Mechanism and Kinetics of Elemental Sulfur Oxidation by Thiobacillus Thiooxidans in Batch Fermenter

1999 ◽  
Vol 20 (9) ◽  
pp. 933-942 ◽  
Author(s):  
Y. C. Cheng ◽  
R. Y. Peng ◽  
J. C. C. Su ◽  
D. Y. Lo
1991 ◽  
Vol 37 (3) ◽  
pp. 182-187 ◽  
Author(s):  
Hector M. Lizama ◽  
Isamu Suzuki

The oxidation of elemental sulfur by two strains of Thiobacillus thiooxidans was studied by measuring the rate of O2 consumption at various concentrations of substrate and cells. In both the laboratory strain ATCC 8085 and the mine isolate SM-6, sulfur oxidation was competitively inhibited by T. thiooxidans cells; the Ki values were 0.65 and 0.05 mg wet cells∙mL−1, respectively. The rate constants were 500 and 143 μM O2∙min−1∙mg wet cells−1∙mL−1 and the Km values for sulfur concentration were 7.5 and 0.32% pulp density, respectively. Mine isolate SM-6 was used also to study pyrite (FeS2) oxidation by measuring the rate of O2 consumption. Oxidation of both washed and unwashed pyrite samples was competitively inhibited by increasing concentrations of cells; with each sample the Ki values was 0.05 mg wet cells∙mL−1. The rate constants for each sample were also the same (100 μM O2∙min−1∙mg wet cells−1∙mL−1), but the Km values were different (1.11% pulp density for washed pyrite and 2.81% pulp density for unwashed pyrite). Based on the rate of Fe solubilization from the washed pyrite sample, T. thiooxidans cells oxidized the sulfide released from pyrite dissolution beyond the oxidation state of elemental sulfur. Key words: Thiobacillus thiooxidans, sulfur, pyrite, oxidation, kinetics.


2020 ◽  
Vol 8 (3) ◽  
pp. 386 ◽  
Author(s):  
Maxim Muravyov ◽  
Anna Panyushkina

A two-step process, which involved ferric leaching with biologically generated solution and subsequent biooxidation with the microbial community, has been previously proposed for the processing of low-grade zinc sulfide concentrates. In this study, we carried out the process of complete biological oxidation of the product of ferric leaching of the zinc concentrate, which contained 9% of sphalerite, 5% of chalcopyrite, and 29.7% of elemental sulfur. After 21 days of biooxidation at 40 °C, sphalerite and chalcopyrite oxidation reached 99 and 69%, respectively, while the level of elemental sulfur oxidation was 97%. The biooxidation residue could be considered a waste product that is inert under aerobic conditions. The results of this study showed that zinc sulfide concentrate processing using a two-step treatment is efficient and promising. The microbial community, which developed during biooxidation, was dominated by Acidithiobacillus caldus, Leptospirillum ferriphilum, Ferroplasma acidiphilum, Sulfobacillus thermotolerans, S. thermosulfidooxidans, and Cuniculiplasma sp. At the same time, F. acidiphilum and A. caldus played crucial roles in the oxidation of sulfide minerals and elemental sulfur, respectively. The addition of L. ferriphilum to A. caldus during biooxidation of the ferric leach product proved to inhibit elemental sulfur oxidation.


1997 ◽  
Vol 48 (4) ◽  
pp. 497 ◽  
Author(s):  
Sholeh ◽  
Rod D. B. Lefroy ◽  
Graeme J. Blair

Elemental sulfur (S) has many attractions as a fertiliser but it must be oxidised to sulfate before it is plant available. Two laboratory incubation experiments with a high S sorbing basaltic soil (Haplohumult) from Walcha, New South Wales, are reported here. The first experiment was conducted to study the effect of ? P and other nutrients on the oxidation of elemental S and the growth of Thiobacillus thiooxidans. The second experiment studied the effect of phosphorus (P) rate, elemental S particle size, and elemental S form on the oxidation of elemental S at different times. There were significant differences between treatments in the percentage and amount of elemental S oxidised, with the lowest oxidation occurring during the 6-week incubation in the P treatment, which represented 1�8% of the applied S compared with 16�0% when all nutrients were supplied. There was a significant linear relationship between T. thiooxidans population at the end of the incubation period and the amount of elemental S oxidised. The oxidation of elemental S was higher when fine (50?150 �m) particle size elemental S was used, compared with coarse (150?250 �m) elemental S. There was no clear difference in oxidation rate between ground and recrystallised elemental S. The S oxidation rates recorded in these experiments were compared with those predicted by an S oxidation model and found to be in close agreement.


1998 ◽  
Vol 18 (4) ◽  
pp. 241 ◽  
Author(s):  
R. Gourdon ◽  
N. Funtowicz

2016 ◽  
Vol 89 ◽  
pp. 282-292 ◽  
Author(s):  
Mabel Mora ◽  
Luis R. López ◽  
Javier Lafuente ◽  
Julio Pérez ◽  
Robbert Kleerebezem ◽  
...  

Soil Research ◽  
2000 ◽  
Vol 38 (3) ◽  
pp. 753 ◽  
Author(s):  
A. D. Mitchell ◽  
P. Loganathan ◽  
T. W. Payn ◽  
R. W. Tillman

Application of Mg fertilisers has been suggested as a means of reducing the incidence of Mg deficiency of forest trees in New Zealand and Europe. The objective of this study was to determine the rates of dissolution of a range of Mg fertilisers applied to a pumice soil (Typic Udivitrand). The rate of fertiliser dissolution was little influenced by whether the fertiliser was applied directly on to the soil surface (litter removed) or on to the litter layer in a Pinus radiata plantation. Twenty-seven months since fertiliser application the mean (with and without litter) percentage of Mg dissolved was in the sequence: Epsom salts > calcined magnesite 1–2 mm > granmag (a partially acidulated and granulated calmag product) > calcined magnesite 2–4 mm > forestry grade dolomite. The specific dissolution rate constants (mg/cm2 .day of fertiliser) for the slowly soluble Mg fertilisers calculated using an elemental sulfur oxidation cubic model were 587 for calcined magnesite 1–2 mm, 426 for calcined magnesite 2–4 mm, 385 for granmag, and 18 for forestry grade dolomite. In a laboratory incubation study the elemental sulfur oxidation cubic model described the rate of dissolution of Mg fertilisers within narrow fertiliser particle size ranges. The specific fertiliser dissolution rate constants, however, increased with decreases in particle size, suggesting that the rate of dissolution depends on factors other than surface area when particle sizes varied widely. Slowly soluble, alkaline Mg fertilisers had a significant liming effect on the soil. They were more effective in increasing soil exchangeable Mg than soluble Mg salts over a long-period and therefore, they are better fertilisers for P. radiata.


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