title: Effect of low molecular weight organic acids on the uptake of226Ra by corn (Zea mays L.) in a region of high natural radioactivity in Ramsar-Iran.
abstract: To study the benefit of including citric and oxalic acid treatments for phytoremediation of226Ra contaminated soils a greenhouse experiment with corn was conducted. A soil was sampled from a region of high natural226Ra radioactivity in Ramsar, Iran. After cultivation of corn seed and using organic acid treatments at 1, 10 and 100 mM concentrations, plants (shoots and roots) were harvested, digested and prepared to measure226Ra activity. Simultaneously, sequential selective extraction were performed to estimate the partitioning of226Ra among geochemical extraction. Results showed that the maximum uptake of226Ra in plants was observed in citric acid (6.3%) and then oxalic acid (6%) at 100 mM concentration. These treatments increased radium uptake by a factor of 1.5 than the control. Enhancement of radium uptake by plants was related to soil pH reduction of organic acids in comparison to control. Also, the maximum uptake of this radionuclide in all treatments was obtained in roots compared to shoots.226Ra fractionations results revealed that 91.8% of radium was in the residual phase of the soil and the available fractions were less than 2%. As the main percent of226Ra was in the residual phase of the soil in this region, it seems that organic acids had not significant effect on the uptake of226Ra for phytoremediation by corn in this condition.
authors.affiliation: Department of Soil Science, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran. Electronic address: snezami1981@gmail.com.
authors.forename: Sareh
authors.initials: S
authors.lastname: Nezami
authors.affiliation: Department of Soil Science, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran.
authors.forename: Mohammad Jafar
authors.initials: MJ
authors.lastname: Malakouti
authors.affiliation: Nuclear Fuel Cycle Research School, Nuclear Science and Technology Research Institute, Tehran, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Bahrami Samani
authors.affiliation: Nuclear Fuel Cycle Research School, Nuclear Science and Technology Research Institute, Tehran, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Ghannadi Maragheh
mesh_terms: D000143:Acids / Q000494:pharmacology*; D001673:Biodegradation, Environmental / Q000187:drug effects; D007492:Iran; D008970:Molecular Weight; D009930:Organic Chemicals / Q000494:pharmacology*; D011883:Radium / Q000737:chemistry* / Q000378:metabolism*; D012990:Soil Pollutants, Radioactive / Q000378:metabolism*; D003313:Zea mays / Q000187:drug effects* / Q000378:metabolism*
chemical_list: D000143:Acids; D009930:Organic Chemicals; D012990:Soil Pollutants, Radioactive; D011883:Radium
keywords: (226)Ra; Corn; Organic acids; Phytoremediation; Uptake