DBPapers
DOI: 10.5593/sgem2017H/43/S19.050

HEAVY METAL TOXICITY AND DECONTAMINATION: TARNITA CLOSED MINE POLLUTION CASE

M. Zaharia, G. Drochioiu, D. Ilieva, A. E. Butnariu, A. Surleva
Thursday 23 November 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgemviennagreen.org, SGEM2017 Vienna GREEN Conference Proceedings, ISBN 978-619-7408-28-7 / ISSN 1314-2704, 27 - 29 November, 2017, Vol. 17, Issue 43, 397-404 pp; DOI: 10.5593/sgem2017H/43/S19.050

ABSTRACT

One of the main worldwide issues today is represented by the need of protecting the environment and human health. This requires prevention and monitoring the pollutant contamination of the environment and food products. Toxic heavy metals may accumulate in plant tissues and inhibit most physiological processes at all metabolism levels. They inhibit growth, photosynthesis, water uptake and nitrate assimilation. Romania is a resourceful country and a number of energy and mineral resources can be found on its territory, but the exploitation of these resources can determine air, water and soil pollution. The research in the environmental domain reveals that Romania has a large number of polluted sites. Mine tailings and heavy metal pollution of soils are two major comprehensive problems around the world. In particular, these issues have been identified as a primary research priority task for the polluted forest areas in Romania. In this study case, Tarniţa site was chosen because it is a strongly polluted area, especially with heavy metals, which results in a persistent ecological disaster. Heavy metal contamination in Tarniţa site represents a major risk to the human and forest health. This research has a high level of novelty and refers to the identification with fast and sensitive methods of some environmental toxic pollutants, their reactivity and biological properties study, as well as finding out of practical methodology of chemical and biological decontamination of some heavy metals. Since the microorganism-based bioremediation in the removal of various pollutants is a promising, relatively efficient, and cost-effective technology, we proposed here the use of Saccharomyces cerevisiae as heavy metals biodegradation and bioaccumulation material, due to its easy availability and the low cost of yeast suspensions. Besides, yeast cells hold the property to switch quickly from respiration to fermentation, being less sensitive to rather high concentration of heavy metals. By our opinion, the high amounts of metallic contaminants should be first removed by chemical ways for example by precipitation at pH 12 (out of contaminated site), filtration or centrifuging and then neutralization of filtrate/supernatant to pH 6-7. Electrolysis could be also used to recover precious or harmful metals. Therefore, in this particular case the ex situ chemical decontamination with alkaline solutions in order to hinder further and continuous contamination of soil and natural waters by the waste huge deposits should be followed by some mild bioremediation procedures able to remove in due time almost all the metal ions found in great excess around the barite and copper closed mines. All the measurements were addressed to the determination of metal concentrations in soil and waters.

Keywords: heavy metal contamination, mining waste, bioremediation, arsenic, wheat germination.