Biological Selenium Removal: The Solution to Pollution?

Selenium is often referred to as an “essential toxin” since only a marginal line divides between the nutritious requirement and toxic effects upon exposure. Too little in the diet can lead to health problems and it is toxic when taken in excess, leading to gastrointestinal disorders, sloughing of nails, fatigue, neurological damage and, in extreme cases, cirrhosis of the liver and death. An estimated 0.5 to 1 billion people worldwide suffer from selenium deficiency, however, very high levels of selenium have been found in groundwater in Ireland, France, and parts of Eastern Europe. Selenium occurs in soils and phosphate fertilizers, in coal burning and sulphide mining.

The study published in the Journal of Environmental Quality reports the efficacy of using an Upflow Anaerobic Sludge Blanket (UASB) reactor to remove selenium from contaminated water. They found out that the use of selenium-respiring microorganisms can efficiently create solid selenium waste that can be easily removed from water and soil at controlled temperate, pH levels and the speed of the water that rise up through the water blanket. Further studies are being conducted to use this technology in industrial scale taking into consideration the intricate harvesting process.

For details see press release at https://www.soils.org/press/releases/2008/0825/188/ and at http://cordis.europa.eu/fetch?CALLER=EN_NEWS&ACTION=D&SESSION=&RCN=29873