HEXAVALENT CHROMIUM REMOVAL BY FUNGAL ADSORBENT, Aspergillus terricola
LATIFA A. MOHAMED
Biotechnology Research Institute, Microbial Chemistry Department, National Research Centre, 33 Bohouth Street, Dokki, Giza, Egypt.
MAGDA A. EL-BENDARY *
Biotechnology Research Institute, Microbial Chemistry Department, National Research Centre, 33 Bohouth Street, Dokki, Giza, Egypt.
*Author to whom correspondence should be addressed.
Abstract
The discharge of hexavalent chromium, Cr (VI), in the environment as a consequence of industrial activities, is threatening the human health and the ecosystem. Removing Cr (VI) by biosorption using fungal biomass is a promising and cost effective technique. In the present study, the potential of Aspergillus terricola as a biosorbent for removing Cr (VI) from aqueous solution was studied. The growth of Aspergillus terricola was stimulated by addition of 1.5 mg/l Cr (VI) and the MIC was found to be 9 mg/l in liquid medium. Also, the highest growth of tested organism in the presence of 1.5 mg/l Cr (VI) in the growth medium was at pH 3 after 6 days. Optimization of biosorption process parameters using Aspergillus terricola biomass in aqueous solution exhibited that increasing the Cr (VI) concentration decreases the removing efficiency. Removing 100% of 20 mg/l Cr (VI) was obtained after 4 days contact time. In addition, the maximum Cr (VI) removal was obtained at pH 3. Furthermore, increasing the mycelium concentration leads to gradual increase in removing percentage of Cr (VI). In conclusion, Aspergillus terricola was an efficient candidate for biosorption of hexavalent chromium and could be used in its bioremediation from wastewater.
Keywords: Chromium bioremediation, Aspergillus terricola, biosorption