Cr, Ni, and Zn removal from landfill leachate using vertical flow wetlands planted with Typha domingensis and Canna indica

MAINE, MARÍA ALEJANDRA; HADAD, HERNÁN RICARDO; CAMAÑO SILVESTRINI, NAHUEL ERNESTO; NOCETTI, EMANUEL; SANCHEZ, GABRIELA CRISTINA; CAMPAGNOLI, MARCELO ABEL

INTERNATIONAL JOURNAL OF PHYTOREMEDIATION

TAYLOR & FRANCIS INC

Año: 2022 vol. 24 p. 66 - 75

1522-6514

Cr, Ni, and Zn removal from landfill leachate using mesocosm-scale vertical flow wetlands, the effect of recirculation, and the ability of macrophytes to retain metals were evaluated. Wetlands were filled with coarse sand and LECA and planted with Typha domingensis or Canna indica. Wetlands were operated using intermittent loading, with and without recirculation. Raw leachate was diluted and spiked with metals to reach the following concentrations: 0.2 mg L-1 Cr + 0.2 mg L-1 Ni + 0.2 mg L-1 Zn, and 1.0 mg L-1 Cr + 1.0 mg L-1 Ni + 1.0 mg L-1 Zn. Wetlands planted with T. domingensis presented higher metal removal than those planted with C. indica. Recirculation enhanced metal removal efficiencies significantly, being for T. domingensis/C. indica: 60/54, 49/47, 61/47% for Cr, Ni, and Zn at 0.2 mg L-1, and 80/71, 76/62, 73/59% for Cr, Ni, and Zn at 1.0 mg L-1, respectively. Metals were efficiently retained by macrophytes. Plant biomass and metal concentrations in roots were significantly higher than in shoots. SEM and X-ray microanalysis showed that metals were absorbed by internal root tissues. A hybrid wetland planted with T. domingensis may be implemented to improve not only metal but also COD and TN removals.