USE OF MICROALGAE IN WASTEWATER TREATMENT IN COLD CLIMATE / Användning av mikroalger vid avloppsvattenbehandling i kallt klimat
The following article is a literature review on possibilities of microalgal improvement of wastewater treatment in oxidation ponds in cold climate. Furthermore the paper covers the possible commercial microalgal products that can be produced using the nutrient resource in the wastewater. Very few investigations have been performed in cold climate. There is evidence that microalgal production, given proper culture conditions and selec-tion, could be high enough to improve wastewater treatment even under low temperature conditions. These indications are results from work on wastewater treatment using microalgae in other parts of the world, biotechnological microalgal production, and microalgal physiology in low temperature environment. Microalgae have the potential to perform tertiary and quinary treatment. Microalgal products with commercial value in wastewater treatment are few today: oxygenation, fertilizer, and biogas production. In biotechnological microalgal production there are, however, many produces on research scale and a few on commercial scale. These may also be produced from wastewater, with benefits on the economic side, but constraints like hygienic aspects, unwanted contaminants, and in many countries probably some concern regarding the use of human excretion products to produce consumables. Possible products are hydrogen gas, feed for aquaculture and in feedlots, and biochemical constituents. Less than one per thousand of the world algal species are sufficiently explored concerning biochemical content.