TITLE:
Laboratory Studies on Phosphorus Removal from Nigeria’s Agbaja Iron Ore by Bacillus Subtilis
AUTHORS:
C. N. Anyakwo, O.W. Obot
KEYWORDS:
Phosphorus, Bacillus Subtilis
JOURNAL NAME:
Journal of Minerals and Materials Characterization and Engineering,
Vol.10 No.9,
July
20,
2011
ABSTRACT: The investigation into whether or not Bacillus subtilis can remove phosphorus from the
Nigerian Agbaja iron ore was carried out with careful monitoring of the population of the
removing agent as well as pH of the system. 1.00mm/0.50mm, 0.50mm/0.25mm, and
0.25mm/0.125mm ore fractions obtained from sieving of the crushed iron ore in Shital Test
kits, were used in sub-merged culture of nutrient broth (NB) medium for 10 weeks. B. subtilis
which was part of the rich microflora found on the ore surface was cultivated in nutrient-rich
media and later inoculated in sterilized 100ml of NB in 250ml conical flask and 1g of each of
the equally sterilized ore fractions was added. At weekly intervals, a set of samples was
removed, treated through series of chemical reactions to obtain ammonium phosphomolybdate
precipitate which was back-titrated with 0.1 N-HCl to determine the amount of
phosphorus left in samples and consequently, the amount removed. The laboratory
investigations found out that B. subtilis has the capability to remove phosphorus from the
Nigerian Agbaja iron ore, recording an impressive average of 65.73% P. Also found out was
the systematic reduction in bacterial cells count in colony forming unit per mililitre, the
initial load 3.4x105 cfu/ml increased to 4.8x107 cfu/ml from where it declined to 1.3x106 cfu/ml, which justified the pH trend observed during the process of cumulative phosphorus removal. The reduction in microbial activity may be attributed to antimicrobial components of the ore, pyrite, and other heavy metals which may have affected the phosphorus uptake from ore.