title: The growth ofChlamydomonas reinhardtiias influenced by high CO2and low O2in flue gas from a silicomanganese smelter.
abstract: The aim of this study was to find an inexpensive and environmentally friendly CO2source for growing the hydrogen-producing microalgaeChlamydomonas reinhardtii. The effect of different flue gas concentrations from a silicomanganese smelter on the growth of these algae at a photon flux density of 200 μmol photons m-2s-1applied 24 h day-1was studied. First, the algae were grown in a laboratory at 1.2, 6.8 and 17.1 % (v/v) pure CO2gas mixed with fresh air. After 5 days of growth, the dry biomass per litre algal culture was slightly higher (17 %) at 6.8 % CO2as compared to at 1.2 % CO2. A further increase to 17.1 % CO2decreased the biomass by about 40 %. Then, the flue gas from a silicomanganese smelter was used as a CO2source for growing the algae. The flue gas was characterized by a high CO2concentration (about 17 %v/v), low oxygen concentration (about 4 %), about 100 ppm NOxand 1 ppm SO2. The culture medium bubbled with undiluted flue gas contained about 490 mg L-1dissolved CO2and 4.0 mg L-1dissolved O2, while the lowest flue gas concentration contained about 280 mg L-1CO2and 7.1 mg L-1O2. Undiluted flue gas (17.4 % CO2) decreased the biomass of the algae by about 40 % as compared with 4.8 % pure CO2gas or flue gas diluted to a concentration of 6.3 % CO2. Flue gas diluted to give 10.0 % CO2gave less reduction in the growth of the algae (22 %). It was concluded that the high CO2concentration itself caused the growth reduction and not the air pollutants, and the very low O2concentrations in the growth medium could not counteract this negative effect.
authors: Department of Plant and Environmental Science, The University of Life Sciences, 1432 Ås, Norway.
authors: Leiv M
authors: LM
authors: Mortensen
authors: Department of Plant and Environmental Science, The University of Life Sciences, 1432 Ås, Norway.
authors: Hans R
authors: HR
authors: Gislerød
keywords: Biomass; Microalgae; Nitrogen oxides; Oxygen concentration (O2)