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Removing lead from Iranian industrial wastewater

100%

Salmani B. K., Amoozegar M. A., Babavalian H., Tebyanian H., Shakeri F.

International Letters of Natural Sciences

2016

tom 57

Metals and chemicals have been increased in industrial processes which they contain a high level of toxic heavy metals and cause a lot of disadvantages for the environment and human health .Biosorption of Pb (П) ions has been studied from aqueous solutions in a batch system by using a bacterial strain isolated from petrochemical wastewaters. Strain 8-I was selected to study the impact of different factors on removal rate. According to morphological, physiological and biochemical characterizations of the strain and in comparison with other studies the strain was tentatively identified as Bacillus sp strain 8-I. The maximum Lead biosorption capacity of 8-I isolate was determined to be 41.58 % at pH 4.0 with 80 mg/l concentration in 48 hours equilibrium time. The comparison between the biosorption capacity of live (45.50 mg/g), heat inactivated (30.23 mg/g) and NaN3 pretreated biomass (26.86 mg/g) were indicated that the ability of live biomass for both of active and passive uptake of lead.

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

86%

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.

Ograniczanie wyników

2 International Letters of Natural Sciences

2 Amoozegar M. A.

2 Babavalian H.

2 Shakeri F.

2 Tebyanian H.

1 Dastgheib S. M. M.

1 Makzum S.

1 Salmani B. K.

2 2016

Wyniki wyszukiwania

Removing lead from Iranian industrial wastewater

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