EFFECT OF THE GROWTH STAGE AND SULFATE CONCENTRATION ON Cr(VI) UPTAKE AND TOLERANCE BY HELIANTHUS ANNUUS

摘要

Phytoremediation refers to the use of plants for the restoration of polluted environments. This green technology exhibits several benefits including low cost, the applicability to large areas and the preservation of the natural state of the environment. Phytoremediation is already being used in several parts of the world to clean up pollution. For phytoremediation purposes, hyperaccumulator plants are preferred. Sunflower (Helianthus annuus) has been identified as a potential Cr hyperaccumulator; however, it displays low tolerance to this element. Leon, Gto., located in central Mexico, is considered one of the main leather producers in the world. In the tannery process Cr(III) salts are used. Under certain conditions, Cr(III) is oxidized to the carcinogenic Cr(VI) thus becoming potentially dangerous for human health. In addition, a chromate factory settled in this city has been identified as responsible for Cr(VI) pollution in soils and waters of this region. As part of an effort to identify new alternatives for the remediation of environments polluted with Cr, the effects of growth stage and sulfate concentration on Cr(VI) uptake and tolerance by H. annuus were studied.