title: Pb(II) adsorption by biomass from chemically modified aquatic macrophytes, Salvinia sp. and Pistia stratiotes.
abstract: This study used two biosorbents obtained from the aquatic plants Salvinia sp. and Pistia stratiotes to establish a sustainable and alternative treatment for industrial wastewater and other water bodies that contain Pb(II). The biosorbent named Salvinia with NaOH (SOH) was obtained from Salvinia sp., and Salvinia and Pistia mixture with NaOH (SPOH) was obtained from a mixture of the two plants in a 1:1 ratio. The biosorbents were characterized by zeta potential, infrared (IR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive spectroscopy and Boehm titration. The results of Boehm titration and IR analysis indicated the presence of basic functional groups, whereas those of SEM analysis indicated that the biosorbents have a structure conducive to adsorption. Batch adsorption experiments were performed to observe the effects of pH, contact time, initial lead concentration and temperature on the metal removal process. The results revealed that the biosorbents efficiently removed Pb(II) from aqueous solutions, with a maximum observed adsorption capacity (saturation limits, qmax) of 202 mg g(-1) and 210.1 mg g(-1) for SPOH and SOH, respectively. The Freundlich, Langmuir and Dubinin-Radushkevich models were applied to the data; these biosorbent studies did not satisfactorily adjust to either of the models, but the information obtained helped us understand the adsorption mechanism.
authors.affiliation: Graduate Program in Environmental Science and Conservation, Federal University of Rio de Janeiro, Macaé, Rio de Janeiro, Brazil E-mail: rachelmoraes@hotmail.com.br.
authors.forename: Rachel
authors.initials: R
authors.lastname: de Moraes Ferreira
authors.affiliation: Analytical and Environmental Chemistry, Federal University of Rio de Janeiro-Campus Macaé, Macaé, Rio de Janeiro, Brazil.
authors.forename: Michael Douglas Peçanha
authors.initials: MD
authors.lastname: de Souza
authors.affiliation: Chemical Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Iracema
authors.initials: I
authors.lastname: Takase
authors.affiliation: Graduate Program in Environmental Science and Conservation, Federal University of Rio de Janeiro, Macaé, Rio de Janeiro, Brazil E-mail: rachelmoraes@hotmail.com.br; Analytical and Environmental Chemistry, Federal University of Rio de Janeiro-Campus Macaé, Macaé, Rio de Janeiro, Brazil.
authors.forename: Danielle Marques
authors.initials: DM
authors.lastname: de Araujo Stapelfeldt
mesh_terms: D000327:Adsorption; D029064:Araceae / Q000737:chemistry*; D018533:Biomass; D005591:Chemical Fractionation; D005240:Feasibility Studies; D029624:Ferns / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007854:Lead / Q000302:isolation & purification*; D008855:Microscopy, Electron, Scanning; D013052:Spectrometry, X-Ray Emission; D013696:Temperature; D062065:Wastewater / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D007854:Lead; D062065:Wastewater; D014874:Water Pollutants, Chemical