中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
Vol. 16 No. 4 August 2006 |
(1. Key Laboratory of Biometallurgy of Ministry of Education,
School of Resources Processing and Bioengineering, Central South University,
Changsha 410083, China;
2. Key Laboratory of Marine Biogentic Resources of State Oceanic Administration,
Xiamen 361005, China)
Abstract: Cobblestone, glass beads and active carbon were selected as bacterial supports to study immobilization of Acidithiobacillus ferrooxidans in packed bed reactors. The production of ferric iron was then investigated in these immobilized reactors in batch and continuous operation modes. The results show that stable biofilm forms in cobblestone and active carbon supports, thus these two kinds of supports are suitable for immobilization of A. ferrooxidans. In batch culture, ferric iron productivity in reactor with cobblestone as supports is 0.61 g/(L∙h), which is 1.49 times higher than that in suspended culture reactor. In continuous operation mode, the maximum ferric iron productivity in reactor with cobblestone as supports is 1.54 g/(L∙h), which is 3.76 times higher than that in suspended culture reactor. The maximum ferric iron productivity in reactor with active carbon as supports is 1.89 g/(L∙h), which is 4.61 times higher than that in suspended culture reactor. In addition to bacteria, the results of X-ray diffraction and scanning electronic microscope analysis show that there is a lot of exopolysaccharide, jarosite and ammoniojarosite in biofilm, which plays important role in the formation of biofilm.
Key words: Acidithiobacillus ferrooxidans; immobilization; biofilm; ferric iron productivity