Abstract:
Lead (Pb) is challenging to remediate due to its persistent toxicity, non-biodegradability, low mobilization and bioaccumulation in food chain. Chelating agents may enhance Pb phytoavailability and phytoextraction. The aim of this study was to investigate effect of EDTA and DIPA to enhance Pb phytoavailability and uptake. For this purpose soil was spiked with Pb concentration (0, 500, 750, 1000 and 1500 mg kg-1) and amended with EDTA and DIPA at dosage level (0, 1.5, 3, 5, 7.5, 10 mmol kg-1) for plantation of Pelargonium hortorum. Soil samples were extracted with MgCl2, plant samples were digested with HNO3:HCl in (3:1) and analyzed through Atomic Absorption Spectroscopy (AAS). The behavior of both EDTA and DIPA was monitored in aspect of vegetative traits, Pb phytoavailability and plant uptake. Biomass of Pelargonium hortorum was decreased with increase in concentration of Pb and chelating agents. Phytoavailability of Pb at 1500 mg kg-1 with EDTA 10 mmol kg-1 was 1.4-folds in comparison to DIPA at same dosage. Pelargonium hortorum found to accumulate Pb in following order EDTA> DIPA> Control. EDTA and DIPA at 10 mmol kg-1with Pb 1000 mg kg-1 were found to uptake Pb 6-fold and 3-foldsin comparison to Pb 1000 mg kg-1 alone. Pb uptake decreased at 1500 mg kg-1 with both chelating agents. Translocation factor of Pelargonium hortorum was <1. On the whole, 10 mmol kg-1 of EDTA and DIPA performed better among all dosage. Increasing concentration of cheating agents enhanced phytoavailability and uptake of Pb. Data from present research provide a new insight to use DIPA in phytoremediation to reclaim contaminated soil.
