Laboratory Studies on Phosphorus Removal from Nigeria’s Agbaja Iron Ore by Bacillus Subtilis

C. N. Anyakwo, O.W. Obot

Department of Mechanical Engineering, Faculty of Engineering, University of Uyo, Nigeria..
Department of Metallurgical and Materials Engineering, Federal University of Technology,Owerri, Nigeria..

DOI: 10.4236/jmmce.2011.109063                

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.

Keywords

Phosphorus, Bacillus Subtilis

Conflicts of Interest

The authors declare no conflicts of interest.

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