Evaluation of mobility, bioavailability and toxicity of Pb and Cd in contaminated soil using TCLP, BCR and earthworms.
The objective of the present study was to investigate the reduction of mobility, availability and toxicity found in soil contaminated with lead (Pb) and cadmium (Cd) from Santo Amaro Municipality, Bahia, Brazil using two combined methods, commonly tested separately according to the literature: metal mobilization with phosphates and phytoextraction. The strategy applied was the treatment with two sources of phosphates (separately and mixed) followed by phytoremediation with vetiver grass (Vetiveria zizanioides (L.)). The treatments applied (in triplicates) were: T1-potassium dihydrogen phosphate (KH2PO4); T2-reactive natural phosphate fertilizer (NRP) and; T3-a mixture 1:1 of KH2PO4 and NRP. After this step, untreated and treated soils were planted with vetiver grass. The extraction procedures and assays applied to contaminated soil before and after the treatments included metal mobility test (TCLP); sequential extraction with BCR method; toxicity assays with Eisenia andrei. The soil-to-plant transfer factors (TF) for Pb and Cd were estimated in all cases. All treatments with phosphates followed by phytoremediation reduced the mobility and availability of Pb and Cd, being KH2PO4 (T1) plus phytoremediation the most effective one. Soil toxicity however, remained high after all treatments.
Post-Graduation Program in Environmental Science, Rio de Janeiro State University-UERJ, Rua Francisco Xavier, 524, Maracanã, Rio de Janeiro 20550-900, Brazil. mluizakede@gmail.com.
Maria Luiza F M
ML
Kede
Department of Natural Science, Universidade Federal do Estado do Rio de Janeiro-UNIRIO, Av. Pasteur, 458, Urca, Rio de Janeiro 22290-240, Brazil. fabio.correia@unirio.br.
Fabio V
FV
Correia
Department of Natural Science, Universidade Federal do Estado do Rio de Janeiro-UNIRIO, Av. Pasteur, 458, Urca, Rio de Janeiro 22290-240, Brazil. paulofellip@hotmail.com.
Paulo F
PF
Conceição
Department of Natural Science, Universidade Federal do Estado do Rio de Janeiro-UNIRIO, Av. Pasteur, 458, Urca, Rio de Janeiro 22290-240, Brazil. sidneysalesjunior@gmail.com.
Sidney F Salles
SF
Junior
Department of Sanitary and Environmental Engineering, Rio de Janeiro State University-UERJ, Rua Francisco Xavier, 524, Maracanã, Rio de Janeiro 20550-900, Brazil. marciam@uerj.br.
Marcia
M
Marques
National School of Public Health, Oswaldo Cruz Fundation-FIOCRUZ, Rua Leopoldo Bulhões, 1480, Manguinhos, Rio de Janeiro 21045-900, Brazil. josinocm@fiocruz.br.
Josino C
JC
Moreira
Nacional Centre of Soil Research EMBRAPA-Solos, Rua Jardim Botânico, 1024, Jardim Botânico, Rio de Janeiro 22460-000, Brazil. daniel.perez@embrapa.br.
Daniel V
DV
Pérez
D001673:Biodegradation, Environmental; D001682:Biological Availability; D002104:Cadmium / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D004787:Environmental Pollution / Q000517:prevention & control*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D005308:Fertilizers / Q000032:analysis; D007854:Lead / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D010710:Phosphates / Q000737:chemistry*; D017680:Potassium Compounds / Q000737:chemistry; D012989:Soil Pollutants / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*
D005308:Fertilizers; D010710:Phosphates; D017680:Potassium Compounds; D012989:Soil Pollutants; D002104:Cadmium; D007854:Lead; C013216:potassium phosphate