PM01 Phytoremediation and Risk Assessment
Exhibit Hall
8:00 AM - Monday
(PM006) Metal accumulator plants in Japan – implications for phytoremediation of Cd and Pb contaminated soils.
Ohba, K1, Watanabe, I1, Motobayashi, T1, Kuno, K1, Noda, K2, Uchida, T3, Yamada, R3, 1 Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan2 Hirosaki University, Hirosaki, Aomori, Japan3 Sato Kogyo Co.,Ltd., Tokyo, Japan
ABSTRACT- To search for the plants that can be applied to phytoremediation of contaminated soils with heavy metals, 28 element concentrations in leaves of 50 plant species collected from paddy field contaminated with Cu, Zn, Cd and Pb, and firing range contaminated with Pb were determined. Heavy metal concentrations of soils collected from these contaminated sites were also analyzed. Cd concentrations of paddy field and firing range soils were 1.5 and 0.3 mg/kg D.W., and Pb concentrations were 63 and 367 mg/kg D.W., respectively. Bioconcentration factor of Cd in leaves of 16 plant species were more than 1 ( 17 in Kummerowia striata, 9 in Artemisia princeps and Erigeron sumatrensis). No plant accumulated Pb at high level in shoot except Persicaria longiseta and Rumex obtusifolius ( 600 and 210 mg/kg D.W.). Hydroponic experiments ( Cd: 5mg/L or Pb: 10mg/L ) were conducted with Ambrosia trifida, Bidens pilosa, Cosmos sulphureus, Achyranthes fauriei, Amaranthus patulus, Chenopodium album and Chenopodium album var. centrorubrum . After 96-hour Cd treatment, chlorosis was observed in Ambrosia trifida and Cosmos sulphureus. Cd concentrations were higher in roots than in shoots, however shoot Cd concentrations were over 100 mg/kg D.W. in all tested plants. Pb concentrations were also higher in roots ( 1200-4500 mg/kg D.W. ) than in shoots ( <3.5 mg/kg D.W. ). Bidens pilosa and Chenopodium album were cultured with Pb-polluted soil ( 4500 mg/kg D.W. ). In contrast with the results of hydroculture experiments, Pb accumulation at exceeding level was observed in shoots of two plants. Chenopodium album accumulated 1700 mg/kg D.W. Pb in its shoot. Three Pb accumulator plants observed herein, Persicaria longiseta, Rumex obtusifolius and Chenopodium album are known to contain oxalate characteristically. Thus, it was expected that oxalate could be involved in Pb accumulation in these plants.
Key words: cadmium, phytoremediation, lead, Chenopodium album