Phytoextration of bromine from contaminated soil

Bromine (Br) is widely distributed in the environment. However, its concentration in soils and plants in ordinary conditions is usually low. Bromine was excessively used in agriculture in the past, and now various compounds of Br are synthesized industrially and have many uses. This led to pollution of soil and accumulation of Br in crops. High concentrations of Br are toxic for plants and man. There is a need to reduce soil Br contamination. The aim of the research was to study the uptake of Br by two plant species, wheat and pea, that differ in the ability to accumulate and tolerate high amounts of Br and to assess the potential of the plants for purposes of phytoextraction of Br from contaminated soil. In the present work, greenhouse pot experiments were conducted. Soil in the pots was spiked with either KBr or NaBr at concentrations 0 mg kg− 1, 50 mg kg− 1, and 100 mg kg− 1. Concentrations of halogens in soil and plant samples were determined using ICP-MS technique after leaching of the samples with tetramethyl ammonium hydroxide at 60 °C. The experimental results showed that wheat and pea seedlings can accumulate rather large amounts of Br. As a consequence of Br bioaccumulation its concentration in the rhizosphere soil decreased. Pea and wheat grown simultaneously under the same conditions were capable of accumulating different amounts of halogens and nutrients. In particular, concentration of Br and Cl in leaves of wheat was always higher than in leaves of pea. This might be due to the fact that these two plant species fall into different classes: wheat belongs to monocotyledons and pea belongs to dicotyledons.