A microbial fungus - Aspergillus terreus was used to degrade phosphorus in Nigeria’s Agbaja iron ore in the laboratory. The ore was first crushed to very tiny particles, screened using Shital test kits and 1.00/0.50m...A microbial fungus - Aspergillus terreus was used to degrade phosphorus in Nigeria’s Agbaja iron ore in the laboratory. The ore was first crushed to very tiny particles, screened using Shital test kits and 1.00/0.50mm, 0.50/0.25mm and 0.25/0.125mm particle size fractions were selected for the experiment. The microbes, obtained from the nascent remains on the ore environment, were cultured, used to inoculate 1g of sterile ore samples in 250ml conical flasks containing 100ml of equally sterile malt extract broth media and left to stand. At weekly interval, the samples were removed, treated through series of chemical reactions and ammonium phospho-molybdate precipitate was obtained. This was back-titrated with 0.1 NHCl to determine the amount of phosphorus left in samples and consequently, the amount removed. Findings reveal that A. terreus is capable of degrading the ore samples. pH monitoring reveals that the P degradation process proceeded in a culture media of increasing acidity. It is recommended to further study the chemistry of the mixture of culture media, ore samples and microbes to find parameters that favour the degradation process. Key words: Ore, microbes, screening, broth, degradation, accumulation,展开更多
Utilization of petroleum coke in the rejuvenating Nigerian metallurgical industry is currently satisfied by importation from more industrialized nations of the world such as the USA, Brazil and Venezuela where delayed...Utilization of petroleum coke in the rejuvenating Nigerian metallurgical industry is currently satisfied by importation from more industrialized nations of the world such as the USA, Brazil and Venezuela where delayed coking plants operate and grow in number. The sad years of poor planning have revealed lapses in integration and synergic planning of our industrial complex. The sources of petroleum coke feedstock have been identified and confirmed as atmospheric and vacuum residues of Nigerian refineries. Analysis has portrayed a symbiotic relationship between the metallurgical industry as one of the major end users of various petroleum coke grades, the shot coke, the sponge coke and the needle coke, and the petroleum industry on its part benefiting while providing ready market for steel sheet metals for even coke drum manufacture. This effort shall greatly increase the Nigerian content in these key industrial sectors, with the resultant reduction in capital flight through importation, if rethinking, and re-strategizing are injected into our industrial planning, and revamps models. Redesign options of existing refineries and reengineering of newly proposed refineries should contain resid processing units such as Delayed Coking Plant which will deepen conversion of residual petroleum feed stocks and produce various petroleum coke grades for utilization in power generation sector and our growing metallurgical and electrode industries.展开更多
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 syst...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.展开更多
文摘A microbial fungus - Aspergillus terreus was used to degrade phosphorus in Nigeria’s Agbaja iron ore in the laboratory. The ore was first crushed to very tiny particles, screened using Shital test kits and 1.00/0.50mm, 0.50/0.25mm and 0.25/0.125mm particle size fractions were selected for the experiment. The microbes, obtained from the nascent remains on the ore environment, were cultured, used to inoculate 1g of sterile ore samples in 250ml conical flasks containing 100ml of equally sterile malt extract broth media and left to stand. At weekly interval, the samples were removed, treated through series of chemical reactions and ammonium phospho-molybdate precipitate was obtained. This was back-titrated with 0.1 NHCl to determine the amount of phosphorus left in samples and consequently, the amount removed. Findings reveal that A. terreus is capable of degrading the ore samples. pH monitoring reveals that the P degradation process proceeded in a culture media of increasing acidity. It is recommended to further study the chemistry of the mixture of culture media, ore samples and microbes to find parameters that favour the degradation process. Key words: Ore, microbes, screening, broth, degradation, accumulation,
文摘Utilization of petroleum coke in the rejuvenating Nigerian metallurgical industry is currently satisfied by importation from more industrialized nations of the world such as the USA, Brazil and Venezuela where delayed coking plants operate and grow in number. The sad years of poor planning have revealed lapses in integration and synergic planning of our industrial complex. The sources of petroleum coke feedstock have been identified and confirmed as atmospheric and vacuum residues of Nigerian refineries. Analysis has portrayed a symbiotic relationship between the metallurgical industry as one of the major end users of various petroleum coke grades, the shot coke, the sponge coke and the needle coke, and the petroleum industry on its part benefiting while providing ready market for steel sheet metals for even coke drum manufacture. This effort shall greatly increase the Nigerian content in these key industrial sectors, with the resultant reduction in capital flight through importation, if rethinking, and re-strategizing are injected into our industrial planning, and revamps models. Redesign options of existing refineries and reengineering of newly proposed refineries should contain resid processing units such as Delayed Coking Plant which will deepen conversion of residual petroleum feed stocks and produce various petroleum coke grades for utilization in power generation sector and our growing metallurgical and electrode industries.
文摘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.
