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- Munoz, Raul, et al.
(författare)
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Photosynthetically oxygenated salicylate biodegradation in a continuous stirred tank photobioreactor
- 2004
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Ingår i: Biotechnology and Bioengineering. - : Wiley. - 1097-0290 .- 0006-3592. ; 87:6, s. 797-803
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Tidskriftsartikel (refereegranskat)abstract
- A consortium consisting of a Chlorella sorokiniana strain and a Ralstonia basilensis strain was able to carry out sodium salicylate biodegradation in a continuous stirred tank reactor (CSTR) using exclusively photosynthetic oxygenation. Salicylate biodegradation depended on algal activity, which itself was a function of microalgal concentration, light intensity, and temperature. Biomass recirculation improved the photobioreactor performance by up to 44% but the results showed the existence of an optimal biomass concentration above which dark respiration started to occur and the process efficiency started to decline. The salicylate removal efficiency increased by a factor of 3 when illumination was increased from 50 - 300 muE/M-2 (.)s. In addition, the removal rate of sodium salicylate was shown to be temperature-dependent, increasing from 14 to 27 mg/l(.)h when the temperature was raised from 26.5 to 31.5degreesC. Under optimized conditions (300 muE/m(2) (.)s, 30degreesC, 1 g sodium salicylate/l in the feed and biomass recirculation) sodium salicylate was removed at a maximum constant rate of 87 mg/l.h, corresponding to an estimated oxygenation capacity of 77 mg O-2/l(.)h (based on a BOD value of 0.88 g O-2/g sodium salicylate for the tested bacterium), which is in the range of the oxygen transfer capacity of large-scale mechanical surface aerators. Thus, although higher degradation rates were attained in the control reactor, the photobioreactor is a cost-efficient process which reduces the cost of aeration and prevents volatilization problems associated with the degradation of toxic volatile organic compounds under aerobic conditions. (C) 2004 Wiley Periodicals, Inc.
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| 2. |
- Munoz, Raul, et al.
(författare)
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Salicylate biodegradation by various algal-bacterial consortia under photosynthetic oxygenation.
- 2003
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Ingår i: Biotechnology Letters. - 1573-6776. ; 25:22, s. 1905-1911
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Tidskriftsartikel (refereegranskat)abstract
- Four green microalgae (Chlorella sorokiniana, Chlorella vulgaris, Scenedesmus obliquus and Selenastrum capricornutum), a wild Bolivian microalga strain and two cyanobacteria (Anabaena catenula and Microcystis aeruginosa) were compared for tolerance to salicylate, O2 production capacity and ability to support salicylate degradation by a Ralstonia basilensis strain in symbiotic microcosms with the microalgae. Microcystis aeruginosa had the highest tolerance to salicylate at 500 mg l-1 and 1500 mg l-1 but only produced 0.7 mg O2 l-1 h-1 in the absence of pollutant. Chlorella sorokiniana resisted salicylate at 1500 mg l-1 with the highest O2 production in the absence of salicylate (26 mg l-1 h-1) closely followed by the Bolivian microalga (23 mg l-1 h-1) and Chlorella vulgaris (21 mg l-1 h-1). Selenastrum capricornutum and Anabaena catenula were completely inhibited by salicylate at 500 mg l-1. When inoculated with Ralstonia sp. and supplied with salicylate, Chlorella sorokiniana had the highest removal rate (19 mg l-1 h-1), followed by the wild Bolivian strain (18 mg l-1 h-1) and Chlorella vulgaris (14 mg l-1 h-1).
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