%0 Journal Article %T Hemp Fibres as Novel Green Support Material for Immobilization of Acidithiobacillus ferrooxidans %J International Journal of Engineering %I Materials and Energy Research Center %Z 1025-2495 %A Akhlaghi, Neda %D 2019 %\ 09/01/2019 %V 32 %N 9 %P 1225-1230 %! Hemp Fibres as Novel Green Support Material for Immobilization of Acidithiobacillus ferrooxidans %K Acidithiobacillus Ferrooxidans %K Bio-oxidation %K Hemp Fibres %K Immobilization %K Packed-bed bioreactor %R 10.5829/ije.2019.32.09c.01 %X The suitability of hemp fibres as green support material for immobilization of Acidithiobacillus ferrooxidans cells in ferrous iron bio-oxidation process was investigated. A series of experiments were carried out in shake flasks and bioreactor for both cell immobilization and iron bio-oxidation. In flask experiments, five successive batch colonization cycles resulted in 6-fold increase in ferrous iron bio-oxidation rate. Evaluation of immobilized cells activity through two approaches as wet and dry storage demonstrated the higher activity of wet stored bacteria than dry ones after a period of two months. The dry stored bacteria lost almost all their activities after eight weeks. Whereas, the activity of wet stored samples was 30% at the same time. In bioreactor experiments, use of a packed-bed bioreactor with hemp fibres, the maximum ferrous iron bio-oxidation rate of 2.46 kg m-3 h-1 was obtained at dilution rate of 3.97 h-1, and retention time of 0.25 h. Our experimental results could pave a new platform for the application of hemp fibre as an inexpensive and environmentally friendly support material in bacterial cell immobilization, especially in ferrous iron bio-oxidation process using acidophilic bacteria.  %U https://www.ije.ir/article_93861_4e0b3ae4ff58ea72cf4d6fef01d367cb.pdf