ISSN:
0006-3592
Keywords:
sulphur
;
thiosulphate
;
Thiobacilli
;
fed-batch reactor
;
oxygen limitation
;
Chemistry
;
Biochemistry and Biotechnology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
This study shows that, in a sulphide-oxidizing bioreactor with a mixed culture of Thiobacilli, the formation of sulphur and sulphate as end-products from the oxidation of sulphide can be controiledinstantaneously and reversibiy by the amount of oxygen supplied. It was found that at sulphide loading rates of up to 2.33 mmol7/L · h, both products can be formed already at oxygen concentrations below 0.1 mg/L. Because the microorganisms tend to form sulphate rather than forming sulphur, the oxygen concentration is not appropriate to optimize the sulphur production. Within less than 2 h, the system can be switched reversibly from sulphur to sulphate formation by adjusting the oxygen flow. This is below the minimum doubling time (2.85 h) of, e.g., Thiobacillus neapolitanus and Thiobacillus 0,18 which indicates that one metabolic type of organism can probably perform both reactions. Under highly oxygen-limited circumstances, that is, at an oxygen/sulphide consumption ratio below 0.7 mol · h-1 mol · h-1 thiosulphate is abundantly formed. Because the chemical sulphide oxidation results mainly in the formation of thiosulphate, it is concluded that, under these circumstances, the biological oxidation capacity of the system is lower than the chemical oxidation capacity. The oxidation rate of the chemical sulphide oxidation can be described by a first-order process (k =-0.87 h-1).© 1995 John Wiley & Sons, Inc
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bit.260470307
Permalink
