Optimization of kaolin bioleaching by Aspergillus niger

M. Ranjbar, E. Aghaie, M. R. Hosseini, M. Pazouki, F. Ghavipanjeh

Research output: Chapter in Book/Report/Conference proceedingConference proceedingpeer-review

4 Citations (Scopus)


In this paper, a central composite design was applied to optimize the bioleaching of iron from a kaolin sample containing 2.2% iron impurity by Aspergillus niger isolated from pistachio shell. The strains were inoculated into 500 ml flasks containing 100 ml media consisted of (g/l): sucrose 120; NH4NO3 0.45; KH2P04 0.1; MgS0 4.7H20 0.3; FeS04.7H20 10 -4; ZnS04.7H20 25x10- 5. The effects of initial pH, sugar and spore concentrations on iron removal extent were investigated. The two-level factorial design points were pH 2 and 5, sugar cone. 70 g/l and 130 g/l, spore conc. 9x107 and 35x107 spores/l. Also, the increase of dissolved iron, oxalic acid concentration, changes in pH value, and sugar concentration were registered. Consequently, after 10 days, the iron concentration of the best condition reached to 179.3 ppm that means 38.8% of the total iron content is removed. Furthermore, the data analysis showed that all the factors are significant, and the iron removal extent increases by increasing the initial pH to 4.4, sucrose content to 93.8 g/l, and spore concentration to 305.5 spores/μl, but further increase in each factor value has negative effect on the response.

Original languageEnglish
Title of host publicationBiohydrometallurgy
Subtitle of host publicationFrom the Single Cell to the Environment
PublisherTrans Tech Publications
Number of pages4
ISBN (Print)0878494529, 9780878494521
Publication statusPublished - 2007
Externally publishedYes
Event17th International Biohydrometallurgy Symposium, IBS 2007 - Frankfurt am Main, Germany
Duration: 2 Sept 20075 Sept 2007

Publication series

NameAdvanced Materials Research
ISSN (Print)1022-6680


Conference17th International Biohydrometallurgy Symposium, IBS 2007
CityFrankfurt am Main


  • Bioleaching
  • Central composite design
  • Iron
  • Kaolin

ASJC Scopus subject areas

  • Engineering(all)


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