The influence of mercury speciation and its transformation in growth medium on the accumulation efficiency by white mustard

Abstract

ABSTRACT Mercury is the most dangerous pollutant prone to the formation of the toxic forms. Therefore, the problem of cleaning mercury contaminated areas seems to be very relevant. Numerous works have been published on the study of mercury uptake depending on the type of plants and natural conditions, but less attention was paid to studying the influence of element’s speciation on their accumulation ability. In the present work, the results of laboratory experiments on the assessment of accumulation efficiency of white mustard growing in medium with artificially introduced mercury species such as HgCl2, CH3Hg Cl and HgS are discussed and bioconcentration factors were evaluated while maintaining plant viability. It was shown that methylmercury is the most intensively accumulated specie while mercury sulphide is more imbibed than HgCl2 during 3 months experiment in spite of its negligible solubility in water. Based on the assumption that the cause of such a phenomenon is associated with the transformation of mercury species in the process of the plants growth, mercury speciation in the growing environment has been studied in dynamics and the results obtained confirmed this suppose. It appeared that HgCl2 and HgS are transformed into other chemical forms.