Removal of heavy metal from polluted river water using aquatic macrophytes Salvinia SP - Espinoza-Quinones, F R; Zacarkim, C E; Palácio, S M; Obregon, C L; Zenatti, D C; Galante, R M; Rossi, N; Rossi, F L; Pereira, I R A; Welter, R A; Rizzutto, Márcia de Almeida (Brazilian Journal of Physics, 2005)