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Study on haloalkaliphilic sulfur-oxidizing bacterium for thiosulfate removal in treatment of sulfidic spent caustic

100%

Makzum S., Amoozegar M. A., Dastgheib S. M. M., Babavalian H., Tebyanian H., Shakeri F.

International Letters of Natural Sciences

2016

tom 57

Due to the disadvantages of physiochemical methods for sulfidic spent caustic treatment, attentions are drawn to the environmental-friendly biotreatments including sulfur-oxidizing haloalkaliphiles. Thioalkalivibrio versutus DSM 13738 was grown at alkaline (pH10) autotrophic medium with sodium carbonate/bicarbonate as the sole source of carbon and amended with sodium thiosulfate as the electron and energy source. The effect of various parameters including temperature (25-40 °C), pH (8-11), NaCl concentration (0.5-5 % w/v) and sodium thiosulfate concentrations (100-750 mM) was evaluated on bacterial growth and thiosulfate removal. This strain could eliminate sodium thiosulfate at very high concentrations up to 750 mM. The results showed that the highest specific growth rate was pH 9.5 and thiosulfate removal of Thioalkalivibrio versutus occurred at pH 10.5. The optimum salt concentration for thiosulfate removal was 2.5 % w/v and 5 % NaCl and specific growth rate elevated 2.5% w/v. It was also specified that this strain thrives occurred in 37 ºC and at 35 and 37 ºC higher removal of thiosulfate. Following chemical oxidation of sulfide to thiosulfate, application of Thioalkalivibrio versutus could be promising for spent caustic treatment. Since thiosulfate is utilized as an energy source, highest removal efficiency occurred at marginally different conditions compared to optimal growth.

Generation of polluted waters from mining wastes in a uranium deposit

72%

Groudev S. N., Spasova I. I., Nicolova M. V., Georgiev P. S.

Polish Journal of Microbiology

2005

tom 54

nr Suppl.

Dump consisting of 9500 tons of rich-in-pyrite mining wastes located in the uranium deposit Curilo, Western Bulgaria, was, after rainfall, an intensive source of acid drainage waters. These waters had a pH in the range of about 1.7-4.5 and contained radionuclides (uranium, radium), heavy metals (copper, zinc, cadmium, lead, nickel, cobalt, iron, and manganese), arsenic and sulphates in concentrations usually much higher than the relevant permissible levels for waters intended for use in the agriculture and/or industry. The generation of these polluted waters was studied under real field conditions for a period of about seven years during different climatic seasons. It was found that the dump was inhabited by a diverse microflora in which some acidophilic chemolithotrophic bacteria were the prevalent microorganisms. The solubilization of the above-mentioned pollutants from the dump material was connected mainly with the oxidation of pyrite and other sulphide minerals by these bacteria. Their activity depended on some essential environmental factors such as temperature, pH, and water, oxygen and nutrient contents in the dump.

Ograniczanie wyników

1 International Letters of Natural Sciences

1 Polish Journal of Microbiology

1 Amoozegar M. A.

1 Babavalian H.

1 Dastgheib S. M. M.

1 Georgiev P. S.

1 Groudev S. N.

1 Makzum S.

1 Nicolova M. V.

1 Shakeri F.

1 Spasova I. I.

1 Tebyanian H.

1 2016

1 2005

Wyniki wyszukiwania

Study on haloalkaliphilic sulfur-oxidizing bacterium for thiosulfate removal in treatment of sulfidic spent caustic

Generation of polluted waters from mining wastes in a uranium deposit