Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5478580 | Algal Research | 2016 | 10 Pages |
Abstract
Municipal wastewater treatment plants discharge large quantities of treated water that, in many regions, is not productively used and is instead released directly into the environment. In this study we examine the use of freshwater macroalgae as an in-line tertiary treatment process for existing municipal treatment plants. We examine the suitability of using the treated discharge water from a 29,000 m3.dayâ 1 municipal wastewater treatment plant as the sole source of water and nutrients for the intensive cultivation of the freshwater macroalga Oedogonium intermedium. A monoculture of algae was initially cultivated for a 3 month period in which water quality and biomass productivity were quantified and the composition of the biomass characterized. These cultures were then maintained for a further 9 months to determine the average monthly biomass productivity, and seasonal variation, over a 12 month period. The cultivation of Oedogonium significantly improved the quality of the discharged water with a 36% reduction in total nitrogen and a 65% reduction in total phosphorous. The average monthly biomass productivity of Oedogonium ranged between a minimum of 8.9 g DW·mâ 2·dayâ 1 in June (austral winter - dry season) and a maximum of 15.8 g DW·mâ 2·dayâ 1 in January (austral summer - wet season) with an average annual rate of 12.5 g DW·mâ 2·dayâ 1. The biomass produced was of a high quality with a total protein content of 23 g·100 gâ 1 and a total lipid content of 10 g·100 gâ 1. Both the protein (10 g·100 gâ 1 of essential amino acids) and lipid (4.5 g·100 gâ 1 of polyunsaturated fatty acids) provide product opportunities for animal nutrition. This study demonstrates that the production of algae integrated with the operation of conventional wastewater treatment can complement and add value to existing processes by recovering residual nutrients and metals and, at the same time, create a high-quality biomass resource for product development.
Related Topics
Physical Sciences and Engineering
Energy
Renewable Energy, Sustainability and the Environment
Authors
Andrew J. Cole, Nicolas Neveux, Anna Whelan, Jeff Morton, Mark Vis, Rocky de Nys, Nicholas A. Paul,