ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Bioreduction of ionic mercury from wastewater in a fixed-bed bioreactor with activated carbon

Paweł Głuszcz, Katarzyna Zakrzewska, Irene Wagner-Doebler, and Stanisław Ledakowicz

Bioprocess Engineering Department, Technical University of Lodz, 90-924 Lodz, Poland

E-mail: pgluszcz@p.lodz.pl

Received: 2 April 2007  Revised: 1 October 2007  Accepted: 4 October 2007

Abstract: Wide industrial use of mercury led to significant mercury pollution of the environment. It requires development of cleanup technologies which would allow treating large volumes of mercury contaminated water in a cost effective and environmentally friendly way. A novel bio-technology, developed from laboratory to industrial scale in Germany at HZI (former GBF), is based on enzymatic reduction of highly toxic Hg(II) to water-insoluble and relatively non-toxic Hg(0) using live mercury resistant bacteria immobilized on a porous carrier material in a fixed-bed bioreactor. Improvement of the original method was based on the use of activated carbon as a carrier for microorganisms and an adsorbent for mercury. Such integration of the process should increase the technology efficiency. In order to compare different carrier materials, activated carbon and pumice stones were used. The strain Pseudomonas putida was immobilized in bioreactors continuously fed with solutions of HgCl₂ enriched with nutrients. Simultaneously, experiments in two more reactors were run in the absence of microorganisms to investigate the influence of nutrients on the adsorption process. In the bioreactor with activated carbon, the outlet mercury concentration was approximately 50 % of that supplied with pumice. It may be concluded that the use of activated carbon in a fixed-bed bioreactor enables improvement of the technology by process integration.

Keywords: wastewater treatment - mercury bioreduction - bioremediation - activated carbon - process integration

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-008-0017-z

Chemical Papers 62 (3) 232–238 (2008)