Phosphorus removal from wastewater by microalgae in Sweden - a year-round perspective
Author
Summary, in English
The phosphorus and nitrogen removing capacity of a microalgal treatment step in Sweden was studied during an annual cycle. The treatment step had been constructed for extended phosphorus removal in a hydroponic wastewater treatment system, which had been built in a greenhouse. Two culture depths (17 and 33 cm) were compared as well as the effect of additional illumination during winter. The results showed large fluctuations in algal biomass production and phosphorus removal as a result of season. The phosphorus removal efficiency showed a clear correlation with pH, and the shallow cultures generally had higher phosphorus removal efficiencies than the deeper cultures. The efficiencies were between 60% and 100% during summer but mostly lower than 25% during winter, except in the shallow culture with extra illumination where efficiencies of 60-80% were recorded even during winter. A nitrogen removal efficiency of around 40% was reached for most parts of the year, and efficiencies of up to 60-80% were achieved during summer in the shallow cultures. In conclusion, the results showed that a large proportion of the phosphorus could be removed on a year-round basis, hence reducing the need for chemical precipitation, and also that significant nitrogen removal is possible.
Department/s
Publishing year
2010
Language
English
Pages
117-123
Publication/Series
Environmental Technology
Volume
31
Issue
2
Document type
Journal article
Publisher
Taylor & Francis
Topic
- Chemical Engineering
Keywords
- assimilation
- phosphorus
- microalgae
- wastewater treatment
- precipitation
Status
Published
ISBN/ISSN/Other
- ISSN: 1479-487X