Phytoextraction of Lead (Pb) with Applied Radish (Rhaphanus Sativa L.).
Mehdi Homaee1, M. Hadi Ghaffariyan Jr.1, and Mohhamad Bybordi2. (1) Tarbiate Modarres, P.B 14115-111, Tehran, Iran, (2) Tehran Univ, Soil Science Dept, Tehran, Iran
Phytoextraction is a type of phytoremediation technology that utilizes plant from cleanup of metal-contaminated soils. The success of phytoextraction depends on the selection of suitable species that produce large biomass and also tolerate and accumulate toxic. Current research on phytoextraction have focused on the identified of plants that are accumulated heavy metals in high levels. Lead (Pb) is a trouble some environmental problem in many industrial countries. Phytexteraction of Pb polluted soils has been especially challenging since few species have been identified that can remediation lead and we say” which are those suitable”. From number of species that Pb phytoextraction. Rhadish was selected because it showed the most appropriate properties for phytoremediation. This plant has a fast–growing period with high biomass and it has high potential to accumulation lead in tissue, therefore we planning to study that objective of this research were to determine the effects of plant density and Pb concentration on Pb phytoextraction with radish. This field study was initiated in 2003 that plant growted in sandy loam. A factorial experimental design with completed randomized block that was consisting of 6 levels of soil lead on factor A and 3 levels of planting density on factor B with 4 replications. The treated soils were further enriched from Pb(No3) to concentration of 228 (normal amount Pb on soil region), 248, 328, 428, 728, 1228 µg/gr and Radish was planted with planting density of 225, 400, 625 plants per square meter. Lead content plant tissue was determined quantitatively using atomic absorption spectrophotometery unit. Observation showed, generally root and shoot Pb content increase with increasing concentrations of Pb in soil. The majority of Pb was retained in the root. Maximum lead concentrations in root were 440 µg/gr and shoot 42 µg/gr. Phytoremediation efficiency enhanced through planting with high density for all levels of Pb in the soil. Radish has 18-20 ton/hec yield and it could culture 4-5 time per year. This study demonstrated that radish could be removed Pb from soil contaminated to standard levels in less than three years. Therefore maybe radish is suitable plant for lead phytoextraction. Key word: Phytoremediation, Phytoexteraction, Lead (Pb), Radish (Rhaphanus Sativa L.).