Abstract

AMABILIS-SOSA, Leonel Ernesto; SIEBE, Christina; MOELLER-CHAVEZ, Gabriela  and  DURAN-DOMINGUEZ-DE-BAZUA, María del Carmen. Removal of mercury by Phragmites australis used as biological barrier in constructed wetlans inoculated with heavy metal-tolerant strains. Rev. Int. Contam. Ambient [online]. 2016, vol.32, n.1, pp.47-53. ISSN 0188-4999.

In this study, accumulation and distribution of mercury in common reed (Phragmites australis) as a biological barrier in constructed wetlands (CW) were assessed during wastewater treatment. Six CW, planted with common reed, were built, three of them were inoculated with heavy metal-tolerant strains and the otherthree were non-inoculated. Also three systems unplanted and non-inoculated were built as control. The feeding water was synthetic wastewater with 0.11 mg/L of mercury, value established in previous studies and reported for effluents of industries related to the use of this metal. After 304 operation days, systems with common reed and metal-tolerant bacteria were able to remove 73 % of total mercury. With similar values, systems with vegetation but without metal-tolerant bacteria, removed 66 % of it. In both systems, mercury was transferred, mostly, to atmosphere due to accumulation, translocation and transpiration exhibited by reed. Meanwhile, systems used as control, removed 52 % of total mercury and transferred the lowest amount of metal to the atmosphere. The results obtained from this study give important basic data to expand knowledge about the technical feasibility of using CW to treat wastewaters containing mercury.

Keywords : mercury bioremediation; metalotolerant bacteria; mercury evapotranspiration.