title: Evaluation of Cajanus cajan (pigeon pea) for phytoremediation of landfill leachate containing chromium and lead.
abstract: Landfill leachates containing heavy metals are important contaminants and a matter of great concern due to the effect that they might have on ecosystems. We evaluated the use of Cajanus cajan to remove chromium and lead from landfill leachates. Eight-week-old plants were submitted to varied tests to select the experimental conditions. Water assays with a solution (pH 6) containing leachate (25% v/v) were selected; the metals were added as potassium dichromate and lead (II) nitrate salts. Soil matrices that contained leachate (30% v/v) up to field capacity were used. For both water and soil assays, the metal concentrations were 10 mg kg(-1). C. cajan proved able to remove 49% of chromium and 36% of lead, both from dilute leachate. The plants also removed 34.7% of chromium from irrigated soil, but were unable to decrease the lead content. Removal of nitrogen from landfill leachate was also tested, resulting in elimination of 85% of ammonia and 70% of combined nitrite/nitrate species. The results indicate that C. cajan might be an effective candidate for the rhizofiltration of leachates containing chromium and lead, and nitrogen in large concentrations.
authors.affiliation: a Escuela de Química y Centro de Investigaciones en Productos Naturales (CIPRONA), Universidad de Costa Rica, Ciudad Universitaria Rodrigo Facio , San Pedro de Montes de Oca, San José , Costa Rica.
authors.forename: José A
authors.initials: JA
authors.lastname: Jerez Ch
authors.affiliation: a Escuela de Química y Centro de Investigaciones en Productos Naturales (CIPRONA), Universidad de Costa Rica, Ciudad Universitaria Rodrigo Facio , San Pedro de Montes de Oca, San José , Costa Rica.
authors.forename: Rosaura M
authors.initials: RM
authors.lastname: Romero
mesh_terms: D001673:Biodegradation, Environmental; D036561:Cajanus / Q000378:metabolism*; D002857:Chromium / Q000378:metabolism*; D003364:Costa Rica; D007854:Lead / Q000378:metabolism*; D012989:Soil Pollutants / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D002857:Chromium; D007854:Lead
keywords: Cajanus cajan; landfill leachates; chromium; heavy metals; lead; phytoremediation; waste disposal