change as the canopy develops and at a leaf area index of about 6-7 there will be no more photosynthetically active radiation available to them. 

Boschker, H.T.S., de Brower, I.F.C., and Cappenberg, T.E. (1999) The contribution of macrophyte-derived organic matter to microbial biomass in salt-marsh sediments Stable carbon isotope analysis of microbial biomarkers. Limnol. Oceanogr. 44, 309-319. 

Kuehn, K. A., Lemke, M. J., Suberkropp, K. Wetzel, R. G. (2000). Microbial biomass and production associated with decaying leaf litter of the emergent macrophyte Juncus effusus. Limnology and Oceanography, 45, 862-70. 

The seasonally changing biomass of floating macrophytes was determined at Lake Calado with a combination of sampling and airborne videography (Fisher and Moline 1992 T.R. Fisher, personal communication Fig. 14.7). Further analysis of these data... 

The complex structure and seasonal dynamics of herbaceous macrophyte communities make it difficult to estimate their total annual contribution to floodplain lake production. Annual production estimates must incorporate the cumulative, sequential production of terrestrial, semiaquatic and aquatic plant communities and the spatial and temporal variation in their distributions. To date all measurements of macrophyte production have been made in a limited area on the central Amazon floodplain near Manaus. Only a few of these estimates have included contributions of more than one species. Junk and Piedade (1993) estimated the cumulative biomass increase of three successive macrophyte communities (terrestrial, semiaquatic, and aquatic) growing under... 

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