Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7483648 | Journal of Environmental Management | 2014 | 7 Pages |
Abstract
The use of microalgae for biomass production and nutrient removal from the reject water produced in the dewatering process of anaerobically digested sludge, sludge liquor, was investigated. The sludge liquor was characterized by a high content of total suspended solids (1590 mg Lâ1), a high nitrogen concentration (1210 mg Lâ1), and a low phosphorus concentration (28 mg Lâ1). Chlorella sp. was grown in sludge liquor diluted with wastewater treatment plant effluent water to different concentrations (12, 25, 40, 50, 70, and 100%) using batch mode. The environmental conditions were 25 °C, a continuous lightning of 115 μmol mâ2 sâ1, and a CO2 concentration of 3.0%. The highest biomass production (0.42-0.45 g dry weight Lâ1 Dayâ1) was achieved at 40-50% sludge liquor, which was comparable to the production of the control culture grown with an artificial fertilizer. The biomass production was 0.12 and 0.26 g dry weight Lâ1 Dayâ1 at 12% and 100% sludge liquor, respectively. The percentage of nitrogen in the algal biomass increased from 3.6% in 12% sludge liquor and reached a saturation of â¼10% in concentrations with 50% sludge liquor and higher. The phosphorus content in the biomass increased linearly from 0.2 to 1.5% with increasing sludge liquor concentrations. The highest nitrogen removal rates by algal biosynthesis were 33.6-42.6 mg TN Lâ1 Dayâ1 at 40-70% sludge liquor, while the highest phosphorus removal rates were 3.1-4.1 mg TP Lâ1 Dayâ1 at 50-100% sludge liquor.
Related Topics
Physical Sciences and Engineering
Energy
Renewable Energy, Sustainability and the Environment
Authors
Anette M. Ã
kerström, Leiv M. Mortensen, Bjørn Rusten, Hans Ragnar Gislerød,